Yangon Thanlyin Bridge 1

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REPUBLIC OF THE UNION OF MYANMAR MINISTRY OF CONSTRUCTION PUBLIC WORKS THE PREPARATORY SURVEY FOR THE PROJECT FOR CONSTRUCTION OF BAGO RIVER BRIDGE FINAL REPORT AUGUST 2014 JAPAN INTERNATIONAL COOPERATION AGENCY ALMEC CORPORATION ORIENTAL CONSULTANTS CO., LTD NIPPON KOEI CO., LTD. EI JR(先) 14-239 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report Existing Yangon-Thanlyin Bridge Proposed Location of Bago River Bridge PROJECT LOCATION MAP The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report Table of Contents Project Location Map 1. 1.1 1.2 1.3 1.4 Introduction ................................................................................................................................ 1 Project Background ................................................................................................................ 1 Project Objective .................................................................................................................... 3 Related Studies ....................................................................................................................... 3 Previously Proposed Three Bridge Locations ........................................................................ 5 2.1 2.2 2.3 Schedule of the Preparatory Survey ........................................................................................... 6 Time Schedule of the Preparatory Survey .............................................................................. 6 Members of the JICA Survey Team ....................................................................................... 7 Progress of the Preparatory Survey ........................................................................................ 7 2. 3. Organization of Public Works (PW) ........................................................................................ 10 4. Design Criteria Applied to the Project Design ......................................................................... 13 4.1 Design Criteria for Structural Design ................................................................................... 13 4.1.1 Structural Guidelines .........................................................................................................13 4.1.2 Design Criteria ..................................................................................................................13 4.2 Design Criteria for Road Design .......................................................................................... 15 4.3 Design Navigation Clearance ............................................................................................... 16 5. Study of Three Alternative Locations for Bago River Bridge.................................................. 18 5.1 Design Conditions for Alternative Study ............................................................................. 18 5.2 Comparison of Three Alternative Locations for Bago River Bridge ................................... 21 5.2.1 Outline of Project Route ....................................................................................................21 5.2.2 Land Use Condition along the Project Route ....................................................................22 5.2.3 Foreseen Natural/Social Environmental Impact ................................................................23 5.2.4 Influence on the Adjacent Road Network/Traffic Environment .......................................26 5.2.5 Possible Superstructure Type ............................................................................................29 5.2.6 Cost Estimates ...................................................................................................................30 5.2.7 Comparison of Alternative Routes from the Transport Planning Point of View ..............31 5.3 Other Information Related to the Project ............................................................................. 32 5.3.1 Port Limit ..........................................................................................................................32 5.3.2 Vessel Operating Route at the Existing Thanlyin Bridge Area .........................................33 5.3.3 Comment of Myanma Port Authority................................................................................33 5.4 Selection of Bago River Bridge Location ............................................................................ 36 6. Preliminary Design of Bago River Bridge ............................................................................... 37 6.1 Alignment Design................................................................................................................. 37 6.2 Study of Superstructure Type ............................................................................................... 38 6.2.1 Selection of Superstructure Type ......................................................................................38 6.2.2 Evaluation Criteria ............................................................................................................39 i The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report 6.2.3 Evaluation Results and Recommendation .........................................................................40 6.3 Study of Substructure ........................................................................................................... 47 6.3.1 Study on Foundation Type ................................................................................................47 6.3.2 Adverse Effect of New Bridge Foundation on Existing Bridge Foundation .....................53 6.3.3 Study on Substructure Type ..............................................................................................53 6.3.4 Study on Abutment Type...................................................................................................54 7. Natural Condition Surveys ....................................................................................................... 55 7.1 Topographic Survey ............................................................................................................. 55 7.1.1 Summary of the Yangon Urban Area ................................................................................55 7.1.2 Topographic Survey ..........................................................................................................56 7.1.3 Survey Result ....................................................................................................................60 7.2 Geological Survey ................................................................................................................ 61 7.2.1 Summary of Geological Condition....................................................................................61 7.2.2 Geological Survey .............................................................................................................62 7.2.3 Geotechnical Design Parameters .......................................................................................70 7.2.4 Summary of Soil Investigation ..........................................................................................72 8. Hydrological Assessment of the Bago River............................................................................ 73 8.1 Meteorological Conditions ................................................................................................... 73 8.1.1 Temperature.......................................................................................................................73 8.1.2 Relative Humidity .............................................................................................................74 8.1.3 Wind Speed and Direction.................................................................................................74 8.1.4 Evaporation .......................................................................................................................74 8.1.5 Sunshine Hours..................................................................................................................75 8.1.6 Rainfall ..............................................................................................................................75 8.2 Hydrological and Hydraulic Conditions............................................................................... 80 8.2.1 Rivers and Characteristics of River Flow ..........................................................................80 8.2.2 Tidal Level around Yangon Area ......................................................................................89 8.2.3 Flood Conditions including Storm Surge ..........................................................................91 8.2.4 Inland Water Transportation Condition.............................................................................92 8.2.5 Dredging Condition of Inner Bar of Yangon Port .............................................................95 8.3 Estimation of Probable Floods and Water Levels ................................................................ 95 8.3.1 Probable Floods at Gauging Stations ................................................................................95 8.3.2 Probable Floods from River Flow for Design ...................................................................96 8.3.3 Probable High Water Level at Tidal Gauging Station.......................................................98 8.3.4 Hydraulic Calculation........................................................................................................98 8.4 Hydrological Assessment of the Proposed Bridge Sites .................................................... 107 8.4.1 Hydraulic Design Criteria of Bridge ...............................................................................107 8.4.2 Assessment of Scouring ..................................................................................................107 8.4.3 Assessment of the Proposed Bridge ................................................................................113 9. Design for Feasibility Study ................................................................................................... 114 9.1 Study of Bridge Location and its Proximity to the existing Thanlyin Bridge .................... 114 9.2 Continuity with Thilawa SEZ Access Road ....................................................................... 115 9.3 Structural Design ................................................................................................................ 117 9.3.1 Design of Superstructures................................................................................................117 9.3.2 Design of Substructure and Foundations .........................................................................127 9.3.3 Design of Substructures...................................................................................................128 9.3.4 Design of Abutments .......................................................................................................129 9.4 Highway Design ................................................................................................................. 130 9.4.1 Alignment Design............................................................................................................130 9.4.2 Cross Sectional Arrangement ..........................................................................................131 9.4.3 Necessity of Soft Ground Treatment ...............................................................................132 9.4.4 Study on Pavement Structure ..........................................................................................134 ii The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report 9.5 Construction Planning ........................................................................................................ 136 9.5.1 Site Conditions ................................................................................................................136 9.5.2 Construction Packaging Plan ...........................................................................................138 9.5.3 Temporary Facilities........................................................................................................140 9.5.4 Construction Procedures..................................................................................................141 9.5.5 Construction Period .........................................................................................................147 10. Project Cost Estimates ............................................................................................................ 148 10.1 General Conditions ............................................................................................................. 148 10.2 Procurement........................................................................................................................ 148 10.3 Construction Work Quantities ............................................................................................ 150 10.4 Construction Cost ............................................................................................................... 152 10.5 Land Acquisition and Resettlement Cost ........................................................................... 153 10.5.1 Demolition Cost and Land Acquisition Cost...................................................................153 10.5.2 Resettlement Cost ............................................................................................................153 10.5.3 Total Cost of Land Acquisition and Resettlement...........................................................153 10.6 Estimated Project Cost ....................................................................................................... 153 11. Demand Forecast and Economic Evaluation of the Project ................................................... 154 11.1 Introduction ........................................................................................................................ 154 11.2 Socio-Economic Framework and Future Transport Demand ............................................. 154 11.2.1 Socio-Economic Framework ...........................................................................................154 11.2.2 Transport Demand Forecast (Do-Nothing Case) .............................................................155 11.2.3 Base Case Demand Forecast (Do Master Plan) ...............................................................161 11.3 Economic Evaluation ......................................................................................................... 162 11.3.1 Methodology and Assumptions .......................................................................................162 11.3.2 Economic Cost of the Project ..........................................................................................164 11.3.3 Economic Benefits of the Project ....................................................................................164 11.3.4 Evaluation Result ............................................................................................................165 11.3.5 Establishment of Operation and Effect Indicators...........................................................167 12. Environmental and Social Considerations ............................................................................. 169 12.1 Policy, Legislative, and Institutional Framework............................................................... 169 12.1.1 Legislation related to Environmental and Social Considerations ....................................169 12.1.2 Environmental Conservation Law, 2012 .........................................................................169 12.1.3 Regulations for Environmental Impact Assessment (EIA) .............................................170 12.1.4 Environmental quality standards .....................................................................................180 12.1.5 Institutional Framework ..................................................................................................183 12.2 Existing Environmental Conditions around the Proposed Route ....................................... 183 12.2.1 Location and Route .........................................................................................................184 12.2.2 Social Environment .........................................................................................................186 12.2.3 Natural Environment .......................................................................................................190 12.2.4 Environmental Pollution..................................................................................................193 12.3 Results of the Initial Environmental Examination (IEE) of the Project ............................. 200 12.3.1 Outline of the Project and its Components ......................................................................200 12.3.2 Comparison of Alternatives.............................................................................................202 12.3.3 Procedures of IEE Level Study of the Project Plan .........................................................203 12.3.4 Identification and Evaluation of Possible Impacts ..........................................................206 12.3.5 Mitigation Measures against Negative Impacts and Environmental Management Plan .215 12.3.6 Environmental Monitoring Plan (EMP) ..........................................................................219 12.4 Abbreviated Resettlement Plan (ARP) ............................................................................... 223 12.4.1 Necessity of Land Acquisition and Resettlement ............................................................223 12.4.2 Legal and Policy Framework for Land Acquisition and Resettlement in Myanmar .......223 12.4.3 Features and Expected Land Acquisition and Resettlement of the Project .....................230 12.4.4 Policy for Land Acquisition and Resettelement ..............................................................234 iii The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report 12.4.5 Estimation of Compensation and Resettlement Assistance .............................................235 12.4.6 Specific Procedures for Loss of Structures and Resettlement for the Project .................236 12.5 Results of the Stakeholder Meetings .................................................................................. 237 12.6 Confirmation of Environmental and Social Consideration by the JICA Environmental Checklist ............................................................................................................................. 239 13. Proposed Implementation Programme ................................................................................... 240 13.1 Implementation Structure ................................................................................................... 240 13.2 Implementation Schedule ................................................................................................... 240 14. Conclusions and Recommendations....................................................................................... 242 14.1 Conclusions ........................................................................................................................ 242 14.2 Recommendations .............................................................................................................. 244 Appendix 1 Minutes of Meeting on the Presentation of Inception Report Appendix 2 Technical Notes on the Presentation of the Study of Three Alternative Locations for Bago River Bridge Appendix 3 Technical Notes on the Selection of the Bridge Type of Bago River Bridge Appendix 4 Public Works Equipment List Appendix 5 Plan and Profile Designs for Study of Three Alternative Locations for Bago River Bridge Appendix 6 Possible Superstructure Type for Study of Three Alternative Locations for Bago River Bridge Appendix 7 Preliminary Cost Estimate for Study of Three Alternative Locations for Bago River Bridge Appendix 8 Six (6) Alternative Bridge Types for Superstructure Type Selection Appendix 9 Drawings Appendix 10 Appendix 10.1 Appendix 10.2 Appendix 10.3 Appendix 10.4 Results of Actual Environmental Survey Participants List of Stakeholder Meeting Results of Survey for Preparation of ARP Confirmation of Environmental and Social Considerations for the Proposed Project by JICA Environmental Checklist Appendix 11 Breakdown of the Cost Estimation iv The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report List of Abbreviations AASHTO American Association of State Highway and Transportation Officials ADB Asia Development Bank ARP Abbreviated Resettlement Plan ASEAN Association of Southeast Asian Nations B/C Cost Benefit Ratio BOD Biological Oxygen Demand BOT Build-Operate-Transfer BRT Bus rapid transit BSW Bo Aung Kyaw Wharf CBD Central business district CBR California Bearing Ratio CDL Chart Datum Level CNG Compressed natural gas CO Carbon Monoxide COD Chemical Oxygen Demand CPLAD City Planning and Land Administration Department CS Consultant Service CT Contractor D/D Detailed Design DF/R Final Report DMH Department of Meteorology and Hydrology, Ministry of Transport DWIR Department of Water Resources and Improvement of River System DWT Dead weight tonnage ECD Environmental Conservation Department EIA Environmental impact assessment EIRR Equity internal rate of return EMP Environmental Management Plan E/S Engineering Service ESAL Equivalent Single Axle Loads FERD Foreign Economic Relations Department FHWA Federal Highway Administration F/R Final Report GAD General Administration Department GDP Gross Domestic Product GIS Geographic Information System GOM Government of Myanmar HEC Hydraulic Engineering Circular HEC-RAS Hydrologic Engineering Center – River Analysis System HHWL The highest high water level HWL High Water Level IC/R Inception report ID, MOAI Irrigation Department, Ministry of Agriculture and Irrigation IEE Initial environmental examination I/P Implementation Program IT/R Interim Report v The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report ITS Intelligent Transport Systems IUCN International Union for Conservation of Nature IWT Inland Water Transport JICA Japan International Cooperation Agency JICAGL JICA Guideline JICA-SUDP Project for Strategic Urban Development Plan of the Greater Yangon JPY Japanese Yen JSHB Japanese Standard for Highway Bridge LARAP Land Acquisition and Resettlement Action Plan LLWL Lowest Low Water Level LOA Length Overall MEPE Myanmar Electric Power Enterprise MES Myanmar Engineering Society MFSL Myanmar Five Star Line MGS Myanmar Geosciences Society MITT Myanmar International Terminal Thilawa MMK Myanmar Kyats MN Myanmar Navy MNPED Ministry of National Planning and Economic Development MOC Ministry of Construction MOE Ministry of Energy MOECF Ministry of Environment Conservation and Forestry MOF Ministry of Fishery MOGE Myanmar Oil and Gas Enterprise MOH Ministry of Health MOHA Ministry of Home Affairs MOI Ministry of Industry MOT Ministry of Transport MPA Myanmar Port Authority MPPE Myanmar Petroleum Product Enterprise MR Myanma Railways MSL Mean Sea Level MWL Mean Water Level MYT-Plan The Survey Program for the National Transporation Development Plan in the Republic of the Union of Myanmar NGO Non-Governmental Organization NO2 Nitrogen Dioxides NPV Net Present Value NTU Unit of Turbidty ODA Official Development Assistance O&M Operation and Maintenance PAPRD Project Appraisal and Program Reporting Department PAPs Project Affected Persons PCD Pollution and Cleaning Department PCU Passenger Car Unit PD Planning Department PG/R Progress Report PM Particulate Matter vi The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report PPGD Playgrounds, Parks and Gardening Department PVD Prefabricated Vertical Drain PW Public Works ROW Right of Way S/C Steering Committee SCF Standard Conversion Factor SEZ Special Economic Zone SIA Social Impact Assessment SLRD Settlement and Land Record Department SO2 Sulfer Dioxides SPT Standard Penetration Test STDs Sexually Transmitted Diseases SUDP The Strategic Urban Development Plan of the Greater Yangon, JICA (2013) TEU Twenty-foot equivalent units T-N Total Nitrogen T-P Total Phosphorus TOD Transit Oriented Development TS Township TTC Travel Time Costs UMRT Urban Mass Rapid Transit USD US Dollar V/C Volume to Capacity VOC Vehicle Operation Cost VOT Value of Time WB World Bank WHO World Health Organization YCDC Yangon City Development Committee YRDC Yangon Region Development Committee YUTRA Project for Comprehensive Urban Transport Plan of the Greater Yangon vii The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report Chapter 1 Introduction The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report 1. Introduction 1.1 Project Background Myanmar is a country of abundant natural resources, and has a great potential to attain rapid economic growth in the coming years. Yangon is the former capital, the main center of Myanmar’s economic activities, and the largest city of Myanmar having about 5 million populations, which is 12% of the national population (2010). The Port of Yangon, the largest international port of Myanmar, is located on the left bank of the Yangon River, next to Yangon downtown area. During the fiscal year of 2010~2011, the scale of the economy of Yangon Region was 23% of the national gross domestic product (GDP). The Myanmar government is now undertaking the fifth five-year plan for 2011~2012 to 2015~2016 fiscal years, which sets a GDP growth target of 6.7% for the 2012~2013 fiscal year. Due to the recent rapid growth of economy, Yangon shows excessive centralization of daily economic activities which generates transport demands that are larger than ever, and which reveals the insufficient capacity of the present transport infrastructure to cope with further economic growth/development. At the same time, the Greater Yangon Region is expanding outward, including Thanlyin area and Dala area. Both areas are separated from Yangon by the Yangon River and the Bago River, respectively. At the moment, there is no bridge between Yangon and Dala area, and Dala Bridge is proposed to be constructed soon. Between Yangon and Thanlyin area, there are two bridges, namely, Thanlyin Bridge and Dagon Bridge, as shown in Figure 1.1. Thanlyin Bridge, completed in 1993, is a road cum rail bridge. It has a dual 1-lane roadway section. Thanlyin Bridge prohibits heavy vehicle traffic over 32 t. Dagon Bridge, completed in 2007, is a dual 3-lane bridge, and therefore has enough traffic capacity. However, Dagon Bridge is located distant from Yangon Central Area (around 14 km) and around 6.4 km upstream of Thanlyin Bridge. Due to this distance from Yangon central area, Dagon Bridge seems to be underutilized for daily traffic, in spite of its ample traffic capacity. Thanlyin area is a developing area. The further development of Myanmar International Terminals Thilawa (MITT) is planned with Japanese assistance under the Project for Development of Yangon Port (Thilawa area). MITT is intended to share cargo handling with the Port of Yangon, and to be the backbone of Myanmar’s future development. The further development of MITT is also expected to ease the traffic congestion caused by Yangon Port activities in Yangon central area. Next to MITT, Thilawa Special Export Zone (SEZ) is planned to provide the industrial area and to be implemented soon. Private developments such as the construction of commercial and residential areas and the construction of recreation center are also quite active. Due to these developments, it is anticipated that Thilawa area will have around 500,000 daytime population in the near future. Consequently, it is believed that the traffic between Yangon area and Thanlyin area will increase. The current traffic capacity of the two existing bridges cannot accommodate the future traffic demand generated in the area, and will soon become a serious bottleneck. 1 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report Dagon Bridge Yangon Area Yangon Port Thanlyin Bridge Thanlyin Area Source: JICA Survey Team Figure 1.1 Two Existing Bridges on the Bago River Therefore, the construction of a new bridge, i.e., Bago River Bridge, is urgently required. At the moment, the Project for the Strategic Urban Development Plan of the Greater Yangon (SUDP) and the Project for Comprehensive Urban Transport Plan of the Greater Yangon (YUTRA) are conducted under Japanese assistance. These projects already pointed out the insufficient transport infrastructure between Yangon area and Thanlyin area. Being aware of the necessity of bridge between these two areas, the SUDP proposed a bridge at Bago Point as an integral part of the future transport network of Greater Yangon. YUTRA is still in its early stage and not able to identify the future traffic demand or the required additional number of lanes between the two areas. However, YUTRA is anticipating the requirement of more lanes to cope with the future traffic demand, which would result in the construction of one or more bridges. The existing Thanlyin Bridge was constructed as a bridge for freight train with road section attachments. When the role of Dagon Bridge is understood as a bridge for freight transport of the region, then it can be said that there is no commuter purpose infrastructure in terms of road transport and railway transport between Yangon area and Thanlyin area. To cope with the increased traffic demand (mainly commuter traffic) between Yangon area and Thanlyin area, it is believed essential to take into consideration the construction of commuter train system, in order to avoid the excessive burden to roadway transport system. In case of deploying the commuter railway system between Yangon area and Thanlyin area, it would be advisable to adopt the double-decked road cum rail bridge with the shortest length, from the transport engineering viewpoint. Instead of two separate bridge constructions, one for road and the other for railway, the application of double-decked bridge will reduce the construction cost. Apart from the bridge type selection between road bridge and road cum rail bridge, the construction of Bago River Bridge will surely guarantee the expected economic growth in Thanlyin area, accelerate Thilawa SEZ development, and greatly contribute to the economic development of Myanmar. Hence, Bago River Bridge needs to be constructed urgently. 2 The Preparatory Survey for The Project for Construction of Bago River Bridge 1.2 Final Report Project Objective As stated in the Minutes of the Meeting between Public Works (PW), Ministry of Construction (MOC), and Japan International Cooperation Agency (JICA), signed on May 15, 2013, the objective of this Preparatory Survey is to conduct a feasibility study on the new construction of Bago River Bridge and approach road to the bridge. 1.3 Related Studies The first phase of SUDP was conducted under Japanese assistance. The Final Report I was submitted in April 2013. In this report, SUDP reported the forecasted cross sectional traffic demand on the Bago River in 2040 as four times of the current volume, which would require a traffic capacity equivalent to 20 traffic lanes. It is noted that the current number of lanes is eight, of which Thanlyin Bridge has two lanes and Dagon Bridge has six lanes. Then, SUDP proposed the construction of Bago River Bridge to cope with the forecasted cross sectional traffic demand on the Bago River. At the moment, YUTRA is conducted under Japanese assistance. YUTRA already pointed out the insufficient transport infrastructure between Yangon area and Thanlyin area. YUTRA is still in its early stage and not able to identify the future traffic demand or the required additional number of lanes between the two areas. However, YUTRA is anticipating the requirement of more lanes to cope with the future traffic demand, which would result in the construction of one or more bridges. 3 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report Proposed Bago River Bridge by SUDP Remarks: SUDP proposed Bago River Bridge at Bago Point with the following reasons: 1. SUDP proposed the waterfront development along the Yangon River. 2. SUDP anticipated the serious traffic congestion in the downtown area of Yangon by Bago River Bridge at Monkey Point, which is not suitable for the waterfront development. Source: SUDP Study Team (Figure 3.4.14) Figure 1.2 Proposed Conceptual Plan of Road Network by SUDP 4 The Preparatory Survey for The Project for Construction of Bago River Bridge 1.4 Final Report Previously Proposed Three Bridge Locations In the Preparatory Study for Urban Development Programme in the Greater Yangon under Japanese assistance, the initial study on Bago River Bridge was conducted. This initial study proposed three alternative locations for Bago River Bridge, which were selected considering the existing road at the Yangon side which has a possibility to form the link with the proposed approach road to Bago River Bridge. The three locations and the assumed existing roads at Yangon side which will link with the proposed approach road to the bridge are as follows: Alternative Route Yangon Side Existing Road Alternative 1: Monkey Point Route Strand Road Alternative 2: Bago Point Route Yamonnar Road Alternative 3: Proximity to the Existing Thanlyin Bridge Route Shukhinthar-Mayopat Road Figure 1.3 shows the three alternative locations for Bago River Bridge. Source: JICA Survey Team Figure 1.3 Three Alternative Locations for Bago River Bridge 5 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report Chapter 2 Schedule of Preparatory Survey The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report 2. Schedule of the Preparatory Survey 2.1 Time Schedule of the Preparatory Survey Table 2.1 shows the proposed time schedule of the Preparatory Survey. It was planned that this Preparatory Survey is to be carried out in two phases as follows: 1st Phase: To conduct the alternative study and propose the most appropriate project scheme covering the bridge location and bridge type. 2nd Phase: To carry out the feasibility study of the Project, upon mutual agreement on the proposed project scheme. As shown in the “Report” row in Table 2.1, the inception report was submitted in early July and the progress report was submitted in the end of August. During the 2nd Phase, the interim report, Final report, and then the final report will be submitted. Table 2.1 Time Schedule of the Preparatory Survey Year 2014 2013 Month Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug First Site Survey in Myanmar [1-1] Presentation and Descussion of the Inception report [1-2] Collection and Review of Existing Information [1-3] Study on Highway/Bridges Operation and Maintenance System [1-4] Site Reconnaissance [1-5] Environmental and Social Considerations (IEE) [1-6] Alternative Study of the Project [1-7] Design Conditions of Approach Road Design [1-8] Preliminary Design of Approach Road Alternatives [1-9] Preliminary Design of Bridge Alternatives [1-10] Preliminary Project Cost Estimates [1-11] Presentation of Proposed Project Scheme [1-12] Preparation of Progress Report Second Site Survey in Myanmar [2-1] Implementation of Site Survey [2-2] Schematic Design of the Project [2-3] Survey of Construction Materials [2-4] Construction Plan and Project Cost Estimates/ [2-5] Study on Operation and Maintenance Programme [2-6] Environmental and Social Considerations (EIA) [2-7] Traffic Demand Forecast [2-8] Economic/Financial Analysis [2-9] Preparation of Final Report Report IC/R PG/R Steering Committee Source: JICA Survey Team 6 IT/R DF/R F/R The Preparatory Survey for The Project for Construction of Bago River Bridge 2.2 Final Report Members of the JICA Survey Team The JICA Survey Team is composed of 11 members, as shown in Table 2.2: Table 2.2 No. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. List of JICA Survey Team Members for the Preparatory Survey Name Takashi Shoyama Eiichi Yokota Toshio Ichikawa Tomoyuki Konishi Ryo Tanahashi Tomokuni Hayakawa Hironobu Kuroe Takeshi Maeda Mazhar Iqubal Rie Tajima Testujiro Tanaka Position/Assignment Team Leader/Comprehensive Urban Transport Plan Road Planning/Road Design Bridge Planning/Bridge Design 1 Bridge Planning/Bridge Design 2 Construction Planning/Cost Estimation 1 Construction Planning/Cost Estimation 2 Hydrologic Characteristic Analysis Geological Condition Data Traffic Demand Forecast Economic and Financial Analysis Social and Environmental Considerations Source: JICA Survey Team 2.3 Progress of the Preparatory Survey The major milestones of the Preparatory Survey are as follows: (1) Presentation of Inception Report (IC/R) and Discussion on the Contents of IC/R On July 2, 2013, the JICA Survey Team visited the Ministry of Construction (MOC), Nay Pyi Taw and made the presentation of IC/R to the concerned personnel of PW. IC/R introduced the time schedule of the Preparatory Survey, work items to be carried out in Myanmar, and proposed design considerations, such as design criteria, typical cross sections, and navigation clearance, for Bago River Bridge and approach road design. In the course of the presentation of the time schedule, the JICA Survey Team said that the bridge location, among the three alternatives shown in Figure 1.3, shall be finalized by at least midAugust. PW agreed to this and requested for the JICA Survey Team to provide the materials for the comparison and final selection of the bridge location. The JICA Survey Team agreed to PW’s request. The minutes of the meeting is attached in Appendix 1. (2) Presentation of Study of Three Alternative Locations for Bago River Bridge and Discussion on the Contents Following the presentation of IC/R, the JICA Survey Team carried out the preliminary design of Bago River Bridge and approach roads to the bridge, along with the initial environmental examination (IEE). The working results were prepared as the report of the Study of Three Alternative Locations for Bago River Bridge. On August 6, 2013, the JICA Survey Team visited MOC, Nay Pyi Taw, and made the presentation of the report. In this meeting, PW invited representatives of concerned organizations. After the presentation of the report by the JICA Survey Team, each representative including PW provided comment on the bridge location. Taking into consideration the various comments given by the representatives of concerned organizations, PW selected Alternative 3, i.e., Proximity of the Existing Thanlyin Bridge Route, as the location of Bago River Bridge. The JICA Survey Team proposed the bridge type of continuous steel box girder with steel plate deck for Alternative 3 route from the viewpoint of construction cost. PW requested for the JICA 7 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report Survey Team to make further study on the bridge type which may include the application of longer span bridge, taking into account the safety requirement for vessel operating route, and the importance of technology transfer of bridge construction into Myanmar. The JICA Survey Team agreed to do so. The Technical Notes for the meeting is attached in Appendix 2. (3) Presentation of Alternative Study of Bridge Type for Bago River Bridge The JICA Survey Team prepared the alternative study report of the bridge type which includes the comparison of the following six alternative bridge types: Alternative-A: Continuous Steel Box Girder with Steel Plate Deck Girder + Continuous Steel IGirder with Precast PC Deck Slab Alternative-B: Nielsen Arch Bridge + Continuous Steel I-Girder with Precast PC Deck Slab Alternative-C: Continuous PC Box Girder + Continuous Precast PC Box Girder (Span by Span) Alternative-D: Extradozed Bridge + Continuous Precast PC Box Girder (Span by Span) Alternative-E: Steel Cable Stayed Bridge + Continuous Steel Box Girder with Steel Deck Slab + Continuous Precast PC Box Girder (Span by Span) Alternative-F: Extradozed Bridge + Continuous Steel Box Girder with Steel Deck Slab + Continuous Precast PC Box Girder (Span by Span) This alternative study report evaluated each alternative bridge type applying the scoring system stated in the report. Alternative-E bridge type attained the highest score. On the occasion of the 3rd Steering Committee Meeting of YUTRA held on August 16, 2013 in Yangon, the JICA Survey Team submitted the report to PW and recommended to apply the Alternative-E bridge type, which was evaluated with the highest score. PW verbally agreed to adopt the bridge type of Alternative-E for Bago River Bridge. This verbal agreement was confirmed through the MOC’s formal decision in Nay Pyi Taw. The Technical Notes for the selection of bridge type is attached in Appendix 3. The alternative study of bridge type is introduced in Subchapter 6.2. (4) Natural Condition Surveys Upon the final decision on the bridge location and bridge (superstructure) type of Bago River Bridge, the following natural condition surveys were conducted: • • Topographic Survey Geological Survey Topographic survey and geological survey were contracted with local contractors at the end of August. However, due to the delay of permission to conduct the survey, both topographic survey and geological survey were completed at the beginning of November. (5) Environmental and Social Considerations Survey Environmental and social considerations surveys were conducted from October 2013. The following natural condition surveys were conducted: 8 The Preparatory Survey for The Project for Construction of Bago River Bridge • Ecosystem Survey - Terrestrial component - Aquatic component - Fish resources • • • • • Water Quality Survey Sediment Quality Survey River Velocity Survey Air Quality Survey Ambient Noise Survey Final Report The stakeholder meeting was conducted on 24 January 2014 with concerned personnel of PW, related organization and PAPs. (6) Design for Feasibility Study, Cost Estimation, Traffic Demand Forecast and Economic Evaluation Based on the natural condition survey, the JICA Survey Team conducted the preliminary design of the Bago River Bridge and its approach roads. Cost estimation was conducted for the purpose of the economic evaluation based on the traffic demand forecast carried out in the YUTRA Project. (7) Presentation of the Draft Final Report and Discussion on the Contents On July 31, 2013, the JICA Survey Team visited MOC, Nay Pyi Taw, and made the presentation of the Draft Final Report to the concerned personnel of PW staff headed Managing Director U Kyaw Linn. The contents of the report were mainly approved without some description of the report. 9 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report Chapter 3 Organization of Public Works The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report 3. Organization of Public Works (PW) The executing agency of the Bago River Bridge is PW which belongs to MOC Figure 3.1 shows the organization of PW. Source: PW Figure 3.1 Organization of Public Works As seen in Figure 3.1, PW consists of four departments under the Managing Director. The Department of Works has four divisions, namely: Building, Airfield, Road, and Bridge. Figure 3.2 shows the organizational chart of the Road Division. Source: PW Figure 3.2 Organizational Chart of the Road Division, PW 10 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report The PW’s counterpart division of the Project for Construction of Bago River Bridge is the Bridge Division. Although the organizational information of the Bridge Division was not obtained, it is anticipated that the Bridge Division also has the organization structure similar to that of the Road Division. Table 3.1 shows the staff number of the Road Division and Bridge Division. The Bridge Division has 106 officials and 854 employees as of August 2013. Table 3.1 List of Employees in MOC as of August 2013 Name of Department Road (Site) Road (Head Office) Bridge (Site) Bridge (Head Office) Total Government Official 189 36 83 23 331 Government Employee 1,220 193 790 64 2,267 Total 1,409 229 873 87 2,598 Source: MOC Table 3.2 shows the summary of equipment and the number of equipment possessed by PW. These huge numbers of equipment are deployed to various states and regions. Table 3.3 shows the equipment distribution status. Table 3.2 No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Summary of Equipment in PW, as of August 2013 Name of Equipment Bulldozer Motor Grader Excavator Loader Road Roller Soil Compactor Vibratory Roller Crane Drilling Rig Vibro Hammer Rock Drill Asphalt Concrete Plant Air Compressor Generator Dump Truck Truck Tyre Roller Asphalt Concrete Paver Agitator Truck Stone Crusher Grand Total Total Units 243 147 146 155 727 29 135 125 22 23 22 16 129 141 908 272 30 9 47 116 3,442 Source: PW 11 Remarks The Preparatory Survey for The Project for Construction of Bago River Bridge 57 3 1 2 1 2 48 4 5 6 3 5 1 2 63 4 1 14 5 6 6 1 1 3 3 1 1 6 1 1 1 1 3 1 5 1 15 3 2 13 2 3 19 3 5 2 1 9 1 3 8 6 2 2 1 2 3 2 5 1 1 1 1 4 8 2 1 7 1 2 3 8 3 1 8 4 19 1 2 1 1 17 1 1 1 1 2 5 20 8 2 7 1 5 18 2 1 6 2 1 9 1 2 2 4 2 7 6 2 73 21 4 2 4 23 2 3 45 10 1 2 7 109 23 8 4 1 2 39 2 4 5 1 66 15 5 3 6 1 1 1 71 12 5 6 4 1 6 2 1 66 23 14 6 7 6 1 1 2 1 255 42 80 1 140 407 138 269 321 298 42 11 10 6 6 1 9 21 8 Remark 40 2 86 2 3 16 7 11 1 2 4 2 1 7 7 5 Total 31 1 9 4 8 7 8 Mechanical Department 26 2 1 3 1 2 3 9 2 Ayarwadi Division 12 41 1 1 6 10 4 Shan State (East) 12 5 2 11 10 11 Shan State (North) Mandalay Division 10 6 1 10 10 10 Shan State (South) Magwe Division 7 2 3 5 5 7 5 2 Yangon Division Bago Division 5 5 1 10 7 9 2 1 1 2 2 2 Rakhaing State Tanantharyi Division 26 13 3 24 14 13 11 4 3 12 8 14 Mon State Sagaing Division 4 4 4 6 5 2 8 5 11 Kayin State Bull Dozer (Large) Bull Dozer (Median) Bull Dozer (Small) Motor Grader Excavator Loader Scraper Road Roller Tyre Roller Sheep Foot Roller Vibrating Roller Compactor Crane Bored Pile Drilling Rig Vibro Hammer Reversed Circulation Drill Desander Pile Driving Machine Asphalt Concrete Plant Asphalt Concrete Paver Decander Distributor Concrete Batching Plant Concrete Mixer Concrete Cutter Concrete Agitator Truck Concrete Pump and Pump Truck Concrete Paver Concrete Texturing M/C Concrete Breaker Gun Stone Crusher Rock Drill Screening & Washing M/C Air Compressor Electric Generator Welding Machine Stressing Jack Cement Pump Cement Bulk Carrier Tipper Truck Water Bowzer Oil Bowzer Wheel Tractor Transporter Service Truck Barge Tug Boat Z- Craft Anchor Boat Total Kayar State 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 Type of Equipment Kackin State Sr. Distribution of Existing Equipment in PW (State and Region) Chin State Table 3.3 Final Report 12 10 3 13 14 24 1 19 8 1 33 2 25 3 4 2 4 19 8 6 2 10 3 29 3 1 11 2 1 3 52 20 1 71 44 25 3 131 85 27 8 11 147 9 13 146 13 14 155 1 65 31 48 35 35 73 727 1 1 1 1 4 30 5 5 22 5 4 6 8 5 13 135 1 3 1 1 29 7 19 4 1 6 10 125 2 5 1 2 1 22 3 5 1 1 1 24 2 2 6 4 2 1 25 4 16 1 9 2 1 11 4 2 2 1 1 3 31 2 4 2 1 26 10 19 1 17 151 6 2 14 4 3 47 2 14 4 3 1 9 7 7 2 2 3 4 116 22 2 1 6 12 9 6 1 2 2 129 5 16 1 2 4 15 141 1 2 2 1 45 6 1 12 5 2 4 64 37 48 47 57 63 91 908 9 22 17 7 9 13 77 272 4 4 2 1 7 5 8 76 4 3 1 2 2 2 1 36 1 13 33 16 18 2 1 1 7 3 10 9 4 35 1 1 4 1 2 1 263 263 180 133 202 303 704 4040 Source: PW Detailed equipment list, including model number, capacity, procured year, and maker name, is presented in Appendix 4. Judging from the number of staff in the Road/Bridge Division and wide variation of equipment owned by PW, it is believed that PW has ample experience and capacity to carry out the appropriate maintenance activities for the completed infrastructures. However, in case of infrastructures built with technology that is new to Myanmar, such as steel cable-stayed bridge and/or steel box girder bridge with steel deck slab, it would be necessary to transfer the maintenance know-how to Myanmar. 12 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report Chapter 4 Design Criteria applied to the Project Design The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report 4. Design Criteria Applied to the Project Design In order to carry out the Project design of Bago River Bridge and its approach roads, design criteria shall be established. The current considerations regarding bridge design, road design, and navigation clearance are discussed in the following subchapters. 4.1 4.1.1 Design Criteria for Structural Design Structural Guidelines With respect to the structural guidelines, specialized structural design criteria associated with complex bridge types are compiled with the Japanese Standard for Highway Bridge (JSHB-2002) associated with developing preliminary bridge concepts. The only cords related to the application of live loading system are applied from AASHTO standard and other design loads such as earthquake, temperature, and wind are studied and applied or modified with JSHB considering local conditions. The general structural limitations and restrictions for Bago River Bridge such as span length restrictions, typical bridge cross sections, location of abutment, and restrictions on distance to adjacent structures on land or water are individually identified and verified. 4.1.2 Design Criteria (1) Live Loading System (AASHTO Standard) Note: V =Variable spacing from 4.267 m to 9.144 m to be used is that which produces maximum stresses Source: JICA Survey Team Figure 4.1 Standard Highway Bridge Loading (HS20-44) AASHTO standard also specifies the track as a single concentrated load and a uniform load as follows: • • Concentrated Load 8.16 T (104 kN) for Moment 11.80 T (116 kN) for Shear Uniform Load 0.95 T/m (9.38 kN) 13 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report (2) Seismic Design The Sagaing Fault is seismically active and running as a north-south trending fault extending to the Sagaing Hill. Along the Sagaing Fault, major earthquakes had occurred in the past as shown in Figure 4.1. Table 4.1 No. List of Major Earthquakes near Yangon along the Sagaing Fault Date 1. March 6, 1913 2. July 5, 1917 3. May 5, 1930 4. Dec. 5, 1930 Epicenter (Lat. N, Long. E) 17°00′, 96° 50′ 17°00′, 96° 50′ 17°00′, 96° 50′ 18°00′, 96° 50′ Richter Magnitude 7.0 7.0 7.3 7.3 Remarks Near Bago Near Bago Near Bago, 500 people killed in Bago and 50 in Yangon Near Pyu Source: JICA Survey Team The proposed bridge site, which is located near the south end of the Sagaing Fault, will be affected by earthquakes. Myanmar Geosciences Society (MGS) has prepared the earthquake zoning map of the Yangon area as shown in Figure 4.2 based on the characteristic earthquake of 7.3 Mw on firm rock that occurred on May 5, 1930. According to the zoning map, ground motion near the bridge site is around 0.135~0.145 gal (maximum: 0.15) which is rather lower than a Level-1 earthquake with ground motion of 200 gal (0.20) in JSHB. Seismic design for this study is carried out using acceleration response spectra for Level-1 earthquake ground motion in JSHB. The verification of Level-1 seismic design is carried out through the seismic coefficient method in Japan. When plastic behaviour of a reinforced concrete column is expected in the seismic design, structure details shall conform with JSHB (Part-V Seismic Design) in order to ensure the plastic deformation performance. (3) Temperature Maximum temperature in Yangon was recorded at 37.6 °C and the minimum was 16.6 °C based on the data of Kaba-Aya Observatory Station from 1999 to 2008. Temperature range for design shall be 15 °C to 40 °C with a mean temperature of about 25 °C (temperature rise of 10 °C, temperature fall of 15 °C) for ordinary bridge and from 15 °C to 50 °C with a mean temperature of about 25 °C (temperature rise of 10 °C, temperature fall of 25 °C) for steel plate deck. (4) Wind The biggest cyclone Nargis with winds up to 54 m/s swept through the neighbouring bridge location on May 2, 2008. There is a wind record with maximum wind speed of 49 m/s in Yangon, which is almost equal to the scale of the large typhoon in Japan. Therefore, wind load acting on the superstructure can be applied with the cord of JSHB. Design reference wind speed is set as 40 m/s at a height of 10 m in JSHB. If suspension bridge, cable-stayed bridge, and other flexible bridges are applied for the main bridge, more detailed study such as wind tunnel test is necessary to examine the stability due to wind in the detailed design. 14 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report Bridge Location Source: Tint Lwin Swe, Earth Sciences and its Applications Figure 4.2 4.2 Earthquake Zoning Map of Yangon Area (Tint Lwin Swe, 2004) Design Criteria for Road Design Road design shall be carried out based on the appropriate geometric design criteria for horizontal/vertical alignment design. Also, the geometric design criteria for horizontal/vertical alignments are governed by the design speed. It is understood that Asian Highway and ASEAN Highway are planned to traverse in Myanmar. Table 4.2 shows the extract of ASEAN Highway Standards which is based on the Asian Highway Standards by ESCAP 1995. 15 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report Table 4.2 Extract of ASEAN Highway Standards Source: The Association of Southeast Asian Nations (http://www.asean.org/communities/asean-economic-community/item/annex-b-asean-highwaystandards) Referring to Table 4.2, it is proposed to apply the “Class I” classification to the Project, with the terrain classification of “L” and the design speed of 80 km/h. The number of carriageway shall be determined by the traffic demand. However, considering the crowded traffic condition of the existing Thanlyin Bridge and the estimated future traffic demand forecasted by relevant studies, it is believed that the application of dual 2-lane bridge would be reasonable. 4.3 Design Navigation Clearance The design height of the bridge is controlled by the design vessels navigating on the Bago River. According to the obtained information, it is clear that Yangon Port is accessible to vessels of 167 m LOA, 9 m draft, and 15,000 DWT. However, the maximum scale of vessel which may navigate on the Bago River is not known. According to the Study on Ship Height by Statistical Analysis (November 2006) by the National Institute for Land and Infrastructure Management, Ministry of Land, Infrastructure and Transport, Japan, it was reported that the navigation clearance for cargo vessels of around 15,000 DWT is about 30 m or more, as shown in Table 4.3. 16 The Preparatory Survey for The Project for Construction of Bago River Bridge Table 4.3 Final Report Height above Water Level: Cargo Vessel DWT 50% 1,000 2,000 3,000 5,000 10,000 12,000 18,000 30,000 40,000 55,000 70,000 90,000 120,000 150,000 18.8 21.4 22.9 24.8 27.5 28.1 29.7 31.6 32.7 33.9 34.8 35.8 36.8 37.7 Coverage 75% Height (m) 20.9 23.5 25.0 27.0 29.6 30.3 31.8 33.7 34.8 36.0 36.9 37.9 39.0 39.8 95% 23.9 26.6 28.1 30.0 32.6 33.3 34.9 36.8 37.9 39.1 40.0 40.9 42.0 42.9 Where: Number of analyzed cargo vessel is 568. Coverage is the applicable ratio against the population (568). Source: JICA Survey Team It is believed that a 15,000 DWT vessel will not navigate through the Bago River. However, considering an emergency case when an out-of-control vessel drifts from the Yangon River to the Bago River under a storm, the proposed height of the new bridge, which may be located near the confluence of the Yangon River and the Bago River, shall have enough vertical clearance. In case the new bridge location is proposed nearby the existing Thanlyin Bridge, the minimum requirement of navigation clearance shall be the same with that of the existing bridge. Taking into consideration the above, the design navigation clearance for Bago River Bridge at each alternative route was proposed as shown in Table 4.4. Table 4.4 Proposed Navigation Clearance for Each Alternative Route Alternative Route Alternative 1: Monkey Point Route Alternative 2: Bago Point Route Alternative 3: Proximity to the Existing Thanlyin Bridge Route Navigation Clearance 35 m 35 m Same with the existing Thanlyin Bridge (around 10.2 m) Source: JICA Survey Team 17 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report Chapter 5 Study of Three Alternative Locations for Bago River Bridge The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report 5. Study of Three Alternative Locations for Bago River Bridge As aforementioned, three locations were proposed for Bago River Bridge. In order to select the most appropriate location for the Project, the preliminary design for the bridge and approach roads at each alternative location was carried out in order to compare the advantages and disadvantages between each alternative route. 5.1 Design Conditions for Alternative Study This alternative study was carried out under the following conditions: 1. The objective of preliminary design is as stated in Subchapter 1.2. 2. The proposed approach road is to be connected to the existing road. In Thanlyin side, the existing road linked to the proposed approach road is expected to be improved/upgraded as dual 2-lane road from the link point with approach road up to Thilawa SEZ area. 3. Design speed for the bridge and approach roads is 80 km/h. Design criteria follows the ASEAN Highway Standards. However, the maximum vertical grade of i = 4.0% was applied, referring to the Japanese Road Structure Ordinance, taking into consideration the presence of low power vehicles. 4. The proposed Bago River Bridge at Alternative 1 (Monkey Point Route) was assumed as a road cum railway bridge. The maximum vertical grade of the railway section is controlled by the design criteria of railways, i.e., imax = 10% (1.0%). 5. Assumed navigation clearance of Bago River Bridge was: - 35 m for Alternative 1 and Alternative 2 - The same height (around 10.2 m) as with the existing Thanlyin Bridge for Alternative 3 6. The Yangon side route of Alternative 1 and Alternative 2 will traverse the built-up area. In order to minimize the social environmental impacts on the area, there would be several variations in the horizontal alignment as shown in Figure 5.1. For Alternative 1, Northern Route along Pazundaung Creek and Southern Route along the Yangon River are considered as variations. For Alternative 2, the loop type ramp is considered to minimize the adverse social environmental impacts along Yamonnar Road. However, for the purpose of this study, simplified alignments as shown in Figure 5.3 were applied as the preliminary design. 7. Typical cross sections applied in this study are given in Figure 5.2. It was judged as appropriate to have dual 2-lane of 3.5 m wide carriageway with inner/outer shoulder. For cost savings purpose, the width of the outer shoulder of the bridge section was reduced to 0.50 m from the 1.50 m of the earthwork section. 18 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report Source: JICA Survey Team Figure 5.1 Several Route Arrangements for Alternative 1 and Alternative 2 8. The Preparatory Survey for the Project for Construction of Bago River Bridge scheduled the conduct of the investigation of natural conditions, such as topographic survey and geological survey, after the selection of bridge location. Therefore, the preliminary design for this alternative study was carried out utilizing aerial photography and 3D terrain data provided by Google Earth. It is noted that there is a certain limitation in the accuracy of the ground elevation. It must be understood that the profile alignment design shows only the design concept, and the work quantity calculations related especially to earthwork would not have a significant meaning. (a) Earthwork Section (b) Bridge Section Note: Superstructure type is for illustration purposes only. Source: JICA Survey Team Figure 5.2 Typical Cross Sections Applied in the Alternative Study 19 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report Source: JICA Survey Team Figure 5.3 Alignment Layout of Three Alternative Routes 20 5.2.1 Comparison of Three Alternative Locations for Bago River Bridge Outline of Project Route The Project consists of approach road + Bago River Bridge + approach road. Since the Project road is proposed as a dual 2-lane road, if the existing road, links to the Project approach road, is a dual 1-lane road, it is expected that the existing road will be improved to a dual 2-lane road under another project. Table 5.1 Project Route Outline of Three Alternatives Alternative 1 Monkey Point Route Alternative 2 Bago Point Route Alternative 3 Proximity to the Existing Thanlyin Bridge Route Right bank Strand Road Yamonnar Road Shukhinthar-Mayopat Road Thanlyin Chin Kat Road Left bank Local road running outskirts of Bo Gyoke Village Local road running outskirts of Bo Gyoke Village Kyaik Khauk Pagoda Road 11,330 m 10,178 m 2,974 m Total Project Length Approach Road (Right bank) Bridge Approach Road (Left bank) 7,120 m 190 m 5,650 m 1,280 m 5,968 m 458 m 3,081 m 2,429 m 2,974 m 419 m 1,909 m 646 m Improvement of Existing Road 4,210 m 4,210 m - Existing road linked to the Project Total Length The Preparatory Survey for The Project for Construction of Bago River Bridge 5.2 21 Remark: Information of Monkey Point Route gives the road section length of road cum railway bridge. Source: JICA Survey Team In Alternative 1 and Alternative 2, the improvement of existing road would be required from the link point with the Project approach road up to the outskirts road of Thilawa SEZ. As it was informed that Kyaik Khauk Pagoda Road will be improved to a dual 2-lane road under Thilawa SEZ Project (northern half by MOC and southern half by Thilawa SEZ Project), the improvement of the existing road is not considered in Alternative 3. Final Report Plan and profile designs of each alternative route for this study are given in Appendix 5. Land Use Condition along the Project Route The JICA Survey Team has started the initial inventory survey regarding the land use and assessment of the scale of involuntary resettlement for each of the three alternatives. However, it would not be appropriate to conduct the detailed inventory survey at this stage in order not to give the unnecessary adverse impact on the related communities. Hence, the following descriptions were not yet confirmed by valid evidence, and may contain wrong information. In case the descriptions are not appropriate, the correct/right information shall be provided to the JICA Survey Team. Table 5.2 Land Use Condition along the Project Route 22 Alternative 1 Required Land for the Project Monkey Point Route The project route starts from Strand Road, and crosses over the Navy land. When the southern route is applied, the project route will pass the south of Than Lyet Soon Road, cross over the Ministry of Energy land, YCDC Sewage Treatment Plant area and Navy land. When the northern route is Right Bank of the Bago River applied, then the project route will pass over the existing railways area, built-up area along Lower Pazundaung Road and jetty area of Navy land. Left Bank of the Bago River Alternative 3 Proximity to the Existing Thanlyin Bridge Route The project route starts from the intersection between Shukhinthar-Mayopat Road and Thanlyin Chin Kat Road. From this starting point to the Bago River, the project road traverses Myanmar Railways land, touching to the existing narrow road beside the PW’s compound. The proposed Bago River Bridge and its approach road runs on Myanmar Railways land parallel to the border of private developer’s land, having Excel River View Hotel inside, and then links to Kyaik Khauk Pagoda Road. Final Report Source: JICA Survey Team Alternative 2 Bago Point Route The project route starts from Yamonnar Road and crosses over the Asian Bowling Club, or fringe of Shu Khin Tar Amusement Park. In order to provide the project approach road, it is necessary to widen the existing Yamonnar Road, which has continuous and dense private premises on both sides. In order to minimize the social and environmental impact, it would be possible to deploy the loop type approach road. In case of loop type approach road, it is noted that the length of around 800 m shall be provide in the loop section, due to the high elevation of the Bago River Bridge. The project route lands on the fringe of Star The alignment of Alternative 2 is the same as City land and passes the land of the Ministry the alignment of Alternative 1. of Energy (MOE) or old oil refinery plant area. The land of MOE is large and the southern area seems to be used for cultivation. After traversing MOE land, the project route links to the existing local road. The proposed railways alignment diverts from the road alignment, and traverses MOE land and then Navy land up to the merging point with the existing railways. The Preparatory Survey for The Project for Construction of Bago River Bridge 5.2.2 Foreseen Natural/Social Environmental Impact The following environmental impacts are the outputs of preliminary site reconnaissance and assessment of available aerial photography. Therefore, the descriptions below are neither the final conclusion nor the results of definitive field assessment. Environmental impacts are evaluated by using the following components: (1) Social environment: involuntary resettlement (land acquisition, resettlement, etc.), cultural heritage and/or religious sites, fishery activities. (2) Natural environment: endangered/valuable plants and animals, protected area, row of trees along the road. (3) Environmental pollution: air pollution and noise. Table 5.3 Item Right Bank of the Bago River Administration 23 Social Environment a) Involuntary resettlement (land acquisition / resettlement, etc.) Foreseen Social and Environmental Impact Alternative 1 Monkey Point Route Alternative 2 Bago Point Route Alternative 3 Proximity to the Existing Thanlyin Bridge Route Botahtaung Township, Pazundaung Township Thaketa Township, Dawbon Township Thaketa Township Assuming the elevated approach road to the bridge, ROW for piers should be secured under the road structure. Thus, number of Project Affected Persons (PAPs) is expected from more than 200 to less than 50, depending on the alignment. However, estimation of the number of PAPs is difficult at present because the road alignment is not yet finalized. (1) The route passes the Than Lyet Soon Road and Strand Road The expected number of PAPs is more than 200. In addition, mostly affected land and structures are those of government properties. Number of PAPs is expected to be more than 200 in order to secure the necessary land for ROW of at-grade road along Yamonnar Road. However, estimation of the number of PAPs is difficult at present because the road alignment is not yet clear. Land and structures (plots, commercial buildings, shops, houses, government offices, etc.) belonging to Dawbon Township (southern side of the road) are expected to be more affected. By contrast, those that belong to Thaketa Township (northern side of the road) are expected to be less affected. Number of PAPs are expected to be less than 10 in order to secure the necessary land around the intersection of Thanlyin Chin Kat Road and Shukhinthar Myo Pat Road and along the approach road to the proposed Bago River Bridge. However, estimation of the number of PAPs is difficult at present because the road alignment is not yet clear. The Preparatory Survey for The Project for Construction of Bago River Bridge 5.2.3 Final Report Alternative 1 Monkey Point Route Alternative 2 Bago Point Route Alternative 3 Proximity to the Existing Thanlyin Bridge Route (2) Southern route: pass along the Yangon River bank The alignment passes through compounds of Navy, Sewage Treatment Plant, Ministry of Energy and jetty, and connected to Strand Road. The expected number of PAPs is less than 50. (3) Northern route: pass along the river bank of Pazundaung Creek The alignment crosses the existing railway line, traverses built-up areas, and connects to Strand Road. The number of PAPs is more than 200. b) Cultural, heritage and/or religious sites 24 Natural Environment a) Endangered/valuable plants and animals No cultural or heritage sites. One monastery and mosque distributed along Than Lyet Soon Road. No cultural heritage or religious sites. No cultural heritage or religious sites. No species are found at present. No species are found at present. No species are found at present. Cutting and/or replanting 30 to 100 trees Cutting and/or replanting about 100 trees including Indian Almond and Ashok species including Indian Teak, Almond, and Ashok is required depending on the alignment. species is required depending on the alignment. Cutting and/or replanting about 20 trees is required depending on the alignment. c) Protected area No protected areas such as designated park and natural reserves are found. No protected areas such as designated park and natural reserves are found. No protected areas such as designated park and natural reserves are found. Considerable impact on air quality is expected because the route is located in a densely urban built-up area. Some impact on air quality is expected Little impact on air quality is expected because the route is located in an urban built- because the route is located in a suburban up area. area. Considerable impact on ambient noise is expected because the route is located in a densely urban built-up area. Some impact on ambient noise is expected Little impact on ambient noise is expected because the route is located in an urban built- because the route is located in a suburban up area. area. Environmental pollution a) Air pollution b) Noise pollution Final Report b) Row of trees along the roads The Preparatory Survey for The Project for Construction of Bago River Bridge Item Alternative 2 Bago Point Route Alternative 3 Proximity to the Existing Thanlyin Bridge Route Thanlyin Township Thanlyin Township Thanlyin Township Necessary land to secure ROW is mostly distributed in the compound of the Ministry of Energy and in a farmland. Number of PAPs is expected to be less than 50. However, estimation of the number of PAPs is difficult at present because the road alignment is not yet clear. Necessary land to secure ROW is mostly distributed in the compound of the Ministry of Energy and in a farmland. Number of PAPs is expected to be less than 50. However, estimation of the number of PAPs is difficult at present because the road alignment is not yet clear. No PAPs are expected because land for ROW is within the compound of the railway department. No cultural, heritage or religious sites. No cultural heritage or religious sites. No cultural heritage or religious sites. Natural Environment a) Endangered/valuable plants and animals No species are found at present. No species are found at present. No species are found at present. b) Row of trees along the roads Cutting and/or replanting of about 30 trees is Cutting and/or replanting of about 30 trees is Cutting and/or replanting of about ten trees is required depending on the alignment. required depending on the alignment. required depending on the alignment. c) Protected area No protected areas such as designated park and natural reserves are found. No protected areas such as designated park and natural reserves are found. No protected areas such as designated park and natural reserves are found. Negligible impact on air quality is expected because the route is located in rural area. Negligible impact on air quality is expected because the route is located in rural area. Some impact on air quality is expected because the route is located in residential area. Left Bank of Bago River Administration Social Environment a) Involuntary resettlement (land acquisition / resettlement, etc.) b) Cultural, heritage and/or religious sites 25 Environmental pollution a) Air pollution b) Noise pollution The Preparatory Survey for The Project for Construction of Bago River Bridge Alternative 1 Monkey Point Route Item Negligible impact on ambient noise is Negligible impact on ambient noise is Some impact on ambient noise is expected expected because the route is located in rural expected because the route is located in rural because the route is located in residential area. area. area. Fishery Activities in the River Fishery activities Final Report Source: JICA Survey Team Impact on fishery activities is expected to be Impact on fishery activities is expected to be Impact on fishery activities is expected to be small, but not clear. small, but not clear. small, but not clear. Influence on the Adjacent Road Network/Traffic Environment Along with the development of Thanlyin area/Thilawa area, when Bago River Bridge is completed and starts its operation, almost all traffic between Yangon area and Thanlyin area will use Bago River Bridge. Traffic volume is anticipated to increase, keeping pace with the regional activity and growth. Hence, the implementation of Bago River Bridge will incur serious traffic problem especially in Yangon area if there is no improvement in the existing road and road network, traffic management/control, or improvement of traffic mode and other countermeasures to realize the desirable transport system in Yangon area. It is understood that, at the moment, YUTRA and SUDP are conducted under Japanese assistance. These projects are aiming to realize the well-balanced future Yangon, avoiding the excessive centralization of every activity in Yangon central area, and providing the appropriate road network and appropriate countermeasures of traffic management, with the provision of medium-/long-term plan proposal. 26 Therefore, it is believed that the magnitude of contribution or adverse influence of Bago River Bridge over the regional transport environment shall be evaluated in line with the abovementioned two projects’ analysis. However, for example, YUTRA is now carrying out the traffic survey to collect the current traffic information. After finishing the data collection/data arrangement and data calibration, YUTRA will start the future traffic demand forecast and future traffic distribution analysis over the planned road network. YUTRA is scheduling these future traffic demand forecast and future traffic analysis in late autumn 2013. At present, it is not possible to address the influence on the adjacent road network/traffic environment by the Bago River Bridge construction in the medium/long term. The Preparatory Survey for The Project for Construction of Bago River Bridge 5.2.4 The descriptions in Table 5.4 give the anticipated influence of Bago River Bridge implementation over the current traffic environment in the short term. Final Report Right Bank of the Bago River Influence on the Adjacent Road Network/Traffic Environment 27 Alternative 1 Monkey Point Route Alternative 2 Bago Point Route Increased traffic by Bago River Bridge implementation will cause serious traffic problems. Due to the convenience of Bago River Bridge route up to Thilawa area, almost all car drivers intending to move between Yangon area and Thilawa area will use Bago River Bridge. Hence, the traffic volume in Yangon downtown area will increase and generate serious traffic jam. However, heavy vehicles bringing goods into/out of Yangon Port may also use Bago River Bridge, instead of passing through Yangon downtown area. It is judged that this detouring manoeuvre of heavy vehicles in Yangon Port area will relieve the current crowded traffic conditions in Yangon downtown area. Heavy vehicle’s freight route is expected as: Yangon PortBago River BridgeThanlyin areaDagon Bridge. Although it is a long distance, heavy vehicle drivers may prefer this route due to time saving. It would be also possible to enforce this detour route to heavy vehicles by providing administrative regulations. From the traffic engineering viewpoint, this Bago Point Route would be the best route if the related road network has ample traffic capacity and traffic management is operated desirably. However, Yamonnar Road, to which Bago River Bridge approach road will link, is already a busy road. It seems Yamonnar Road is now receiving saturated traffic volume. Yamonnar Road has an intersection with Maha Bandula Road - Min Nandar Road. During peak time, this intersection shows serious traffic congestion now. When Bago River Bridge is completed and traffic volume is increased in this area, the traffic conditions would be worsened. In order to avoid such situation, providing an independent road, from Bago River Bridge to Yangon area, would be one of the options. However, this independent road construction will need an additional bridge over Pazundaung Creek, and will result in shifting the traffic congestion into Yangon downtown area. Alternative 3 Proximity to the Existing Thanlyin Bridge Route The Bago River Bridge approach road is proposed to connect with the intersection with Shukhinthar-Mayopat Road and Thanlyin Chin Kat Road. The intersection would be a 5-leg irregular shape. The appropriate traffic control by traffic signal shall be provided in this intersection. Increased traffic by Bago River Bridge implementation will use ShukhintharMayopat Road or Thanlyin Chin Kat Road which links to Ayer Wun Main Road. In between Bago River Bridge and Yangon central area, there is a certain extent of road network. It is anticipated that the increased traffic would be distributed among this road network, and would not cause excessive traffic problems in Yangon central area in a concentrated manner. The Preparatory Survey for The Project for Construction of Bago River Bridge Table 5.4 Final Report Alternative 2 Bago Point Route Alternative 3 Proximity to the Existing Thanlyin Bridge Route As the road network in this area is not Same as the situation in Alternative 1. developed yet, no serious influence would be incurred over the area. The existing narrow local road shall be upgraded to a dual 2-lane road, in order to connect Bago River Bridge traffic to Thilawa SEZ area. If the local road is upgraded, the dual 2-lane Bago River Bridge and dual 2-lane local road will link to Thilawa SEZ area. It is believed that the traffic condition in this area will be improved. It is essential to provide the traffic safety measures to local communities, as local people may not have enough living experience with high speed vehicle traffic. As mentioned before, it is expected that Kyaik Khauk Pagoda Road will be upgraded to a dual 2-lane road. Connecting the dual 2lane Bago River Bridge and dual 2-lane Kyaik Khauk Pagoda Road, it is expected that the traffic condition up to Thilawa SEZ area will be improved. Railways Bago River Bridge at Alternative 1 route No railways. would be constructed as a road cum railway bridge. The railways will apply a commuter train system. As Thilawa SEZ is forecasting 200,000 to 400,000 daytime population, it is judged as an appropriate plan to construct the new railways between Yangon area and Thilawa area. The deployment of railway system will prevent the concentration of vehicle transportation and contribute to the harmonized transport modal development. The construction of new railways shall be justified with its feasibility. However, at this moment, it is not possible to confirm the sound feasibility of railway system. YUTRA will conduct the analysis in autumn this year. No railways. 28 Left Bank of Bago River The Preparatory Survey for The Project for Construction of Bago River Bridge Alternative 1 Monkey Point Route Source: JICA Survey Team Final Report Possible Superstructure Type Possible superstructure types for each alternative route were provided for study purpose as given in Table 5.5. Considering its economical construction cost, the continuous box girder with steel plate deck was adopted for the Alternative 3 route. Elevation plans and typical cross sections of each bridge type are provided in Appendix 6. Table 5.5 Alternative 1 Monkey Point Route Alternative 2 Bago Point Route Alternative 3 Proximity to the Existing Thanlyin Bridge Route Steel Plate Girder Bridge + Double-decked Truss Bridge + Double-decked Cable-stayed Bridge - - Steel Plate Girder + Continuous Box Girder with Steel Plate Deck + Cable Stayed Bridge Continuous Box Girder with Steel Plate Deck or Nielsen Arch Bridge or Extradozed Bridge or PC Box Girder Bridge Possible Superstructure Type Road cum Railway Bridge Possible Superstructure Types for Each Alternative Route Case – 1: No structure for railways except the section over the Bago River 29 Road Bridge Steel Plate Girder Bridge + Double-decked Truss Bridge + Double-decked Cable-stayed Bridge Case - 2 Steel Plate Girder + Continuous Box Girder with Steel Plate Deck + Cable Stayed Bridge The Preparatory Survey for The Project for Construction of Bago River Bridge 5.2.5 Source: JICA Survey Team Final Report Cost Estimates This alternative study was prepared based on the preliminary design of bridge and approach roads. Therefore, work quantities were not estimated properly. Further, as the JICA Survey Team is still in the early stages of the survey period in Myanmar, reasonable construction cost inventory was not obtained yet. However, in order to know the project scale in terms of the construction cost, the cost estimates of the main bridge was conducted. Reference was made to unit construction costs in Japan in 2010 and unit construction costs of Hinthata Bridge, as given in Appendix 7. Table 5.6 Preliminary Cost Estimates Alternative 1 Monkey Point Route 8,550 m/5,650 m Alternative 2 Bago Point Route 3,081 m Alternative 3 Proximity to the Existing Thanlyin Bridge Route 1,909 m Steel Plate Girder Bridge + Double-decked Truss Bridge + Double-decked Cable-stayed Bridge Case – 1 (No structure for railways except the section over the Bago River) - - Steel Plate Girder + Continuous Box Girder with Steel Plate Deck + Cable Stayed Bridge Continuous Box Girder with Steel Plate Deck JPY 40,010,000,000 JPY 31,500,000,000 JPY 22,000,000,000 JPY 18,000,000,000 JPY 10,200,000,000 Approach roads L = 1,470 m L = 2,887 m Improvement of existing road L = 4,210 m L = 4,210 m Bridge Length Assumed Bridge Type Road cum Railway Bridge 30 Road Bridge Steel Plate Girder Bridge + Double-decked Truss Bridge + Double-decked Cable-stayed Bridge The Preparatory Survey for The Project for Construction of Bago River Bridge 5.2.6 Case - 2 Steel Plate Girder + Continuous Box Girder with Steel Plate Deck + Cable Stayed Bridge Approximate Construction Cost Road cum Railway Bridge Road Bridge Case – 1 Case – 2 In addition to the bridge construction cost, the following works are required. Final Report Source: JICA Survey Team L = 1,065 m and Improvement of Intersection - Comparison of Alternative Routes from the Transport Planning Point of View When comparing alternative routes from purely transport planning point of view, advantages/disadvantages of each route will be described as given in Table 5.7. Table 5.7 Aspect Comparison of Alternative Routes from the Transport Planning Point of View Alternative 1 Monkey Point Route Alternative 2 Bago Point Route - Enough (to be examined) Alternative 3 Proximity to the Existing Thanlyin Bridge Route - Enough (to be examined) Road Network - Shortest distance between Yangon central - Consistent with the network planned by business district (CBD) and Thilawa SUDP - Consistent with the planned reconstruction of Thaketa Bridge - Not changed Railway Network - Possible new line connecting Yangon CBD and Thilawa - Utilize existing railway system Traffic Congestion - May worsen traffic congestion in Yangon - May worsen traffic congestion in CBD Yamonnar Road and adjacent road network Urban Development - May hinder waterfront development planned by SUDP 31 Capacity to Transport Demand - New line proposed by SUDP - Enough (to be examined) The Preparatory Survey for The Project for Construction of Bago River Bridge 5.2.7 Note: Green - Advantage Red - Disadvantage Source: JICA Survey Team Final Report The Preparatory Survey for The Project for Construction of Bago River Bridge 5.3 5.3.1 Final Report Other Information Related to the Project Port Limit Source: JICA Survey Team Figure 5.4 Location of Yangon Port Limit shown in Red Oval Myanma Port Authority (MPA) defines the “port limit” on the Yangon River, the Bago River, and Pazundaung Creek as shown in Figure 5.4. The downstream area from these port limits is under the jurisdiction of MPA. It is noted that, on the Bago River, the location of the existing Thanlyin Bridge is assigned as the port limit. Hence, the design of Bago River Bridge for Alternative 1/Alternative 2 routes shall follow MPA’s design control. 32 The Preparatory Survey for The Project for Construction of Bago River Bridge 5.3.2 Final Report Vessel Operating Route at the Existing Thanlyin Bridge Area The Inland Water Transport (IWT) was informed about the facilities (jetty and dockyard) along the Bago River at the meeting with the JICA Survey Team on July 5, 2013, as follows: (a) Dockyard of IWT for small boats (200 ft) upstream of the existing Thanlyin Bridge; (b) Jetty for Myanma Five Star Line (MFSL), and (c) Jetty for the Navy between the existing Thanlyin Bridge and the Bago River mouth. Further, IWT specified the vessel operating route under the existing Thanlyin Bridge to the dockyard of IWT as shown in Figure 5.5. (a) IWT Dockyard (b) MFSL Jetty Vessel Operating Route (c) NAVY Jetty Source: JICA Survey Team Figure 5.5 Vessel Operating Route at the Existing Thanlyin Bridge Area In case the Alternative 3 location is selected for Bago River Bridge, the pier arrangement shall be carefully studied taking into consideration the vessel operating route, in consultation with IWT. 5.3.3 Comment of Myanma Port Authority The JICA Survey Team visited MPA on July 5, 2013 to consult on the design controls of Bago River Bridge. Mr. Cho Than Maung, Managing Director of MPA, attended the meeting and gave his comment as given in the scanned copy of the meeting record in Figure 5.6. 33 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report Source: JICA Survey Team Figure 5.6 Scanned Copy of Meeting Record with MPA (1/2) 34 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report Source: JICA Survey Team Figure 5.7 Scanned Copy of Meeting Record with MPA (2/2) 35 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report As indicated in Figure 5.8, it would be worth to propose the curved bridge alignment over the Bago River in order to avoid traversing just above the vessel operation route. Source: JICA Survey Team Figure 5.8 5.4 Proposed Alignment of Curved Bridge at Monkey Point Route Selection of Bago River Bridge Location As reported in Subchapter 2.3 (2), a meeting was held on August 6, 2013 at the conference room of the Ministry of Construction, Nay Pyi Taw to present the Study of Three Alternative Locations for Bago River Bridge given in Subchapter 4.2 of this report. As a conclusion of the meeting, the location of Alternative 3, Proximity to the Existing Thanlyin Bridge Route, was selected for Bago River Bridge. 36 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report Chapter 6 Preliminary Design of Bago River Bridge The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report 6. Preliminary Design of Bago River Bridge 6.1 Alignment Design The Bago River Bridge at Alternative 3 (Proximity to the Existing Thanlyin Bridge Route) was proposed to run parallel to the existing Thanlyin Bridge at the downstream side due to land availability and desirable connection arrangement to the existing roads. If the straight alignment, parallel to the existing bridge, is applied from the beginning point, the project road will start from Shukhinthar-Mayopat Road nearby the existing intersection, as shown with the red arrow in Figure 6.1. This is not recommended from the viewpoint of traffic safety. It is believed that the project road shall be designed along with the remodelling of the existing intersection as given in the yellow line of Figure 6.1. In the course of the intersection design, it is required to secure the access to the National Races Village. Source: JICA Survey Team Figure 6.1 Plan at Yangon Side The alignment at Thanlyin side is relatively simple. In between the existing Thanlyin Bridge and private development land, the project road will traverse and link to the existing Kyaik Khauk Pagoda Road. Intersections with the existing approach roads to the Thanlyin Bridge would be required. Source: JICA Survey Team Figure 6.2 Plan at Thanlyin Side The vertical grade of the approach road section is 2.50% in the preliminary design. It is noted that a grade steeper than 2.50%, up to 4.00%, is still allowable referring to the design standards. 37 The Preparatory Survey for The Project for Construction of Bago River Bridge 6.2 6.2.1 Final Report Study of Superstructure Type Selection of Superstructure Type The bridge in this feasibility study is mainly composed of a main bridge and approach bridge on both sides as shown in Figure 6.3. The main bridge maintains the navigational requirement and the approach bridge is a connection to the main bridge from the highway. The types of the main bridge are each evaluated based on the engineering criteria such as span length, navigation requirement, structural stability, constructability, construction cost, maintenance, new technology, and aesthetic point. The key criteria to examine the viability among them are span length, structural stability, and new technology. Other items such as construction cost, constructability, maintenance, aesthetic point, and navigation are also comprehensively examined for the selection of bridge type. Regarding new technology of bridge, the PW strongly requested the JICA Survey Team to add alternative types of bridges with combination of various bridge types such as long-span steel cable bridge and continuous box girder with steel deck plate in the meeting held in the MOC on August 6, 2013. Source: JICA Survey Team Figure 6.3 Composition of Bridge (1) Main Span The span of the main bridge is determined as the same span of the existing Thanlyin Bridge in the above meeting held on August 6, 2013 in consideration of the navigational requirements including the adjacent existing bridge and river conditions. The span arrangement is 104 m + 10@112 m + 104 m, with total length of 1,328 m. IWT also proposed that the navigation span used at present should be wider at the existing navigation channel because the river boat pilots use the channel to pass diagonally under the bridge. PW requested the JICA Survey Team to add the alternative bridge type with 224 m span at the navigation channel that may be a new type of bridge and contribute to the development of Myanmar bridge construction. Six alternative types are comprehensively selected based on the engineering criteria, and requests of PW and IWT, as follows: 1) Alternative-A: Continuous Steel Box Girder with Steel Deck 2) Alternative-B: Continuous PC Box Girder 3) Alternative-C: Nielsen Arch 4) Alternative-D: Extradozed Bridge 5) Alternative-E: Combination with Steel Cable Stayed and Continuous Steel Box Girder with Steel Deck 6) Alternative-F: Combination with Extradozed Bridge and Continuous Steel Box Girder with Steel Deck 38 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report Drawings of the alternative bridge (superstructure) types of the main bridge are presented in Appendix 8 (Six (6) Alternative Bridge Types for Superstructure Type Selection). (2) Approach Bridge The cross section of the approach bridge is adopted in the outline of the cross section from the main bridge to keep a consistent depth of the main bridge. Therefore, span length of the approach bridge is 40 m ~ 60 m applied in consideration of girder depth restriction and economical viewpoint. The length of the approach bridge may be different for every superstructure type of the main bridge. The following two bridge types for the approach bridge are selected in matching with the main bridge and new bridge technology in Myanmar. 1) Precast Continuous PC Box Girder (Span by Span) 2) Steel I-Girder with Precast PC Slab Drawings of approach bridge (superstructure) types are presented together with the main bridge in Appendix 8 (Drawings of Alternative Bridge Type). 6.2.2 Evaluation Criteria For the selection of the most appropriate bridge type, the JICA Survey Team has prepared the evaluation criteria as shown in Table 6.1 and Table 6.2, using score (point) ranking to evaluate priority of each category. Table 6.1 N o. 1 2 3 4 5 6 7 8 Evaluation Criteria of Alternative Study Category Technical Viability (30 points) Economic Viability (25 point) Other Viability (45 points) Evaluation Criteria Structural Stability Constructability Construction Cost Maintenance New Technology Landscape Navigation Environment Total Points Maximum Score (Point) 20 10 20 5 20 10 10 5 100 Source: JICA Survey Team Table 6.2 Description Grade Rate Good 100% Fair 50% Poor 30% Bad 0% coring System for Evaluation of Alternative Bridge Type Structura Constructl ability Stability (20) 20 10 6 0 (10) 10 5 3 0 Construction Cost (20) 20 10 6 0 Ratio 1.00 ~ 1.10 1.10 ~ 1.20 1.20 ~ 1.30 Over 1.30 Maintenance New Technology Landscape Navigation Environment (5) 5 3 2 0 (20) 20 10 6 0 (10) 10 5 3 0 (10) 10 5 3 0 (5) 5 3 2 0 Source: JICA Survey Team 39 The Preparatory Survey for The Project for Construction of Bago River Bridge 6.2.3 Final Report Evaluation Results and Recommendation Evaluation for each alternative bridge type is presented in Table 6.4 to Table 6.9, and the results of the selection are shown in Table 6.3. Table 6.3 Results of Selection of Bridge Type Category Structural Stability Constructability Construction Cost Maintenance New Technology Landscape Navigation Environment Total Score Priority Order (20) (10) (20) (5) (20) (10) (10) (5) A 20 10 20 3 6 3 5 5 72 2 B 10 5 6 3 10 5 5 5 49 6 Alternative C D 10 10 5 5 20 10 3 3 6 10 3 5 5 5 5 5 57 53 4 5 E 20 5 6 3 20 10 10 5 79 1 F 10 3 6 3 20 10 10 5 67 3 Note: Figure in ( ) shows the maximum score. Source: JICA Survey Team The above table shows the results of bridge type selection among the six alternatives. Alternative-A is the lowest cost type of bridge but Alternative-E has the highest score in the comprehensive engineering assessment considering the preferences of PW, IWT, MPA, and other relative authorities. In consideration of the compilation of new bridge technologies in Myanmar, opinions of river boat pilots, and aesthetic viewpoint, Alternative-E (Combination with Cable-Stayed Bridge and Continuous Steel Box Girder with Steel Plate Deck) is also recommended as the most suitable bridge type. 40 The Preparatory Survey for The Project for Construction of Bago River Bridge Table 6.4 Alternative-A: Continuous Steel Box Girder with Steel Plate Deck 41 Continuous Steel I- Girder with Precast PC Deck Slab Category Technical Viability Economic Viability Other Viability Evaluation Criteria Source: JICA Survey Team Description Multi-continuous spans are structurally strong against earthquake resistance and results in smooth driving. Light and short steel members are advantageous for erection. Construction period is 24 months. μ=1.00 Economical bridge type because steel fabrication cost is considerably low in comparison with Japan. Periodical maintenance for painting on steel is only required. Steel and precast PC deck slabs are only new approaches. This type of bridge is relatively visually simple and associated with the existing Thanlyin Bridge. Navigation clearance is secured but careful sailing is required due to the adjacent existing Thanlyin Bridge. Almost no impact. Recommended in case of minimum cost Evaluation Good Good Good Fair Poor Poor Fair Good 20 10 20 3 6 3 5 5 72 Final Report Structural Stability Constructability Construction Cost Maintenance New Technology Landscape Navigation Environment Evaluation Max. Point 20 10 20 5 20 10 10 5 Continuous Steel Box with Steel Deck Alternative-B: Nielsen Arch Bridge The Preparatory Survey for The Project for Construction of Bago River Bridge Table 6.5 42 Continuous Steel I- Girder with Precast PC Deck Slab Category Technical Viability Economic Viability Structural Stability Constructability Construction Cost Maintenance New Technology Landscape Navigation Environment Evaluation Source: JICA Survey Team Max. Point 20 10 20 5 20 10 10 5 Description Multi-simple spans are structurally weak against earthquake resistance and make noise when passing at expansion joints. Lift-up barge erection method using tidal movement can be applied. Construction period is 26 months. =1.21 112 m span is not economical span for Nielsen arch in comparison with continuous steel box girder. Periodical maintenance for painting on steel is only required. Nielsen arch using cables is new technology but too small scale (Span 112 m) for technology transfer. This type is an aesthetical bridge but has relatively visual complexity associated with the existing Thanlyin Bridge. Navigation clearance is secured but careful sailing is required due to the adjacent existing Thanlyin Bridge. Almost no impact. Not recommended Evaluation Fair Fair Poor Fair Fair Fair Fair Good 10 5 6 3 10 5 5 5 49 Final Report Other Viability Evaluation Criteria Nielsen Arch The Preparatory Survey for The Project for Construction of Bago River Bridge Table 6.6 Alternative-C: Continuous PC Box Girder 43 Precast Continuous PC Box (Span by Span) Category Technical Viability Economic Viability Other Viability Evaluation Criteria Source: JICA Survey Team Description Multi-continuous spans are structurally strong against earthquake resistance but cause deflection problem at center joints. Pre-cast concrete cantilever method is a reliable and safe method in the river. Construction period is 26 months. Concrete bridge has relatively high cost because procurement of the materials is difficult and costly. =1.05 Maintenance is almost free except expansion joints at center hinges. Pre-cast PC box girder is new erection method but not enough for technology transfer. This type of bridge has relatively visual simplicity associated with the existing Thanlyin Bridge. Navigation clearance is secured but careful sailing is required due to the adjacent existing Thanlyin Bridge. Almost no impact. Not recommended Evaluation Fair Fair Good Fair Poor Poor Fair Good 10 5 20 3 6 3 5 5 57 Final Report Structural Stability Constructability Construction Cost Maintenance New Technology Landscape Navigation Environment Evaluation Max. Point 20 10 20 5 20 10 10 5 Continuous PC Box The Preparatory Survey for The Project for Construction of Bago River Bridge Table 6.7 Alternative-D: Extradozed Bridge 44 Precast Continuous PC Box (Span by Span) Category Technical Viability Economic Viability Other Viability Evaluation Criteria Source: JICA Survey Team Extradozed Bridge (At Pier) Description Multi-continuous spans are structurally strong against earthquake resistance but cause deflection problem at center joints. Cast-in-place concrete cantilever method using outer cables is applied. Construction period is 30 months. Concrete bridge has relatively high cost because procurement of the materials is difficult and costly. =1.15 Maintenance is almost free except expansion joints at center hinges. Extradozed bridge using cables is new technology but too small scale (Span 112 m) for technology transfer. This type is an aesthetical bridge but has relatively visual complexity associated with the existing Thanlyin Bridge. Navigation clearance is secured but careful sailing is required due to the adjacent existing Thanlyin Bridge. Almost no impact. Not recommended Evaluation Fair Fair Fair Fair Fair Fair Fair Good 10 5 10 3 10 5 5 5 53 Final Report Structural Stability Constructability Construction Cost Maintenance New Technology Landscape Navigation Environment Evaluation Max. Point 20 10 20 5 20 10 10 5 Extradozed Bridge (At Center) The Preparatory Survey for The Project for Construction of Bago River Bridge Table 6.8 Alternative-E: Combination with Steel Cable Stayed Bridge and Continuous Steel Box Girder with Steel Plate Deck 45  Precast Continuous PC Box (Span by Span) Category Technical Viability Economic Viability Structural Stability Constructability Construction Cost Maintenance New Technology Landscape Navigation Environment Evaluation Source: JICA Survey Team Max. Point 20 10 20 5 20 10 10 5 Cable Stay Bridge Description Steel cable stay and continuous steel box girders have strong earthquake and wind resistance. Erection of cable stay and steel bridges is performed from barge-mounted crane. Construction period is 28 months. =1.23 Cable-stayed bridge is rather costly but is an economical type for long span of 224 m. Periodical maintenance for painting on steel is only required. Steel cable stay and box girder with steel deck slab and precast PC box girder (Span by Span) are new technologies. Excellent view and symbolic structure due to high towers and its cables. Wide navigation clearance is secured when sailing from and toward the adjacent existing Thanlyin Bridge. Almost no impact. Comprehensively Recommended At Tower Evaluation Good Fair Poor Fair Good Good Good Good 20 5 6 3 20 10 10 5 79 Final Report Other Viability Evaluation Criteria Continuous Steel Box with Steel Deck Slab The Preparatory Survey for The Project for Construction of Bago River Bridge Table 6.9 Alternative-F: Extradozed Bridge and Continuous Steel Box Girder with Steel Plate Deck 46 Precast Continuous PC Box (Span by Span) Category Technical Viability Economic Viability Other Viability Evaluation Criteria Source: JICA Survey Team Extradozed Bridge Description Extradozed bridge alternated with steel bridges is applied for this span arrangement but not suitable. Extradozed bridge with long span (224 m) is technically the most difficult option. Construction period is 32 months. =1.28 Extradozed bridge is costly because center span of 224 m is out of the economical span (120 m~200 m). Periodical maintenance for painting on steel part is required. Extradozed, precast PC box girder (span by span) and steel box girder with steel deck slab are new technologies. Extradozed bridge has excellent view but inferior to cable-stayed bridge as a symbolic structure due to low pylons. Wide navigation clearance is secured when sailing from and toward the adjacent existing Thanlyin Bridge. Almost no impact. Not recommended Pylon Evaluation Fair Poor Poor Fair Good Good Good Good 10 3 6 3 20 10 10 5 67 Final Report Structural Stability Constructability Construction Cost Maintenance New Technology Landscape Navigation Environment Evaluation Max. Point 20 10 20 5 20 10 10 5 Continuous Steel Box with Steel Deck Slab The Preparatory Survey for The Project for Construction of Bago River Bridge 6.3 Final Report Study of Substructure 6.3.1 Study on Foundation Type The geological investigation conducted at five locations (three locations in the river and two locations on the land). According to the investigation results, it is assumed that the dense sand supporting layer is existing at around EL=-40~-50 m. (A1) (P7) (P11) (P15) (A2) Source: JICA Survey Team Figure 6.4 Geotechnical Investigation Result The study of foundation type is conducted in two patterns, i.e., one in the river and another on the land, as the general condition is greatly different. On Land In the Bago River On Land CL 1928000 Precast PC Continuous Box Girder( Span by Span) Steel Cable Stay Steel Continuous Box Girder with Steel Plate Deck 6@50000=300000 776000 50000 50000 50000 50000 50000 50000 104000 112000 112000 Precast PC Continuous Box Girder( Span by Span) 448000 112000 112000 112000 112000 112000 4@50000=200000 204000 224000 112000 52000 52000 50000 50000 50000 50000 50000 50000 70.000 60.000 50.000 40.000 30.000 20.000 10.000 HWL = 4.579 0.000 -10.000 -20.000 -30.000 -40.000 -50.000 -60.000 A1 P1 P2 P3 P4 P5 P6 P7 P8 P9 P10 P11 P12 P13 P14 P15 P16 Source: JICA Survey Team Figure 6.5 Area In the Bago River and On Land 47 P17 P18 P19 P20 P21 P22 P23 A2 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report a) Foundation In the Bago River The following is a summary of conditions to be studied for the foundation of the river crossing bridge:     The maximum water depth for proposed bridge sites is more than 10 m. Sufficient attention must be paid to scouring in the vicinity of the foundation. The foundation must be able to support a large vertical load. The supporting layer will be at relatively deep location (EL -40~-50 m). Table 6.10 shows the selection table of foundation type (from Japan Road Bridge Specifications). Caisson Steel Pipe Sheet Pile Diaphragm wall Applicable Condition Steel Pipe Pile Foundation Type PHC / SC Pile Applicability Criteria of Foundation Types for Main Bridge Cast- in-place Concrete Pile Table 6.10 Ground Condition Condition of Construction Depth < 5 m       Depth > 5 m             Vibration Noise Environment Impact on Adjacent Structure             Normal Loading       Large <5m             5~15 m       15~25 m Depth of Supporting Layer       25~40 m       40~60 m >= 60 m             Clay (20 =< N) Soil Condition       Sand/Gravel (30 =< N) Note: : Suitable, : Possible, : Impossible Source: Japan Bridge Standard Temporary Jetty According to the above table, four foundation types (cast-in-place concrete pile, steel pipe pile, steel pipe sheet pile, and caisson) can be applied to the bridge over the river. However, the steel pipe pile will require temporary cofferdam. Thus, steel pipe sheet pile will be cheaper and more reasonable than steel pipe pile. Accordingly, three foundation types (cast-in-place concrete pile, steel pipe sheet pile, and caisson) can be considered as the foundation type of the bridge over the river. When the foundation is to be constructed more than 10 m deep from the water surface, in accordance with the above conditions, the size of the temporary cofferdam would be large. Therefore, a foundation that allows the use of a temporary cofferdam also for the main part of the bridge or that omits the temporary cofferdam is considered advantageous. According to the present result of river crossing survey at Thanlyin Bridge in February 2012 and January 2013, maximum 2 m scouring can be seen at the pier location in only a year (see Figure 6.6). Therefore, it is necessary to pay close attention to scouring. 48 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report 10.0 Thanlyin Side 8.0 Yangon Side 6.0 4.0 2.0 Elevation (m) 0.0 ‐2.0 ‐4.0 ‐6.0 ‐8.0 ‐10.0 2 m scoured in one year ‐12.0 ‐14.0 January‐13 (DWIR) February‐12 (DWIR) ‐16.0 0 100 200 300 400 500 600 700 800 900 1,000 1,100 1,200 1,300 1,400 1,500 1,600 1,700 1,800 Distance (m) Source: DWIR Figure 6.6 River Crossing Survey Results at Thanlyin Bridge Cast-in-place concrete pile will be a multi-pile type since the depth of the water is very deep. Therefore, it is greatly easy to receive influence of scouring. Table 6.11 shows the foundation type alternatives in the river. In addition, the three piers (P12, P14, and P18) which are representatives in each type of superstructure, a comparison between cast-in-place concrete pile and steel pipe sheet pile was carried out (refer to Table 6.12~Table 6.14). Source: PW Photo 6.1 Scouring around Castin-place Pile Foundation As a result of the comparison mentioned above, steel pipe sheet pile foundation is considered the optimal solution in terms of its applicability to deep-water construction and anti-scouring properties. As illustrated in Figure 6.7, steel pipe sheet pile foundations can be categorized into three types based on construction method, i.e.: (1) temporary cofferdam-combined method, (2) build-up method, and (3) cofferdam method. Because the temporary cofferdam-combined method is commonly used for general bridges, it was applied to the project site based on economic, construction timeframe, and safety considerations. In addition, as for the foundation shape, round shape or oval shape will be adopted in consideration of the river flow (refer to Figure 6.8). 49 The Preparatory Survey for The Project for Construction of Bago River Bridge Table 6.11 Final Report Foundation Type Alternatives for the Main Bridge Cast-in-place Concrete Pile Steel Pipe Sheet Pile Concrete Caisson Water Water Water Foundation Type Workability on Water Work Period Against Ship Collision Inferior - Temporary cofferdam is separately required. - Permanent casing is required. - Loading test is required. Moderate - Driving of many piles takes time. Inferior - Because multi-pile structure. Against Scouring Safety of Works Cost Experience in Myanmar Evaluation - Superior - Temporary cofferdam is not separately required. - Loading test is not required. Moderate - Temporary cofferdam is not separately required. - Loading test is not required. Superior - After driving steel pipe, construction is fast and safe. Superior - Because rigid and massive structure. Inferior Superior Because multi-pile structure. - Because rigid and massive structure. Moderate Superior Temporary cofferdam is - Temporary cofferdam is not separately required. separately required. Superior Moderate Many None No new technology - New technology and technical transfer can be done Although the construction cost - Although the construction cost is cheapest among the is inferior to cast-in-place alternatives, it is inferior for concrete pile, it is superior in ship collision and scouring. other aspects. - Also, technical transfer will be done since there is no experience yet with this type in Myanmar. “Not Recommendable” “Recommendable” Moderate - It takes time for excavation. Superior - Because rigid and massive structure. Superior - Because rigid and massive structure. Superior - Temporary cofferdam is not separately required. Moderate Some - No new technology. - Although the construction cost is inferior to cast-in-place concrete pile, it is superior in some aspects. - Some aspects are inferior to steel pipe sheet pile. “Not Recommendable” Source: JICA Survey Team Footing Temporally cofferdam Sheet piles Cutting Footing Slab concrete Footing Leveling concrete or aggregate ⅰ) Foundation & temporary cofferdam method ⅱ) Vertical pile method ⅲ) Cofferdam method Source: Japanese Association for Steel Pipe Piles Figure 6.7 Cofferdam Method for Steel Pipe Sheet Pile Foundation 50 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report Table 6.12 Comparison of Foundation Type In the River (P12: Box Girder with Steel Plate Deck Section) Steel Pipe Sheet Pile (φ 1000) 25.500 (右 + 4. 57 9 6.000 1.000 - 4. 75 9 1 0 0 06 0 0 0 5.000 -9 .2 2 9 1 200 0 23.500 11.000 9.125 + 5. 2 71 2 000 17.000 16.500 9.125 17.000 6.000 3.000 9.750 9.000 Foundation 9.750 16.500 28.500 11.000 6.000 23.500 17.000 1.000 17.000 6.000 23.500 6.000 6.000 Cast-in-Place Concrete Pile (φ 1500) 29.250 ) 29 25 0 7 @3 750 1 50 0 1 500 12144 .6 1 500 25 50 0 Plan 6@3 750 Plan -5 5 .7 29 17135 8 8567.9 8567.9 Description 1 500 17135.8 ■P ie r Column ・6m x 11m ・Main re-bar : D32 ・Seismic time ■Foundation ・Cast-in-place concrete pile, φ1500-56, L=40.0ｍ ■P ie r Column ・6m x 11m ・Main re-bar : D32 ・Seismic time ■Foundation ・Steel pipe sheet pile, φ1000-44, L=61.0ｍ Cost ratio 1 .1 0 1 .0 0 Evaluation △　 (Co n st ru ct io n t erm will b e very lo n g sin ce t h ere are so man y p iles) ○   Source: JICA Survey Team Comparison of Foundation Type In the River (P14: Cable-stayed Bridge Section) Foundation + 4. 5 79 - 7. 3 72 8.000 40.500 17 000 14.750 + 5. 3 38 - 11 . 66 2 40.500 2000 14.750 11.000 3.000 16.250 12.000 16.250 8.000 100 070 00 11.000 11.000 27.500 8.000 8.000 27.500 11.000 35.500 8.000 Steel Pipe Sheet Pile (φ 1000) 27.500 Cast-in-Place Concrete Pile (φ 1500) 140 00 Table 6.13 40 500 Plan 1 0 @3 750 Plan - 55 .6 6 2 8113.08113.0 16226.0 1 5 00 Description 44 00 0 1 500 1 50 0 1 0 @3 750 68 65.268 65.2 13730 .4 4 0 5 00 1 500 ■P ie r Column ・8m x 11.0ｍ ・Main re-bar : D32 ・Seismic time ■Foundation ・Cast-in-place concrete pile, φ1500-121, L=33.5ｍ ■P ie r Column ・8m x 11. 0ｍ ・M ain re -bar : D32 ・Se ismic time ■Foundation ・Steel pipe sheet pile, φ1000-55,　L=61.0ｍ Cost ratio 1 .8 0 1 .0 0 Evaluation △　 (Co n st ru ct io n t erm will b e very lo n g sin ce t h ere are so man y p iles) ○ Source: JICA Survey Team 51   The Preparatory Survey for The Project for Construction of Bago River Bridge Comparison of Foundation Type In the River (P18: PC Box Girder Section) Cast-in-Place Concrete Pile (φ 1500) 160 00 25.000 - 6 .1 3 9 -1 0 .5 17 12 000 7.625 +5 .4 83 29.250 450 00 25.500 + 4 .5 7 9 200 0 14.000 1 0 0 06 0 0 0 20.000 5.000 Foundation 20.000 4.500 18.000 7.625 4.500 3.000 10.500 9.000 10.500 18.000 30.000 14.000 25.000 1.000 20.000 6.000 20.000 4.500 25.000 4.500 Steel Pipe Sheet Pile (φ 1000) 6.000 1.000 Table 6.14 Final Report 29 25 0 7 @3 750 1 50 0 9767.9 Plan 6@3 750 Plan 25 50 0 1 500 1 500 19750.3 - 55 . 51 7 9875.1 9875.1 Description 1 500 19750.3 ■Pie r Column ・4. 5m x 14. 0ｍ ・M ain re -bar : D32 ・Se ismic time ■Foundation ・Cast-in-place concrete pile, φ1500-56, L=40.0ｍ ■Pie r Column ・4. 5m x 14. 0ｍ ・M ain re -bar : D32 ・Se ismic time ■Foundation ・Steel pipe sheet pile, φ1000-44,　L=61.0ｍ Cost ratio 1 .1 0 1 .0 0 Evaluation △　 (Co n st ru ct io n t er m will b e very lo n g sin ce t h ere are so man y p iles) ○   Source: JICA Survey Team As for the foundation shape, round shape or oval shape will be adopted in consideration of the river flow. Generally, the smallest shape of steel pile sheet pile foundation is decided by the shape of piers. In case of concrete piers, the distance between the inside of the sheet pile and pier shall be kept more than 1.5 m in consideration of the size of falsework, thickness of inter-filling concrete, working space, and formwork of pier. Round Shape Oval Shape Steel Pipe Pier Pier ≧1500 Source: JICA Survey Team Figure 6.8 Possible Shape of Steel Pipe Sheet Pile Foundation b) Foundations on Land As for the foundation type on land, piers and abutment are constructed on existing ground surfaces. A multi cast-in-place pile foundation using bored piles will be selected for its easy constructability and procurement of materials/equipment as well as the availability of experience in Myanmar. 52 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report Although several construction methods for the cast-in-place pile foundation (e.g., all casing, reverse, earth drilling method, etc.) could be considered, the reverse method using casing pipe, which is widely used in Myanmar, will be adopted. Comparison of Cast-in-place Concrete Pile on Land (P1: PC Box Girder Section) Cast-in-Place Concrete Pile (φ 1000) Foundation 9.500 4.000 3.500 11.000 3.500 6.500 4.000 10.500 (右側が背面側とな 17.000 Plan 18.000 ます) Plan ■P ie r Column ・2.5m x 11m ・Main re-bar : D32 ・Seismic time ■Foundation ・Cast-in-place concrete pile, φ1000-28, L=40.5ｍ Description 17.000 1.000 5.000 0.500 3.000 17.000 2.500 2.000 11.000 2.500 3.000 3.000 6.500 3.500 3.000 3.500 1.000 5.000 0.500 17.000 2.000 17.000 2.500 8.500 2.500 Cast-in-Place Concrete Pile (φ 1500) 8.500 Table 6.15 ■Pie r Column ・2.5m x 11m ・Main re-bar : D32 ・Seismic time ■Foundation ・Cast-in-place concrete pile, φ1500-13, L=41.0ｍ Cost ratio 1 .0 0 4 1 .0 0 0 Evaluation △　 (Co n st ru ct io n t erm will b e very lo n g sin ce t h ere are so man y p iles) ○ Source: JICA Survey Team 6.3.2 Adverse Effect of New Bridge Foundation on Existing Bridge Foundation When the new bridge is constructed in the neighbourhood of the existing bridge, the construction sometimes gives some adverse effects on the existing bridge due to ground movement. However, it can be judged that the adverse effects to the existing Thanlyin Bridge by the construction of the new bridge will not occur at all since the new bridge is approximately 140 m away from the existing Thanlyin Bridge. 6.3.3 Study on Substructure Type The substructure would be constructed by reinforced concrete. As for the substructure shape, round shape or oval shape will be adopted in consideration of the river flow. Besides, the direction of substructure should be the same direction as the river flow. 53 The Preparatory Survey for The Project for Construction of Bago River Bridge Table 6.16 Final Report Substructure Type Alternatives for Main Bridge Oval Round Substructure Type Pier Head Pier Head Oval Shape Round Shape Flow Flow Feature It is applied to the river bridge. Oval shaped pier is set parallel to the water flow in order to keep smooth water flow. It is applied to the river bridge. When the direction of the river flow is not fixed such as in the river junction, it is applied. Source: JICA Survey Team 6.3.4 Study on Abutment Type Although few abutment types can be considered, reverse T shape will be applied in consideration of cost and constructability. Table 6.17 Abutment Type Alternatives Reverse T Type Abutment Type Counterfort Type Abutment Abutment Corner Wall Feature It is very common and has an economical shape. Source: JICA Survey Team 54 It is difficult to construct corner wall. It is not a common shape. Although box type is also considered, it is not an economical shape. The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report Chapter 7 Natural Condition Surveys The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report 7. Natural Condition Surveys 7.1 7.1.1 Topographic Survey Summary of the Yangon Urban Area The Yangon urban area is situated between latitudes 17°06’ N and 16°35’ N, and between longitudes 95°58’ E and 96°24’ E, and is located in the east side of the Aveyarwaddy River delta area. There is a range of mountains and hills about 25-30 m above sea level called the Bago Yoma that stretches from north to south in the central delta. The altitude of the low-lying area is very low and parts of this area often experience flood during the rainy season. A map of Yangon City is shown in Figure 7.1. Source: Japan International Cooperation Agency (JICA) and Survey Department Ministry of Forestry in the Union of Myanmar, 2004 Figure 7.1 Map of Yangon City 55 The Preparatory Survey for The Project for Construction of Bago River Bridge 7.1.2 Final Report Topographic Survey The topographic survey commenced on August 29, 2013 and was completed on November 30, 2013. The topographic survey is divided into the following nine subcomponents: 1) Mobilization and demobilization, 2) Benchmark installation, 3) Control point installation, 4) Plane survey by total station, 5) Profile leveling survey for road centerline, 6) Profile leveling survey for road cross section, 7) Profile leveling survey for river axial direction, 8) Profile leveling survey for river cross section, and 9) Mapping and reporting. All these surveys were carried out on the Kyak Khauk Pagoda Road for the design of Bago River Bridge including its approach road. The areas where the topographic survey was conducted are shown in Figures 7.2 to 7.7. 200,000m2 Source: JICA Survey Team Figure 7.2 Area of Plane Survey (1/2) 56 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report 150,000m2 Source: JICA Survey Team Figure 7.3 Area of Plane Survey (2/2) 3,200m Source: JICA Survey Team Figure 7.4 Area of Profile and Cross Section Survey for Road (1/3) 57 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report 650m (26points) 50m 50m Total Survey Area=2,600 m2 Source: JICA Survey Team Figure 7.5 Area of Profile and Cross Section Survey for Road (2/3) 850 m (34 points) 50m 50m Total Survey Area = 3,400 m2 Source: JICA Survey Team Figure 7.6 Area of Profile and Cross Section Survey for Road (3/3) 58 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report 1,000 m @400 m @400 m 1,900 m 140 m 140 m 140 m Thanlyin Bridge 1,500 m 500 m 2,000 m 3,500 m Source: JICA Survey Team Figure 7.7 Area of Cross Section Survey for the River 59 The Preparatory Survey for The Project for Construction of Bago River Bridge 7.1.3 Final Report Survey Result Figure 7.8 shows the result of the plane survey. Source: JICA Survey Team Figure 7.8 Plane Survey Result 60 The Preparatory Survey for The Project for Construction of Bago River Bridge 7.2 Final Report Geological Survey 7.2.1 Summary of Geological Condition The geological condition of the surface in Yangon is divided in three categories, as follows (refer to Figure 7.9): • • • Alluvium, Irrawaddy formation, and Pegu group. Generally, the Yangon area is covered by alluvium. The Irrawaddy Formation comprises the bedrock along the Bago Yoma, the Arzamigone Sandstone in the north of the Shwedagon Pagoda, and Danyingone Clay in the east of the Arzamigone Sandstone. The Pegu Group comprises the Besapet Alternation, Thadugan Sandstone, and Hlawga Shale distributed in the north of the Yangon area. (a) Alluvium Recent Alluvium Top soil has been covered with river deposits in recent years, which blankets all over the project area. It has brown to gray, mottled brown, and yellow colors, and the main constituents frequently found are clay and organic matters, which come from decayed plant roots and wood. The formation of these materials is caused by flood action and yields moderate to high water content. Older Alluvium The older alluvial deposits consist of medium to very dense and poorly graded sand with silt, mainly yellowish brown in color,. In all borehole locations, trace amounts of gravel were found. Moreover, water content is low to moderate in those layers. (b) Irrawaddy Formation This formation is composed of yellowish fine sand of the Irrawaddian Group. The outcropping areas can be seen in Danyingone, Arzarnigone, Southern Twin Te, and the left bank of YangonThan Hlyn across the Pegu River. (c) Pegu Group This formation is mainly composed of sand and shale interbeds. Outcropping areas are found along the anticlinal ridges of the Danyingone and Than Hlyn areas. Most of them are composed of reddish brown oxidized lateritic soil. 61 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report Source: Geology of Burma, 1983, Dr. Friedrich Bender Figure 7.9 7.2.2 Geological Structure Geological Survey The geological survey commenced on August 29, 2013 and was completed on November 30, 2013. This survey is divided into five subcomponents: 1) 2) 3) 4) 5) Mobilization and demobilization, Borehole drilling on land and in the river, Standard penetration test (SPT), Laboratory test, and Reporting. The locations where the survey was conducted are shown in Figure 7.10. 62 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report : Borehole drilling, SPT 400 m 400 m 140 m On Land In River In River In River On Land 5 points, 70 m in depth, Total quantity is 350 m on Borehole drilling and 350 number on SPT Source: JICA Survey Team Figure 7.10 Position of Survey The contents of the laboratory test are the following: - Natural moisture content test, Specific gravity test, Particle size analysis, Atterberg limit test, Unit weight, and Unconfined compression test. Figure 7.11 shows the soil profile of the Project area based on the boring logs of BH-01 to BH-05 (samples logs are shown in Figures 7.12 to 7.16). 63 The Preparatory Survey for The Project for Construction of Bago River Bridge 64 Source: JICA Survey Team Figure 7.11 Soil Profile of the Project Area Final Report The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report Source: JICA Survey Team Figure 7.12 Boring Log (BH-01) 1/3 65 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report Source: JICA Survey Team Figure 7.13 Boring Log (BH-01) 2/3 66 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report Source: JICA Survey Team Figure 7.14 Boring Log (BH-01) 3/3 67 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report Source: JICA Survey Team Figure 7.15 Boring Log (BH-04) 1/2 68 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report Source: JICA Survey Team Figure 7.16 Boring Log (BH-04) 2/2 69 The Preparatory Survey for The Project for Construction of Bago River Bridge 7.2.3 Final Report Geotechnical Design Parameters Geotechnical parameters can be directly evaluated in many ways such as in situ and laboratory tests. Some of the design parameters could not be evaluated directly from field tests or laboratory tests due to the unfavorable nature of deposits or investigation methods. However, some parameters would be derived from other instrumental testing of past events, and some mechanical and physical properties obtained from field and laboratory tests. In evaluating ground stability, shear strength parameters are significant. The geotechnical design parameters required for foundation design analysis are listed in Table 7.1. Table 7.1 Soil Type Fill Material Gravel Gravelly Sand Sand Silty Sand Clayey Sand Silt, Clay Kanto Loam Natural Ground Gravel Gravelly Sand Sand Silty Sand Clayey Sand Sandy Silt Sandy Clay Silt Clay Kanto Loam Soil Parameters Recommended by J.H.C Condition of Soil Bulk Dens ity γt (tf/m3) Internal Friction Angle φ (°) Cohes ion Cu (tf/m2 ) Remarks (Soil Name) 2.0 40 0 (GW), (GP) 2.0 1.9 35 30 0 0 (SW), (SP) 1.9 25 Less than 3 (SM), (SC) 1.8 15 Less than 5 1.4 2.0 20 40 Less than 1 0 1.8 35 0 2.1 1.9 2.0 40 35 35 0 0 0 1.8 30 0 1.9 1.7 1.8 1.7 1.6 1.7 1.6 1.4 1.4 30 25 25 20 15 20 15 10 5 Less than 3 0 Less than 5 Less than 3 Less than 1.5 Less than 5 Less than 3 Less than 1.5 Less than 3 Compacted Compacted Well graded Poorly graded Compacted Compacted Compacted Densely or well graded Less dens e and poorly graded Dens e one. Less dens e Densely or well graded Less dens e and poorly graded Dens e Less dens e Stiff Firm Soft Stiff Firm Soft --- Source: JICA Survey Team 70 (ML), (CL) (MH), (CJ) (VH) (GW), (GP) (GW), (GP) (SW), (SP) (SM), (SC) (ML), (CL) (CH) (MH), (ML) (VH) The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report Table 7.2 shows the soil parameters extracted from several correlations and formulas proposed. The geotechnical design parameters recommended for future analysis are described in Table 7.3. Table 7.2 No. Soil Parameters for Geotechnical Analysis Extracted from Several Formulas Soil Name N-value Cohesion ( Cu) (Average) kN/m2 Angle of Friction N by SPT by Lab by JHC 1 Silty Sand-Filled Materials 2 0 N/A <30 21 N/A 2 Clay-Filled Materials 3 20 N/A N/A 0 3 Silty Sand-River Deposit 4 0 N/A 0 4 Clay-I 1 7 18 <15 5 Sandy Clay-I 5 33 25 6 Silty Sand-I 14 0 N/A 7 Sand-I 19 0 8 Silty Clay-I 6 40 9 Clayey Sand-I 8 Soil Unit Weight γsat (degree) by by by Lab SPT JHC γ̕ γsat γ̕ Modulus of Elasticity (kN/m2) Poisson's Ratio 1400 0.4 2000 0.4 Lab Test by JHC 19 20 10 19 N/A N/A 19 9 24 N/A 25 19 9 17 7 2800 0.5 0 19 10 17 7 14 4 1800 0.5 <30 0 N/A 20 18 8 17 7 2500 0.4 0 32 N/A 25 20 10 17 7 9800 0.4 N/A 0 34 N/A 30 19 9 18 8 13300 0.4 N/A <30 0 N/A 15 18 8 16 6 4000 0.4 0 N/A 0 28 N/A 25 19 9 17 7 5600 0.5 9 N/A N/A 10 Clay-II 8 53 N/A <30 0 N/A 15 19 9 16 6 5333 0.5 11 Silty Clay-II 27 180 N/A <50 0 N/A 20 18 8 17 7 18000 0.4 12 Sandy Clay-II 14 93 N/A <50 0 N/A 25 19 9 18 8 9333 0.4 13 Silty Sand-II 30 0 N/A 0 39 N/A 25 20 10 17 7 21000 0.3 14 Clayey Sand-II 48 0 N/A <30 46 N/A 30 20 10 19 9 33600 0.2 15 Sand-II 50 0 N/A 0 47 N/A 35 21 11 20 10 35000 0.2 Source: JICA Survey Team Table 7.3 Geotechnical Design Parameters Recommended for Future Analysis No. Soil Name Angle of Friction Soil Unit weight N-Value Cohesion (Average) Cu φ N kN/m2 (degree) γsat γ' kN/m3 Modulus of Poisson's Elasticity (kN/m2) Ratio 1 Silty Sand-Filled Materials 2 0 20 20 10 1400 0.4 2 Clay-Filled Materials 3 20 0 19 9 2000 0.4 3 Silty Sand-River Deposit 4 0 20 19 9 2800 0.5 4 Clay-I 1 15 0 17 7 1800 0.5 5 Sandy Clay-I 5 30 0 18 8 2500 0.4 6 Silty Sand-I 14 0 30 20 10 9800 0.4 7 Sand-I 19 0 30 19 9 13300 0.4 8 Silty Clay-I 6 40 0 18 8 4000 0.4 9 Clayey Sand-I 8 0 25 19 9 5600 0.5 10 Clay-II 8 50 0 19 9 5333 0.5 11 Silty Clay-II 27 180 0 18 8 18000 0.4 12 Sandy Clay-II 14 90 0 19 9 9333 0.4 13 Silty Sand-II 30 0 40 20 10 21000 0.2 14 Clayey Sand-II 48 0 45 20 10 33600 0.2 15 Sand-II 50 0 45 21 11 35000 0.2 Source: JICA Survey Team 71 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report In this chapter, the geotechnical design parameters are determined only for shallow footing. For bridge construction, pile foundation will be applied, and the geotechnical design parameters will be directly applied from standard penetration test results. Moreover, the geotechnical design parameters identified from SPT will be directly applied for liquefaction potential analysis. 7.2.4 Summary of Soil Investigation According to the investigation results, the left side of the Bago River (BH-01 and BH-02) and the right side of the Bago River (BH-04 and BH-05) have different soil conditions because of river dynamism. Clayey soil layers are well observed in the left side of the river, while granular soil layers are more observed in the right side of the river. Although there is a difference in soil deposition, the top soil layer (Clay-I) and reliable bearing layer (Clayey Sand-II) of BH-01 and BH-02 are the same. In the left side boreholes (BH-01 and BH-02), clayey soil layers are deposited from ground surface to EL -50 m to EL -55 m. Among the clayey soil, the Clayey Sand and Silty Sand layers are observed as intercalated layers. As for the right side boreholes (BH-04 and BH-05), the top soil layer of BH-05 is of clayey soil with a thickness of 14 m. The top soil layer of BH-04 is of silty sand (river bed), which is 4.0 m thick, and is underlain by a sandy clay layer. The frictional soil layer, which is 30.0 m thick, is underlying the clayey soil layer. Moreover, clayey soil layers are observed as lens forms within the silty sand layer. The reliable bearing layer (Clayey Sand-II) is underlying the Silty Sand-II layer. According to the investigation results, the Sand-II layer is observed under the Clayey Sand-II layer. This Sand-II layer is only observed in BH04. The borehole in the center of the river (BH-03) has the same soil conditions with the right side boreholes, except for the absence of upper clayey soil layer and thick clayey soil lens forms. However, the reliable bearing layer in BH-03 is deeper than those of the other boreholes. In Figure 7.17, the reliable bearing layer, which has an SPT N-value of more than 50, for the proposed Bago River Bridge is indicated with a red line. Source: JICA Survey Team Figure 7.17 Ground Condition and Reliable Bearing Layer 72 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report Chapter 8 Hydrological Assessment of Bago River The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report 8. Hydrological Assessment of the Bago River In order to design the new bridge, it is necessary to collect and correlate all the basic meteorological and hydraulic data. 8.1 Meteorological Conditions Yangon City has a tropical monsoon climate. Rainfall is highly seasonal, being concentrated in the hot humid months of the southwest monsoon (May to October). By contrast, the northwest monsoon (December to March) is relatively cool and dry. In some occasions, severe cyclones cross the Myanmar coast in the months of April to May. There are three meteorological stations in and around Greater Yangon, which were installed and have since been operated by the Department of Meteorology and Hydrology (DMH) of MoT, as shown in Table 8.1. The locations of meteorological and hydrological stations are shown in Figure 8.1. Table 8.1 Inventory of Meteorological Stations Coordinates Period of Records Height Code Tempera- Relative Evapora(WMO) Latitude Longitude (m) Rainfall Sunshine ture Humidity tion 1. Kaba Aye (Yangon) 48097 16-54 96-10 20 1968~ 1968~ 1968~ 1977~ 1975~ 2. Bago 48093 17-20 96-30 9 1965~ 1965~ 1965~ 3. Tharrawady 48088 17-38 95-48 15 1965~ 1965~ 1965~ Meteorological Station Wind 1968~ 1965~ 1965~ Source: DMH Source: DMH, MPA, ID (Google Earth) Figure 8.1 Location Map of Meteorological and Hydrological Stations 73 Remarks The Preparatory Survey for The Project for Construction of Bago River Bridge 8.1.1 Final Report Temperature The monthly mean temperature ranges between 24.8 °C and 30.3 °C in and around Yangon City. According to the collected data for the past 18 years, the mean monthly maximum temperature is 37.6 °C (April) while the mean minimum temperature is 16.4 °C (January) within the Yangon region. Source: JICA Survey Team based on the data from DMH Figure 8.2 8.1.2 Mean Monthly Maximum and Minimum Temperatures at Kaba-aye Station (1991-2008) Relative Humidity Relative humidity is observed twice a day (at 9:30 and 18:30). As seen in Figure 8.3, difference in humidity between the morning and evening is quite small. Mean monthly relative humidity in Yangon City ranges between 51 and 91%. Source: JICA Library (The Study on Improvement of Water Supply System in Yangon City in the Union of Myanmar, 2002), DMH Figure 8.3 8.1.3 Mean Monthly Maximum and Minimum Relative Humidity at Kaba-aye Station (1991-2008) Wind Speed and Direction The mean monthly wind speed is stable at 1.0-1.2 m/s throughout a year. Wind condition in Yangon area depends on the influence of the southwest monsoon during the rainy season. The highest maximum wind speed of 42.9 m/s was recorded during the passage of Cyclone Nargis in May 2008. Source: JICA Survey Team based on the data from DMH Figure 8.4 Maximum Wind Speed and Mean Monthly Wind Speed recorded at Kaba-aye Station (1999-2008) 74 The Preparatory Survey for The Project for Construction of Bago River Bridge 8.1.4 Final Report Evaporation The annual mean evapotranspiration in Yangon area is 1,349 mm, which is 50% of the annual rainfall. Source: JICA Survey Team based on the data from DMH Figure 8.5 8.1.5 Mean Monthly Evaporation at Kaba-aye Station (1981-2000) Sunshine Hours The annual mean sunshine hours are about 6.5 hours/day in Yangon area. Sunshine hours during the rainy season are shorter than the other seasons, showing different patterns of fluctuation. Source: JICA Survey Team based on the data from DMH Figure 8.6 8.1.6 Mean Monthly Sunshine Hours at Kaba-aye Station (1977-2000) Rainfall (1) Annual Rainfall and Seasonal Fluctuation Seasonal variation of monthly total is similar in Yangon City (Kaba-aye) and Bago City. Regarding seasonal fluctuation of rainfall, about 96% of annual rainfall is brought by the rainy season from May to October, with the highest amount of rainfall in July or August. The annual mean rainfall is 2,745 mm in Yangon City and 3,288mm in Bago City. Annual rainfall in Yangon City fluctuates between 3,592 mm and 2,127 mm. According to the collected data/documents, the following characteristics in Yangon area can be observed:  Bago, located in the eastern side of Yangon area, has the highest annual rainfall volume; and  Tharrawady, located in the northwestern side of Yangon area, has the lowest annual rainfall. Annual rainfall gets progressively smaller towards the north (upstream) side of the Hlaing River. 75 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report Source: JICA Survey Team based on the data from DMH Figure 8.7 Mean Monthly Rainfall in and around Greater Yangon (2) Long-term Fluctuation of Annual Rainfall Figure 8.8 shows the long-term fluctuation of annual rainfall by using a five-year running mean at Kaba-aye. Although the cycle of wet and dry periods is not clear, the aforementioned figure gives a clear presentation of such periods. It is indicated that a limited rising trend of annual rainfall is going on in recent years. Source: JICA Survey Team based on the data from DMH Figure 8.8 Annual Rainfall and Five-Year Running Mean Rainfall at Kaba-aye Station (1968-2008) (3) Exceedance Probability and Intensity Curve of Rainfall Kaba-aye, Bago, and Tharrawady Stations have been measuring the annual maximum daily rainfall data (extreme value) for over 40 years. The 24-hour rainfalls of 2- to 500-year probabilities are calculated by using the extreme values measured from the three stations. Also, the correlation between intensity of short-time rainfall duration and 24-hour rainfall is estimated using Mononobe's equation. Probable rainfalls and intensity curve are shown in Table 8.2 to Table 8.4 and Figure 8.9 to Figure 8.11. 76 The Preparatory Survey for The Project for Construction of Bago River Bridge Table 8.2 Correlation between intensity of short-time rainfall duration and 24-hour rainfall at Kaba-aye Station (Mononobe's equation, 1968-2012) Return Period (Probability) (Year, %) Kaba-aye Station 2 3 5 10 20 25 30 50 80 100 150 200 300 400 500 Final Report 50.0% 33.3% 20.0% 10.0% 5.0% 4.0% 3.33% 2.0% 1.25% 1.0% 0.667% 0.5% 0.33% 0.25% 0.2% Daily Rainfall Rainfall Intensity of each Rainfall Duration (mm/hr): It = R24/24*(24/t)m, m=2/3 R24 (mm/day) Remarks 24 hour 24 12 8 6 3 2 1.5 1 0.75 0.5 0.333 0.167 1,440 min. 1,440 720 480 360 180 120 90 60 45 30 20 10 115.5 4.8 7.6 10.0 12.1 19.3 25.2 30.6 40.0 48.5 63.6 83.3 132.2 134.2 5.6 8.9 11.6 14.1 22.4 29.3 35.5 46.5 56.4 73.9 96.8 153.6 156.0 6.5 10.3 13.5 16.4 26.0 34.1 41.3 54.1 65.5 85.9 112.5 178.6 184.6 7.7 12.2 16.0 19.4 30.8 40.3 48.8 64.0 77.5 101.6 133.1 211.3 213.2 8.9 14.1 18.5 22.4 35.5 46.6 56.4 73.9 89.5 117.3 153.7 244.1 222.5 9.3 14.7 19.3 23.4 37.1 48.6 58.9 77.1 93.4 122.4 160.5 254.7 230.2 9.6 15.2 20.0 24.2 38.4 50.3 60.9 79.8 96.7 126.7 166.0 263.5 252.0 10.5 16.7 21.8 26.5 42.0 55.0 66.7 87.4 105.8 138.7 181.7 288.5 272.5 11.4 18.0 23.6 28.6 45.4 59.5 72.1 94.5 114.4 150.0 196.5 311.9 282.3 11.8 18.7 24.5 29.6 47.1 61.7 74.7 97.9 118.6 155.4 203.6 323.2 300.6 12.5 19.9 26.1 31.6 50.1 65.6 79.5 104.2 126.2 165.4 216.8 344.1 313.8 13.1 20.8 27.2 32.9 52.3 68.5 83.0 108.8 131.8 172.7 226.3 359.2 332.8 13.9 22.0 28.8 34.9 55.5 72.7 88.0 115.4 139.8 183.1 240.0 381.0 346.6 14.4 22.9 30.0 36.4 57.8 75.7 91.7 120.2 145.6 190.7 249.9 396.8 357.4 14.9 23.6 31.0 37.5 59.6 78.1 94.6 123.9 150.1 196.7 257.7 409.1 Calculation formula of probable rainfall = Iwai's quantile method Source: JICA Survey Team based on the data from DMH Table 8.3 Correlation between intensity of short-time rainfall duration and 24-hour rainfall at Bago Station (Mononobe's equation, 1965-2012) Return Period (Probability) (Year, %) Bago Station 2 3 5 10 20 25 30 50 80 100 150 200 300 400 500 50.0% 33.3% 20.0% 10.0% 5.0% 4.0% 3.33% 2.0% 1.25% 1.0% 0.667% 0.5% 0.33% 0.25% 0.2% Daily Rainfall Rainfall Intensity of each Rainfall Duration (mm/hr): It = R24/24*(24/t)m, m=2/3 R24 (mm/day) Remarks 24 hour 24 12 8 6 3 2 1.5 1 0.75 0.5 0.333 0.167 1,440 min. 1,440 720 480 360 180 120 90 60 45 30 20 10 129.7 5.4 8.6 11.2 13.6 21.6 28.3 34.3 45.0 54.5 71.4 93.5 148.5 146.8 6.1 9.7 12.7 15.4 24.5 32.1 38.8 50.9 61.7 80.8 105.9 168.0 166.5 6.9 11.0 14.4 17.5 27.8 36.4 44.1 57.7 69.9 91.6 120.1 190.6 192.1 8.0 12.7 16.6 20.2 32.0 42.0 50.8 66.6 80.7 105.7 138.5 219.9 217.4 9.1 14.4 18.8 22.8 36.2 47.5 57.5 75.4 91.3 119.6 156.8 248.9 225.6 9.4 14.9 19.6 23.7 37.6 49.3 59.7 78.2 94.7 124.2 162.7 258.2 232.3 9.7 15.4 20.1 24.4 38.7 50.7 61.5 80.5 97.6 127.8 167.5 265.9 251.4 10.5 16.6 21.8 26.4 41.9 54.9 66.5 87.2 105.6 138.4 181.3 287.8 269.2 11.2 17.8 23.3 28.3 44.9 58.8 71.2 93.3 113.1 148.1 194.1 308.2 277.8 11.6 18.4 24.1 29.2 46.3 60.7 73.5 96.3 116.7 152.9 200.3 318.0 293.7 12.2 19.4 25.5 30.8 49.0 64.1 77.7 101.8 123.3 161.6 211.8 336.2 305.1 12.7 20.2 26.4 32.0 50.9 66.6 80.7 105.8 128.1 167.9 220.0 349.3 321.4 13.4 21.3 27.9 33.7 53.6 70.2 85.0 111.4 135.0 176.9 231.8 367.9 333.2 13.9 22.0 28.9 35.0 55.5 72.8 88.2 115.5 139.9 183.4 240.3 381.4 342.5 14.3 22.7 29.7 36.0 57.1 74.8 90.6 118.7 143.8 188.5 247.0 392.1 Calculation formula of probable rainfall = Iwai's quantile method Source: JICA Survey Team based on the data from DMH 77 The Preparatory Survey for The Project for Construction of Bago River Bridge Table 8.4 Correlation between intensity of short-time rainfall duration and 24-hour rainfall at Tharrawady Station (Mononobe's equation, 1965-2012) Return Period (Probability) (Year, %) Tharrawady Station 2 3 5 10 20 25 30 50 80 100 150 200 300 400 500 Final Report 50.0% 33.3% 20.0% 10.0% 5.0% 4.0% 3.33% 2.0% 1.25% 1.0% 0.667% 0.5% 0.33% 0.25% 0.2% Daily Rainfall R24 (mm/day) 24 hour 1,440 min. 105.6 121.5 140.3 165.4 190.8 199.2 206.1 225.7 244.4 253.4 270.2 282.4 300.0 312.8 322.9 Rainfall Intensity of each Rainfall Duration (mm/hr): It = R24/24*(24/t)m, m=2/3 24 12 8 6 3 2 1.5 1 0.75 0.5 1,440 720 480 360 180 120 90 60 45 30 4.4 7.0 9.2 11.1 17.6 23.1 27.9 36.6 44.3 58.1 5.1 8.0 10.5 12.8 20.3 26.5 32.1 42.1 51.0 66.9 5.8 9.3 12.2 14.7 23.4 30.6 37.1 48.6 58.9 77.2 6.9 10.9 14.3 17.4 27.6 36.1 43.8 57.3 69.5 91.0 8.0 12.6 16.5 20.0 31.8 41.7 50.5 66.1 80.1 105.0 8.3 13.2 17.3 20.9 33.2 43.5 52.7 69.1 83.7 109.6 8.6 13.6 17.9 21.6 34.4 45.0 54.5 71.5 86.6 113.4 9.4 14.9 19.6 23.7 37.6 49.3 59.7 78.2 94.8 124.2 10.2 16.2 21.2 25.7 40.7 53.4 64.7 84.7 102.6 134.5 10.6 16.8 22.0 26.6 42.2 55.3 67.0 87.8 106.4 139.5 11.3 17.9 23.4 28.4 45.0 59.0 71.5 93.7 113.5 148.7 11.8 18.7 24.5 29.7 47.1 61.7 74.7 97.9 118.6 155.4 12.5 19.8 26.0 31.5 50.0 65.5 79.4 104.0 126.0 165.1 13.0 20.7 27.1 32.8 52.1 68.3 82.8 108.4 131.4 172.1 13.5 21.4 28.0 33.9 53.8 70.5 85.4 111.9 135.6 177.7 Calculation formula of probable rainfall = Iwai's quantile method Source: JICA Survey Team based on the data from DMH Source: JICA Survey Team based on the data from DMH Figure 8.9 Rainfall Intensity Curve at Kaba-aye Station 78 0.333 20 76.2 87.6 101.2 119.3 137.6 143.6 148.6 162.8 176.2 182.7 194.8 203.6 216.3 225.6 232.9 0.167 10 120.9 139.1 160.6 189.3 218.4 228.0 235.9 258.4 279.8 290.1 309.3 323.3 343.4 358.1 369.6 Remarks The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report Source: JICA Survey Team based on the data from DMH Figure 8.10 ainfall Intensity Curve at Bago Station Source: JICA Survey Team based on the data from DMH Figure 8.11 Rainfall Intensity Curve at Tharrawady Station On the other hand, the short intensity rainfall data prepared by the Irrigation Department of MoAI is shown in Table 8.5. There are differences in the values shown between Table 8.2 and Table 8.5 due to differences in data/theory used. These differences shall be clarified by collecting and studying the annual maximum rainfall data for short periods again. Table 8.5 Short Intensity Rainfall Data at Kaba-aye Station Return Period Rainfall Intensity 60 min. rainfall 75 min. rainfall 120 min. rainfall 5 year 10 year 20 year 50 year 63.5 52.1 40.6 71.1 63.9 45.7 78.7 69.9 49.5 104.6 77.5 55.9 Source: Study on Drainage System of Mingalar Taung Nyunt Area, Nov. 2002, Fukken Co. Ltd. 79 The Preparatory Survey for The Project for Construction of Bago River Bridge 8.2 Final Report Hydrological and Hydraulic Conditions In order to predict the flow rate and water level during flood season, it is necessary to collect and correlate the hydrological and hydraulic conditions of the Yangon (Hlaing) River, the Bago River, and the Pazundaung Creek surrounding Yangon City. This survey was examined in reference to previous reports (e.g., JICA report) with the collected information from relevant organizations in Myanmar. Six existing gauging stations (water level/discharge) are managed by the Department of Meteorology and Hydrology (DMH) and Myanma Port Authority (MPA) in the Hlaing, Bago, and Yangon River basins. Of these stations, three stations of MPA do not record discharge measurements. Also, Bago Station of DMH is influenced by tidal levels during the dry season (October to May); therefore, discharge records during this period are not available. However, discharge records at Bago Station during the rainy season can be utilized for flood probability calculation. DMH has its own discharge rating tables, which have been changed several times by use of discharge measurement records taking into account the flow conditions. The inventory of river/tidal gauge stations is shown in Table 8.6. Table 8.6 River/Gauging Station 1. Hlaing River/Khamonseik 2. Bago River/Zaungutu 3. Bago River/Bago (Pegu) 4. Hlaing River/Yangon Port 5. Yangon River/Thilawa Point 6. Yangon River / Elephant Point Inventory of River/Tidal Gauging Stations Code Coordinates Latitude Longitude 6020 16-35 95-30 6220 17-38 96-14 48093 17-20 96-30 Catchment Area (km2) 5,840 1,927 2,580 Height (m) 14.465 9.8 9 210 16-46 96-11 - - - 16-40 96-15 - - - 16-28 96-19 - - Type of Period of Gauge Record Pile Gauge 1987~ Pile Gauge 1987~ Pile Gauge 1970~ Steel Plate (Automatic) Steel Plate (Automatic) Steel Plate (Manual) Water (Tide) level ○ ○ ○ Discharge ○ ○ ○ Observed by DMH DMH DMH ○ - MPA ○ - MPA ○ - MPA Remarks Other 2 stations at Yangon port Source: DMH, MPA 8.2.1 Rivers and Characteristics of River Flow The Yangon Riverine system is located at the eastern end of Ayeyarwady (Irrawaddy) Delta as shown in Figure 8.12. In Yangon City, the Yangon River is formed by the junction of the Panhaling and Hlaing rivers at a point about 13 km (8 miles) upstream of Monkey Point. The Panhlaing River is a distributary of the Ayeyarwady River, while the Hlaing River is a true river rising in the Bago Yomas and having a drainage area of about 12,950 km2 (5,000 mi2). The Pazundaung Creek, named the Ngamoyeik Creek in the northern part of the city, joins the Yangon River at Monkey Point, the southeastern extremity of the city. 2 The Pazundaung Creek has a drainage area of about 1,487 km (574 mi2). The Bago River, with a 2 drainage area of 5,180 km (2,000 mi2), also joins the Yangon River just east of the city, the point where the Yangon River flows south some 45 km (28 mi) into the Gulf of Bengal. The catchment area at the 2 mouth of the Yangon River is 25,640 km (9,900 mi2). 80 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report ■ Yangon Source: A one dimensional analysis of the tidal hydraulics of deltas (Nicholas Odd, Report OD 44, July 1982, Hydraulics Research Station, UK), from the MoAI Library Figure 8.12 Ayeyarwady (Irrawaddy) Delta and Yangon River (1) Hlaing/Yangon River The Hlaing River, also known as Myitmakha River, has its source near Paunk Kaung. It flows from north to south approximately parallel to the Ayeyawady River; first joining the Bawle River in Taikkyi Township, then the Kotekowa River in Hmawbi Township, and finally the Penhlaing River near Hsinmalaik. When it reaches Yangon, it flows into the sea as the Yangon River. At Schwelaung Village, the Hlaing River meets the Thenet River, a branch of the Ayeyarwaddy (Irrawaddy) River. The inflow of water from the Ayeyarwaddy River goes into the Hlaing River through the Thenet River during high water level period during the rainy season. The total length from its source to its mouth at the confluence of the Yangon River is about 330 km (205 miles). As it flows directly into the sea, tidal flow affects a distance of about 100 km (62 miles) upstream (around Tharrawaddy of the Myitmaka River). 81 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report (2) Bago River The Bago River has its source near Thikkyi in the Bago Yoma. It flows down the east-facing slope of the Bago Yoma from north to south approximately parallel to the Sittang River. When it reaches Bago, it turns to the southwest and flows into the sea as the Yangon River. The total length from its source to its mouth at the confluence of the Yangon River is about 260 km (162 miles). The Bago River at the Bago Gauging Station is clearly influenced by tidal level during the low-flow period. (3) Characteristics of River Flow 1) Characteristics of Upstream Part in Related River (Freshwater Area) The discharge-duration curve, which is often used in Japan, was examined in order to understand the potential surface water characteristics of the river throughout the year. The flow regime shows the annual flow condition using the daily discharge at each hydrological station, and is indicated by the daily discharge and the number of exceeded days. The annual flow regime shows the following:  High discharge (95th daily discharge from the greatest),  Normal discharge (185th daily discharge from the greatest),  Low discharge (275th daily discharge from the greatest), and  Drought discharge (355th daily discharge from the greatest). The flow regime that was computed at Zaungtu and Khamonseik stations for a period of 14 years (1987-2000) is summarized in Table 8.7 and Figure 8.13. As seen in the aforementioned table and figure, the coefficient of river regime differs extremely by river. Although the low flow of the Hlaing River at Khamonseik and the flow of the Bago River at Zaungtu are not steady, their coefficients of river regime are very large. Moreover, it was found that the flow regime of the Bago River at Zaungtu does not have a sustainable quantity of base flow. Also, the magnitude of coefficient of river regime indicates that the flow fluctuation is large; and a large value indicates that the full year water intake is difficult and flood damage can easily occur. 82 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report Table 8.7 Flow Regime (1987-2000) of the Hlaing and Bago Rivers River: Bago Station: Zaungtu Year Max. 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 Mean 741 538 623 1,108 708 1,069 752 1,237 790 933 1,034 510 722 951 837 Daily Discharge (m3/s) High Normal Low Drought Discharge Discharge Discharge Discharge 95th day 185th day 275th day 355th day 89 11 1 1 59 14 1 1 80 23 5 1 183 6 1 1 49 2 1 1 66 7 1 1 44 1 0 0 64 3 1 0 31 3 0 0 65 6 1 0 74 2 1 1 75 31 1 0 133 15 1 0 141 69 22 1 82 14 3 1 Min. 1 1 1 1 1 0 0 0 0 0 1 0 0 1 1 Mean 72 56 64 122 59 67 54 71 60 64 73 63 82 103 72 Coefficient Remarks of River Regime 741.0 538.0 623.0 1,108.0 708.0 1,034.0 951.0 837.0 River: Hlaing Station: Khamonseik Year Max. 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 Mean 2,577 2,260 2,570 2,652 1,680 2,390 2,330 2,752 2,133 2,026 1,842 2,292 Daily Discharge (m3/s) High Normal Low Drought Discharge Discharge Discharge Discharge 95th day 185th day 275th day 355th day 1,366 24 11 8 1,177 33 20 17 1,460 46 15 11 1,238 51 16 13 869 22 17 14 1,452 228 5 3 1,290 172 22 9 1,214 22 11 9 932 57 36 20 1,161 356 34 27 1,332 77 28 23 1,226 99 20 14 Min. 8 17 10 13 13 3 9 8 11 27 21 13 Mean 612 520 687 656 426 703 602 609 574 656 573 602 Coefficient Remarks of River Regime 322.1 132.9 257.0 204.0 129.2 796.7 258.9 344.0 193.9 75.0 87.7 176.3 Source: JICA Library (The Study on Improvement of Water Supply System in Yangon City in the Union of Myanmar, 2002), DMH 83 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report 10,000.0 Daily Discharge (m3/s) at Khamonseik 1987 1989 1,000.0 1990 1991 100.0 1992 1995 10.0 1996 1997 1.0 1998 1999 0.1 0 30 60 90 120 150 180 Day 210 240 270 300 330 360 2000 10,000.0 1987 Daily Discharge (m3/s) at Zaungutu 1988 1989 1,000.0 1990 1991 1992 100.0 1993 1994 10.0 1995 1996 1997 1.0 1998 1999 2000 0.1 0 30 60 90 120 150 180 Day 210 240 270 300 330 360 Source: JICA Library (The Study on Improvement of Water Supply System in Yangon City in the Union of Myanmar, 2002), DMH Figure 8.13 Flow Regime (1987~2000) of the Hlaing and Bago Rivers In reference to the previous JICA report (recorded in 1987-2000), the mean monthly flow pattern at Khamonseik and Zaungtu stations are shown in Table 8.8 and Figure 8.14. As seen in Figure 8.14, the monthly discharge shows an increase during the rainy season, with the peak runoff occurring in August. 84 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report Table 8.8 Mean Monthly Flow Pattern at Khamonseik and Zaungtu Stations (1987-2000) Hlaing River at Khamonseik (C.A.=5840 km2) (Unit: m3/s) Year 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 Average Jan Feb Mar Apr May Jun 13 11 10 9 12 374 16 15 44 - 448 28 21 20 18 18 144 22 15 12 11 59 777 19 16 15 13 68 348 23 20 18 19 17 32 13 11 13 16 17 451 5 260 7 5 4 3 126 552 37 13 13 34 130 239 11 10 9 10 16 238 36 34 39 24 69 520 35 33 29 28 65 602 39 29 26 23 61 664 23 18 17 19 51 404 Bago River ar Zaungtu (C.A.=1927 km2) Year 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 Average Jan 2 1 12 1 1 1 1 1 0 1 1 1 7 1 2 Feb 1 1 17 1 1 1 0 1 0 3 1 1 1 2 2 Jul 1177 1156 1022 2155 1738 1195 1625 1245 2129 1608 1599 1584 1409 1588 1516 Aug 2071 1661 1722 2148 2323 1461 1902 1352 1978 2059 2109 1837 1796 1499 1851 Sep 2039 1930 1174 1420 1419 887 2211 1228 1534 1656 1470 1789 1806 1610 1584 Oct Nov Dec Total 1460 88 24 7287 871 305 87 1413 569 32 6183 1405 118 24 8166 1314 495 34 7801 1016 365 14 5068 641 49 9 1538 330 151 8358 1027 313 50 7179 1650 83 22 7228 630 240 38 6842 1014 834 186 7837 1073 184 48 6844 1158 306 55 7003 (Unit: m3/s) Mar Apr May Jun 1 3 3 90 1 2 6 96 23 1 19 82 1 1 110 275 1 1 1 42 1 2 8 37 0 0 3 109 3 1 14 168 0 0 16 128 1 1 12 93 1 1 4 106 1 0 9 63 1 1 40 112 11 28 37 134 3 3 20 110 Jul Aug Sep Oct Nov Dec Total 253 213 193 54 47 3 863 173 179 61 82 53 15 670 144 247 157 56 6 2 766 352 361 263 75 13 3 1456 213 306 78 34 14 3 695 174 283 203 78 11 2 800 96 257 160 14 2 1 644 287 208 116 16 0 32 846 229 146 182 7 11 2 721 209 214 160 50 12 2 759 219 327 157 46 4 2 868 180 166 144 109 44 30 747 162 324 236 84 10 1 979 233 157 323 139 91 75 1231 209 242 174 60 23 12 860 Source: JICA Library (The Study on Improvement of Water Supply System in Yangon City in the Union of Myanmar, 2002), DMH Source: JICA Library (The Study on Improvement of Water Supply System in Yangon City in the Union of Myanmar, 2002), DMH Figure 8.14 Mean Monthly Flow Pattern at Khamonseik and Zaungtu Stations (1987-2000) 85 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report 2) Characteristics of Related Tidal River (Tidal Area of Mixed Tide) As mentioned above, the lower reaches of the Yangon Riverine system are tidal rivers that are affected by tidal variability more than 100 km from the estuary. The tidal range around Yangon Port is about 5.1 m and 2.5 m at spring tide and neap tide, respectively. The spring tide from the estuaries to Yangon Port is accompanied by a flow of up to 3.0 m/s. Velocities around Yangon Port according to the nautical chart are about 1.6-1.8 m/s. In addition to “upland flow (river’s own flow) arising from the catchment area” and “tidal flow based on tidal motion”, there are “density current at the river mouth due to the difference in salinity between seawater and river water”, “density flow by difference in concentration of suspended solids”, “heat convection” and “wind-driven current”, among others, in the river tidal compartment. The scale of these flows varies greatly in both time and space, and as it shows a complex phenomenon, its prediction is difficult. However, because these flows are assumed as a well-mixed type tide under great tidal variability, it is considered that the effects of stratified flow and density flow under actual streaming motion are smaller at the time of rising tide and ebb tide. Thus, in this survey, the hydraulic analysis is performed only by simulating the river flow (upland flow) and tidal flow. In addition, tide is based on celestial motion, it is represented as the sum of many periodic components, and tidal flow (rising tide and falling tide) in tidal rivers also shows periodic fluctuations. Furthermore, the average velocity in one tidal cycle at one point in a tidal compartment is not zero. The average flow associated with oscillatory tidal motion like this is defined as the tide-induced residual current resulting from the asymmetry of tidal motion. Therefore, the simulation period desired is the relatively long period from the neap tide to the spring tide, and not only a one tidal cycle. Also, all riverine systems which affect tidal motion are desirable as the simulation range. On the other hand, a large amount of sediments has been flowing out of the vast basin of the Yangon Riverine system. Sediments are deposited on the estuarine regions from Yangon Port. Hence, the river channel and bed of the tidal reach in the Yangon River have not changed much. According to Myanmar Rivers Reference (1996, DWIR of MoT), the estimated annual sediment transport is 37 million tons for the Yangon River based on the size and character of its drainage area. In the vicinity of Yangon Port, MPA has been dredging the sediment deposits in order to secure the navigation channel. 3) Aggradations and Degradations of Rivers The collected bathymetric survey data are listed in Table 8.9. From these data, cross-sectional data of related rivers were prepared by the JICA Survey Team. These cross section data are useful in checking and understanding the change in cross-sectional and longitudinal profiles, such as aggradations and degradations of rivers. 86 The Preparatory Survey for The Project for Construction of Bago River Bridge Table 8.9 Organization MPA - nautical chart MPA - bathymetric survey Final Report Bathymetric Survey Data List Reach Yangon River mouth –Bago River, Pazundaung Creek, Hlaing River to the Port limit Inner bar (Monkey Point) Liffy reach of the Yangon River Monkey Point to Bo Aung MPA - bathymetric survey Kyaw Wharves of the Hlaing River Upstream of Thanlyin to DWIR - bathymetric survey upstream of Dagon Bridge Confluence of Hlaing to DWIR - bathymetric survey Thanlyin Bridge Thanlyin Estate Development Ltd. Monkey Point to Thanlyin (Star City) – bathymetric survey Bridge of the Bago River Confluence of Hlaing to JICA Survey Team upstream of Thanlyin Bridge, Pazundaung Creek MPA - bathymetric survey Survey Date Remarks Sep. 2007 Feb. 2010, Partial data Feb., Jun., and Jul. 2013 Apr. 2011 Partial data Feb. 2010 Jan. 2013 May 2007 Jul. 2012 Aug. 2013 This Survey Source: JICA Survey Team The fluctuations of cross-sectional profiles of rivers in recent years are shown in Figure 8.15 and 8.16.  At Station No. 7534 and No. 5910, the profiles indicate a trend toward increasing erosion to the outer bending part of the Bago River caused by washout.  At Station No. 8336 at Thanlyin Bridge of the Bago River and 8334 at Thaketa Bridge of the Pazundaung Creek, local scouring of bridges is progressing, and its depths are fluctuating on a large scale.  At station No. 5082 at Bago Point, riverbed depth seems to be almost stable in recent years.  At station No. 4148 at Monkey Point, riverbed height seems to be unstable due to the sedimentation of sand from the Hlaing River and Pazudaung Creek. 87 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report Source: JICA Survey Team based on the data collected from MPA, DWIR, Star City Figure 8.15 Change of Cross-sectional Profiles of Rivers (1) 88 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report Source: JICA Survey Team based on the data collected from MPA, DWIR, Star City Figure 8.16 Change of Cross-sectional Profiles of Rivers (2) 89 The Preparatory Survey for The Project for Construction of Bago River Bridge 8.2.2 Final Report Tidal Level around Yangon Area Hourly calculated data of astronomical tide at Yangon Port (located 36 km upstream from the mouth of the Yangon River) and at Elephant Point (located at the river mouth) are available from the website. Both station's astronomical tide level records in March 2005 are shown in Figure 8.17, while the tide chart diagram of Yangon Port is shown in Figure 8.18 (ground elevation of land survey is normally indicated as zero from the MWL+3.121m at Bo Aung Kyaw Street Whalf Station of MPA.) From the tide chart diagram, observed fluctuations of spring, average, and neap tides are 5.13 m, 4.00 m, and 2.84 m, respectively. According to MPA, the maximum storm surge (namely, the sea level departure from normal or the difference between astronomical tide and observed tide) at Yangon Port is reported to be 2.13 m. During the passage of Cyclone Nargis on May 3, 2008, MPA measured 2.13 m from flood mark after the storm. For comparison, the probable surge amplitudes (or sea level departure from normal) at Elephant Point as calculated by the Hydrology Branch of the Irrigation Department are shown in Table 8.10. Comparing with probable surge amplitude, it can be said that the storm surge during the passage of Cyclone Nargis at Yangon port is very high. In addition, the calculated tides in four and eight major constituent tides at Elephant Point are shown in Table 8.11 based on the existing study. Source: Earthquake Research Institute, the University of Tokyo Figure 8.17 Astronomical Tide at Elephant Point and Yangon Port (2005) 90 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report (Approximate) Highest High Water Level (H.H.W.L.) + 6.74 m (1899) High Water of Ordinary Spring Tide (H.W.O.S.T.) + 5.80 m High Water Observed Mean Tide (H.W.O.M.T.) + 5.13 m High Water Ordinary Neap Tide (H.W.O.N.T.) + 4.42 m Mean Water Level (M.W.L.) - No.7 Sule Pagoda Wharf - Bo Aung Kyaw Street Wharf Mean Sea Level (M.S.L.) - Amherst +3.234 m (1954) +3.121 m (up to 1936) +2.73m Low Water Ordinary Neap Tide (L.W.O.N.T.) Low Water Ordinary Mean Tide (L.W.O.M.T) Low Water of Ordinary Spring Tide (L.W.O.S.T.) Historical tide 6.98m Spring tide Mean Neap 5.13m tide tide 4.00m 2.84m + 1.58 m + 1.13 m + 0.67 m Chart Datum Level (C.D.L.) (Approximate) Lowest Low Water Level (L.L.W.L.) + 0.00 m - 0.24 m Source: MPA Figure 8.18 Tide Level at Yangon Port Table 8.10 Return Period and Surge Amplitude at Elephant Point Return Period (year) 5 10 20 25 50 200 100 Surge (m) 0.889 1.046 1.196 1.244 1.391 1.537 1.682 Source: JICA Library (The Project for Preservation of Farming Area for Urgent Rehabilitation of Agricultural Production and Rural Life in Areas affected by Cyclone Nargis, 2011), MoAI, Table 8.11 Amplitude of Major Tidal Constituents Actual Measurement in 1978-79 at Elephant Point (Past Computation Result of Harmonic Decomposition) Latitude : 16 30' Latitude : 96 18' M2 K1 S2 Major 8 O1 ConstituN2 ents K2 P1 Q1 Sum of Major 4 Constituents Major 4 Constituents Amplitude H Phase G ft m degree 5.743 1.750 99.18 0.673 0.205 20.53 2.299 0.701 141.96 0.305 0.093 40.86 1.097 0.334 90.91 0.625 0.191 141.96 0ss.223 0.068 20.53 0.049 0.015 307.42 2.749 Source: Irrawaddy Delta Hydrological Investigations and Delta Survey, Volume 3 – Analysis, Sir William Halcrow & Partners, January 1982, MoAI, Note: 8.2.3 In the abovementioned document, 32 major constituents were calculated by harmonic analysis. Flood Conditions including Storm Surge According to the Hazard Profile of Myanmar, 2009, flooding has always been one of the major hazards in Myanmar, accounting for 11% of all disasters and second only to fire. Floods around Yangon area can be classified into three types as follows: 91 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report  Riverine floods in the river delta;  Localized floods in urban areas due to a combination of factors, such as cloudburst, saturated soil, poor infiltration rates, and inadequate or poorly-built infrastructure (e.g., blocked drains); and  Flooding due to cyclone and storm surge in the coastal areas. Floods that have caused the largest damage are due to cyclones and storm surges Figure 8.19 shows the flood inundation areas resulting from Cyclone Nargis, taken by satellite imagery on May 5, 2008. The Hazard Profile of Myanmar described that the damage brought by Cyclone Nargis caused 138,373 people dead or missing, killed 300,000 cattle, and destroyed over 4,000 houses and schools in more than 6,000 villages, with a total damage cost of MMK 13 trillion, including those in Ayeyarwady and Yangon areas. Source: UNOSAT (www.unosat.org) Figure 8.19 Flood Waters surrounding Yangon City (Cyclone Nargis, 5 May 2008) 8.2.4 Inland Water Transportation Condition The Port of Yangon is a river port having 18 wharves and is the premier international port of Myanmar. The port lies along the Yangon Riverbank at the Yangon City side. General cargoes handled at the Port of Yangon are as follows:  Main Export Commodities - timber, pulses, rice and rice products, yellow maize, and fishery products; and  Main Import Commodities - construction materials, machinery and equipment, fertilizer, crude oil, palm oil, wheat grain, and cement. 92 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report General cargo handled at the Yangon Port in 2011-2012 was 20,408 thousand metric tons (imports at 12,590 and exports at 7,818), volume of handled container is 408,043 twenty-foot equivalent unit (TEU: imports at 207,540 and exports at 200,503). Most of the abovementioned comes from the trading volume in the inner harbor of the Port of Yangon. In the proposed bridge sites of the Bago River and Pazundaung Creek, ships owned by some organizations only sail around the Tharkata Jetty at a rate of about once a day except for small ships and fishing boats. Also, there is a small shipyard upstream of the existing Thanlyin and Thaketa bridges, where some small ships crosses under them. Among the organizations that own vessels are Myanmar Five Star Line (MFSL), Myanmar Port Authority (MPA), Myanmar Navy (MN), Myanmar Oil and Gas Enterprise (MOGE) and Yuzana Company Limited. The largest ship, owned by MFSL, is as follows:  Ship's name : M.V. Mongla  Length Overall (LOA)/Beam : 92.45 m/15.8 m  Depth : 7.8 m  GRT/NRT : 3388 t/1421 t  Hatches :2  Draft : 5.3 m  DWT : 3,309 t  Ship Height above Sea Level : 28 m (light draft) On the other hand, the list of navigation channel limitation of related existing bridges is shown in Table 8.12. Table 8.12 Navigation Channel Limitation of Related Existing Bridges Bridge Name River Name Maha Bandoola Bridge (Thaketa Township) Thanlyin Bridge (Thanlyin Township ) Pazundaung Creek Bago Clearance(m) Width Height 120.0 16.8 106.1 10.2 Source: IWT From the above, in the navigation channel of this proposed bridge site up to the Thaketa Jetty, the largest allowable ship weight is 3,309 t and necessary navigation channel height is 28 m at present. Navigation channel height for the Pazundaung Creek and the upstream part from Thaketa Jetty is about 10 m for small ships. Based on an interview with MPA and IWT, the navigation fairways at Monkey Point and the Thanlyin Bridge are commonly navigated as shown in Figure 8.20 and Figure 8.21. 93 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report Source: JICA Survey Team based on the data from MPA Figure 8.20 Navigation Fairway at Monkey Point (Yangon Port) Source: IWT Figure 8.21 Navigation Fairway at Thanlyin Bridge 94 The Preparatory Survey for The Project for Construction of Bago River Bridge 8.2.5 Final Report Dredging Condition of Inner Bar of Yangon Port MPA has conducted a bathymetric survey at the inner bar (Monkey Point) of their navigation channel every week. Based on the results, MP has dredged using its self-propelled suction hopper dredger (8001,000 m3, three ships), conducted during low tide. It takes about 30 min until the dredger is full. The dredging cycle includes a one-hour trip to the dumpsite that is 3.6 km (2.2 mi) away. Dredging of mud and sand at the inner bar is performed by one ship during the rainy season. As sand increases during the dry season, dredging is then performed by two or three ships. Annual dredging soil volume for maintenance is 1.5-2.0 million m3 per year, annual budget for dredging is secured at USD 950,000. Records of dredging volume and number of trips of dredgers are shown in Figure 8.22. 600 250,000 500 200,000 400 150,000 300 100,000 200 50,000 100 0 0 300,000 Dredging Volume (M3) Dredging Volume (M3) 300,000 Number of Trip of Dredger/month Dredging Volume Dredging Volume 600 250,000 500 200,000 400 150,000 300 100,000 200 50,000 100 0 0 Number of Trip of Dredger/month Dredging Volume at Inner Bar 2012 Dredging Volume at Inner Bar 2008-2009 Source: JICA Survey Team based on the data from MPA Figure 8.22 Dredging Volume and Dredger Trips at Yangon Port 8.3 Estimation of Probable Floods and Water Levels 8.3.1 Probable Floods at Gauging Stations Past annual maximum discharges (extremal values) of Zaungtu, Bago, and Khamonseik gauging stations collected for the calculation of design discharges are shown in Table 8.13. Table 8.13 Zaungtu Bago River Name Bago Bago Khamonseik Hlaing Station Name Collected Data List for Annual Maximum Discharge Catchment Area (km2) 1,927 2,580 Period of Record 1987~ 1970~ 5,840 1987~ Collected Data No. Remarks 25 (1987-2011) 43 (1970-2012) 22 (1987-2011) 3-year missing observation Source: DMH Probable discharges are calculated according to the following:  To select the appropriate model for probability distribution from the three methods: Gumbel distribution, Iwai distribution and Lognormal distribution. In this survey, Iwai distribution of most common method is adopted.  Calculations are for 2, 3, 5, 10, 20, 25, 30, 50, 80, 100, 150, 200, 300, 400 and 500 year return periods. 95 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report The results of probable discharge at Zaungtu, Bago, and Khamonseik gauging stations are shown in Table 8.14. Table 8.14 Return Period (Probability) (Year, %) 2 50.0% 3 33.3% 5 20.0% 10 10.0% 20 5.0% 25 4.0% 30 3.33% 50 2.0% 80 1.25% 100 1.0% 150 0.667% 200 0.5% 300 0.33% 400 0.25% 500 0.2% Probable Flood Calculation at Zaungtu, Bago, and Khamonseik Gauging Stations Probable Discharge Qmax (m3/s) Bago Zaungtu Khamonseik 2 2,580 km 1,927 km2 5,840 km2 1,024 855 2,227 1,114 942 2,374 1,211 1,030 2,517 1,329 1,127 2,671 1,437 1,210 2,800 1,471 1,235 2,838 1,498 1,255 2,868 1,574 1,308 2,947 1,642 1,354 3,015 1,674 1,375 3,046 1,732 1,412 3,101 1,773 1,438 3,138 1,830 1,473 3,188 1,871 1,498 3,223 1,902 1,516 3,249 Source: JICA Survey Team based on the data from 8.3.2 Probable Floods from River Flow for Design The discharge at the proposed bridge sites are calculated by multiplying the proportion of of each catchment area to the probable discharges of each gauging stations upstream (or “specific discharge” method). Probable discharges used for the hydraulic calculation are shown in Table 8.15. Incidentally, these discharges are runoff volumes from the river’s own flow, but excluding additional flow rates from the influence of the falling tide. 96 The Preparatory Survey for The Project for Construction of Bago River Bridge Table 8.15 Final Report Probable Floods from River Flows for this Design Riverine System Name River Name Gauging Station Name Catchment Area at Station (km2) Catchment Area at Construction Site (km2) Return period 1/2 1/3 1/5 1/10 1/20 1/25 1/30 1/50 1/80 1/100 1/150 1/200 1/300 1/400 1/500 100 year discharge per unit drainage area (m3/sec/km2) Yangon River Bago River Hlaing River Pazundaung Creek Bago Khamonseik 5,840 12,950 (Bago) 1,490 2,580 - Remarks Probability Probability Discharge Discharge Discharge value value 1,024 2,056 2,227 4,938 591 1,114 2,237 2,374 5,264 643 1,211 2,431 2,517 5,581 699 1,329 2,668 2,671 5,923 768 1,437 2,885 2,800 6,209 830 1,471 2,953 2,838 6,293 850 1,498 3,008 2,868 6,360 865 1,574 3,160 2,947 6,535 909 1,642 3,297 3,015 6,686 948 1,674 3,361 3,046 6,754 967 1,732 3,477 3,101 6,876 1,000 1,773 3,560 3,138 6,958 1,024 1,830 3,674 3,188 7,069 1,057 1,871 3,757 3,223 7,147 1,081 1,902 3,819 3,249 7,205 1,098 Q1 Q3 Q2 0.64884 0.52158 =specific discharge Bago River Q1 Catchment Area (km2) 10 year flood (m3/s) 30 year flood (m3/s) 50 year flood (m3/s) 100 year flood (m3/s) 500 year flood (m3/s) 5,180 5,180 2,668 3,008 3,160 3,361 3,819 Pazundaung Creek Q2 1,490 768 865 909 967 1,098 Source: JICA Survey Team based on the data from DMH 97 Hlaing River Q3 12,950 5,923 6,360 6,535 6,754 7,205 Yangon River Yangon (Monkey P.) River-mouth Q4 Q5 19,620 9,359 10,232 10,604 11,082 12,122 Remarks (25,640) (12,112) (13,189) (13,642) (14,222) Design Discharge (15,471) The Preparatory Survey for The Project for Construction of Bago River Bridge 8.3.3 Final Report Probable High Water Level at Tidal Gauging Station Past annual maximum high water level records (extremal values) at Yangon Port stations for the calculation of design high water level are as shown in Table 8.16. From these values, probable high water levels are calculated as shown at the right side of the same table. Table 8.16 Return Period (Probability) (Year, %) 2 50.0% 3 33.3% 5 20.0% 10 10.0% 20 5.0% 25 4.0% 30 3.33% 50 2.0% 80 1.25% 100 1.0% 150 0.667% 200 0.5% 300 0.33% 400 0.25% 500 0.2% Probable High Water Level and Observed High Water Level (1997-2013) at Yangon Port (Monkey Point) Probable High Water Level (HWL) (m) Remarks Year Yangon Port 13 years (1997-2013) Collected Data No. (1998-2001 was not observed) MPA 7.0 7.1 7.2 7.4 7.4 7.5 7.5 7.6 7.7 7.7 7.8 7.8 7.9 7.9 8.0 Land Survey Benchmark 3.9 4.0 4.1 4.3 4.3 4.4 4.4 4.5 4.6 4.6 4.7 4.7 4.8 4.8 4.9 Observed Maximum Annual Water Level (m, MPA-based) Remarks Yangon Port 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 7.04 Not observed Not observed Not observed Not observed 7.00 6.80 7.30 7.20 7.20 7.20 6.80 6.70 6.61 6.90 7.00 7.30 Note: Adopted probability distribution is the Gumbel distribution. Source: JICA Survey Team based on the data from MPA 8.3.4 Hydraulic Calculation Hydraulic phenomena (rising tide, falling tide, etc. in addition to the river’s own flood) at tidal compartments of the river are needed for simulating all of the tidal reaches. Therefore, the range of numerical calculation shall target all tidal areas of the Yangon Riverine system together with its tributaries such as the Bago River and Pazundaung Creek. The downstream boundary is assumed to be at Elephant Point (located at the river mouth of the Yangon River). The upstream boundary of tributaries is assumed in reference to past documents (Figure 8.24), river length is measured from the river route on the topographic map, and river cross section at the upstream end is assumed as the virtual cross-section. Distance from the river mouth to the upstream boundary is measured at 100 km or more. The hydraulic calculation model of the Yangon Riverine system is shown in Figure 8.23. 98 The Preparatory Survey for The Project for Construction of Bago River Bridge Virtual Cross-section Final Report Virtual Cross-section Virtual Cross-section Pazundaung Creek Hlaing River Bago River Yangon River ←Elephant Point Source: JICA Survey Team Figure 8.23 Hydraulic Calculation Model of the Yangon Riverine System 99 The Preparatory Survey for The Project for Construction of Bago River Bridge Note: Final Report High Water Level around Yangon on the figure above is estimated at 6.23 m (=2.73 m+3.5 m). (Tide level on the figure above is based on Amherst station chart. Difference between Amherst and Yangon station chart is 2.73 m.) Source: A One Dimensional Analysis of the Tidal Hydraulics of Deltas (Nicholas Odd, Report OD 44, July 1982, Hydraulics Research Station, UK), from MoAI Library Figure 8.24 Past Simulation Example of High Water and Low Water Profiles at the Yangon River (during the wet season in August 1980) 1) Analysis Software Hydraulic analysis was carried out to simulate the tidal and flood phenomena in the Yangon River using HEC-RAS (Hydrologic Engineering Center - River Analysis System), a software developed by the US Army Corps of Engineers, USA. HEC-RAS has the capability to compute one-dimensional water surface profiles for both steady and unsteady flows. Sub-critical, supercritical, and mixed flow regime profiles can be calculated. Water surface profiles are computed from one cross section to the next by solving the energy equation using the standard-step method. Energy losses are evaluated by friction (Manning’s equation) and contraction/expansion coefficients. HEC-RAS requires inputs for boundary conditions of upstream discharge and either downstream water level or known energy gradient. Also, tidal waves are very dynamic. According to the user manual of this software, in order for the solution to be able to accurately model a tidal surge, the theta implicit weighting factor must be close to 0.6. 2) Hydraulic Analyses and Precondition Hydraulic analyses were conducted through the following procedure: 100 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report  The roughness coefficient of the river channel is estimated by using the existing astronomical tide levels at two places during the dry season. The upstream water level of Yangon Port, which is calculated from the downstream astronomical tide for Elephant Point, is approximated as the astronomical tide waveform of Yangon Port by changing the roughness coefficient of tidal reaches. The 2005 tide table at Elephant Point and Yangon Port are given as known water level data.  The calculation case at the time of flood (rainy season) was conducted by using the abovementioned roughness coefficient calculated from real tide level. Also, preconditions of the calculation case are as follows:  The cross sections for hydraulic calculation are given by using the bathymetric survey results (MPA Datum), nautical charts, and other data in reference to the above hydraulic model.  The dry season downstream boundary for hydraulic calculation is given based on the tide level (from February 2 to 24, 2005, neap tide-spring tide-neap tide) at Elephant Point which varies from hour to hour; hence, the flow becomes unsteady. The dry season upstream boundary is given based on the steady low water runoff (275th day discharge).  The rainy season downstream boundary for hydraulic calculation is given based on the tide level (from October 17 to 21, 2005, spring tide) at Elephant Point. The rainy season upstream boundary is given based on the 100-year flood as steady flow in each river.  The flow rate to the upstream end is given as the proportional distribution of the catchment area at the upstream end with the total area. The flow rate of remaining catchment area is given as the uniform lateral inflow against the stream length. 3) Hydraulic Analyses and the Result Two cases of hydraulic analysis were performed as shown in Table 8.17. Table 8.17 Case No. Cases of Hydraulic Analysis Upstream Boundary Condition (m3/s) Discharge 1 Low water runoff 2 100-year flood PazunHlaing Bago daung 44 8 6,754 3,361 5 967 Downstream Boundary Condition of (Elephant Point) Period of Tidal Waveform Feb 4– 24, 2005 (Annual minimum tide, Neap Spring – Neap tide) Oct 17 to 21, 2005 (Annual Maximum Tide, Spring tide) Source: JICA Survey Team Note: Discharge is indicated as the value at confluence of Hlaing, Bago and Pazundaung. 101 Remarks (Objectives) (For the calibration of roughness coefficient) (For the calculation of HWL) The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report If the riverbed material is very small and the riverbed slope is very gentle such as those in the delta area, the roughness coefficient of river channel is generally very small and its coefficient is estimated to be about 0.015 according to past literatures1. From the results of the geotechnical survey in this study, the mean grain size of riverbed material in the Thaketa/Bago Bridge site is very small at 0.015-0.15 mm. The roughness coefficients for Case 1 were set at 0.010, 0.015, 0.020, and 0.025. From the results of hydraulic calculation, the calculation case of surge amplitude that was properly synchronized with astronomical tide, where a roughness coefficient of 0.015 is applied, with a maximum margin of error of about 40 cm as shown in Figure 8.25. Plan: P lan_ULL River: Yangon River Reach: Hlaing RS: 4313.6 6 Legend Stage Obs Stage Stage (m) 4 2 0 06 08 10 12 14 2005/02/01 Time 16 18 20 22 Source: JICA Survey Team Figure 8.25 Synchronization between Astronomical Tide and Calculated Tide at Yangon Port by Hydraulic Calculation (Roughness Coefficient: 0.015, Case 1) From the results of low discharge calculation during the dry season, hydraulic calculation of high water level is calculated by using a roughness coefficient of 0.015. The results of hydraulic calculation for Cases 1 and 2 are shown in Table 8.18 and in Figure 8.26 to Figure 8.32. Moreover, the estimation of high water level made an allowance for the elevation of water surface due to a decrease in atmospheric pressure caused by cyclones. The increment by waves is not considered in this survey. The elevation of water surface due to a decrease in atmospheric pressure is estimated through the following equation: - Rising value of static water level by barometric depression; ηPS = 0.991･(1013 - p) = 0.991･(1013 - 962) = 50.54 cm = 0.505 m where; ηPS: Rising value of static water level by barometric depression (hPa) p: Atmospheric pressure value which is decreased due to cyclone (hPa) (2008 Cyclone Nargis: 962 hPa) 1 Bed Form and Bed Variation During Floods of the TONE River Mouth, Journal of Japan Society of Civil Engineers, Ser. B1 (Hydraulic Engineering) Vol. 54(2010), Japan 102 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report Table 8.18 Item Option 1 Unit < Hydraulic Calculation Results > High Water Level Maximum Discharge Low Discharge Tidal flow Minimum Discharge 100-year Flood Tidal flow < Hydraulic Calculation Results > High Water Level: (1) Water Level Departure from Normal by Cyclone: (2) High Water Level: (1)+(2) Maximum Discharge 100-year Flood Tidal flow Minimum Discharge 100-year Flood Tidal flow < Probability Calculation > Probable H.W.L. < Planned Value > Design Discharge Design H.W.L. (MPA-based) Design H.W.L. (Land Survey) Results of Hydraulic Analyses New Bago Bridge Option 2 Option 3 +4,148.6 +5,082.2 5.86 12,269.11 13.17 12,255.94 -18,511.03 13.17 -18,524.20 5.86 10,379.84 8.06 10,371.78 -15,870.22 8.06 -15,878.28 m 6.74 6.74 m 0.505 0.505 7.25 18,291.25 4,327.74 13,963.51 -17,421.38 4,327.74 -21,749.12 7.25 15,502.38 3,360.98 12,141.40 -15,468.58 3,360.98 -18,829.56 7.7 7.7 m m3/s m3/s m3/s m3/s m3/s m3/s m m3/s m3/s m3/s m3/s m3/s m3/s m m3/s m m 18,292 7.7 4.579 15,503 7.7 4.579 New Thaketa Remarks Bridge +8,144.4 +8,404.1 Case 1: Annual Minimum Tide and Flood 5.88 5.87 at Low Discharge 9,298.12 1,705.62 8.06 5.10 9,290.06 1,700.52 falling tide -14,428.05 -2,405.57 8.06 5.10 -14,436.11 -2,410.67 rising tide Case 2: Annual Maximum Tide and Flood 6.79 6.81 at 100 year Flood Cyclone Nargis: 0.505 0.505 962 hPa 7.30 7.32 14,397.53 2,556.37 3,360.98 966.77 11,036.55 1,589.60 falling tide -13,942.54 -1,657.47 3,360.98 966.77 -17,303.52 -2,624.24 rising tide 7.7 14,398 7.7 4.579 7.7 2,557 7.7 4.579 △3.121 m Source: JICA Survey Team Plan: P lan_UHH River: Pazundaung Creek Reach: P azundaung RS: 8404.1 3000 8 Legend Stage HW Stage TW Flow 2000 6 Flow (m3/s) Stage (m) 1000 4 0 2 -1000 0 17Oct2005 2400 1200 18Oct2005 2400 1200 19Oct2005 2400 Time 1200 20Oct2005 2400 21Oct2005 1200 -2000 Source: JICA Survey Team Figure 8.26 Tidally Dominated Water Level and Discharge Fluctuation (Rising and Falling Tide) at New Thaketa Bridge – Case 2 103 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report Plan: P lan_UHH River: Bago River Reach: Monkey Point RS: 4148.6 8 20000 Legend Stage Flow 15000 6 10000 4 0 Flow (m3/s) Stage (m) 5000 -5000 2 -10000 -15000 0 17Oct2005 2400 1200 18Oct2005 2400 1200 19Oct2005 2400 Time 1200 20Oct2005 2400 21Oct2005 1200 -20000 Source: JICA Survey Team Figure 8.27 Tidally Dominated Water Level and Discharge Fluctuation (Rising and Falling Tide) at the New Bago Bridge (Option 1) - Case 2 Plan: P lan_UHH River: Bago River Reach: Bago RS: 5082.2 8 20000 Legend Stage Flow 15000 6 10000 4 0 Flow (m3/s) Stage (m) 5000 -5000 2 -10000 -15000 0 17Oct2005 2400 1200 18Oct2005 2400 1200 19Oct2005 2400 Time 1200 20Oct2005 2400 21Oct2005 1200 -20000 Source: JICA Survey Team Figure 8.28 Tidally-dominated Water Level and Discharge Fluctuation (Rising and Falling Tide) at the New Bago Bridge (Option 2) - Case 2 104 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report Plan: P lan_UHH River: Bago River Reach: Bago RS: 8144.437 8 15000 Legend Stage HW Stage TW Flow 10000 6 4 0 Flow (m3/s) Stage (m) 5000 -5000 2 -10000 0 17Oct2005 2400 1200 18Oct2005 2400 1200 19Oct2005 2400 Time 1200 20Oct2005 2400 21Oct2005 1200 -15000 Source: JICA Survey Team Figure 8.29 Tidally Dominated Water Level and Discharge Fluctuation (Rising and Falling Tide) at the New Bago Bridge (Option 3) – Case 2 Plan: P lan_UHH River: Yangon River Reach: Yangon-Outfall RS : -34380.1 8 100000 Legend Stage 80000 Flow 60000 6 40000 4 0 Flow (m3/s) Stage (m) 20000 -20000 -40000 2 -60000 -80000 0 17Oct2005 2400 1200 18Oct2005 2400 1200 19Oct2005 2400 Time 1200 20Oct2005 2400 21Oct2005 1200 -100000 Source: JICA Survey Team Figure 8.30 Tidally Dominated Water Level and Discharge Fluctuation (Rising and Falling Tide) at the Yangon River Mouth – Case 2 105 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report Bago existing_HH Plan: P lan_UHH 2013/11/12 Bago River Bago B a g o Yangon River Yangon-Outfall 20 Le ge nd EG Ma x WS W S M ax W S R i v e r EG 1 9 OC T2 0 0 5 0 5 0 0 W S 1 9 O C T2 0 0 5 0 5 0 0 EG 1 8 OC T2 0 0 5 1 7 0 0 W S 1 8 O C T2 0 0 5 1 7 0 0 EG 1 9 OC T2 0 0 5 0 2 0 0 W S 1 9 O C T2 0 0 5 0 2 0 0 M o n k e y 10 EG 1 8 OC T2 0 0 5 1 4 0 0 W S 1 8 O C T2 0 0 5 1 4 0 0 EG 1 9 OC T2 0 0 5 0 8 0 0 W S 1 9 O C T2 0 0 5 0 8 0 0 EG 1 8 OC T2 0 0 5 2 0 0 0 W S 1 8 O C T2 0 0 5 2 0 0 0 P o i n t EG 1 8 OC T2 0 0 5 2 3 0 0 W S 1 8 O C T2 0 0 5 2 3 0 0 EG 1 8 OC T2 0 0 5 1 1 0 0 W S 1 8 O C T2 0 0 5 1 1 0 0 Elevation (m) EG 1 9 OC T2 0 0 5 1 1 0 0 W S 1 9 O C T2 0 0 5 1 1 0 0 C r it 1 9 O C T2 0 0 5 0 8 0 0 0 C r it 1 9 O C T2 0 0 5 0 2 0 0 C r it 1 8 O C T2 0 0 5 2 0 0 0 C r it 1 8 O C T2 0 0 5 1 4 0 0 C r it 1 9 O C T2 0 0 5 1 1 0 0 C r it M a x W S C r it 1 8 O C T2 0 0 5 2 3 0 0 C r it 1 8 O C T2 0 0 5 1 1 0 0 C r it 1 8 O C T2 0 0 5 1 7 0 0 C r it 1 9 O C T2 0 0 5 0 5 0 0 Gr o u n d 10000 0 30000 20000 24763.2* 22804.8* 20846.4* 11284.0 12061.6* 12839.3 13592.5* 14407.1* 15115.8* 15774.2* 16549.5 17285.8* 18086.9* 18888.0 5082.2 5910.2 6728.7 7534.3 8144.437 8806.5* 9467.35* 10293.2* 4147.597 393.433* 1180.3 1907.8 -481.34* -1444.0* -2406.7* -3369.4* -4332.1 -5320.2* -6308.4* -7296.5* -8284.7* -9272.9 -10207.* -11142.* -12076.* -13011.* -13945.* -14880.6 -15878.* -16877.* -17875.* -18874.* -19872.* -20870.* -21869.* -22867.* -23865.* -24863.* -25861.* -26859.* -27858.* -28820.* -29747.* -30673.* -31600.* -32526.* -33453.* -20 -34380.1 -10 50000 40000 60000 Main Channel Distance (m) Source: JICA Survey Team Figure 8.31 Longitudinal Profile of the Bago River to the Yangon River Reach – Case 2 Bago existing_HH Plan: P lan_UHH 2013/11/12 Yangon River Yangon-Outfall Pazundaung Creek Pazundaung B a g o 20 Le ge nd EG Ma x WS W S M ax W S R i v e r EG 1 9 OC T2 0 0 5 0 5 0 0 W S 1 9 O C T2 0 0 5 0 5 0 0 EG 1 8 OC T2 0 0 5 1 7 0 0 W S 1 8 O C T2 0 0 5 1 7 0 0 EG 1 9 OC T2 0 0 5 0 2 0 0 W S 1 9 O C T2 0 0 5 0 2 0 0 M o n k e y 10 EG 1 8 OC T2 0 0 5 1 4 0 0 W S 1 8 O C T2 0 0 5 1 4 0 0 EG 1 9 OC T2 0 0 5 0 8 0 0 W S 1 9 O C T2 0 0 5 0 8 0 0 EG 1 8 OC T2 0 0 5 2 0 0 0 W S 1 8 O C T2 0 0 5 2 0 0 0 Elevation (m) P o i n t EG 1 8 OC T2 0 0 5 2 3 0 0 W S 1 8 O C T2 0 0 5 2 3 0 0 EG 1 8 OC T2 0 0 5 1 1 0 0 W S 1 8 O C T2 0 0 5 1 1 0 0 EG 1 9 OC T2 0 0 5 1 1 0 0 W S 1 9 O C T2 0 0 5 1 1 0 0 C r it 1 9 O C T2 0 0 5 0 8 0 0 0 C r it 1 9 O C T2 0 0 5 0 2 0 0 C r it 1 8 O C T2 0 0 5 2 0 0 0 C r it 1 8 O C T2 0 0 5 1 4 0 0 C r it 1 9 O C T2 0 0 5 1 1 0 0 C r it M a x W S C r it 1 8 O C T2 0 0 5 2 3 0 0 C r it 1 8 O C T2 0 0 5 1 1 0 0 C r it 1 8 O C T2 0 0 5 1 7 0 0 C r it 1 9 O C T2 0 0 5 0 5 0 0 Gr o u n d 0 10000 20000 30000 40000 50000 25601.6* 23612.9* 21624.3* 19635.7* 17647.1* 15658.5* 13669.9* 11681.3* 5458.0 6158.7 6864.1 7726.8 8334.0 9071.5 9692.8 4147.597 393.433* 1180.3 1907.8 -481.34* -1444.0* -2406.7* -3369.4* -4332.1 -5320.2* -6308.4* -7296.5* -8284.7* -9272.9 -10207.* -11142.* -12076.* -13011.* -13945.* -14880.6 -15878.* -16877.* -17875.* -18874.* -19872.* -20870.* -21869.* -22867.* -23865.* -24863.* -25861.* -26859.* -27858.* -28820.* -29747.* -30673.* -31600.* -32526.* -33453.* -20 -34380.1 -10 60000 Main Channel Distance (m) Source: JICA Survey Team Figure 8.32 Longitudinal Profile of the Pazundaung Creek to the Yangon River Reach – Case 2 (5) Design High Water Level and Discharge From the above hydraulic analyses, the design high water level and discharge are determined as shown in the Table 8.20. As for discharge, most of the total discharge is decided by the component of tidal flow other than the river’s own flow (upland flow) from the catchment area for large tidal variations. For the determination of the design high water level and discharge, the following aspects are left as future challenges:  The number of data for observed annual maximum high water level at Yangon Port is just 13 years, which somewhat lacks reliability (i.e., problem on statistics analysis). 106 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report  The flows of rising and falling tide during the dry season were restaged well by using unsteady flow simulation. However, the observed data on past storm surge tide level and discharge during the rainy season is difficult to obtain as most of the data format are not organized in a manual. Hence, the calculation result of hydraulic analysis is difficult to calibrate against the observed data at the time of storm surge.  The bathymetric survey data of tidal section is much less. However, all survey data of tidal area for the Yangon Riverine system, including all its tributaries, is difficult to obtain. Also, hydraulic analysis for the tidal area of the Yangon River, including all its tributaries, is difficult to perform for a road project as the workload required is enormous (e.g., problem on hydraulic analysis). In view of the above issues, various studies and surveys shall be performed in the detailed design stage. 8.4 8.4.1 Hydrological Assessment of the Proposed Bridge Sites Hydraulic Design Criteria of Bridge In designing the opening of the bridge waterway, the following design criteria for hydraulics are required:  Backwater shall not significantly increase flood damage to properties upstream of the bridge;  Velocity through the bridge shall not damage the road facility or increase the damages to downstream properties:  The existing flow distribution shall be maintained to the most practicable extent;  The pier and abutment shall be designed to minimize the flow disruption;  Potential local scour shall be within acceptable limits; and  Clearance at the structure shall be adequately designed in order to provide safety for falling debris (the elevation of bottom of bridge girder must be higher than the highest high water level plus the navigation channel height.) The design return period and the clearance from the bridge girder to the high water level shall be compliant with standards authorized by the organizations concerned. In this survey, the design return period is 100 yearss. Also, the design standard is based on the HEC series of FHWA 2 as well-used international standards. 8.4.2 Assessment of Scouring (1) Basic concept Scour at bridge occurs due to the erosion caused by flowing water, excavation, and carrying away of materials from the riverbed and its banks. Scour process is cyclic in nature which complicates the determination of its magnitude. Scour can be deepest near flood peak; however, it is hardly visible as scour holes are covered with sediments during the receding stage of flood. In general, several floods may be needed in order to attain maximum scour under typical flow conditions at bridge crossings. 2 Hydraulic Engineering Circular, Federal Highway Administration, USA 107 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report (2) Methodology of scour computation In designing the bridge substructure, it is very important to evaluate the scour potential at piers and abutments and carefully studying site-specific subsurface information. Total scour at a bridge crossing is comprised of three components: 1. Long-term aggradation or degradation 2. Contraction scour 3. Local scour 1) Aggradation and Degradation Aggradation and degradation are long-term changes in streambed elevation due to natural or man-induced causes. Aggradation involves the deposition of material eroded from the stream or watershed upstream of the bridge; whereas, degradation involves the lowering of streambed due to lack of sediment supply from upstream. Both are evaluated independently in the hydraulic model. Generally, streams are considered to have stable and balance of sediment transport if the configuration is not changed in the long term. In this survey, the river bed/course fluctuation analysis is not conducted. In the detailed design stage, this analysis shall be conducted and their results will be studied after surveying the past and current topographic data of rivers. 2) Contraction Scour Contraction scour at a bridge crossing involves the removal of material from the streambed and banks across the channel width, resulting from a contraction of the flow area and an increase in discharge at the bridge. In case of constructing a new bridge, common causes for contraction of flows are constriction (encroachment) of road embankment onto the floodplain and/or into the main channel or piers blocking a portion of flow. As a result, flow area decreases velocity and bed shear stress increase. Hence, more bed material is removed from the contracted reach than those transported into the reach. As bed elevation lowers, flow area increases while velocity reduces, reaching a state of relative equilibrium. 3) Local Scour Local scour at piers or abutments involves the removal of bed material as a result of formation of vortices known as the horseshoe vortex and wake vortex at their base. The horseshoe vortex results from the pileup of water on the upstream surface of the obstruction and subsequent acceleration of the flow around the nose of the pier or abutment. The action of the vortex removes bed material around the base of the obstruction. In addition to the horseshoe vortex around the base of a pier, there are vertical vortices downstream of the pier, called the wake vortex. Both the horseshoe and wake vortices remove material from the pier base region. The intensity of wake vortices diminishes rapidly as the distance downstream of the pier increases. As a result, there is often deposition of material immediately downstream of a long pier. Factors that affect the magnitude of local scour depth at piers and abutments are:  Velocity of the approach flow,  Depth of flow, 108 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report  Width of the pier,  Discharge intercepted by the abutment and returned to the main channel at the abutment,  Length of the pier if skewed to flow,  Size and gradation of bed material,  Angle of attack of the approach flow to a pier or abutment,  Shape of a pier or abutment,  Bed configuration, and  Ice formation or jams and debris. A sample illustration of scour at a cylindrical pier is shown in Figure 8.33. Source: Evaluating Scour at Bridges (2012 Fifth Edition), Hydraulic Engineering Circular No. 18 (HEC 18), FHWA, USA Figure 8.33 Simple Schematic Representation of Scour at a Cylindrical Pier (3) Scour Estimation All major streams intercepted by the proposed bridge alignment were modelled using HEC-RAS developed by Hydrologic Engineering Center, USA. The model reach covered a sufficient length from upstream to downstream of the bridge location. These models were simulated for 100-year return period discharges under existing conditions (or without the bridge) and incorporating the bridge. In Geometric Data window of HECRAS, all bridge data including deck/roadway and piers are given and the schematic diagram of the bridge are shown in Figure 8.34 to Figure 8.37. Scour estimation by steady flow analysis of HEC-RAS was conducted based on Hydrologic Engineering Circular No. 18 (HEC 18) of the Federal Highway Administration (FHWA), USA, by using the value of maximum discharge and high water level resulting from unsteady flow analysis. The results of scour estimation are shown in Table 8.19. 109 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report Bridge S cour RS = 8144.437 20 Legend WS PF 1 Ground 15 Ineff Bank Sta 10 Contr Scour Elevation (m) Total Scour 5 0 -5 -10 -15 -1500 -1000 -500 0 500 1000 1500 Station (m) Source: JICA Survey Team Figure 8.34 Scouring Computation Result at the New Bago Bridge (Option 3) Bridge S cour RS = 8335.608 20 Legend WS PF 1 Ground Ineff 10 Bank Sta Contr Scour Elevation (m) Total Scour 0 -10 -20 -30 -1500 -1000 -500 0 500 1000 Station (m) Source: JICA Survey Team Figure 8.35 Scouring Computation Result at the Existing Thanlyin Bridge 110 1500 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report Bridge S cour RS = 8404.1 20 Legend WS PF 1 Ground 15 Ineff Bank Sta 10 Contr Scour Elevation (m) Total Scour 5 0 -5 -10 -15 -200 -150 -100 -50 0 50 100 150 200 Station (m) Source: JICA Survey Team Figure 8.36 Scouring Computation Result at the New Thaketa Bridge Bridge S cour RS = 8384.014 20 Legend WS PF 1 Ground Ineff 10 Bank Sta Contr Scour Elevation (m) Total Scour 0 -10 -20 -30 -200 -150 -100 -50 0 50 100 150 Station (m) Source: JICA Survey Team Figure 8.37 Scouring Computation Result at the Existing Thaketa Bridge 111 200 The Preparatory Survey for The Project for Construction of Bago River Bridge Table 8.19 Pier No. P1 P2 P3 P4 P5 P6 P7 P8 P9 P10 P11 P12 P13 P14 P15 P16 P17 P18 P19 P20 P21 P22 P23 New Bago Bridge Total Scour (m) 2.08 5.38 5.81 2.8 3.08 3.1 3.1 3.98 6.4 6.27 3.95 3.59 3.74 3.81 3.96 3.95 3.67 3.55 2.16 0.32 0.28 0.25 0 Local Scour (m) 1.88 5.18 5.61 2.61 2.88 2.91 2.9 3.78 6.2 6.08 3.75 3.4 3.54 3.61 3.76 3.75 3.47 3.36 1.97 0.32 0.28 0.25 0 Final Report Results of Scouring Computation Existing Thanlyin Bridge Contraction Scour (m) 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0 0 0 0 Total Scour (m) 3.31 11.46 11.64 12.6 12.81 12.32 12.39 11.61 11.1 10.93 11.73 11.91 12.51 12.25 11.64 11.55 3.17 - Local Scour (m) 3.31 11.46 11.64 12.6 12.81 12.32 12.39 11.61 11.1 10.93 11.73 11.91 12.51 12.25 11.64 11.55 3.17 - New Thaketa Bridge Contraction Scour (m) 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 - Total Scour (m) 0 3.32 4.38 - Local Scour (m) 0 3.32 4.38 - Existing Thaketa Bridge Contraction Scour (m) 0 0 0 - Total Scour (m) 3.25 6.08 6.08 9.62 9.62 6.08 6.08 3.25 - Local Scour (m) 3.25 4.38 4.38 7.91 7.91 4.38 4.38 3.25 - Contraction Scour (m) 0 1.7 1.7 1.7 1.7 1.7 1.7 0 - Pier No. is indicated as the pier number on calculation. Source: JICA Survey Team From the above scouring computations, the scouring depths at each pier were estimated. As for hydraulic issues of the new and existing bridges, the following aspects are left as future challenges:  Contraction scour occurs at the existing Thaketa and Thanlyin bridges. Particularly in the existing Thaketa Bridge, contraction scour of 1.7 m will occur due to the decrease of water flow area for the main channel and the pier section. Water flow area at the existing bridge decreases by 18% compared to the upstream cross-section. Regarding the bridge length of the new Bago Bridge, the value of contraction scour is small, and it may not cause any problem.  Based on the results of computation, local scouring occurs at all bridges, and is more pronounced at the existing Thanlyin and Thaketa bridges. The riverbed around the piers of both existing bridges is not provided with bed protection works. Therefore, bed protection and refilling works using appropriate materials shall be immediately conducted for the existing piers.  Also, for the two new bridges, the study of appropriate bed protection and revetment works shall be conducted during the detailed design stage. In addition, estimation of scouring is necessary to be further studied using other prediction formula including that of HEC during the detailed design stage. 112 The Preparatory Survey for The Project for Construction of Bago River Bridge 8.4.3 Final Report Assessment of the Proposed Bridge Hydraulic and navigation channel conditions at each proposed bridge site from above study are shown in Table 8.20. Table 8.20 Assessment of Proposed Bridges Bago Bago (Option (Option 1) 2) Highest High Water Level (HHWL) m 7.70 7.70 Mean High Water Springs (HWL) m 5.80 5.80 Design Water Level Mean Water Level (MWL) m 3.121 3.121 Mean Low Water Springs (LWL) m 0.67 0.67 Chart Datum Level (CDL) m 0.00 0.00 (1)+(2) m3/s 18,291 15,502 Upland Flow (River’s Own Flow) 4,328 3,361 m3/s Design Discharge (1) 100-Year Flood (2) m3/s 13,964 12,141 Maximum Ship Size DWT 15,000 Height m 351) Navigation Channel 288 Limitation m(=1.5×LOA2)), (Assuming Future Ships) Width m in case of Bothway) Maximum Ship Size DWT 3,309 Height m Navigation Channel 283) Limitation m 139 (Assuming Current m(=1.5×LOA4)), Width Ships) in case of Bothway) Item Unit Bago (Option 3) 7.70 5.80 3.121 0.67 0.00 14,398 3,361 Thaketa Remarks 7.70 5.80 3.121 0.67 0.00 2,556 967 From probable H.W.L. From MPA (observed W.L.) From MPA (observed W.L.) From MPA (observed W.L.) From MPA (observed W.L.) From hydraulic calculation Falling tide 11,037 1,590 Upland flow Ships crossing the bridges are small and there is no plan to expand. Hence, these conditions are the same as existing bridge condition. (Refer to Table 8.12) Source: JICA Survey Team Note. 1) Determine the height with reference to “Study on Ship Height by Statistical Analysis - Standard of Ship Height of Design Ship (Draft) (National Institute for Land Infrastructure Management, Japan, 2006)”. 2) Assumed as “Length overall (of a ro-ro ship) = 192.0 m “. Determine the height with reference to “Technical Standards for Port (Ports & Harbours Association of Japan, 1999)”. 3) Height above water level (of a current ship) = 28 m. From an interview with MFSL. 4) Length overall (of a current ship) = 92.45 m. From an interview with MFSL. 113 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report Chapter 9 Design for Feasibility Study The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report 9. Design for Feasibility Study 9.1 Study of Bridge Location and its Proximity to the existing Thanlyin Bridge The proposed bridge location was selected downstream of the existing Thanlyin Bridge. The alignment of the bridge section is parallel to the existing bridge with a center to center offset of 140 m. This location was selected from three possible locations as illustrated in Figure 9.1. These three locations were proposed under the following conditions:  Approach roads of Bago River Bridge shall be connected with existing roads by the shortest length.  No involuntary resettlement or minimum involuntary resettlement due to project implementation.  No land acquisition or minimal acquisition of private lands. It is noted that there are limited road networks in this area. The major roads are Shukhinthar-Mayopat Road and Thanlyin Chin Kat Road on the right bank of the Bago River, and Kyaik Khauk Pagoda Road on the left bank. Furthermore, National Races Village is located upstream of the existing bridge on the right bank of the Bago River, while two private development areas, including Star City, are located downstream of the existing bridge on the left bank side. Having these situations, three routes, namely Route A and Route B in the upstream and Route C in the downstream of the existing bridge, were studied. The horizontal alignment outlines of these routes are given in Table 9.1. Table 9.1 Location Length Exiting road to be connected Source: JICA Survey Team Figure 9.1 Three Possible Bridge Locations Brief Aspects of the Three Studied Routes Route A 950 m upstream 3,440 m Route B 140 m upstream 2,730 m Route C 140 m downstream 2,830 m Local road traversing the north of Approach road of the existing National Races Village Thanlyin Bridge Intersection of ShukhintharMayopat Road and Thanlyin Chin Kat Road Kyaik Khauk Pagoda Road Kyaik Khauk Pagoda Road Kyaik Khauk Pagoda Road Right bank Running the east fringe of National Races Village. Starts from the approach road of the existing Thanlyin Bridge and Starts from the intersection, and traverses the Myanmar Railwaystraverses the west fringe of owned land. National Races Village. Left bank Approach road uses the existing Bogyoke Road alignment. Traverses the west fringe of a private land and connects with the existing road. Right bank Left bank Outline of Alignment Source: JICA Survey Team 114 Traverses a land owned by Myanmar Railways and connects with the existing road. The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report Features of these three routes are described as follows: Route A • On the right bank, the route connects to a local road at a T-shaped intersection. This is not appropriate for the Bago River Bridge Project which is expected to form a major road network. • On the right bank, the route traverses a small dock area. In case Route A is selected, the operation of this small dock shall be abandoned. • On the left bank, the route will utilize the existing Bogyoke Road alignment up to the link point with Kyaik Khauk Pagoda Road in a T-shaped intersection. This existing road is around 10 m wide, and runs through the center of the township area. In order to accommodate the dual two-lane approach road for Bago River Bridge, the widening of existing road is inevitable. Consequently, land acquisitions and involuntary resettlement would be generated. Route B • On the right bank, the route crosses under the existing railway and traverses the green space at the fringe of National Races Village. In case Route B is selected, it will be necessary to cut down many trees. • On the left bank, the route passes through the western fringe of a private land, and connects to Kyaik Khauk Pagoda Road after it crosses under the existing railway. • Thus, the route will cross under the existing railway twice. Although the railway crossing points are in the approach road section and the actual running speed at these points will not be fast, it is considered inappropriate to have two rather sharp bending portions when the design speed of the Project is 80 km/h. Route C • On the right bank, the route starts from the intersection between Shukhinthar-Mayopat Road and Thanlyin Chin Kat Road, and traverses a land owned by Myanmar Railways, which has no permanent houses or assets at the moment. • On the left bank, the route also passes through a land owned by Myanmar Railways, which is empty at the moment, and connects to Kyaik Khauk Pagoda Road smoothly. • Among the three routes, it was judged that Route C has smoothest horizontal alignment and is appropriate for the project design speed of 80 km/h. Based on the above considerations, Route C was adopted as the bridge location adjacent to the existing Thanlyin Bridge. 9.2 Continuity with Thilawa SEZ Access Road The existing Kyaik Khauk Pagoda Road will be upgraded to a dual two-lane road similar to Thilawa SEZ Access Road that starts from a point near the existing Thanlyin Bridge to the proposed Thilawa SEZ Area. Figure 9.2 shows the proposed horizontal alignment for Thilawa SEZ Access Road. It is believed that the new Bago River Bridge along with its approach roads shall be connected to Thilawa SEZ Access Road and form one continuous trunk road. Figure 9.3 shows the horizontal alignment elements and coordinates of SEZ Access Road end section. Figure 9.4 shows the vertical alignment and proposed height of the same section. Based on these data, the data summary of the point to which the approach road for Bago Bridge connects is as follows: 115 The Preparatory Survey for The Project for Construction of Bago River Bridge      Station on SEZ Access Road: End Point Coordinates: Horizontal Alignment Element: Proposed Height: Vertical grade: Final Report 8+700.000 (205789.549518, 1857219.291051) Straight Line 5.380 m -0.04% Source: JICA Survey Team Figure 9.3 SEZ Access Road Horizontal Alignment As shown in Figure 9.5, SEZ Access Road was proposed to have two typical cross sections for two different ROW width sections. It is noted that the outer shoulder and median widths are different from the proposed crosssectional arrangement of the Project. It is required to provide a transition section in order to adjust these width differences. Source: JICA Survey Team Figure 9.2 Source: JICA Survey Team Figure 9.4 SEZ Access Road Profile 116 Horizontal Alignment of Thilawa SEZ Access Road The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report Typical Cross Section for 22 m ROW Section Typical Cross Section for 24 m ROW Section Source: JICA Survey Team Figure 9.5 9.3 9.3.1 Typical Cross Section of SEZ Access Road Structural Design Design of Superstructures The design of the superstructure is preliminarily performed for the recommended bridge from among the alternatives. The purpose of the preliminary design is to define the structural element sizes so that better estimates of cost and constructability could be obtained. The refinement of alternative study also allows the preliminary design to have a more efficient structure and to more accurately show those member sizes which are reflected in the drawing. Structural analysis are initially carried out for each of the recommended types of superstructure in order to assess the vertical reaction loads from the superstructure for the design of substructure and foundation and structural stability considering site specific loadings such as temperature, stream flow, wind and seismic loads. Types of superstructure applied for Bago River Bridge are a cable-stayed bridge and a continuous steel box girder with steel plate deck for the main bridge, and continuous PC box girder for the approach bridge as shown in Figure 9.6. Figure 9.6 General Plan of Bago River Bridge Steel Cable-stayed Bridge Steel cable-stayed bridge having a total length of 448 m consists of the main channel bridge with a center span of 224 m and side span of 112 m on both sides of the main bridge as shown in Figure 9.6 and Figure 9.7. Configurations of the cable-stayed bridge are determined in the following studies: Figure 9.7 Configuration s of Steel Cable Stay ed Bridge 117 The Preparatory Survey for The Project for Construction of Bago River Bridge 118 Figure 9.6 General Plan of Bago River Bridge Final Report Source: JICA Survey Team The Preparatory Survey for The Project for Construction of Bago River Bridge 119 Figure 9.7 Configurations of Steel Cable Stayed Bridge Final Report Source: JICA Survey Team The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report (1) Arrangement of Stay Cables From the various longitudinal cable arrangements of steel cable-stayed bridges, two basic systems, namely parallel and fan-shaped systems as shown in Figure 9.8, are recommended. The parallel-shaped system may be preferred from an aesthetic point of view. However, it has a tendency to cause bending moment in the tower as it requires a higher tower than for a fan-shaped system. In addition, the lower cables are fixed at the lower part of the tower leg that do not function properly as stay cables. The quantity of steel and cable required for a parallel-shaped cable arrangement is slightly higher than for a fan-shaped arrangement. Therefore, the fan-shaped system is applied for Bago River Bridge in consideration of technical and economical points. Fan-shaped System Parallel System Source: JICA Survey Team Figure 9.8 Stay Cable Arrangements (2) Position of Stay Cables There are two alternative layouts that may be adopted when using the fan-shaped system: the cable anchorages may be situated outside the deck structure (double plane system), or they may be built inside the main girder (single plane system) as shown in Figure 9.9. The single plain system is better than the double plain system for small cable-stayed bridges and will be applied for Bago River Bridge due to the following reasons: Two Vertical Plane System Single Plane System Source: JICA Survey Team Figure 9.9 patial Positions of Stay Cables 120 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report 1) Single plane of stay cables along the longitudinal axis located in the wide central median of superstructure will not be affected by any traffic limit even in a curve alignment. 2) Single plane system creates a lane separation so that there can be a smooth natural continuation of the approach bridge to the cable-stayed bridge. 3) It is an economical and aesthetically acceptable solution, providing an unobstructed view from the bridge. 4) In addition, this system also offers the advantage of requiring relatively small piers, because pier size is determined by the width of the main girder. In the case of a single plane system, the towers are generally fixed to one main box girder. With this arrangement, it is necessary not only to reinforce the box girder but also to provide strong bearings for the towers. The supports should also resist the horizontal forces caused by the increased friction forces in the bearings due to temperature. (3) Taper Length For the bridge is adopted the single plane system, the center strip shall be wider than the standard cross section and the taper shall be introduced to the carriageways. The shift length to lateral direction is 0.85m to each side. Application of the Japanese Road Specifications, the taper length is calculated as 34.0m. L=VxdW/2=80x0.85/2=34.0 Here, L: taper length (m) V: design speed (km/h) dW: shift length to lateral direction Continuous Steel Box Girder with Steel Plate Deck Continuous steel box girder bridge, having a total length of 776 m, consists of five main spans of 112 m each, a side span of 112 m in the Thanlyin side, and a side span of 104 m in the Yangon side as shown in Figure 9.6 and Figure 9.10. Configuration of the steel box girder with steel plate deck reinforced by ribs and its wearing surface are determined in the following studies: Figure 9.10 Co nfiguration of Con tinu ous Steel Box Girder with Steel Plate Dec k (1) Continuous Steel Box Girder with Steel Plate Deck For relatively small spans in the 60-90 m range, it is convenient to use a reinforced concrete deck with steel box girder acting as a composite section as the main girder. On the other hand, for spans over 100 m, steel plate deck systems with crossbeams and longitudinal ribs have been widely used to reduce the weight and depth of girders. In the design of long-span bridges, dead load of steel plate deck is 30-40% lower than concrete deck slab. For the main spans of Bago River Bridge, three types of steel box girders with steel plate deck are considered as shown in Table 9.2. Twin narrow width rectangular box girder is applied for this type of main bridge in consideration of the fabrication capacity and welding techniques of Myanmar companies and transportation route to the site. In addition, small box girders will require smaller erection equipment and simplified fabrication steps. 121 The Preparatory Survey for The Project for Construction of Bago River Bridge 122 Figure Figure 9.10 Configuration of Continuous Steel Box Girder with Steel Plate Deck Final Report Source: JICA Survey Team The Preparatory Survey for The Project for Construction of Bago River Bridge Table 9.2 Arrangement 1. Single Rectangular Box Girder Final Report Type of Main Girder of Steel Box Girder Deck Cross Section Comments Fabrication and transportation of box girders are difficult and erection will require larger equipment. 2. Twin Rectangular Box Girder Since interval of box girder is narrow, it is reasonable for reinforced concrete slab but not economical for steel plate deck. 3. Twin Narrow Width Rectangular Box Girder Fabrication and transportation of box girder are relatively easy and erection will requiresmaller equipment. Source: JICA Survey Team (2) Rib The open- and closed-rib systems are the basic types of ribs. Ribs are normally welded to the transverse floor beams and steel deck plate as shown in Figure 9.11. The trapezoidal rib (called U-Rib in Japan) has been widely used and is the most practical for steel plate deck of long span steel box girders and cable-stayed bridges in Japan. Source: JICA Survey Team Figure 9.11 Details of Trapezoidal Rib connected to Steel Plate Deck and Floor Beam (3) Wearing Surface on Steel Plate Deck 123 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report Typical structures of wearing surface on steel plate deck are: 1) guss asphalt and 2) epoxy asphalt concrete, which are commonly applied on base course to function as waterproofing layer, as shown in Figure 9.12. The structure of wearing surface used in Japan is 35 mm for guss asphalt and 25 mm for densely graded asphalt concrete. 1) Guss Asphalt 2) Epoxy Asphalt Concrete Source: JICA Survey Team Figure 9.12 Typical Structures of Wearing Surface on Steel Deck The performances of both wearing surfaces on steel plate decks vary from poor to excellent depending largely on local climate, deck plate flexibility, and volume of heavy truck traffic. In general, comparing between guss asphalt and epoxy asphalt concrete, the performance and condition of the latter is better but the cost is higher. On the other hand, the application of guss asphalt is economical and simple using penetration asphalt as a binder heated to a high temperature of over 200°C and applied, usually by pouring and leveling by guss asphalt finisher or by hand. Moreover, it has been used widely and successfully for steel plate deck of long span bridges in Japan. In this feasibility study, it is recommended that guss asphalt be applied over the base course of wearing surface on continuous steel box girder and steel cable-stayed bridge. However, further laboratory studies and field tests are necessary in order to determine the most appropriate wearing surface on steel deck bridge considering local climate and its cost. Continuous PC Box Girder with Precast Segmental and Span by Span Method Continuous PC box girder bridge, having a total length of 704 m,consists of the approach bridge, six spans of 50 m each in the Yangon side and two spans of 52 m and six spans of 50 m each in the Thanlyin side, as shown in Figures 9.6, 9.13, and 9.14. Continuous PC box girder for the approach bridge uses precast segmental construction, which is widely used in the world. The segmental method has the following advantages: 1) Concrete segments are produced under high quality control standards using a casting machine. 2) Site works can be minimized and construction period can be greatly shortened in comparison with cast in situ construction method. 3) This precast segment method is still new in Myanmar but possible to be applied widely not only for river bridges but also for viaducts in urban areas. 124 The Preparatory Survey for The Project for Construction of Bago River Bridge 125 Figure 9.13 Configuration of Continuous PC Box Girder (1/2) Final Report Source: JICA Survey Team The Preparatory Survey for The Project for Construction of Bago River Bridge 126 Figure 9.14 Configuration of Continuous PC Box Girder (2/2) Final Report Source: JICA Survey Team The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report Single-cell box girder, which is used for the approach bridge in this design, provides the most efficient section for precast segment construction and its inclined webs improve aesthetics. Span-todepth ratio for constant-depth PC box girders is between 16 and 20. However, box girders shallower than 2 m in depth has practical difficulties for stressing operations inside the box. As girder depth at the connection between cable-stayed bridge and continuous steel box girder is 3.0 m, girders of with a constant depth of 3.0 m is used for continuous PC box girder in order to maintain a constant horizontal line through the whole bridge length, and its span length of 50 m is in the economical range in this feasibility study. Span-by-span erection is selected for the segmental PC box girders because the erection equipment is widely used for spans shorter than 50 m and easily procured in neighbouring countries. 9.3.2 Design of Substructure and Foundations As described above, geological investigation was carried out at five locations. The layer supporting the foundation is assumed as shown in Figure 9.15 based on the geological investigation results. 7 0. 000 6 0. 000 5 0. 000 4 0. 000 3 0. 000 2 0. 000 1 0. 000 HWL = 4 .579 0 .0 00 -10 .0 00 -20 .0 00 -30 .0 00 -40 .0 00 -50 .0 00 -60 .0 00 BH-5 BH-4 Assumed Supporting Layer (GL-40m~-50m) BH-2 Assumed Supporting Layer (GL-40m~-50m) Source: JICA Survey Team Figure 9.15 Assumed Supporting Layer 127 BH-3 BH-1 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report The outline design of foundation is carried out for the following four types in consideration of location (in and out the river) and type of superstructure: - Type 1: In the River (Section of Steel Stay Cable) - Type 2: In the River (Section of Steel Box Girder with Steel Plate Deck) - Type 3: In the River (Section of PC Box Girder) - Type 4: On the Land (Section of PC Box Girder) As described in Section 6.3.1, Study on Foundation Type, steel pipe sheet pile foundation is used for foundations in the rivers in consideration of deep-water construction, scouring, and technical transfer from Japan. Cast-in-place concrete pile is used for foundations on land. 9.3.3 Design of Substructures An oval or round shape for the substructure can be applied as described in Section 6.3.3, Study on Substructure Type. This bridge has a relatively wide width with four lanes; and in consideration of smooth river flow, oval-shaped piers shall be used. The shapes of substructure and foundation based on the outline design are shown in Figure 9.16. 24000 11000 11000 11000 20000 0 00 R10 Various Various 6000 1000 4700 3000 CL 11000 1000 1613 1000 14226 16226 1000 1000 1875 14000 1000 1875 1000 17750 19750 1000 1000 17750 19750 1000 2000 2000 7000 6000 1000 1613 9768 8000 1000 14226 16226 1000 Steel Cable-stayed Bridge Section In the River 1000 4500 1000 1635 1633 1000 1865 11000 1000 1865 13730 22300 300 Steel Box Girder with Steel Plate Deck Section In the River 128 The Preparatory Survey for The Project for Construction of Bago River Bridge 22300 300 11000 Final Report 11000 CL 3000 1000 17000 000 6000 R10 22300 300 11000 11000 3000 Various 11000 1000 2068 3000 00 R80 11000 3500 3000 3500 2000 6000 2000 1000 2068 17000 5000 1000 Various CL 1500 1000 15136 17136 1500 1000 18000 4@3750=15000 1500 1000 2072 6000 10500 2@3750=7500 1500 1500 2500 1000 2072 1500 12144 4@3750=15000 18000 1000 15136 17136 1000 PC Box Girder Section In the River PC Box Girder Section on the Land Source: JICA Survey Team Figure 9.16 Substructure and Foundation Shapes 9.3.4 Design of Abutments Inverted T shape is applied to the abutments in consideration of cost and constructability as described in Section, 6.3.4 Study on Abutment Type. The shapes of abutment based on the outline design are shown in Figure 9.17. 129 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report CL 10500 6500 2500 1500 11000 5000 (4500) 3500 8500 (8000) 2000 11000 22300 300 10500 1500 2@3750=7500 1500 2500 6500 1500 4@4825=19300 22300 1500 1500 2@3750=7500 1500 10500 22300 Note : ( ) shows A2 Abutment Source: JICA Survey Team Figure 9.17 Abutment Shapes 9.4 9.4.1 Highway Design Alignment Design The horizontal and vertical alignments were reviewed, adjusted, and finalized based on the draft output of the topographic survey. On the right bank, the route starts from the intersection between Shukhinthar-Mayopat Road and Thanlyin Chin Kat Road and traverses a land owned by Myanmar Railways. The horizontal alignment was adjusted so as not to affect the local road running along the western side of the Myanmar Railways-owned land. On the left bank, the route also traverses the Myanmar Railways-owned land and connects smoothly to Kyaik Khauk Pagoda Road. The end point of the alignment is the starting point of Thilawa SEZ Access Road. Taking into consideration the drainage efficiency, the main bridge section has 0.30% vertical grade with a crest at the centre of the main bridge section. Vertical grades at both sides of this 0.30% section, approach bridges, and approach roads, were proposed at 2.50%. The plan and profile of Bago River Bridge are given in Appendix 9. 130 The Preparatory Survey for The Project for Construction of Bago River Bridge 9.4.2 Final Report Cross Sectional Arrangement The cross sectional elements are as follows: Sectional Element Carriageway Inner shoulder Outer shoulder Median Sidewalk Width [email protected] m = 7.00 m 0.50 m 1.50 m 0.60 m 2.00 m According to the information from the geological investigation, the existence of soft ground layer was confirmed at the riverbank area. Therefore, it is required to implement soft ground treatment works. As it is difficult to know the extent of the soft ground area in this Preparatory Survey stage, a concrete structure with concrete pile was proposed as shown in Figure 9.18. Source: JICA Survey Team Figure 9.18 Typical Earthwork Cross Section In the bridge section, the width of outer shoulder was reduced to 0.50 m as shown in Figure 9.19. Source: JICA Survey Team Figure 9.19 Typical Bridge Cross Section (Steel Box Girder) 131 The Preparatory Survey for The Project for Construction of Bago River Bridge 9.4.3 Final Report Necessity of Soft Ground Treatment The geological investigations found the soft soils, with N-Value ranging from 0 to 5, exist at both the right and left banks of the Bago River. Therefore, it is needed to provide soft ground treatment for the construction of the approach road. Figure 9.20 shows the data extracted from the boring logs of BH01 and BH-05, which were conducted on the land side. According to the geological investigation, the left bank of the Bago River has thicker soft soil layers of around 10-20 m. For soft ground treatment, the following methods are usually applied:  Soil Replacement with Preloading  Vertical Drain with Preloading The vertical drain system would be sand drain or prefabricated vertical drain (PVD).  Vacuum Consolidation with Preloading  Soil Cement Columns  Piled Foundation System (piles and a concrete slab) The method shall be selected based upon the characteristics of soil, soft soil depth, soft soil areal extent, and others such as constraints of construction period and available budget. In this Preparatory Survey, it is not possible to select the improvement method as the details of spreading situation of soft soil layers are not available. As shown in Figure 9.18, an inverted T-shaped retaining wall with continuous footing with piles was used for the design of the approach road section, which will require minimal land area for construction in the urban area and give safer stability against soft ground behaviour. 132 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report BH-01 Boring Log: Left Bank BH-05 Boring Log: Right Bank Source: JICA Survey Team Figure 9.20 Extraction of Boring Log at Land Side 133 The Preparatory Survey for The Project for Construction of Bago River Bridge 9.4.4 Final Report Study on Pavement Structure The pavement structure of approach road section was studied using the AASHTO Guide for Design of Pavement Structures, 1993. In this guide, the pavement structure is designed by taking the vehicle’s cumulative axle load in terms of equivalent single axle load (ESAL) during the design period. In this study, a design period of 20 years was used Table 9.3 shows the forecasted traffic volumes in 2018, 2025, and 2035 at Bago River Bridge conducted by YUTRA. The traffic volume given in the said table is the total sectional traffic volume on Bago River Bridge in passenger car unit (pcu) per day. Table 9.3 Traffic Demand Forecast at Bago River Bridge Section 2018 2025 2035 Existing Thanlyin Bridge Bago River Bridge Existing Thanlyin Bridge Bago River Bridge Existing Thanlyin Bridge Bago River Bridge Total Truck Bus Taxi Car Year Crossing Section Motorcycle Unit: pcu/day 841 12,446 9,195 534 4,583 27,600 Not constructed yet Occupied by BRT 1,089 19,103 9,319 2,530 4,610 36,651 Occupied by BRT 1,352 27,593 12,874 1,106 6,578 49,503 Source: JICA Survey Team If the bridge construction is assumed to commence in late 2017, Bago River Bridge will be opened to the public in late 2019. Therefore, ESAL shall be estimated based on the traffic volume in 2020 to 2039. Table 9.4 shows the traffic volume in pcu from 2018 to 2039, applying interpolation and extrapolation of given values in Table 9.3, with total traffic volume from 2020 to 2039 in pcu/day. Table 9.4 Traffic Volume from 2018 to 2039 9,195 9,213 9,231 9,249 9,267 9,285 9,303 9,319 9,625 9,941 10,267 10,604 10,952 11,312 11,684 12,068 12,464 12,874 13,297 13,734 14,185 14,651 23,973 455,156 223,312 Source: JICA Survey Team 134 534 667 833 1,040 1,299 1,622 2,026 2,530 2,329 2,144 1,974 1,817 1,673 1,540 1,418 1,305 1,201 1,106 1,018 937 863 794 4,583 4,587 4,591 4,595 4,599 4,603 4,607 4,610 4,777 4,950 5,129 5,315 5,507 5,706 5,912 6,126 6,348 6,578 6,816 7,063 7,319 7,584 Total Taxi 12,446 13,232 14,067 14,955 15,899 16,903 17,970 19,103 19,819 20,561 21,331 22,130 22,959 23,819 24,711 25,637 26,597 27,593 28,627 29,699 30,811 31,965 Truck 841 873 906 940 975 1,012 1,050 1,089 1,113 1,137 1,162 1,187 1,213 1,240 1,267 1,295 1,323 1,352 1,382 1,412 1,443 1,475 Bus 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 Total pcu/day from 2020 to 2039 Car Year Motorcycle Unit: pcu/day 27,600 28,741 29,929 31,167 32,456 33,798 35,196 36,651 37,769 38,922 40,110 41,334 42,595 43,895 45,234 46,614 48,036 49,503 51,014 52,571 54,175 55,828 29,469 112,735 846,797 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report PCU conversion rates of YUTRA are given in Table 9.5. Applying these rates, the total traffic volume in vehicles/day from 2020 to 2039 was calculated as shown in Table 9.6. Bus Truck PCU Conversion Rate Taxi Vehicle Type Car PCU Conversion Rate Motor Cycle Table 9.5 0.25 1.00 1.00 1.75 1.75 Source: JICA Survey Team Bus Truck Total vehicles/day from 2020 to 2039 Taxi Vehicle Type Car Total Traffic Volume from 2020 to 2039 (in vehicles/day) Motor Cycle Table 9.6 95,892 455,156 223,312 16,839 64,420 Source: JICA Survey Team A unit of ESAL is 18 kip, where kip stands for 1,000 pounds-force, which is equivalent to 4.4482216 kN. Therefore, 18 kips is equivalent to 80 kN, or 8.157 tonne-force. Table 9.7 shows equivalency factors (or load equivalency values) for converting axle load of each vehicle class into ESAL numbers. Table 9.7 Equivalency Factor of Vehicles Type of Vehicle Passenger Car Bus Rigid trucks 2-axles Equivalency Factor 0.001 0.87 0.98 Source: JICA Survey Team As seen in Table 9.7, the equivalency factor for a passenger car is small; hence, the value for motorcycles is negligible. Therefore, motorcycles are excluded in the traffic volume for the estimation of ESAL. ESAL number is calculated using the following formula: ESAL = DD × DL × ŵ18 where, DD : a directional distribution factor = 0.5 DL : a lane distribution factor = 0.8 ŵ18 : the cumulative two-directional 18 kip ESAL units = Σ (cumulative two-directional traffic volume/day of each vehicle class × 365 days × equivalency factor) Applying the traffic volumes in Table 9.4, ESAL number was calculated in Table 9.8 as 11,455,160. 135 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report Table 9.8 Vehicle Type Total vehicles/day from 2020 to 2039 Total vehicles from 2020 to 2039 (vehicles/day×365 days) Equivalency Factor ŵ18 Calculation of ŵ18 Car Taxi Bus Truck 455,156 223,312 16,839 64,420 166,131,940 81,508,880 6,146,235 23,513,300 0.001 166,132 Total 0.001 0.87 0.98 81,509 5,347,224 23,043,034 ŵ18 = 28,637,899 ESAL = DD × DL × ŵ18 = 0.5 × 0.8 × ŵ18 = 11,455,160 Source: JICA Survey Team Based on this obtained ESAL number, the following pavement structure was estimated: Asphalt concrete surface course: Asphalt concrete binder course: Base course: Subbase course: 4 cm 6 cm 30 cm 35 cm Assumptions in major input values for estimating the layer thickness of pavement structure were given in Table 9.9. Including an assumed CBR of 7% for subgrade, there are many uncertain variables at this stage. The pavement structure must be reviewed in the detailed design stage by utilizing the laboratory test results of available materials for the Project. Table 9.9 Design Variables Performance Criteria Material Properties Pavement Characteristics Input Value Assumptions Design Input Requirements Performance Period (years) Reliability Design Serviceability Loss, ∆PSI Roadbed Soil CBR Effective Roadbed Soil Resilient Modulus, MR (psi) Subbase Course Resilient Modulus, MR (psi) Base Course Resilient Modulus, MR (psi) Asphalt Concrete Surface Course Resilient Modulus, MR (psi) Asphalt Concrete Binder Course Resilient Modulus, MR (psi) Drainage Coefficients for Base Course and Subbase Course, m2, m3 Value 20 90 1.7 7% 1,500 × CBR 15,000 28,400 300,000 300,000 1.0 Source: JICA Survey Team 9.5 9.5.1 Construction Planning Site Conditions (1) Basic Construction Conditions The location of the Bago River Bridge site is about 4 km upstream of the confluence of the Bago and Yangon rivers. The Yangon River flows into the Gulf of Martaban in the Andaman Sea (a part of the Indian Ocean) at 40 km downstream of the confluence. Most construction materials and machines will be transported by water. The Bago River is relatively shallow (about 6.5 m at MSFL Port), but freights can be reshipped by small barges at Thilawa Port near the location. Freights will be unloaded at the temporary jetty on the each bank of the Bago River. Most of the construction site lies on public land, which has an ample space for construction and accommodating the precast segment fabrication yard. The major facilities of the construction yard is as shown in Table 9.10. 136 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report Table 9.10 Major Facilities of the Construction Yard Thaketa Side Facilities Thanlyin Side Concrete and Asphalt Plant, Precast Segment Fabrication, Steel Box Girder Assembly, Stockyard, Office, Accommodation, etc. Area (m2) 100,000 Concrete and Asphalt Plant, Precast Segment Fabrication, Stockyard, etc. 70,000 Source: JICA Survey Team Source: JICA Survey Team Figure 9.21 Proposed Construction Yard in Thaketa Side (Right Bank) Source: JICA Survey Team Figure 9.22 Proposed Construction Yard in Thanlyin Side (Left Bank) 137 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report (2) Work Content The works contain the following major items: 1) Temporary Works (a) Temporary jetties (b) Construction yard (c) Office and accommodation (d) Concrete and asphalt plant 2) Road Works (a) Soft soil treatment works (piled slab) (b) Embankment works (c) Retaining wall (d) Pavement works (e) Ancillary works 3) Bridge Works (a) Foundation works (b) Substructure works (c) Superstructure works (d) Surface works (e) Ancillary works 9.5.2 Construction Packaging Plan In order to select the optimal construction package, the alternatives as shown in Figure 9.23 were studied and discussed in the sections below. Alternative 2 Package 1: Start to P13 Alternative 2 Package 2: P13 to End Alternative 1: All Section Source: JICA Survey Team Figure 9.23 Plan of Construction Packaging Alternatives Table 9.11 Alternative No.1 One Package Location All Sections Construction Packaging Alternatives Alternative No.2 Package No. 1 Right Bank Side: West Approach Road (L=539 m) Bridge (L=1,076 m, PC Box & Steel Box) Source: JICA Survey Team 138 Package No. 2 Left Bank Side: East Approach Road (L=647 m) Bridge (L=852 m, Cable Stay& PC Box) The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report (1) Alternative No.1: One Package Another proposed alternative is to incorporate all construction works into one package. Advantages: a) Construction schedule can be managed comprehensively, which is good in terms of overall project implementation. b) Problems concerning interference can be solved as part of the scope of one contractor. c) The number of necessary temporary facilities such as offices and plants can be minimized. Disadvantages: a) As the contract amount is too large, many construction companies cannot afford to bid. There is a risk where no companies would intend to apply to bid. (2) Alternative No.2: Two Packages Another proposed alternative of construction contract packaging are as follows: Package 1: Right Bank from KM 0 to KM 1+500, Pier P13 Package 2: Left Bank from KM 1+500 to KM 2+826, Project End. Advantages: a) Both packages have reasonable contract amounts in terms of road and bridge works. b) The boundary of the packages at the west end of the cable-stayed bridge; hence, no major interference to the construction works is anticipated. Disadvantages: a) It is difficult to control the overall construction schedule as the completion of each package varies. b) Some temporary facilities such as offices and plants should be duplicated. c) Construction of P13 by Package 2 is critical for the construction of the end span of the steel box girder of Package 1. (3) Recommendation As shown in the comparison in Table 9.12, Alternative No. 1 with a single package is recommended than Alternative No. 2 with two packages. 139 The Preparatory Survey for The Project for Construction of Bago River Bridge Table 9.12 Final Report Comparison among Alternatives in Construction Packaging Plan Evaluation Item Alternative No. 1 Alternative No. 2 Schematic Plan View All Sections No. of Packages Manageability Interference between packages Package1 One (1) Construction schedule can be managed comprehensively, which is good for overall project implementation. Problems concerning interference can be solved as part of the scope of one contractor. ○ No major differences even if a few temporary facilities will be reduced. The contract amount is larger and the length of the bridge is longer than many construction Qualification of companies have accomplished. The Bidders requirements for pre-qualification should be decided after discussion with MOT and JICA. Attractiveness of Attractive only for big general contractors packages because of the large contract amount. Construction Cost Evaluation ○ ○ △ ○ Two (2) It is difficult to control the overall construction schedule as the completion of each package varies. The boundary of the packages is at the west end of the cable-stayed bridge; hence, there will be no major interference to the construction works although adjustment in construction schedule is necessary at the boundary. No major differences even if a few temporary facilities will be duplicated. No major problem in qualification of bidders as there are many construction companies having experience in similar works. Both packages have reasonable contract amounts in terms of road and bridge works. Recommended - Remarks: ○:Good, △:Fair Source: JICA Survey Team 9.5.3 Package2 Temporary Facilities Temporary facilities contain the following major items: 1) Temporary offices and plant yard (a) Temporary office for contractor with contractors’ accommodation. (b) Concrete batching plant (c) Asphalt plant (d) PC segment fabrication yard (e) Steel girder fabrication yard (f) Material stockyard (g) Machinery work shop 2) Temporary jetties (a) Loading and unloading jetty 3) Temporary access (a) Entrance access road from public road (b) Temporary bridges 140 △ △ ○ ○ ○ The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report 4) Navigation safety measures Summary of temporary facilities are shown on the table below. Table 9.13 Description Temporary Yard Temporary Jetty Temporary Access Summary of Temporary Facilities Location Thaketa Side Thanlyin Side Thaketa Side Thanlyin Side Thaketa Side Thanlyin Side Quantity 100,000 m2 70,000 m2 1,300 m2 1,300 m2 4,016 m2 5,191 m2 Remark Source: JICA Survey Team 9.5.4 Construction Procedures Construction of Substructure A construction plan of the substructure is developed for each bridge type and commented in the following subsection. (1) Abutment Construction of the abutments starts with foundation work utilizing a temporary casing, a boring machine, etc., followed by pile cap concreting. After installation of scaffoldings and temporary support for the formworks, reinforcing work, and concrete casting for the abutment wall and its wing walls follow. A series of construction procedures is shown in Figure 9.24. Source: JICA Survey Team Figure 9.24 Construction Procedures for Abutment 141 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report (2) Pier on Land Construction of the piers on land starts with foundation work utilizing a temporary casing, a boring machine, etc., followed by pile cap concreting. After installation of scaffoldings and temporary support for the formworks, reinforcing work, and concrete casting for the pier follow. A series of construction procedures is shown in Figure 9.25. Source: JICA Survey Team Figure 9.25 Construction Procedures for Pier on Land (3) Pier in the River Construction of the piers in the river starts with driving steel pipe sheet piles utilizing a silent pile driver with locating piles and a temporary guide frame, followed by excavation inside the cofferdam with temporary bracings. After casting the concrete pile cap, reinforcing work, and concrete casting for the pier follow. A series of construction procedures is shown in Figure 9.26. 142 The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report Source: JICA Survey Team Figure 9.26 Construction Procedures for Pier on River Erection of Superstructure In consideration of general constructability relating to the erection of superstructure, it is important to maintain the main navigational channel free from any obstruction during construction, and minimize the number and period required for temporary bents in the Bago River. An erection plan of the superstructure was developed for each bridge type and commented in the following subsection. It is anticipated that materials and equipment for erection of the superstructure will have to be loaded on barges and transported to the erection site on the river. There are a number of areas downstream of the site that would permit the loading and storage area for erection equipment and fabricated steel girder blocks. Consequently, temporary jetties are provided for loading and unloading on both river banks. The major erection works for the superstructures will be performed using the balanced cantilever method by barge-mounted cranes or erection equipment, or using the span-by-span method by erection truss girder. (1) Cable-stayed Bridge Cable-stayed bridge erection is performed utilizing a permanent tower and stay cable that will support all loads during the assembly of the superstructure. After the majority of the tower construction is completed, the first steel girder blocks will be connected directly to the tower using temporary supports attached to the tower pier. Additional steel girder blocks will be erected on the temporary support and will extend alternately up to the installation of the first permanent stay cable. Then, alternating cantilever erection of steel girder blocks continues along with stay cable installation until the mid-span is reached. When two adjacent cantilever end steel girder blocks are completed, the closure block will be installed and the erection will be complete. A series of construction procedures is shown in Figure 9.27. 143 The Preparatory Survey for The Project for Construction of Bago River Bridge 144 Figure 9.27 Construction Procedure of Steel Cable Stayed Bridge Final Report Source: JICA Survey Team The Preparatory Survey for The Project for Construction of Bago River Bridge Final Report (2) Continuous Steel Box Girders The cantilever method of erection for continuous steel box girder starts with assembling the sections over a pier top using pier brackets. Once the initial steel box girder blocks are assembled on the pier top, new blocks are added to each end and erected by cantilever method using TEG erection equipment or travelling derrick in an alternating process until mid-span is reached. Cantilever erection will proceed simultaneously with the adjacent pier. When the two adjacent cantilever end steel girder blocks are completed, the closure block will be installed and the erection will be completed. A series of construction procedures is shown in Figure 9.28. (3) Continuous PC Box Girder All of the segments are precast at the casting yard and transported by trailer or barge to the site. All segments that make up one span are positioned and adjusted on the assembly truss girders, and then partial post-tensioning force is exerted. The adjacent spans of continuous box girders are adjusted and joined together with a closure space that avoids the short-line segmental match-casting geometric tolerances. The closure joint is then casted. After the closure concrete has hardened, continuous prestressing cables are installed in the box girder and tensioned to connect all spans as a continuous box girder. A series of construction procedures is shown Figure 9.29. 145 The Preparatory Survey for The Project for Construction of Bago River Bridge 146 Figure 9.29 Construction Procedure of Continuous Steel Box Girder with Steel Deck Slab Source: JICA Survey Team Figure 9.28 Construction Procedure of Continuous PC Box Girder with Span by Span Final Report Source: JICA Survey Team The Preparatory Survey for The Project for Construction of Bago River Bridge 9.5.5 Final Report Construction Period The total construction period is 28 months. The construction time schedule with overall construction sequence and major critical activities is shown in Figure 9.30. Source: JICA Survey Team Figure 9.30 Construction Schedule 147