Friday, October 14, 2011

Design and Details of Padma Bridge Bangladesh




                          
Bridge Length, which was decided by the river study        
                              Paturia-Goalundo= 6.5 km
                             Mawa-Janjira =6.2 km        
Applicable Bridge Types over 100m Span Length                 
                                                Concrete Bridge: PC Continuous Box, Extradosed, Cable-stayed                 
                                                Steel Bridge: Steel Continuous Box, Cable-stayed              
  Foundation Types             
                                                Steel Tubular Driven Piles, Cast-in-situ RC Piles, RC Caissons          
 Cost-Span Relation                           
                                                Minimum cost would be at approx. 200m span length.    
Favorable Bridge Types and Span Length               
                                               
PC extradosed girder bridge or PC cable-stayed girder bridge would be the most favorable bridge type from the view points of construction cost, maintenance cost, etc. Favorable span lengths will be further examined in a rage of 150m to 250m.
                


Timing of Submission Main Contents

Inception Report
June 2003
-Scope, methodology and implementation plan of the Study

Progress Report 1
September 2003
Selection of the bridge location alternatives, Traffic demand projection

Interim Report
March 2004
-Results of Preliminary Engineering  Studies
- Results of IEE and SIA
- Decision of  the Bridge Location

Progress Report 2
September  2004
-Design criteria and design  standards
-Comparative analysis, preliminary  design and construction plan

Draft Final Report
January  2005
-All Study results

Final Report
March 2005
- All study results, reflecting   comments by the Bangladeshi   Government

Findings of Progress report - 1
Four alternative bridge sites were identified as alternative locations in the following areas:
Site-1 : Paturia-Goalundo
Site-2 : Dohar-Charbhadrasan
Site-3 : Mawa-Janjira
Site-4 : Chandpur-Bhedarganj
-Four alternative locations were examined from the view points of existing transport of the project area, traffic demand forecast, preliminary river study and technical consideration in highway planning, preliminary bridge planning, environmental & social consideration.
-JICA study team considers site-1 and site-3 to be most advantageous for a new fixed crossing and recommends these sites for further study until Interim report.

Findings of the Interim report Basic Policy of the Feasible Study:
Main Function of Padma Bridge
Location of Padma Bridge
Socio-Economic Impacts of Padma Bridge
Associated Road Development Project
Associated Road Development Project
Impact of Macro Balance of the Country
Private Sector Participation
Study Items completed by Progress Report (1)
Collection & Review of Existing Data, Information and Reports related to the Study
Identification of Conceivable Bridge Crossing Sites
Traffic Survey & Traffic Demand Forecast
Preliminary River Study
Preliminary Technical Consideration of Highway & Bridge Planning
Preliminary Environment & Social Condition
Screening of Alternatives
The Study Items completed by Interim Report

Engineering Survey
Preliminary River Facility Design
Preparatory Preliminary Study for Bridge & Highway
IEE
SIA & Resettlement Issue
Economic Effect & Preliminary Feasibility
Findings from Geotechnical Investigation
Difference of Subsoil Conditions between 2 Sites
N-values of SPT at Mawa-Janjira site are higher than those at Paturia-Goalundo site.
Horizontal Ground Reaction
As the coefficients of horizontal ground reaction in the bored holes showed relatively smaller values, such characteristics would have to be considered in the preliminary design of foundations.
Liquefaction
Paturia-Goalundo site has high potential risks of liquefaction when sever earthquake takes place. On the other hand, Mawa - Janjira site has lesser potential risks of the same.
Finding (1 )
N -values of SPT at Mawa-Janjira site are higher than those at Paturia-Goalundo. Main reason of this result might come from the subsoil composition at Paturia - Goalund that consists of relatively singular particle size distribution of fine sand.
Finding (2)
Below maximum scour levels El -40m PWD, N-values of SPT at Mawa-Janjira are higher than those at Paturia-Goalundo.
Finding (3)
From the pressure - meter tests in situ bored holes, the following relation was obtained:
Em=4.52N
Where, N:N-value of SPT
Em: Coefficient of horizontal ground reaction
Ref.: Em+7N.....Design specification of Highway Bridges adopted by JRA.
        Em=7n
 
Finding (4)
As a result of liquefaction analysis, there is no potential risk of liquefaction at Mawa-Janjira site.
On the other hand , there is some protential risks of liquefaction at Paturia-Goalundo site in some depts either before or after scour.
                     

Preparatory Study for Preliminary Design on Bridge
Bridge Length, which was decided by the river study
Paturia-Goalundo= 6.5 km
Mawa-Janjira =6.2 km
Applicable Bridge Types over 100m Span Length
Concrete Bridge: PC Continuous Box, Extradosed, Cable-stayed
Steel Bridge: Steel Continuous Box, Cable-stayed
Foundation Types
Steel Tubular Driven Piles, Cast-in-situ RC Piles, RC Caissons
Cost-Span Relation
Minimum cost would be at approx. 200m span length.
Favorable Bridge Types and Span Length
PC extradosed girder bridge or PC cable-stayed girder bridge would be the most favorable bridge type from the view points of construction cost, maintenance cost, etc. Favorable span lengths will be further examined in a rage of 150m to 250m.
Initial Environmental Examinations (IEE)
Initial Environmental Examination (IEE) was conducted for the two preferred sites to identify the significant environmental impacts
A tailor made project specific 6 step template was developed exclusively for this project and applied for two sites
For the two sites, most of the impacts are found to be similar

There is no significant advantage of one site over other
SIA and Resettlement Issues
SIA was conducted for two alternative sites to ascertain the likely impacts of :
1.
Land acquisition
2.
Local response to the project
3.
Resettlement needs of the potentially affected persons
Survey Results
Estimated amount of land to be acquired is almost same (about 1,250 ha ) in both cases
The number of affected households / structure varies due to differences in population density
Current estimate suggests:-
Mawa - Janjira 70,000 to 80,000
Paturia - Goalundo 40,000 to 45,000
Estimated LA and resettlement cost for M-J site is $39 million, and G-P is $24 million
The Study Team found strong support to the project at both locations
Traffic Study and Economic Analysis (Main Work Items)
1)
Traffic Surveys (Traffic counts, OD Survey)
2)
Establishment of Future Socioeconomic Framework (Population, GDP, GRDP)
3)
Traffic Demand Forecast (Target year 2025)
4)
Confirmation of Economic Feasibility
5)
Economic Impacts of the Padma Bridge
1)
Improvement of Accessibility
2)
Regional Economic Development
3)
Formation of International Road Network
Summary of Comparisons of Two Sites from traffic and Economic Point of View
Evaluation Criteria
Paturia-Goalundo
Mawa-Janjira
Traffic Demand (2025)
19,850 vehicles/day
41,550 vehicles/day
Economic Feasibility
EIRR=9.6%
EIRR=16.9%
Financial Project Cost (Million US$)
1,260
1,074
Improvement of
Accessibility
(Travel time)
Dhaka - Mongla
Dhaka - Benapole

(Beneficiary Population)
Within 3 hours from Dhaka
Within 4 hours from Dhaka

4.5 hours
4.6 hours

2,791,000 (9%)
12,738,000 (42%)
3.6 hours
3.6 hours

10,417,000 (35%)
22,247,000 (74%)
Density of Feeder Roads
No big difference
Formation of International Road Network
Asian Highway A-1. Short distance to Benapole Land Port and Mongla Sea Port
Regional Economic Development
GDP of Southwest region will increase by 18% (1.2% /year) GDP of Southwest region will increase by 35% (2.3% /year)
Growth centers around the bridge sites
No big difference
Indicative Cost
Paturia - Goalundo
Mawa - Janjira
US$ 1,260 million
US$ 1,074 million
Evaluation of P-G & M-J sites
Evaluation Criteria
Paturia - Goalundo
Mawa - Janjira
Economic
Feasibility
EIRR
9.6%
16.9%
B/C Ratio
0.71
1.81
NPV (Mil.Taka)
-9,857
23,140
Regional
Development
Increase of GRDP of Southwest Region
18% up
(1.2% per year)
35% up
(2.3% per year)
Environmental
Impact
Result of IEE
No big difference
Social impact and Resettlement Issues Households requiring relocation
1,842
2,635
Community structures affected
18
60
Total population affected (both direct and indirect)
40,000-45,000
70,000-80,000
Preliminary RAP cost
23.7 mil. US$
38.79 mil. US$
                                         
RIVER TRAINING WORKS (RTW)
Types of RTW: Guide Bund works (GBW),abutment protection works (APW) and bank protection works (BPW).
GBW: To guide river flow to the bridge opening and to protect bridge abutment and approach road from erosion.
APW: To protect bridge abutment from erosion.
BPW: To ensure the functions of the GBW and APW by maintaining present flow conditions around the bridge sites.
ALTERNATIVES SCHEMES
For RTW on Left Bank: Two alternative measures
(1) GBW facing to Padma river, or
(2) APW behind the less erodible riverbank (1km apart considering possible erosion during 100 years in future)
For RTW on Right Bank: GBW facing to Padma River were proposed, since no reliable stable bank for abutment could not be found on the right bank according to the erodibility study.
Alternative Schemes: In combination with the left and right RTW mentioned above, two alternative schemes with same functions were established each for PG-site and MJ-site.
BPW: The BPW were also planned for each site considering respective site conditions.
SELECTION OF OPTIMUM SITE
RTW in combination of GBW(R), APW(L) and BPW are proposed for both PG- and MJ- sites.
Construction Cost: According to the preliminary cost estimate, MJ-site requires less construction cost than PJ-site.
0ptimum Site: The optimum site will be finally proposed afterward considering economic, social and environmental aspects as well as the engineering aspect.
Steps of Environmental Study
Initial Environmental Assessment for Padma River eco-system particularly for four alternative sites
Initial Environmental Examination (IEE) for two preferred sites (reporting in Interim Report)
Environmental Impact Assessment (EIA) for the selected site
Environmental Management Plan (EMP)
Objectives of IEE
To identify the significant environmental impacts
Prepare Scope of EIA
Prepare a preliminary EMP with cost estimates
Features of the IEE Study
Impact area is considered as 10,000 km2
ROW is considered as 60m and Bridge landing site requirement is assumed as 6 km2
Secondary data was collected on related parameters
Primary data was collected by questionnaire survey, reconnaissance, and discussion with local people.
Assessment Procedure
A tailor project specific 6 step template was developed and applied
Environmental parameters are identified with rational
Numerical weightage values are decided with justification
Project specific mitigation guidelines are prepared
Impact analysis template is used
An impact rating template is employed (screening)
A Leopold graded impact matrix is applied
Impact Assessment
40 parameters used for screening
There are 8 positive impacts
No impacts for 8 parameters
There are 24 negative impacts (befort mitigation)
There are 14 negative impacts after mitigation (however, impact will be reduced much)
Impact Comparison
For two sites, most of the impacts are similar
More erosion/siltation at Paturia site
More water bodies loss at Paturia site
More fisheries loss at Paturia site
More homestead loss at Mawa site
More Income loss at Mawa site
More split of communities at Mawa site
There is no significant advantage of one site over other
Scoping of EIA
(as Identified in IEE)
Erosion and siltation (including regional hydrology and drainage congestion)
Agricultural / vegetation loss (including plant cutting)
Fisheries (including water bodies)
Wildlife
Land acquisition (including split of communities)
Resettlement (including Income loss)
Navigation
Road accident
Air, noise and vibration pollution
Preliminary EMP
A rough cost estimates show that the EMP requirement will be between 2 and 3 million US$ (the EMP cost for the Jamuna Bridge was about 3 million US$)
However the cost requirement variation between the two sites is insignificant
SIA & Resettlement Issues
Objectives of the SIA
SIA was conducted for two alternative sites -
(I) Mawa / janjira and (II) Paturia / Goalundo
Planned and carried out to ascertain the likely impacts of
-Land acquisition
-Local response to the project
-Resettlement needs of the potential APs
Primary objectives were to
-Develop comparative SIA of the two alternatives
-Preliminary Cost estimates
- Develop social/ resettlement criteria for site selection
SIA was not designed for a full scale resettlement study
SIA Methodology
Conducted over two months (Nov / Dec 2003)
Similar ecological and socioeconomic features
Methodology adopted include
-
-
Participatory Rapid Appraisal (PRA)
Focus Group Discussion (FGD)
-
Meetings with local govt. officials/community leaders
-
Sample survey using structured questionnaire
200 heads of households were interviewed
SIA – Survey Results
Impacts of Land Acquisition
Estimated amount of LA is same in both sites
Mawa / janjira 1272 ha
Paturia / Daulatdia 1239 ha
impact on households/ population varies
- M/J 2,635 hhs (13,204 APs)
- P/G 1,842 hhs (8,732 APs)
These numbers limited to affected hhs requiring relocation
Those affected by loss of land are not Included
Jamuna experience - three times higher than those requiring relocation
SIA – Survey Results
Loss of residential /commercial structure
Mawa /Janjira - 2635 units
Paturia / Goalundo - 1842 units
Close to 80% of the units are made of
straw / bamboo, Cl sheet/tile roof - can easily be dismantled and moved
Community structures /facilities will also be affected - (I) M/J - 60, and (ii) P/G - 18
SIA – Observations
Total population affected (directly and indirectly) may run into:
Mawa - 70,000-80,000
Paturia - 40,000-45,000
Impacts surely will be greater than currently understood
More accurate assessment will be possible only after the site is selected and preliminary design available
Awareness and Response to the Project
Local people are fairly aware of the impacts of LA & Resettlement Impacts
Also Informed about donor policies due to the Jamuna and Southwest Road Projects
Association and lobby groups have been established at both crossings for selection of their favored sites
Strong support to the project
- Improved transportation
- Business and new income opportunities
- Control of riverbank erosion
- Opportunities for regional industrial development
Resettlement and Preferred Options
Survey included questions with regard to choices and preferred options
(i) Mawa / Janjira - 75% of those Interviewed prefer
    relocation on their own (self -relocation)
(ii) Paturia / Goalundo - 96% indicated their preferences for self-relocation
     Over all, there will be limited demand for resettlement site development
Cost estimate - too early for an accurate cost estimate: M-j $39 million; P-G $24 million
Review and analysis of the Findings
SIA data should be treated as indicative of the potential impacts
The data is generally in line with the pre-feasibility study
A more extensive survey to be carried out for the selected site
The detailed information would be crucial for preparing the RAP
Criteria for Final Site Selection
Preliminary results shows greater impacts In Mawa-Janjira over
Paturia site
Site selection should be more on technical - engineering grounds-future safety of the bridge infrastructure
Major Impacts of the project - Irrespective of sites
Selection of Final site Is critical to set the next agenda preparation of RAP
Task would be to minimize Impact, develop Improved policy for mitigation of adverse Impacts, management and capacity building for resettlement management
Experience of the Jamuna and other donor-funded projects will be used In the planning and Implementation of RAP for Padma
Traffic Demand Forecast of
the Padma Bridge
Traffic Volumes across Padma River
(both ways 2003: From Traffic Survey)
Paturia-Goalundo Mawa-Charjanjat Cross-Padma
Total
Light Vehicle 572 128
700
Bus 687 227
914
Truck 1,217 78
1,295
Total 2,476 433
2,909
Launch Passenger 15,559 9,126
24,685
Present Traffic Movement Pattern
At present, traffic at Mawa is lower than Paturia due to the following reasons:
1) Road condition of NH 8 is now very poor.
2) A narrow approach road to the Mawa ghat.
3) Quality of ferry services at Mawa is lower than Paturia in general.
4) No sufficient parking space for trucks.
5) Two hour river crossing time at Mawa is significantly longer than 35 minutes of Paturia.
Future Traffic Movement Pattern
Future traffic movement pattern will be drastically changed if the Padma Bridge is constructed at Mawa with following reasons:
1) Improvement of NH 8 (Dhaka - Khulna Road Project by ADB) will be completed by the end of 2004.
2) Direct road link from Dhaka for the largest traffic demands to Khulna and Jcssore.
3) Elimination of two hour crossing time.
Quantification of Benefits
1) Vehicle Operating Cost (VOC) Savings
2) Travel Time Cost (TTC) Savings
3) Freight Value Deterioration Savings
4) Ferry Operation Cost Savings
5) Traffic Accident Savings
6) Air Pollution (C02,NOx) Reduction
7) Benefits from Utility Facilities
8) Land Enhancement Benefits
Preliminary Economic Evaluation
- Evaluation period : 30 years
- Opportunity Cost of Capital : 12 %
Tentative results: 1) EIRR: Paturia = 9.6%
Mawa = 16.9%
Relationship Between GRDP and Travel Time to / from Dhaka
[Model]
Ln (G)=3.0453-0.5482 Ln (T)+Q.4926 Ln (F)
where: (R=0.902)
G=Gross Regional Domestic Product/kM2
T=Time to Dhaka from districts in Southwest region (hours)
F=Density of feeder roads (km/kM2)
Estimated Impact on Economic Growth
in
Southwest Region (Growth of GRDP)
Paturia Mawa
SW region 18% up
(1.2%/year)
35% up
(2.3%/year)
Bangladesh 4% up 7% up
Conclusion
From the result of the engineering studies, the economic feasibility including costs for social and resettlement issues and future effect on GRDP growth in Southwest Region, the best bridge site is concluded at Maws - Janjira .
Findings of Progress report - 2
This report mainly deals with
-Natural condition survey such as topographic survey, geotechnical investigation, river
Morphology & mathematical modeling
-Preliminary design of Padma Bridge, approach roads, toll plaza, service area, minor Bridges, underpass, riverbank protection works public utilities etc.
-Operation & Maintenance plan of Padma Bridge
-Construction plan & procedure of preliminary cost estimate
-Environmental study & social impact & resettlement study
Design Criteria & standards
The preliminary design in the study would be conducted on the basis of Asian Highway (AH) standards and Roads & Highways Department (RHD) standards. RHD standards are similar to AASHTO standards. Standards adopted by Japan Road Association (JRA), BSI and Indian Road Congress (IRC) would be used as supplementary ones.
Parameters related to River Engineering
Water levels:
Design High Water Level( 100 year return period) : DHWL=+7.35m PWD
Standard High Water Level : SHWL=+5.81m PWD
Mean Water Level : MWL=+3.02m PWD
Standard Low Water Level : SLWL=+1.43m PWD
Water Discharge and velocity:
Design Discharge( 100 year return period) : Qd=134,400m3/sec
Design Water velocity( 100 year return period) : Vd=4.6m/sec
Scour Levels:
Adjacent to Riverbank ( 100 year return period)
300m from riverbank
: Zs=-37.56m PWD
In middle of river( 100 year return period) : Zs=-23.63m PWD
Reasons for review on bridge types, span-cost relation of Interim
-
Bridge width was changed from 17.2m in the interim report to 21.5m in this report
-
In the interim report foundation stability was examined based on the ship collision force 23.3 MN, which is slightly refined 23.7 MN in this report.
-
In the interim report current market prices in Japan were used for estimating the indicative cost of steel girder bridge (US$5,000/ton including materials, fabrication, transport, erection). It would have to be re-estimating taking into consideration the possible case of internationally prevailing market prices (US$3,800/ton including materials, fabrication, transport, erection).
Girder Depths and Bridge lengths
Bridge Type Girder Depth at mid span Aprox. Bridge length
PC Box Girder(Span 160m) 4.8m 5,680m
PC Extradosed(Span 180m) 3.3m 5,580m
PC Cable Stayed(Span 200m) 1.8 5,480m
Indicative cost by Bridge type without Railway
Bridge Type Unit cost/m Bridge length Indicative cost
PC Box Girder(Span 160m) US$99,010 5,680m 562 million US$
PC Extradoses(Span 180m) US$91,620 5,580m 511 million US$
PC Cable Stayed(Span 200m) US$109,640 5,480m 601 million US$
Reduced river widths by bridge type
Bridge Type Number of Piers in the river Pier width per each Reduced river width % Reduced river width
PC Box Girder(Span 160m) 34 15.0m 510m 9.6%
PC Extradoses(Span 180m) 31 15.0m 465m 8.8%
PC Cable Stayed(Span 200m) 28 16.20m 454m 8.6%
Present river width in 2004=approx. 5,300m
Total Bridge length
Padma main bridge : 5,400m
Left(North) bank Viaduct : 60m
Right(South) bank Viaduct : 120m
Total tength : 5,580m
Specific bridge type and alternatives for preliminary design
PC extradosed girder Type Bridge has been selected for the main bridge structure of the Padma Bridge from the view points of less construction cost, aesthetics and river aspect. In addition Bangladesh side requested the study team to include alternative options that has cable stayed girder at the center portion of approximately 800m in length. As a result the following five alternatives will be examined in the preliminary design of the study:
Alternative-1(Base case)
:
PC extradosed girder bridge without railway provision
Alternative-2
:
PC extradosed girder bridge with cable stayed girder at bridge center portion without railway provision
Alternative-3
:
PC extradosed girder bridge with railway provision
Alternative-4
:
PC extradosed girder bridge with cable stayed girder at bridge center portion with railway provision
Alternative-5
:
PC extradosed girder bridge with minimum investment case
Approach & service Roads
-12,163 m long approach roads on the both river banks (213 m at left & 11,950 m at right banks)
- 6 m width service road on both sides along the approach road & 2m lower than that of the approach road
-No of minor bridges on approach roads-6nos (total length=1000m)
-No of culverts (for underpasses for crossing RHD/LGED road) on approach roads-13nos
 Source: www.munshigonj.com

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