Padma Multipurpose Bridge Project

DurabilitySafetyConcrete Extradosed Bridge Steel Truss Bridgeconvenient to transfer traffic to the opposite carriagewayacting as a contra-flow. This can be achieved foradjacent carriageways by incorporating breaks in themedian which can be opened or closed as required. Ifthe railway is between the carriageways this is no longeran option.If for some reason (fire, train breakdown etc.) a trainneeds to be evacuated, passengers should be kept awayfrom the live highway. On a single level structure it willbe difficult to ensure this is the case.Durability of the concrete works is achieved through thedesign of the concrete mix design, sufficient allowancefor clear cover to the reinforcement and controls onplacement and compaction of the concrete.Durability of the extradosed cables is provided byspecification of sufficient levels of protection of the cableelements.Not safe. Easy access to gas pipeline and henceopportunities for terrorism and sabotagenot be available.To aid evacuating passengers, and to enable maintenanceworkers to move along the bridge, walkways each side of the trackand upper deck will be provided. The walkway will be one meterwide and 1.22 meters above the rail level so it is near level with apassenger car floor. The walkway is also located beyond the fixedstructure gaugeDurability of the steelwork is provided by the specification of aproven, robust protective coating system.While it is true that the paint system of the bridge will need to bemaintained, by carefully choosing the coating system (such aszinc rich parameters), this cost can be minimized. From previousresearch and case studies, the use of zinc coatings can increaseperiods between reapplication to 20 years or greaterSafe as it provides restricted access to gas pipeline.CostConstruction cost estimateO&M cost estimateTotal cost of BridgeCost of Viaducts (both rail androad)US $ 953.9 MUS $ 52.4 M (for maintenance requirements)US $ 1.007.3 MUS $ 193 MUS $ 790.9 MUS $ 59.8 MUS $ 850.7 MUS $ 176 MSocial & ResettlementEmployment More labor intensive Less labor useEnvironmentImpacts on River ecologyMoreDue to the longer construction period major impacts willLessFewer disturbances on the River ecology due to the shorter6-15