TYLin provided comprehensive design services for the Jamuna Multipurpose Bridge in Sirajganj, Bangladesh.
The Jamuna River is one of Bangladesh’s three largest rivers and highly susceptible to channel migration and avulsion. The bridge connects Bhuapur on the east bank to Sirajganj on the west bank and provides residents with an alternative to unreliable ferry service.
Working with Hyundai Engineering and Construction on the design-build project, TYLin designed the 4.7-kilometer-long bridge, which provides the country’s first hard link across the Jamuna River. The multipurpose bridge carries a railway line (Indian Railway standard meter gauge), four lanes of vehicle traffic, a high-voltage electrical interconnector, telecommunications lines, and a gas pipeline.
The superstructure is a haunched, prestressed concrete segmental box-girder. The precast segments were erected by balanced cantilever using a 210-meter steel truss gantry. Subdivided into seven modules, each module is approximately 700 meters long and separated from adjacent modules by expansion joints located at the quarter span point. A typical module consists of seven spans, each 100 meters long.
The substructure has large-diameter steel piles, with diameters of 3.15 meters and 2.5-meters. To ensure foundation stability from heavy scour conditions, piles were driven 80 meters deep.
The Jamuna Multipurpose Bridge is in an active seismic zone. Energy dissipation devices and shock transmission units connect the piers to the superstructure and limit loads on the foundations. These devices allow low-velocity thermal, creep, and shrinkage movements of the box girder, but lock and engage the isolators for high-velocity seismic, wind, and braking forces movements.
- TYLin’s services included providing the winning pre-bid design and final design, plans, and quantities.
- TYLin developed an alternative design to reduce the group of substructure piles to two or three, providing an arrangement that optimally resists vertical, longitudinal, and transverse loads while significantly saving on construction costs.
- The box girder is 18.9 meters wide, 6.5 meters deep at the piers, and 3.25 meters deep at mid-span.
- The webs are inclined for aesthetic reasons while the haunched soffit varies according to a parabolic profile.
- The bridge design included pier protection that followed project-specific design criteria and used non-linear dynamic analysis for ship impact.
- The Jamuna Multipurpose Bridge was designed according to British Standards and funded by the World Bank and Asian Bank for Development.