Desk Report,
The country’s first six-lane Madhumati Bridge
A recently built bridge in Bangladesh is the Madhumoti Bridge, also known as the Kalna Bridge. This 690-meter-long, six-lane bridge is a large infrastructure. This bridge directly connects the capital Dhaka with 10 districts in the southwestern region, including Narail, Khulna, Magura, Satkhira, Chuadanga, Jessore, and Jhenaidah. Its strategic importance as part of the Asian Highway 1 is immense. A reflection of modernity in design and architecture
The country’s first six-lane Madhumati Bridge
This bridge has been built with JICA funding under the Cross Border Road Network Improvement Project of the SEZ. A 150-meter-long steel span has been installed in the middle of the bridge. The span of the Nelson Lows Arch type (curved like a bow) was built in Vietnam. The other spans on both sides of that span are of PC girder (concrete). High-speed vehicles operate in four main lanes and low-speed vehicles in two lanes. The bridge is 690 meters long and 27.10 meters wide. The connecting road on both sides is 4.273 kilometers, with a width of 30.50 meters. The total cost of the bridge is 959.85 crore taka. It is the first 6-lane bridge in the country. It has been built using the Nielsen-Lohse arch design method. This design is very effective and well-known in Japan. The main feature of this design is its steel-made arch superstructure, which gives the bridge a unique and attractive appearance. Engineering Challenges and Solutions
There were various engineering challenges in the construction of the Madhumati Bridge. The course and depth of the Madhumati River posed a major challenge during construction. Although regular pile caps are usually placed 4 meters below, they are constructed 6-8 meters deep in the middle of the river. Due to excessive river erosion, sand swelling occurs in the area of the pile caps, which hinders the construction work. Cofferdams are used to solve this problem. This method helps to keep the work site dry by retaining water and soil. Cement grout was used to stop sand swelling inside the cofferdam. Grout was injected after equalizing the internal and external water levels, which stabilized the soil within five to six days.
Another significant challenge at the construction site was the effect of tides. A temporary barge and walkway were constructed to facilitate workers during high tide, which helped the construction work continue even in adverse conditions. Implementing the complex arch design of the Nielsen-Lohse arch design, the first of its kind in Bangladesh, was a major challenge for the engineers. Proper placement of the steel superstructure, maintaining the correct balance between the arch and the deck, and ensuring the fine coordination of each part was a very complex task.
