This project is a national initiative implemented through the cooperation of Japan and Bangladesh, based on the “Dhaka Urban Transport Master Plan” formulated by JICA, which aims to develop a Mass Rapid Transit (MRT) system in stages. MRT Line 6, extending approximately 20 kilometers in a north-south direction from northern Dhaka to the National Parliament House and the central business district, is designated as the highest-priority corridor. In Contract Package CP-05, executed by the TEKKEN-AML-Abe Nikko Joint Venture, we constructed approximately 3.2 kilometers of elevated railway viaduct and three stations between Bijoy Sarani Station and Karwan Bazar Station.

　The critical path of this work section was the erection of the superstructure girders using the span-by-span construction method. The most technically challenging portion was a 45-meter span crossing an existing roadway on a horizontal curve with a radius of 200 meters. Due to the sharp curvature, the launching girder could not be advanced to the next pier using standard methods. To overcome this  limitation, a hinged mechanism was incorporated into the truss system, enabling it to be articulated by up to 12 degrees during launching. This innovation ensured construction safety while reducing the overall construction schedule. At Karwan Bazar Station, the station building works and viaduct works had to be carried out concurrently. A temporary staging area was established on the first floor of the station structure, where segments were lifted by a crawler crane and then hoisted by the launching girder for erection. This construction sequence enabled both schedule optimization and minimizing traffic disruption in a highly congested urban area.

　The successful resolution of such technical challenges was made possible through continuous coordination among the Employer, Engineer, and Contractor, supported by the cooperation of JICA, the Embassy of Japan, and all other stakeholders involved.