【Introduction of the project】
In the Republic of Madagascar, transport capacity is being improved through the Antananarivo-Toamasina Economic Corridor Bridge Development Project, which is leading to the revitalization of logistics both within the country and in neighboring countries, with cooperation from the Government of Japan and other partners. This project targeted two bridges on National Road 2 located within the aforementioned section: Mangoro Bridge (approximately 17 km west of Moramanga) and Antsapanzana Bridge (approximately 6 km west of Moramanga). These bridges had previously acted as traffic bottlenecks due to their single-lane alternating traffic sections. The
project was planned to enhance logistical performance and improve the safety and security of bridge users by constructing new two-lane bridges.
The existing Mangoro Bridge, which had been in service for at least 50 years, was a structure shared by both road and rail. The new design preserved the railway bridge and involved constructing a three-span continuous Prestressed Concrete (PC) box girder bridge on the upstream side, supported by a spread foundation. The construction method adopted for the superstructure was the cantilever method using form travelers. Antsapanzana Bridge, on the other hand, was designed as a single-span PC hollow-core slab girder bridge. Its pile foundation, designed as cast-in-place piles, was constructed using the all-casing method. As both construction methods had limited application history in the country, the project attracted a large number of visitors, including the client, fellow engineers, students, and local residents, underscoring the high level of interest in bridge construction technology.
During the execution phase, the project had to overcome various significant challenges, such as the commencement of work during the COVID-19 pandemic, the impact of flooding caused by cyclones, and transport disruptions resulting from the conflict in Ukraine. Despite these difficulties, the project was successfully completed in 2024 through the collaboration of all involved parties.