Design and Construction Challenges-Extradosed Bridge over River Hatania Doania in West Bengal

Bridge across river Hatania-Doania is a priority project which now connects the island of Bhakkali with the main land Namkhana in South 24 Parganas, in the state of West Bengal at about 100km south of Kolkata. Though Bakkhali and its neighbourhood being a popular tourist attraction, tourists used to avoid the area because of the delay that is caused in crossing the river. To reach Bakkhali, the tourists had to cross Hatania-Doania river by motorboats while vehicles were ferried by the barges. Under emergency, during late night hours, crossing the river was a nightmare. The navigable river serves as a shorter route channel for inland waterway traffic, hence requires a vertical clearance of 10m in 100m central width. Large size barges ply on the route. The project is meant for three lane of traffic and have a main module of 85m+170m+85m extra-dosed bridge deck across main river followed by viaduct portion on either side of the bridge. Bridge Deck is monolithically connected at intermediate pylon location and resting on POT-cum-PTFE bearings at end spans. Deck is laterally supported by 2 plane of stay cables arranged in a semi-fan fashion. The spans are resting on twin-D well foundation at pylon locations.