Third Narmada Bridge will be the first extradosed bridge in Gujarat, India
In the district of Bharuch in the federal state of Gujarat, northwestern India, National Highway 8 crosses the Narmada River. The motorway is one of the country's most important connections linking Delhi with the economic centre of Mumbai and other economically important cities.
In order to provide relief from the heavy traffic congestion which often occurs in this area, the Third Narmada Bridge is being built. It will include four lanes and a pedestrian crossing and will be used together with the existing bridge that will remain in service.
New bridge will have the longest spans in India
The new, 1,344 m long and 20.8 m wide bridge consists of two 96 m long side spans and eight 144 m long main spans. The structure will be the first extradosed bridge in the federal state of Gujarat and will have the country's longest spans. Each of the centre spans consists of 38 3.55 m long precast concrete hollow box girder segments. At each of the pylons, there are two stay cable planes consisting of six stays arranged in a fan pattern that support the bridge deck.
216 stay cables with 500 t strand were installed
In total, DSI-BRIDGECON supplied and installed 216 stay cables, each 27.5 to 70 m long, with a strand tonnage of 500 t. The stay cables were anchored at the bridge deck using anchorages and at the pylons using an anchor box system. In this system, the fact that the stay cable anchorages are located outside permits slender pylon shapes because the interior of the pylon does not need to be accessible.
In addition, sensors were installed in order to permit long-term monitoring of the forces acting on the stay cables.