Project: Zuari Bridge, Goa

 

Details: The bridge, with an overall length of 810 meter, comprises 5 "T" arms of varying length, 2 suspended spans and 5 viaduct spans of 36 meter each. The carriageway width on the bridge is 7.5 meter with a 1.5 meter wide cantilever footpath on either side.

 

Challenge: On account of proximity to the saline environment the existing prestressed cables were corroded resulting in loss of stresses. Excessive deflection of the cantilevers combined with vertical cracks in the web near the pier was also observed.

 

Solution: A scheme of external cables was devised to compensate for the loss of prestress, thereby improving the serviceability of the structure. The cables were located on the underside of the deck and over the soffit by deviating them from the web. A load test was performed in association with IIT, Mumbai, which proved the efficacy of the measures taken.