BRIDGES FAILURES IN EXTREME FLOOD EVENTS BY TAKING A CASE STUDY

Transportation is an important requirement in people's daily lives. Both urban and rural areas are linked by highways and bridges. Road networks and critical road structures such as bridges, culverts and floodways have vital role before, during and after extreme events to reduce the vulnerability being served. The performance of the bridge is dependent on the strength and durability of its components. Since bridges cannot resist indefinitely all the natural forces and hazards including time-related degradation of materials, these structures have limited service life. The bridges have to maintain in order to have better and longer service life and in order to prevent premature failure. The service life expectancy of a bridge may generally be about 70 years for superstructure and about 100 years for substructure. But many bridges fail before service 20 year life term due to lack of maintenance. This paper presents an analysis of the case study of 2014 floods in Kashmir valley region in India to identify the failure mechanism of the road bridges exposed to flood events. In Jammu and Kashmir state as many as 60 major and minor roads were cut-off and over 30 bridges were damaged due to 2014 floods. Major failure mechanism of the bridges were identified as scouring of the abutments and piers, damage to bridge decks due to urban debris, and in some areas due to continuous striking of the heavy stones with the bridges. Some bridges were closely analyzed and causes of the failure were studied also. The possible retrofit techniques were studied.