FULL SCALE FIELD TESTING FOR PERFORMANCE EVALUATION AND RETROFITTING OF OPEN WEB GIRDER TYPE ROAD CUM RAILWAY BRIDGE

V. Srinivas, Saptarshi Sasmal , Nawal Kishor Banjara, A. Kanchana Devi , B.S. Sindu , K. Ramanjaneyulu

Abstract: Field testing and evaluating the structural performance of bridges is becoming essential as most of the bridges that are serving are becoming old and deteriorating because of environmental effects, increase in vehicular loading, poor maintenance etc. The present paper discusses the full scale field testing carried out on a rail cum road bridge of open web girder type of truss bridge configuration. As the bridge experiences damages to some of the members, it became necessary to investigate and assess the performance of the bridge through field tests and analytical studies. Instrumentation and field testing of the bridge has been carried out to measure the structural and vibration responses of damaged and undamaged portals of the bridge span under moving vehicular and train loading. Numerical modeling at both global and local level is carried out to simulate the responses obtained from the field testing. It is found that, the cross girders of the portal at intermediate expansion joint locations are subjected to excessive torsion due to improper seating of the stringer beams at the edge of the cross girder flange. By assessing the requirement and envisaging the practical suitability, a suitable rehabilitation scheme has been proposed.

Keywords: Open web girder rail cum road bridge; full-scale field testing; vibration monitoring; damage assessment; retrofitting

DOI: https://doi.org/10.15623/ijret.2015.0425070