Performance of Integral Bridge by Addition of Cross Girders

Abstract

The bridges without expansion joints are Integral Abutment bridges (IAB’s). In conventional bridges, the bearings are generally corroded due to water seepage through joints which are avoided in IAB’s. However there will be stresses developed due to thermal induced movements of the bridge which is to be taken into account. In this paper, finite element analysis is carried out using STAAD ProV8i on a typical model of IAB. Here various models are prepared by adding different no of cross girders (i.e., 2,3,4,5,7, and 9) to study the trends in bending moment, shear force and deflection in longitudinal girders and deck slab due to dead load, live load in combination of thermal loads. This paper emphasis that the deflection and shear force increases linearly with the increase in the no. of cross girders from 2 to 9. It is found that bending moment in longitudinal girder and deck slab decreases when cross girders are increased from 3 to 4 and then increases by further increase in no. of cross girders. Hence optimum no. of cross girders is observed to be 4.

Keywords: cross girders, deck, integral bridge, thermal stresses