SEISMIC RESISTANCE OF ELASTOMERIC BEARING IN BRIDGES

Abstract

The main emphasis of this dissertation is to evaluate the resistance offered by elastomeric bearings in bridges to seismic excitations. Literature has been reviewed from the various journal papers and proceedings of world conference on earthquake engineering in order to understand the behaviour of elastomeric bearings. The elastomeric bearings used in the analyses models have been designed according to the Method B of AASHTO Bridge Design Specifications, 2005. A bridge has to be analyzed in the best and accurate manner for an adequate earthquake resistant design. It is widely accepted that non linear time history analysis is the most precise way to predict the response of structures subjected to strong ground motions. Hence, in order to simulate the response of the bridge and to accommodate the non linear effects, non linear time history analysis has been done. A Finite Element model has been made in SAP2000 software to utilize current techniques for obtaining reasonable nonlinear results. The material nonlinearities have been considered and piers have been modelled as fibre hinge. The geometric non linearity of reinforced concrete piers has been considered by P-A effect. Discrete zero length spring elements are used to model the bearings. Various parameters of the bridge, before and after the use of elastomeric bearings, have been studied and compared.