A numerical solution for seismic response prediction of bridge piers with high damping rubber bearings

Abstract

The motion equation of a one-degree-of-freedom system when subjected to earthquakes is usually not solved by analytic methods. This problem can only be solved through the time step method, when integrating differential equations. This paper is devoted to presenting a numerical solution for a seismic analysis problem of a highway bridge pier with high damping rubber bearings under earthquakes. Based on time-stepping Newmark’s method, a numerical solution is developed to predict the seismic responses of the piers. The iteration Newton-Raphson method is also applied in the problem for static analysis of this nonlinear system. The ground acceleration in the analysis is the type- II earthquake in JRA 2004 (Japan Road Association). Further-more, high damping rubber bearings are modeled by the two models: the bilinear design model and the rheology model proposed by authors. After that, the stress responses and the displacement responses of the pier are obtained by a program that is implemented in Matlab software. The comparison results obtained from the two models show that the seismic responses of the pier strongly depend on the modeling of the rubber bearings. This is the important note for engineers to design the earthquake resistance of bridges with high damping rubber bearings. The solution is also a useful tool for engineers to predict the seismic responses of bridge piers in the design procedure.