Effects of Factors on the Bi-direction Seismic Response of LRB Isolated Bridge

The seismic response of the LRB isolated bridge under the bi-direction earthquake motions can more accurately simulated considerate bidirectional couple action of the LRB.The selected bridges is a typical three spans continuous deck supported on the LRB.The finite element analytic model which involved the force contribution of the lead rubber bearings is established by make the structure discrete.Bouc-wen model can be used to simulate the nonlinear dynamic behavior of the force-displacement relationship for LRB,both the increment form Newmark and the Runge-Kutta iterative strategy are used to solve the nonlinear governing equation of motion.The seismic response of different bridge parameter and bearings parameter for bridges isolated by lead rubber bearing(LRB) is investigated under two horizontal components of real earthquake ground motions.The effect is investigated by comparing their response under different parameters.The consequences indicate that the pir stiffness and the initial stiffness and the hardened rate and the yield stress of the LRB have large effect on the seismic response of isolated bridge.when we do a earthquake-resistance design,the parameter optimum design must be completed so that the best value can be selected and the seismic response of the isolated bridge is the minimum.