摩擦摆支座参数对隔震桥梁地震响应的影响

Effects of Parameters of Friction Pendulum Bearings on Seismic Responses of Seismically Isolated Bridge

为了研究摩擦摆支座隔震桥梁的地震响应特性,结合某在建城市轨道交通大跨连续梁桥,考虑摩擦摆支座的非线性滞回模型,采用ANSYS有限元软件建立全桥模型,通过非线性时程分析方法,研究了摩擦摆支座的摩擦系数、曲率半径及抗剪栓钉抗力等因素对连续梁桥地震响应的影响。结果表明:在纵向地震动作用下,随着摩擦系数的增大,墩底最大弯矩和墩顶最大位移不断增大;随着曲率半径的增大,主墩墩底弯矩逐渐减小;随着栓钉抗力的增大,制动墩墩底最大纵向弯矩、墩顶最大纵向位移先保持不变后增长明显。因此,建议摩擦摆支座中栓钉的抗力不宜过高。

To study the seismic response characteristics of the bridge seismically isolated by the friction pendulum bearings,the model for the whole bridge of a continuous beam bridge was established,using the finite element software ANSYS,with reference to a long span urban rail transit continuous beam bridge that was being built and also in regard of the nonlinear hysteresis model for the friction pendulum bearings.By way of the nonlinear time-history analysis,the effects of several factors like the friction coefficients,curvature radii of the friction pendulum bearings and the resistance of the shear studs of the bearings on the seismic responses of the bridge were investigated.The results of the investigation demonstrate that under the longitudinal ground motion,with the increase of the friction coefficients,the maximum bending moment of the pier footings and the maximum displacement of the pier tops of the bridge increases incessantly,with the increase of the curvature radii,the bending moment of the main pier footings decreases gradually and with the increase of the resistance of the shear studs,the maximum longitudinal bending moment of the braking pier footing and the maximum longitudinal displacement of the pier top remains unchanged first and then increases notably.Therefore,it is suggested that the resistance of the shear studs should preferably not be set too high.