行波激励下考虑结构碰撞的非规则桥梁抗震性能研究
Seismic Performance of Irregular Bridges Considering Structural Pounding under Traveling Wave Excitation

基于动力学基本原理，建立非规则桥梁的多自由度动力简化模型，根据拉格朗日方程推导简化模型的动力方程，结合龙格-库塔方法，采用自编程序研究行波激励下非规则桥梁综合考虑支座摩擦滑移、结构碰撞等非线性因素作用时的抗震性能。结果表明，行波效应和碰撞效应的共同作用可使矮墩的弯矩需求增大；行波激励可使板式橡胶支座位移增大，地震波最后到达的桥墩其上方支座位移峰值增加最为明显；相比高墩，地震作用下矮墩上部的板式橡胶支座易发生滑动。因此非规则桥梁进行防碰撞设计时应考虑行波激励及支座摩擦，找出相邻结构的最大碰撞力，以指导设计。
Based on the basic principles of dynamics, a simplified dynamic mechanical model with multiple degrees of freedom was established for an irregular bridge. The dynamic equation of the model was derived according to Lagrange's equations. Combined with Runge-Kutta method, the seismic behavior of irregular bridges under traveling wave excitation were studied using a self-compiled program, while considering the influence of some nonlinear factors, i.e., the bearings friction sliding and structural pounding. The results show that the combined action of traveling wave effect and pounding effect can increase the bending moment of short piers. The traveling wave excitation can increase the rubber bearing displacement, and the increase in peak displacement of the bearing above the last pier the seismic wave reaches is most obvious. Under the action of earthquake, the laminated rubber bearing above short piers is prone to slide; therefore, in anti-collision designs of irregular bridges, the traveling wave excitation and bearings friction sliding should be considered to find out the maximum pounding force of adjacent structures, in order to guide the design of irregular bridges.