采用摩擦摆支座的高墩弯桥邻梁碰撞响应研究

Study on Collision Response of Adjacent Beams of High-pier Curved Bridge with Friction Pendulum Bearing

为研究高墩连续弯桥在地震作用下邻梁间的碰撞效应,考虑了板式橡胶支座的滑动效应以及摩擦摆支座的减震效应,基于Kelvin单元建立了非线性时程分析模型,分析了桩-土相互作用、邻梁初始间隙以及摩擦摆支座的等效活动半径等因素对结构地震响应的影响。研究结果表明:考虑桩-土相互作用后邻梁曲线外侧的碰撞力约减小3.74%,而其他位置碰撞力则增大8.07%左右;忽略邻梁碰撞效应会低估墩底内力;摩擦摆支座对墩梁相对位移的减小程度约为4.89%;随着邻梁初始间隙的增加,碰撞次数会减小,但碰撞力的变化较为复杂;随着摩擦摆支座等效活动半径的增加,曲线外侧的碰撞力逐渐减小,变化率可达到31.24%,曲线内侧碰撞力的变化率在5.13%以内。

In order to study the collision effect between the adjacent beams of high-pier continuous curved bridge under earthquake,the sliding effect of plate rubber bearing and the damping effect of friction pendulum bearing are considered.Based on Kelvin element,a nonlinear time history analysis model is established to analyze the effects of pile-soil interaction,initial clearance of adjacent beams and equivalent active radius of friction pendulum bearing on the structural seismic response.The results show that after the pile-soil interaction,the impact force on the outside of the adjacent beam curve decreases by about 3.74%,while the impact force at other positions increases by about 8.07%.Ignoring the collision effect of adjacent beams will underestimate the internal force at the pier bottom.The reduction of relative displacement of pier beam by friction pendulum bearing is about 4.89%.With the increase of the initial gap between adjacent beams,the number of collisions will decrease,but the change of collision force is more complex.With the increase of the equivalent active radius of the friction pendulum support,the impact force on the outside of the curve decreases gradually,and the change rate can reach 31.24%,and the change rate of the impact force on the inside of the curve is less than 5.13%.