基于摩擦摆支座的城市大跨连续梁桥减震性能研究

Study of Vibration Mitigation Property of Urban Long-Span Continuous Girder Bridge with Friction Pendulum Bearings

为研究摩擦摆支座在提高城市大跨连续梁桥抗震性能上的适用性,以位于8度区的(90+170+90)m某城市大跨连续梁桥为研究对象,对该桥摩擦摆支座进行设计,并采用非线性时程反应分析法研究摩擦摆支座的减震效果。结果表明:摩擦摆支座对城市大跨连续梁桥下部结构的纵、横向内力减震效果显著;从自复位能力的角度,摩擦摆支座的摩擦系数取值不宜过大,应根据非线性时程反应分析获得的支座最大位移量验算摩擦摆支座的自复位能力;由于该桥上部结构恒载较大,摩擦摆固定支座的静摩擦力远大于全桥的制动力,因此在不设置剪力键的条件下,也能满足桥梁的正常使用功能。

To study the applicability of friction pendulum bearings in enhancing the seismic performance of urban longspan continuous girder bridge ,a bridge with span arrangement of （90＋170＋90） m in the area of 8 degree seismic intensity is taken as the study background .Designs were undertaken to the friction pendulum bearings of the bridge ,and the nonlinear timehistory response analysis method was used to study the seismic mitigation effect of the friction pendulum bearings .The results of the analysis indicate that friction pendulum bearings exhibit remarkable seismic mitigation effect on the longitudinal and transverse internal force of the substructures of the urban longspan continuous girder bridges .From the perspective of selfreset ability ,the values of friction coefficient of the friction pendulum bearings should not be very great , and the selfreset ability of the friction pendulum bearings should be checked according to the maximum displacement amount of the bearings gained by the nonlinear timehistory response analysis .Because the dead load of the superstructure of the bridge is great ,the static friction force of the fixed friction pendulum bearings is far greater than the braking force of the whole bridge , which is able to satisfy the requirements of the normal operation of the bridge in the context that no shear stud connectors are installed .