抗剪栓钉对隔震桥梁地震响应的影响

摘要

目的 研究抗剪栓钉对城市轨道交通隔震桥梁纵向地震响应的影响,分析考虑栓钉的摩擦摆支座组合刚度.方法 以某在建城市轨道交通矮墩连续梁桥为研究对象,基于非线性时程分析方法,对比了不同工况下桥梁结构关键部位的地震响应,并分析了不同栓钉抗力对桥梁地震响应的影响.结果 曲线、制动墩墩底纵向弯矩时程曲线及梁端纵向最大位移有较大影响;当栓钉剪断时,栓钉抗力对制动墩支座纵向最大位移几乎没有影响,制动墩墩顶纵向最大位移、制动墩墩底纵向最大弯矩随着栓钉抗力的增大而增大,抗剪栓钉的极限抗剪能力宜控制在竖向荷载的6％以内.结论 对于城市轨道交通矮墩连续梁桥,进行摩擦摆支座减隔震设计时,要充分考虑抗剪栓钉抗力的影响.%In order to study the effects of shear studs on the seismic responses of isolated bridge of the city light-track traffic viaduct,composite stiffness of the friction pendulum beating with shear studs was introduced.Based on a continuous girder bridge of the city light-track traffic viaduct under constructing with short piers,seismic responses of bridge under different cases were compared by the nonlinear time history analysis method and the effects of shear studs were analyzed.The results showed that the snipping of shear studs had a giant influence on the hysteretic curve of friction pendulum bearing,the time history curve of the longitudinal moment of the fixed pier and the maximum longitudinal beam displacement.After shear studs were snipped,shear resistance of studs had almost no effect on the maximum longitudinal bearing displacement of the pier top,but the maximum longitudinal displacement of the pier top and the longitudinal moment of the fixed pier were lager with the growth of shear resistance.The shear resistance of shear stud should no more than 6 ％ of the vertical loading.Forthe continuous girder bridges of the city light-track traffic viaduct with short piers,shear resistance of studs should be considered fully when seismic isolation design of friction pendulum bearing was used.