考虑摩擦滑移的板式橡胶支座桥梁位移设计方法

Displacement-based design method for bridges with laminated rubber bearing considering fiction slipping

通过5个板式橡胶支座的摩擦滑移拟静力试验,研究板式橡胶支座摩擦滑移后等效阻尼比的变化,并给出等效阻尼比的拟合公式,进一步给出考虑摩擦滑移的板式橡胶支座桥梁的位移设计方法,并对一双自由度简化桥梁模型进行时程分析验证。结果表明,考虑摩擦滑移的板式橡胶支座等效阻尼比与实际情况符合较好,可应用于直接基于位移的抗震设计中;建议的位移设计方法假定上部结构位移,利用体系等效阻尼比通过迭代收敛得出桥梁替代结构系统的最大位移,作为非线性结构的最大位移。基于位移的设计方法简单有效而且满足工程设计精度要求,可用于考虑摩擦滑移的板式橡胶支座桥梁的抗震设计。

Through five laminated rubber bearing friction slipping of quasi static test, the equivalent damping ratio after friction slipping was studied, and the fitting formula of equivalent damping ratio was presented, the displacement-based design method for bridges with laminated rubber bearing was also given, and time history analysis of a double degrees of freedom simplified bridge model have been carried out to verify. Results showed that, the equivalent damping ratio of laminated rubber bearing considering the friction slipping coincided well with the actual situation which can be used in the direct displacement-based seismic design; the suggested displacement design method by assuming that the upper structure system of displacement and equivalent damping ratio of bridge through iterative convergence which result the maximal displacement of nonlinear structure. The displacement-based seismic design method is simple and effective which can meet the requirements of engineering design precision and can be used to seismic design of bridge with laminated rubber bearing considering friction and sliding.