铅芯橡胶支座在简支梁桥减隔震中的应用

为研究在高地震烈度区将铅芯橡胶支座应用于简支梁桥的减隔震效果,以水晶大桥为例进行分析.采用ANSYS分别建立隔震状态和非隔震状态的全桥有限元模型,考虑地基桩一土作用效应,取用50年超越概率10％和2％的计算反应谱进行反应谱分析,并取用与反应谱相同超越概率的地震波进行时程分析.分析结果表明:非隔震状态时,该桥在E1和E2地震作用下桥墩的位移和内力均较大,普通板式橡胶支座不能满足强度和变形的要求；采用铅芯橡胶支座隔震后,该桥桥墩的位移和内力得到了有效的减小,取得了良好的隔震效果；采用反应谱法分析隔震桥梁,通过计入隔震构件的等效刚度,能将非线性问题简化为线弹性问题处理.

Application of Lead Core Rubber Bearings to Seismic Mitigation and Isolation of Simply-Supported Girder Bridges

To study the effect of seismic mitigation and isolation of the lead core rubber bearings applied to the simply-supported girder bridges in high intensity seismic region,the Shuijing Bridge was cited as an example and was analyzed.The ANSYS was used to respectively set up the finite element models for the whole bridge of the bridge in both the seismic isolation state and non-seismic isolation state and in consideration of the ground base pile～soil interaction of the bridge,the response spectrum analysis was made,using the calculated response spectra of 10% and 2% of the 50-year exceeding probability and the time-history analysis was made as well,using the seismic waves of the exceeding probability that are identical to the response spectra.The results of the analysis indicate that in the non-seismic isolation state,the displacement and internal forces of the piers of the bridge under the action of Earthquake E1 and E2 are great.The common plate rubber bearings can not cater for the need of strength and deformation of the piers while with the applying of the lead core rubber bearings,the displacement and internal forces of the piers are effectively reduced and sound effect of the seismic isolation has been achieved.In the analysis of the seismically-mitigated and isolated bridge,using the response spectrum analysis method and by way of considering the equivalent rigidity of the seismic isolation components in the analysis,the nonlinear issue can be simplified as the linear-elastic issue for handling.