地震动特性对隔震桥梁地震响应的影响

Effects of Ground Motion Characteristics on the Performance of Isolated Bridges

为分析地震频谱特性及隔震支座参数对隔震结构地震响应的影响,以PGA/PGV(地震动峰值加速度与峰值速度之比)代表频谱特性选取了8条地震波,计算分析了不同地震动作用下隔震桥梁模型的地震反应.计算结果表明:随着PGA/PGV的增大,隔震桥梁地震响应总体上呈下降趋势,但PGA/PGV对结构的影响还受结构自振周期、支座初始刚度的影响,实际设计中应综合考虑.

The effect of isolator bearings and the frequency characteristics of the ground motion on the performance of isolator bridges is analyzed.For this purpose,based on ratios of peak ground acceleration to peak ground velocity（PGA/PGV）,8 earthquake waves of different spectra are selected.According to reactions of isolator bridges to different ground motions,it is found that reactions of bridges generally decrease with increasing of PGA/PGV,but the the results are not totally decided by PGA/PGV,which is also influenced by other parameters such as natural vibration period of bridge and initial stiffness of bearings.