汶川地震中远场深覆盖土层动力反应分析

对上海佘山地震台在汶川地震中测得的基岩波地震记录进行频谱特性分析,然后以同济大学教学科研综合楼场地土层为研究对象,应用水平成层土层地震反应的一维有限元方法,分析该深覆盖场地在这一实测地震记录作用下的动力反应,并将其与同济大学强震监测台在汶川地震中获得的地表波记录进行对比。结果表明：汶川地震的远场地震动记录中,基岩波的长周期卓越性比地表波更为明显;而在土层剪应变为10-6~10-4的小变形阶段,《上海市地震动参数区划》中给出的各类土壤的阻尼比建议值明显偏小。最后,对阻尼比的修正进行了一些探讨。

Dynamic Response Analysis of Far-Field Soil Layer with Deep Deposit during Wenchuan Earthquake

The characteristics of frequency spectrum of seismic acceleration records during Wenchuan Earthquake obtained by the Sheshan seismic station in Shanghai were analyzed.Then,the seismic ground responses of the Teaching and Research Building site in Tongji University were computed with the 1-D finite element method for horizontal layer.Furthermore,the simulated results were compared with the measured data recorded by the strong earthquake monitoring station in Tongji University during Wenchuan Earthquake.The results show,in the far-field ground motions of Wenchuan Earthquake,long period components of the bedrock waves are even more remarkable than the ground waves.Besides,the suggested values of soil damping ratio in Shanghai Seismic Ground Motion parameter zonation are relatively small.Finally,authors discussed the correction of damping ratio.