地震动空间差异对沥青混凝土心墙土石坝-覆盖层地基系统响应影响研究  

Effects of spatial difference of ground motion on seismic response of asphalt concrete core wall rockfill dam-overburden foundation system

作　　者：李闯 宋志强[1] 王飞[1] 刘云贺[1] 张存慧 LI Chuang;SONG Zhiqiang;WANG Fei;LIU Yunhe;ZHANG Cunhui(State Key Lab of Ecological Water Conservancy in Northwest Arid Area,Xi’an University of Technology,Xi’an 710048,China;Changjiang Survey,Planning,Design and Research Co.,Ltd.,Wuhan 430010,China)

机构地区：[1]西安理工大学省部共建西北旱区生态水利国家重点实验室,西安710048 [2]长江勘测规划设计研究有限责任公司,武汉430010

出　　处：《振动与冲击》2022年第19期37-47,共11页Journal of Vibration and Shock

基　　金：国家自然科学基金重点项目(52039008);国家自然科学基金(51479165,51779208)。

摘　　要：地震动的空间差异性往往对结构-地基系统的响应具有显著影响。从地震动差异形成的物理机制出发,基于二维设计地震动确定入射P波、SV波时程,在波动输入模型基础上引入地震动组合效应构建了空间非一致地震动场,建立了空间差异地震动的波动输入模型。进一步研究了地震动场空间一致输入和非一致输入下沥青混凝土心墙土石坝-覆盖层地基系统的地震响应。结果表明,非一致地震动场输入模型获得的地表自由场控制点位移水平和竖直分量均与设计地震动吻合良好,能够在考虑地震动空间相关性基础上模拟地震波传播的时间滞后、幅值变化和时程形状差异等空间差异特征。与一致输入相比,非一致输入下覆盖层建基面水平向和竖直向加速度分布方差最大增大341%和50%。地震动的空间差异引起心墙竖向应力和剪应力峰值最多增加198%和51.9%。坝顶加速度和永久变形平均值均有所增加,最大结果分别增加25.53%和13.06%。传统的一致波动输入方法可能会低估结构地震动响应,分析沥青混凝土心墙土石坝-覆盖层地基系统的地震响应有必要考虑地震动的空间差异性。Spatial difference of ground motion often has a significant impact on response of structure-foundation system.Here,starting from the physical mechanism of formation of ground motion difference,incident P-wave and SV wave time histories were determined based on two-dimensional design for ground motion.Based on wave input model,spatial non-uniform seismic field was constructed by introducing ground motion combination effect,and the wave input model of spatial difference ground motion was established.The seismic response of asphalt concrete core wall rockfill dam-overburden foundation system under uniform and non-uniform seismic field spatial input was further studied.The results showed that horizontal and vertical components of displacements of control points of ground surface free field obtained using the non-uniform seismic field input model agree well with designed seismic motion values,and can simulate spatial difference characteristics of seismic wave propagation,such as,time-delay,amplitude variation and time history shape difference,etc.considering the spatial correlation of ground motion;compared with the case of uniform input,horizontal and vertical acceleration distribution variances of overburden foundation surface under non-uniform input increase by 341% and 50%,respectively;peak values of vertical stress and shear stress of core wall increase by 198% and 51.9%,respectively due to spatial difference of ground motion;both average values of dam crest acceleration and permanent deformation increase,their maximum results increase by 25.53% and 13.06%,respectively;the traditional uniform wave input method may underestimate structure seismic response,it is necessary to consider spatial difference of ground motion when analyzing seismic response of asphalt concrete core wall rockfill dam-overburden foundation system.

关 键 词：空间差异地震动 地震波组合 非一致输入 沥青混凝土心墙土石坝 地震响应 

分 类 号：TV312[水利工程—水工结构工程]