SV波斜入射下河谷地形地震动分布特征分析  

Characteristic analysis of ground motions of a canyon topography under obliquely incident SV waves

作　　者：孙纬宇 汪精河 严松宏[1,3] 欧尔峰[1,2] 梁庆国 SUN Weiyu;WANG Jinghe;YAN Songhong;OU Erfeng;LIANG Qingguo(School of Civil Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China;Key Laboratory of Road&Bridge and Underground Engineering of Gansu Province,Lanzhou Jiaotong University,Lanzhou 730070,China;Engineering Laboratory of Mechanics Application of Railway Transportation of Gansu Province,Lanzhou 730070,China)

机构地区：[1]兰州交通大学土木工程学院,兰州730070 [2]兰州交通大学甘肃省道路桥梁与地下工程重点实验室,兰州730070 [3]甘肃省轨道交通力学应用工程实验室,兰州730070

出　　处：《振动与冲击》2019年第20期237-243,265,共8页Journal of Vibration and Shock

基　　金：国家自然科学基金(41562013;51268030);兰州交通大学青年科学基金项目(2017020);甘肃省道路桥梁与地下工程重点实验室开放基金项目(1200110206-2)

摘　　要：基于黏弹性边界结合等效荷载的输入方法,实现了平面SV波斜入射的地震动输入。研究了SV波入射角度和河谷斜坡坡度对河谷场地地震动放大系数分布特征的影响。结果表明:地震波入射角度和斜坡坡度越大,斜坡坡面以及坡顶平台一定范围内的地震动放大系数越大,坡顶平台的影响宽度也越大;地震波从左侧倾斜入射时,河谷两岸地震动放大系数呈不对称形式分布,且入射角度越大,河谷左岸x分量的地震动放大系数越大,河谷右岸z分量的地震动放大系数越大,不对称现象越明显;以不同角度入射时,坡顶处地震动放大系数和坡顶平台影响区域均随坡度的增大呈线性增大趋势;入射角度与斜坡坡度越大,坡顶处水平加速度反应谱越大,反应谱峰值有向右偏移的趋势。Based on the input method of the visco-elastic artificial boundary combined with the equivalent load,the ground motion input of the obliquely incident SV waves was realized.The effects of the incident angles of the SV waves and the canyon slope angles on the ground motion amplification coefficient distribution characteristics were studied.It shows that:with the incident angle and slope angle increase,the ground motion amplification coefficient of the slope surface and a certain range of slope crest are increased,and the impact width of the slope top is also larger;when the seismic wave is incident at left,the ground motion amplification coefficient distribution is asymmetry on both sides of the canyon,x component of canyon left bank and z component of canyon right are greater with the incident angle,the greater of incident angle,the more obvious of asymmetry;the ground motion amplification coefficient of slope top and impact width of the slope top are increased linearly with the slope angle in different incident angles;the more incident angle and slope angle,the greater of slope top acceleration response spectrum of x component and the peak has a tendency shift to the right.

关 键 词：河谷地形 黏弹性边界 SV波 斜入射 放大系数 

分 类 号：P315.9[天文地球—地震学]