P波垂直入射下盆地内凹陷地形地震动的谱元法模拟  

Spectral element method for seimic motion of concave terrain in a basin under P-wave Vertical incidence

作　　者：丁昕 芮志良 DING Xin;RUI Zhiliang(Key Laboratory of Structural Engineering of Jiangsu Province,Suzhou University of Science and Technology,Suzhou 215011,China)

机构地区：[1]苏州科技大学江苏省结构重点实验室,江苏苏州215011

出　　处：《四川建材》2024年第12期79-82,共4页Sichuan Building Materials

摘　　要：给出一种谱元法与多次透射边界(MTF)相结合的三维散射问题波动数值模拟方法。其方法的本质是通过在谱元内节点上实现Lagrange插值与多次透射边界计算点相结合。基于以上方法研究散射问题下考虑P波垂直入射对于盆地耦合凹陷模型的地表地震动反应。重点分析凹陷宽度与其深度的比值κ(定义为“宽深比”)对地震动放大效应的影响研究结果表明:①宽深比的变化能够显著改变凹陷附近区域的地震动峰值的分布情况;②宽深比在较小的情况下对地表的放大作用明显,随着宽深比增加,凹陷底部的峰值放大显著增大;③随着宽深比增大,靠近盆地附近区域受到盆地的边缘效应影响,其峰值放大系数明显增加;④P波垂直入射下有凹陷的地形对于地表的地震动反应比无凹陷情况对于地表的地震动大。A numerical simulation method for three-dimensional scattering problems using spectral element method combined with multiple transmission boundary(MTF)is presented.The essence of the method is to combine Lagrange interpolation on nodes within the spectral element with multiple transmission boundary calculation points.Based on the above methods,the ground motion response of a basin coupled depression model considering the vertical incidence of P-waves under the scattering problem is studied.The ratio of the width of the depression to its depth is emphatically analyzedκ,the research results on the influence of“width depth ratio”on the amplification effect of ground motion indicate that:①the change of width depth ratio can significantly change the distribution of ground motion peaks in the vicinity of the depression;②When the width to depth ratio is small,the amplification effect on the surface is obvious.As the width to depth ratio increases,the peak amplification at the bottom of the depression increases significantly;③As the width-to-depth ratio increases,the peak amplification coefficient of the area near the basin affected by the edge effect of the basin increases significantly;④The ground motion response of terrain with depressions under the vertical incidence of P-waves to the surface is greater than that of terrain without depressions.

关 键 词：谱元法 凹陷地形 地震动响应 盆地 

分 类 号：P315[天文地球—地震学]