甘肃文县城关镇山体-沉积河谷三维地震动IBEM模拟  

Three-Dimensional Seismic Ground Motion IBEM Simulation of Mountain-Sedimentary River Valley in Chengguan Town,Wen County,Gansu Province

作　　者：刘中宪 卢飞龙[1] 边煜凯 黄振恩 LIU Zhongxian;LU Feilong;BIAN Yukai;HUANG Zhenen(School of Civil Engineering,Tianjin Chengjian University,Tianjin 300384,China;Tianjin Key Laboratory of Soft Soil Characteristics and Engineering Environment,Tianjin 300384,China;School of Civil Engineering,Tianjin University,Tianjin 300354,China;Beijing Glory PKPM Technology Co.,Ltd.,Beijing 100013,China)

机构地区：[1]天津城建大学土木工程学院,天津300384 [2]天津市软土特性与工程环境重点实验室,天津300384 [3]天津大学建筑工程学院,天津300354 [4]北京构力科技有限公司,北京100013

出　　处：《防灾减灾工程学报》2025年第1期1-12,共12页Journal of Disaster Prevention and Mitigation Engineering

基　　金：国家自然科学基金项目(U2139208,52278516)资助。

摘　　要：针对镇域尺度甘肃文县城关镇山体-沉积河谷三维地震动模拟问题,利用边界元法求解无限域弹性波动问题时降维和自动满足弹性波无限远辐射的优势,将间接边界元法拓展到城关镇山间河谷场地三维地震动模拟。根据钻孔资料及高精度地形数据建立三维精细化模型,以平面P波和SV波作为输入,在频域内分析了城关镇山间河谷地形对地震动的放大效应。为提高计算效率,在计算耗时严重的散射波场构造和虚拟荷载求解部分采用OpenMP(Open Multi-Processing)并行编程,并通过与半解析解对比验证了方法的准确性。城关镇的模拟结果表明:(1)沉积河谷和山体均会放大地震动,但沉积河谷的放大效应更为明显,在P波入射下,沉积河谷和山体观测点的位移放大系数(地震动位移与入射波位移幅值的比值)最大值分别为19.64和3.66,SV波入射下则为14.13和3.48;(2)两侧山体对地震波的反射会加剧山间河谷的边缘效应,河谷边缘的地震动放大系数最大可达19.64;(3)沉积河谷地震动的空间分布随频率变化明显,随着频率的升高,强震区从河谷中心逐渐往边缘转变。研究可为此类场地的地震区划和抗震设防提供一定参考。This study aims to address the issue of the three-dimensional seismic motion simulation for the mountain-sedimentary river valley in Chengguan Town,Wen County,Gansu Province,at the town scale.By leveraging the advantages of boundary element method in reducing dimensionality and automatically satisfying far-field radiation condition for elastic waves when solving elastic wave propagation problems in an infinite domain,the indirect boundary element method(IBEM)was extended to simulate the three-dimensional seismic ground motion in the mountainous and river valley sites of Chengguan Town.Based on the drilling data and high-precision terrain data,a three-dimensional re-fined model was established.Plane P waves and SV waves were used as inputs to analyze the amplifi-cation effect of the mountain river valley terrain in Chengguan Town on the seismic motion in the fre-quency domain.In order to improve calculation efficiency,OpenMP(Open Multi-Processing)parallel programming was used in the time-consuming processes of constructing the scattered wavefield and solving virtual loads.The accuracy of the method was verified by comparison with the semi-analytical solutions.The simulation results of Chengguan Town showed that:(1)both the sedimentary river val-leys and the mountains amplified seismic motion,but the amplification effect in the sedimentary river valleys was more pronounced.Under P wave incidence,the maximum displacement amplification co-efficients(the ratio of seismic motion displacement to incident wave displacement amplitude)at obser-vation points in the sedimentary river valleys and the mountains were 19.64 and 3.66,respectively,while under SV wave incidence,they were 14.13 and 3.48,respectively.(2)The reflection of the seis-mic waves by the mountains on both sides would aggravate the edge effect of the mountain river val-ley,with the maximum seismic motion amplification coefficient at the edge of the river valley reaching 19.64.(3)The spatial distribution of seismic motion in the sedimentary river valleys varie

关 键 词：间接边界元方法 山间河谷地形 放大效应 OpenMP并行 

分 类 号：TU443[建筑科学—岩土工程]