摘要
沉积盆地对于地震动具有显著的放大效应。基于二维盆地计算模型,考虑震源位于模型内部的情况,利用高精度谱元法,通过对比不同模型下观测点的速度时程、峰值及放大系数,探究了盆地倾角、盆地深度对盆地地震动响应的影响。结果显示考虑内部震源输入时的盆地响应特征与平面波入射的结果存在差异:(1)沉积盆地倾角改变会显著影响盆地边缘的地震动响应,但无一致规律,而盆地中心区域的地震动受此影响较小;(2)沉积盆地深度增加时,盆地中心区域的地震动峰值及放大系数减小,而盆地边缘区域的地震动放大效应逐渐增强。同时,盆地边缘产生的次生面波的幅值逐渐增大。
Sedimentary basins can significantly amplify the basin internal ground motions. In this paper, based on the two-dimensional basin model and considering the internal source incidence case, the influence of basin dip angle and sediment depth on seismic response is investigated by using the high-accuracy spectral element method, and by comparing the seismograms, peak ground velocities and amplification factors of the observation points at the surface of different testing models. The results show that obvious difference existing between the basin response characteristic in ease of internal source and the result of the plane wave incidence： （1）The change of basin dip angle will significantly affect the seismic response of the basin edge regions, but no uniform trend can be found. In addition, ground motions of basin central regions are not sensitive to this parameter. （2） With the increasing of the basin sediment depth, the seismic amplifications of the basin central area greatly decrease, and the seismic response of the basin margin regions is strengthened. Meanwhile, the amplitudes of the basin induced surface waves also increases gradually.
作者
丁海平
吕思东
于彦彦
DING Haiping;LV Sidong;YU Yanyan(Key Laboratory of Structure Engineering of Jiangsu Province,SUST,Suzhou 215011,China)
出处
《苏州科技大学学报（工程技术版）》
CAS
2018年第3期1-6,共6页
Journal of Suzhou University of Science and Technology（Engineering and Technology Edition）
基金
国家自然科学基金项目(51378479
51808371)
江苏省高等学校自然科学研究面上项目(18KJB560017)
关键词
沉积盆地
内源
谱元法
盆地倾角
盆地深度
sedimentary basin
internal source
spectral element method
basin dip angle
basin sediment depth
