SH波入射下圆弧状沉积盆地地震反应瞬态解析解计算  

Analytical Solution to Transient Response of Arc-shaped Basin Incident by SH Wave

作　　者：任朋 陈三红 张郁山 Ren Peng;Chen Sanhong;Zhang Yushan(Institute of Geophysics,China Earthquake Administration,Beijing 100081,China;China Earthquake Disaster Prevention Center,Beijing 100029,China)

机构地区：[1]中国地震局地球物理研究所,北京100081 [2]中国地震灾害防御中心,北京100029

出　　处：《震灾防御技术》2021年第2期352-361,共10页Technology for Earthquake Disaster Prevention

基　　金：国家重点研发计划子专题:基于人工智能方法的地震动场构建技术研究(2019YFC1509402-01A);地震科技星火计划项目:SV波斜入射下成层场地的时域非线性地震反应分析研究(XH21049Y)。

摘　　要：地震波散射问题的解析解是研究局部场地、地形、盆地等不规则地层结构对地震动参数放大效应影响的重要理论工具。现有解析解大部分在频域内给出,无法直接用于研究不规则地层结构对地震动峰值、反应谱等参数的放大效应。本文基于平面SH波入射下圆弧状沉积盆地动力响应宽频带稳态解析解,通过Fourier变换,获取瞬态响应解析解。基于此,研究El Centro波入射下,沉积盆地对地震动峰值加速度、峰值速度、峰值位移及不同周期反应谱的放大效应。研究结果表明,盆地宽度和深度、沉积介质波速、入射波角度等对盆地放大效应具有显著影响,地震动反应谱谱比最大值超过2.0,且宽度达10 km的较大型盆地对长周期地震动参数具有显著放大效应,对于位于该类盆地的超高层建筑、大型储液罐、大跨度桥梁等长周期结构,应充分考虑盆地对抗震设防参数的影响。Analytical solution to scattering problem of seismic waves is an important tool to study amplification effects induced by irregular surficial earth structures,such as local site,topography,and basin,on ground motion.However,most analytical solutions are presented in frequency domain,and cannot be applied directly to probe the amplification effects of such irregularities on the peaks and response spectra of ground motion.In this paper,based on the stationary broad-band analytical solution for the dynamic response of arcshaped basin incident by SH wave,presented in this paper is the transient analytical solution for the out-plane dynamic response of arcshaped basin is derived..From the transient solutions,studied are the amplification effects of alluvial basin on peak ground acceleration,velocity,displacement,and spectral accelerations at different natural periods are studied.The results reveal that the width,depth,and shear velocity of alluvium significantly influence the amplification effects of basin on ground motion,and the maximum value of spectral ratio of ground-motion response spectrum exceeds 2.0.Furthermore,as to large basin with the width to 10 km,it imposes significant influence on long-period ground motion.Therefore,the aseismic design of long-period structures located in large basins,such as high-rise building,large-scale fluid reservoir,and long-span bridge,should take into account of the effects of basin on the design ground motion parameters.

关 键 词：平面SH波 盆地 解析解 反应谱 长周期 

分 类 号：P315.9[天文地球—地震学]