斜入射地震波在土体中产生的动应力路径及试验模拟  

Seismic stress path induced by obliquely incident waves and its simulation

作　　者：黄博[1,2] 凌道盛[1,2] 丁浩[1,2] 汪清静[1,2] 袁江宏[1,2] 

机构地区：[1]浙江大学岩土工程研究所,浙江杭州310058 [2]浙江大学软弱土与环境土工教育部重点实验室,浙江杭州310058

出　　处：《岩土工程学报》2013年第2期276-283,共8页Chinese Journal of Geotechnical Engineering

基　　金：地震行业科研专项项目(200808022);国家自然科学基金项目(50708095;51178427);国家重点基础研究发展计划项目(2007CB714203)

摘　　要：针对地震波传播时并非垂直的情况,基于半无限弹性空间地震波的传播理论,对地震波进行简化,考虑斜入射时地震波在自由界面处的反射,推导了地震波斜入射时地震应力的计算公式,并通过计算实例分析了不同入射角度下,P波、SV波单独斜入射时在土单元体中所产生的地震应力以及所形成的应力路径。结果表明:当P波、SV波单独斜入射时,土单元体在平面应力差–剪应力平面上形成的应力路径均为一个倾斜椭圆,斜椭圆的倾角和长短轴之比随地震波入射角度、频率、波速等影响因素在一定范围内变化。文中还针对如何实现倾斜椭圆形应力路径的室内试验模拟进行了初步探讨分析。Considering the fact that seismic waves do not vertically propagate near the surface especially under near field earthquakes, a simplified model is deduced to analyze the seismic response under obliquely incident waves based on the propagation theory in elastic half-space. It is considered the incident waves are harmonic, reflected at the free surface. The seismic stresses at arbitrary depth and the corresponding dynamic stress paths are estimated to investigate the effect of the incident angle of input waves. Under the single incidence of P-waves or SV-waves, it is shown that in the coordinate plane （ （σy - σx ）/2, τ xy ）, the stress path will be a fluctuating ellipse, the angular between Xaxis and the long axis of the ellipse, and the ratio of long axis to short axis of the ellipse are related to the incident angle, frequency, wave velocity, etc. Moreover, preliminary discussion is also made on the way to simulate such a dynamic stress path in laboratory tests.

关 键 词：弹性半空间 P波 SV波 斜入射 应力路径 

分 类 号：TU435[建筑科学—岩土工程]