Rayleigh波在浅圆凹陷地形附近的散射:高频解答  

Scattering of Rayleigh waves by a shallow circular canyon:high-frequency solution

作　　者：梁建文[1] 李方杰[1] 顾晓鲁[1] 

机构地区：[1]天津大学土木工程系,天津300072

出　　处：《地震工程与工程振动》2005年第5期24-29,共6页Earthquake Engineering and Engineering Dynamics

基　　金：国家自然科学基金项目(50378063);教育部优秀青年教师计划项目

摘　　要：利用波函数展开法给出了Rayle igh波在浅圆凹陷地形附近散射的一个高频解析解,并分析了入射频率、凹陷地形宽度和深度等因素对波散射的影响。数值结果表明,由于Rayle igh波幅值随深度而衰减,凹陷地形表面位移幅值整体上较小,且随着凹陷地形深度的增加而减小;由于Rayle igh波幅值还随频率而衰减,随着入射频率的升高,凹陷地形表面位移幅值逐渐减小;由于凹陷地形的屏障作用,在入射波的近端,地表位移分布变得相对复杂,地表位移峰值出现在左角点附近,而在入射波远端,地表位移分布相对简单,地表位移峰值出现在距凹陷地形较远的地方。A high-frequency analytical solution for scattering of Rayleigh waves by a shallow circular canyon was derived using wave function expansion method, and the solution was utilized to analyze the effects of incident frequency, width of the canyon, and depth of the canyon, etc. on the wave scattering. Numerical results show that, because the amplitude of Rayleigh wave decreases with the depth of the canyon, the displacement amplitude in the canyon is relatively small, and decreases with the depth of the canyon; because the amplitude of Rayleigh wave decreases also with its frequency, the displacement amplitude in the canyon gradually decreases with the increase of the frequency; because of the effect of barrier of the canyon, the displacement amplitude becomes relatively complicated at the left side, and the peak of the displacement amplitude appears near the left rim; and the displacement amplitude becomes relatively simple at the right side, and the peak of the displacement amplitude appears at a relatively far place to the right rim.

关 键 词：凹陷地形 RAYLEIGH波 散射 高频 解析解 

分 类 号：P315.3[天文地球—地震学]