摘要
在层剪切波速随层深度递增的规则层状弹性介质中,基阶模态瑞利波在表面波场起主导作用,基阶模态频散曲线计算在表面波测试分析中非常重要。层状弹性介质中各阶模态瑞利波频散曲线计算常采用矩阵方法,由矩阵行列式根得到频散曲线,但行列式需用搜索方法求解。为了避免复杂计算,基于Aki和Richards给出的基阶模态频散曲线计算式,假设瑞利波相速度是层剪切波或瑞利波速与基阶瑞利波位移振型函数积分加权均方根。通过对规则层状介质中基阶瑞利波位移振型及土参数与第1层相同的均匀半无限体瑞利波位移振型比较,可知两者变化规律具有相关性,以层剪切波速度差异为参数对半无限体中瑞利波位移振型修正可估算分层介质中基阶瑞利波振型。分析结果表明,相较于矩阵方法,该方法算法简单,相较于半波法,精度较高。
In regularly layered elastic media where the shear velocity of layer increases with increasing layer depth, the surface wave-fields are dominated by Rayleigh waves of the fundamental mode. Thus, it is very important for calculation of the dispersion curve of the fundamental mode in the surface wave tests. The matrix methods are often used to calculate the dispersion curves of Rayleigh waves in the layered elastic media. The dispersion curves could be obtained from the determinant of the matrix. However, the determinant must be solved using root searching techniques. To avoid the complex algorithm, based on the expression for calculation of the fundamental mode dispersion(Aki & Richards), the phase velocity is assumed to be the root-mean square of the shear wave velocity and/or Rayleigh wave velocity of layer weighted by the integral of the displacement shape functions of the fundamental mode. It can be known that the displacement shape functions of the fundamental mode in regularly layered media are highly correlated to those in the homogenous half space with the properties equal to the first layer. The displacement shape functions in the regularly layered media can be evaluated by calibrating the displacement shape functions in the homogenous half space with the shear wave velocity contrasts between layers. It is shown from the results that the algorithm of the proposed approach is simple compared to the matrix methods, and the accuracy is higher than that of the empirical half wavelength method.
作者
柴华友
柯文汇
陈健
王章琼
黄祥国
CHAI Hua-you;KE Wen-hui;CHEN ELTON J;WANG Zhang-qiong;HUANG Xiang-guo(School of Civil Engineering and Architecture,Wuhan Institute of Technology,Wuhan,Hubei 430073,China;Wuhan Municipal Construction Group Co.,Ltd.,Wuhan,Hubei 430023,China;Department of Civil Engineering,Tsinghua University,Beijing 100084,China;School of Civil Engineering&Mechanics,Huazhong University of Science&Technology,Wuhan,Hubei 430074,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2019年第12期4873-4880,4889,共9页
Rock and Soil Mechanics
基金
国家自然科学基金面上项目（No.41474113）
武汉工程大学人才专项经费资助项目
湖北省建设科技计划项目（2019）~~
关键词
瑞利波
基阶模态
半波法
位移振型函数
频散
Rayleigh wave
fundamental mode
half wavelength method
displacement shape function
dispersion
