论文部分内容阅读
基于多相孔隙介质弹性理论,给出了非饱和土中不同弹性波的传播方程。根据分界面上的边界条件,建立了各势函数波幅值之间的关系式,讨论了入射剪切波在不同饱和度土层分界面上的反射与透射问题。在无限空间非饱和土体中存在3种压缩波和1种剪切波,因此,当剪切波传播到不同饱和度的非饱和土层分界面上将分别在上、下土层激发产生4种反射波和4种透射波。推导出不同反射波和透射波的振幅比例系数和能量比例系数的理论表达式,并且在此基础上进行数值分析。在数值算例中分别研究了各反射波与透射波的能量比例系数(即能量反射率和能量透射率)受入射频率、入射角度以及上、下土层土体饱和度变化的影响情况。计算结果表明:各能量反射率和能量透射率不仅与入射角和入射频率有关,而且其受上、下土层饱和度变化的影响也同样不能忽视。
Based on the elastic theory of multiphase porous media, the propagation equations of different elastic waves in unsaturated soil are given. According to the boundary conditions on the interface, the relationship between the amplitudes of the potential functions is established, and the reflection and transmission of incident shear waves at the interfaces of different saturation layers are discussed. There are three kinds of compressional waves and one kind of shear wave in the unsaturated soils with infinite space. Therefore, when the shear waves propagate to the interface of unsaturated soil with different saturations, they will generate 4 Kind of reflected wave and 4 kinds of transmitted wave. The theoretical expressions of the amplitude ratio coefficient and the energy ratio coefficient of different reflected waves and transmitted waves are derived, and numerical analysis is carried out on the basis of this. Numerical examples show that the energy ratio coefficients (ie, energy reflectivity and energy transmissivity) of each reflected wave and transmitted wave are affected by the incident frequency, the incident angle and the saturation of soils under the upper and lower soil layers respectively. The calculated results show that the energy reflectivity and energy transmittance are not only related to the incident angle and incident frequency, but also affected by the changes of the saturation of the upper and lower soil layers.