弹性波在准饱和土和弹性土界面的反射与透射

考虑土颗粒和孔隙流体的压缩性,根据准饱和土体的变形连续条件和平衡条件,推导了P1波(快压缩波)、P2波(慢压缩波)和S波的计算公式．根据Snell定理,研究了平面P1波从准饱和土体入射到弹性土层时在界面上的反射和透射,并绘制了反射系数、透射系数和界面应力、位移随入射角的变化曲线,结果表明:饱和度是影响界面效应的一个重要因素,当饱和度低于99％时,反射和透射系数以及应力和位移基本相等,变化不大,但当饱和度为100％时,虽然饱和度比99％提高了1％,但反射和透射系数以及应力和位移值比饱和度为99％时明显降低．

REFLECTION AND TRANSMISSION OF ELASTIC WAVE AT THE INTERFACE OF NEARLY SATURATED SOIL AND ELASTIC SOIL

The calculation formulas for the wave velocities of P1 wave (fast compressional wave), P2 wave (slow compressional wave) and S wave were derived from continuity of deformation and equilibrium conditions and considering the compression of soil grains and pore fluid. According to Snell theorem, the reflection and transmission of incident plane P1 wave from the nearly saturated soil at the interface of elastic soil was studied, and curves of reflection coefficients, transmission coefficients, stresses and displacements of the interface were numerically obtained. The results show that the saturated degree is an important factor that affects the reflection and transmission. The reflection coefficients, transmission coefficients, stresses and displacements change little when the saturated degree increases by 4% from 95% to 99%, but they change obviously when the saturated degree increases by only 1% from 99% to 100%.