非饱和土地基中体波传播特性研究

Study on the propagation characteristics of body wave in unsaturated soil foundation

基于非饱和土波动控制方程,引入Helmholtz势函数,经过Fourier变换,推导得出了非饱和土中体波的弥散特征方程。考虑饱和度的变化对动剪切模量等参数的影响,通过数值模拟分析了非饱和土中饱和度、频率和固有渗透系数等因素对体波波速和衰减系数的影响。结果表明:饱和度对P_(1)波、S波波速有显著影响,对P_(2)、P_(3)波波速影响较小;高频率下饱和度对4种体波的衰减系数均有显著影响。频率对P_(2)、P_(3)波波速影响显著,而P_(1)波和S波波速几乎不受频率的影响;频率对P波和S波的衰减系数影响显著。固有渗透系数对3种P波的波速和衰减系数影响较大,对S波影响较小。

Based on the wave control equation of unsaturated soil,the dispersion characteristic equation of body wave in unsaturated soil is derived by introducing Helmholtz potential function and Fourier transform considering the effects of saturation variations on dynamic shear modulus and other parameters.The effects of saturation,frequency and inherent permeability coefficient on the velocity and attenuation coefficient of body wave in unsaturated soil are through numerical simulation.The results show that saturation has a significant effect on P_(1)and S waves velocities,and has a small effect on P_(2)and P_(3)waves velocities.Saturation at high frequencies has a significant effect on the attenuation coefficients of four body waves.Frequency has a significant effect on P_(2)and P_(3)wave velocities,while P_(1)and S wave velocities are almost independent of frequency;it also shows significant effect on the attenuation coefficients of P and S waves.The inherent permeability coefficient has a greater impact on the wave velocity and attenuation coefficient of the three P waves,while has a smaller impact on the S wave.