饱和地基中骨架非流动黏性对体波传播特性的影响分析

Effect of skeletal flow-independent viscosity on the propagation characteristics of body waves in saturated foundations

基于饱和多孔介质的研究成果,考虑天然土体中骨架的非流动黏性和孔隙流体的流动黏性的影响,研究了黏弹性饱和地基中体波的传播特性.利用Biot波动理论,引入Kelvin-Voigt线性黏弹性模型,建立了饱和土体的黏弹性动力耦合模型.通过引入位移势函数,根据Helmholtz势函数分解定理推导给出了黏弹性饱和地基中体波的特征方程.利用数值算例,结合参数分析讨论了各类体波的波速和衰减系数随土体非流动黏性松弛时间、频率和渗透系数等物理力学参数的变化规律.结果表明:土体非流动黏性松弛时间的增大将引起P_(1)波、P_(2)波和S波的波速和衰减系数的增大;频率和渗透系数的不同区间对P_(1)波、P_(2)波和S波的波速和衰减系数的影响不同.

Based on the research results of saturated porous medium,considering the influences of flow-independent viscosity of natural soil,the propagation behaviors of body waves in viscoelastic saturated foundation were studied in the present work.The viscoelastic dynamic coupling model of saturated soil were established by employing Biot model and Kelvin-Voigt linear viscoelastic model.The characteristic equations of body waves in viscoelastic saturated foundation were theoretically derived by Helmholtz potential function decomposition theorem with introducing displacement potential function.The variations law of the wave velocity and attenuation coefficient of body waves with physical parameters such as flow-independent viscosity relaxation time of soil,frequency and permeability were analyzed using a numerical example.The results show that the wave velocity and attenuation coefficient of P _(1),P _(2 )and S waves increase with the extension of relaxation time of soil causes.Frequency and permeability in different ranges have different effects on the wave velocity and attenuation coefficient of P _(1),P _(2) and S waves.