论文部分内容阅读
考虑土颗粒、孔隙流体的压缩性以及各相物质间的黏性、惯性耦合,采用Bishop有效应力公式和毛管压力函数的V-G模型,建立了非饱和土的动力控制方程。通过引入位移函数,并利用Cauchy-Reimann条件,在直角坐标系下将非饱和土的波动方程进行解耦,进而采用双重Fourier变换,求得了位移和应力在变换域上的一般解。结合一定的边界条件,研究了非饱和半空间体在任意分布的表面谐振荷载作用下的动力响应问题。数值分析中,考虑了饱和度对土的动剪切模量的影响,并提出了一个计算任意饱和度下粘性土的动剪切模量的经验公式。算例结果表明:饱和度对地基动力响应的影响非常显著,通常情况下,饱和度增大时,地表位移幅值随之增大,但当土体接近完全饱和时,地表位移幅值随饱和度进一步增大而减小。孔隙渗透性和地表排水条件则只有在饱和度很高时才会对地表位移产生明显的影响。
Considering the soil particles, the compressibility of pore fluid and the viscous and inertial coupling between the phases, the dynamic governing equations for unsaturated soils are established using the Bishop effective stress formula and V-G model of capillary pressure function. By introducing the displacement function and using the Cauchy-Reimann condition, the wave equation of unsaturated soil is decoupled in Cartesian coordinates, and then the double Fourier transform is used to obtain the general solution of displacement and stress in the transform domain. With some boundary conditions, the dynamic response of unsaturated half-space body under arbitrary distributed surface resonance loads is studied. In numerical analysis, the influence of saturation on the dynamic shear modulus of soil is considered, and an empirical formula for calculating the dynamic shear modulus of clay under arbitrary saturation is proposed. The results of numerical examples show that the influence of saturation on the dynamic response of foundation is very significant. Under normal circumstances, the amplitude of surface displacement increases with the increase of saturation. However, when the soil is close to full saturation, Degree further increase and decrease. Pore permeability and surface drainage conditions have a significant effect on surface displacement only when saturation is high.