两相非连续介质固结理论

CONSOLIDATION THEORY OF TWO-PHASE DISCONTINUOUS MEDIA

基于两相非连续介质（如饱和土）的力学模型，导出一个有效应力方程，在该方程中总应力分布取决于孔隙率和孔压传递系数以α（α=∈[0，1]），将其引入Blot固结理论，导出三维固结新方程。以圆柱土体径向受压为例，用Abaqus对两相非连续介质固结理论进行分析，求解得到孔压和位移，并比较新老理论结果的差异。根据相关文献的渗透性数据，获得几种黏土的n值，其合理范围为0．35～0．54。在相同的模量和渗透系数条件下，随着孔隙率和孔压传递系数的减小，固结过程加快，Mandel-Cryer效应更加显著。当孔隙率和孔压传递系数减小为0，固结在瞬间完成，两相非连续介质固结理论自动过渡为连续介质的弹性理论。两相非连续介质固结理论在传统固结理论和弹性理论之间搭建一座桥梁，从侧面印证两相非连续介质力学模型的合理性。

Based on a concise mechanical model of two-phase discontinuous media such as saturated soil, a new expression of effective stress was derived. In the expression, the distribution of total stress depends on the porosity n and the coefficient of pore pressure＇s transfer α（α=∈ [0, 1]）. The new expression was then applied to Biot theory. Consolidation of a columnar sample was analyzed with FEM software Abaqus and solutions of pore pressure and displacement were obtained. The results from the new equations were compared with those from original Biot theory. From the permeability data in relevant literatures, values of ocof clays in a reasonable range of 0.32 - 0.54 were obtained. With the same modulus and coefficient of permeability, the consolidation process speeds up as n and a decrease and Mandel-Cryer effect becomes more significant. When n = α = 0, the consolidation process becomes instantaneous. A transition is presented from the consolidation behavior of porous media to that of continuum mechanics. The consolidation theory of the two-phase discontinuous medium bridges the traditional consolidation theory and the elastic theory; the confirming the rationality of the mechanical model of two-phase discontinuous medium indirectly.