二维有限区域饱和软土Biot固结的数值模拟

Numerical simulation of Biot’s consolidation of water-saturated soft soils due to loading within a finite two-dimensional domain

针对二维有限矩形区域饱和软土固结问题,选取四种不同边界条件组合,利用数值模拟方法研究了在上表面剪切载荷作用下土体沉降变形的特征和规律。结果表明:在剪切载荷单独作用下,土体位移以水平位移为主,同时竖向位移也客观存在。这反映了土体固结过程中流固耦合的物理现象。土层最终变形量(沉降和水平位移)由剪切载荷与土体物性决定,与边界透水性无关;边界条件对土体的变形模式有着决定性影响。剪切载荷作用、法向载荷作用及二者联合作用的计算结果对比表明:虽然软土Biot固结是复杂的流固耦合过程,但在这个过程中载荷叠加原理依然成立。

Biot’s consolidation caused by shear loading within a finite two-dimensional area is studied using finite difference method,and four cases with upper and lower surfaces of pervious or impervious are analyzed.The results show that,among the displacements due to shear loading,the horizontal displacement is predominant,while the vertical displacement does occur.This exactly reflects the flow-deformation coupling nature of the consolidation process.The long-term soil deformation is dependent on shear loading and soil properties,but independent of boundary conditions.Although boundary conditions have no influence upon the steady-state settlement and horizontal displacement,yet the consolidation processes corresponding to various boundary conditions differ from each other.The comparison among the effects of shearing loading,the effects of normal loading,and those of combined loading depicts that the principle of superposition is applicable to the Biot’s consolidation despite the fact that it is a complicated process of flow-deformation interaction.