饱和软土大应变自重固结非线性分析

饱和软土的自重固结涉及许多复杂的非线性问题，而现有分析方法一般基于线性假设，将固结控制方程简化，在沉降变形较大的情况下并不合理。基于Gibson大变形固结方程，推导在单面排水和双面排水条件下的边界条件，综合考虑饱和软土的自重特性与非线性压缩、渗透关系，采用稳定性较好的Crank-Nicolson型差分格式离散并求解非线性控制方程，并从孔隙比、沉降、孔隙水流速3个方面将数值解与CS2固结数值模型进行对比验证。结合工程实例，研究土层不同初始厚度和初始孔隙比对自重固结的影响。结果表明：初始厚度与初始孔隙比较大土层最终沉降也较大。与传统方法相比，该方法所得出的数值解精度较高，实现了高度非线性固结方程的快速求解，其成果更能广泛运用于实际工程的分析之中。

Nonlinear analysis of one-dimensional consolidation of saturated clay including dead-weight effects and large strain

The process of dead-weight consolidation of the soil layer involves many complex nonlinear problems. However, the existing analysis methods are generally based on the linear assumption to simplify the consolidation governing equation, which is unreasonable for the large strain consolidation. In this article, the boundary conditions of Gibson's large strain governing equation are deduced first. Then, the changing compressibility and permeability relationship of soil mass is taken into consideration. The finite difference method (FDM) in Crank-Nicolson scheme is used to disperse and solve the nonlinear governing equations. Verification of FDM solutions shows an excellent agreement with the CS2 simulations, in the aspects of void ratio, settlement and relative discharge velocity. Moreover, the effects of initial layer height and initial void ratio on the consolidation behavior are investigated. The results reveal that both a larger initial layer height and a larger initial void ratio result in a larger final settlement of the foundation. Compared with the traditional method, the method presented in this article realizes the fast solution of the highly nonlinear equation of large strain consolidation, and it can be widely used in the analysis of practical engineering.