关键词: 饱和软土, 自重固结, 大应变, 非线性, 有限差分法

Abstract: 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.

Key words: saturated clay, dead-weight consolidation, large strain, nonlinear analysis, finite difference method