Finite difference numerical solution of one-dimensional large strain and#br#
self-weight consolidation of dredged-fill soil
Jiang Wenhao1,2 Zhan Liangtong1,2 Guo Xiaogang1,2
1. Institute of Geotechnical Engineering, Zhejiang University, Hangzhou 310058, China;
2. Key Laboratory of Soft Soils and Geoenvironmental Engineering of the Ministry of Education, Zhejiang University, Hangzhou 310058, China
Abstract：The dissipation of the excess pore water pressure and the increase of the effective stress are the physical essence of the self-weight consolidation of dredgedfill soil. However, in the past, the solutions to the problem of large strain and self-weight consolidation of the soil are mostly based on the Gibson’s large strain consolidation theory, which does not reflect the consolidation process of the soil physically. In this paper, based on the assumptions in Gibson’s large strain consolidation theories, a governing equation of one-dimensional large strain and self-weight consolidation with excess pore water pressure as a variable is derived. The governing equation is simple in form and the physical significance of the coefficient is clear. By introducing the modified implicit difference scheme, the finite difference numerical solution of the governing equation is obtained by using the finite difference method with the boundary conditions and initial conditions of the selfweight consolidation of dredged-fill soil. The numerical solution can solve the self-weight consolidation process of dredged-fill soil under arbitrary e-σ′ and e-k relationship. The excess pore water pressure, void ratio and settlement obtained with the analytical solution using the Lee & Sills and the solution of SWC model agree well with those by the proposed method, which validates the the numerical solution. The influences of the initial thickness, the initial void ratio and the specific gravity on the large strain and self-weight consolidation behaviors are further analyzed by using the method proposed in this paper. The analysis results show that the consolidation degree defined by settlement in the consolidation process is always greater than that defined by the stress. The initial thickness influence much on the stress consolidation degree, while the initial void ratio and the specific gravity have a greater influence on the settlement consolidation degree.
