关键词: 软土, 一维固结, 非线性, 有限差分法, 孔隙演变

Abstract: A one-dimensional nonlinear consolidation equation considering transient loading and time-dependent loading is established based on a new nonlinear compression model of soil. The solution of the consolidation equation is obtained by using finite difference method, and the correctness of the difference method is verified by comparison with a semi-analytical solution. Based on the proposed solution, the effects of external load, initial compressibility coefficient of soil and C_c/C_k (ratio of compressibility index to permeability index) on soil's consolidation and settlement characteristics are discussed in detail. Results reveal that C_c/C_k affects the consolidation rate of soil by changing the consolidation coefficient, which increases with the decrease of C_c/C_k; therefore the consolidation rate of soil increases with the decrease of C_c/C_k. When the initial compressibility coefficient of soil is small, the compressibility of soil is small and close to elasticity. In this case, the nonlinear characteristics of soil can be ignored and the Terzaghi consolidation solution can be used directly. Compared with the consolidation solution obtained by Li Binghe, the nonlinear model used in this paper does not need to consider the influence of the initial effective pressure of soil, and therefore is relatively more convenient for engineering applications.

Key words: soft soil, one-dimensional consolidation, nonlinear, finite difference method, pore evolution