ANALYSIS OF ONE-DIMENSIONAL NONLINEAR CONSOLIDATION FOR SOFT SOIL CONSIDERING EXPONENTIAL FLOW BASED ON CONTINUOUS DRAINAGE BOUNDARY

In order to study the consolidation of saturated soft soil considering the time-dependent characteristics of boundary drainage, variable loading, non-Darcian flow and nonlinear characteristics of soil, the one-dimensional consolidation equation considering exponential flow and nonlinear characteristics of soil is established by introducing the continuous drainage boundary. The solution of one-dimensional nonlinear consolidation problem of soft soil considering exponential flow based on continuous drainage boundary under variable loading and instantaneous loading is obtained using finite difference method. By means of flow degradation and boundary degradation, the proposed solution is compared with the solution under Darcian flow and the solution under traditional drainage boundary to verify the reliability of the finite difference method in this paper. Based on the proposed solution, the influences of interface parameter, exponential flow and soil nonlinearity on consolidation characteristics are analyzed in detail. The results show that the boundary drainage capacity increases with the increase of the interface parameter, and increasing the interface parameter can effectively improve the boundary drainage capacity when the boundary drainage performance is weak. Boundary drainage performance mainly affects the early stage of soil consolidation, while exponential flow mainly affects the later stage of consolidation. In practical engineering, if the whole consolidation process is concerned, the influence of boundary drainage performance should be considered. However, if only the settlement value at the later stage of consolidation is concerned, the influence of boundary drainage performance can be ignored.