Analysis of One-Dimensional Consolidation for Double-Layered Soil with Non-Darcian Flow Based on Continuous Drainage Boundary

The boundary drainage performance controls the rate of pore water discharge in the soil and plays an important role in the prediction of soil consolidation and settlement. Based on a continuous drainage boundary that can reflect the change of boundary drainage performance with time, a one-dimensional consolidation model of double-layered soil considering non-Darcian flow is established. The finite-difference method and semianalytical method are used to solve the consolidation equation, and the reliability of the two methods is verified by comparing with existing solutions. Based on the proposed solution, the consolidation behaviors of the double-layered soil are explored in depth through a systematic parametric study. The results show that, if the time effect of drainage boundary and the influence of non-Darcian flow are ignored, the estimated consolidation rate is relatively fast in the whole consolidation stage. The non-Darcian flow has a greater influence on soil consolidation under the continuous drainage boundary condition compared with that under the traditional drainage boundary condition. The consolidation rate of the foundation can be improved by appropriately increasing the permeability of the underlying soil layer or decreasing the compressibility of the underlying soil layer.