One-dimensional consolidation of soft ground considering non-Darcy flows

The flows of pore water in the soil and drainge boundaries have great influence on the dissipation of excess pore pressures. Based on the non-Darcy flows suggested by Hansbo described by the power function for the lower velocity of flows and the linear function for higher velocity of flows, finite element formulations are derived by Galerkin’s weighting residual method for one-dimensional consolidation of ground with impeded boundaries. A program is developed based on the finite element formulations. The existing one-dimensional consolidation explicit analytical solution based on the Darcy flows of the ground with partially drained boundaries is used to verify the validity of the present method and correctness of the program. Then the one-dimensional consolidation behavior of ground with impeded boundaries based on the non-Darcy flows is investigated. The numerical results indicate that partially drained boundaries parameter R_t=200 can be thought as conventional pervious boundaries. There is a boundary depth for the non-Darcy flow consolidation under impeded boundaries. The pore pressures of the soil above the boundary depth dissipate more quickly than those of Darcy flows, whereas pore pressures of the soil below the boundary depth dissipate more slowly than those of Darcy flows. Boundary depth becomes deep with the increase of m, however it becomes shallow with the increase of i₁.