Nonlinear consolidation model for stratified soils with vertical drains based on spectral method

Many soft soil foundations with vertical drains are stratified, and the permeability and compressibility of soils change nonlinearly during the consolidation process. A nonlinear consolidation model that can consider both vertical and radial drainage is proposed based on the void-ratio dependent compressibility and permeability (e-lgσ' and e-lgk), and a nonlinear consolidation model for the stratified soils with vertical drains is obtained based on the spectral method. The validation of the solution is verified by the degradation study and the comparative analysis with the existing nonlinear consolidation analytical solutions and laboratory tests. The results show that the average relative error between the calculated value and the analytical solution and the measured value is lower than 0.7% and 2.0%, respectively. A field case is also studied and analyzed. The results show that the calculated values of settlement and pore pressure at different depths are in good agreement with the measured data, which can predict the development of settlement and the dissipation of pore pressure in different soil layers during the consolidation process. The case study further illustrates the feasibility and applicability of the proposed model in the consolidation calculation of stratified soils with vertical drains.