One-dimensional Nonlinear Large Deformation Consolidation Analysis of Highly Compressible Soft Soil

Consolidation theory reveals the change law of soil deformation with time,the consolidation behavior of highly compressible soils is related to the varied compressibility and permeability,the current large-strain consolidation theory had not adequately considered the effects of materials nonlinear on the consolidation behavior start from low stress level.Based on the proposed expressions of void ratio- effective stress,and the expressions of void ratio-permeability incorporating the void ratio at liquid limit,the one-dimensional nonlinear large-strain consolidation governing equation with pore water pressure as the variable is proposed.The Crank-Nicolson finite difference method is used for the solution of the degree of consolidation determined from deformation-time curve and the degree of consolidation determined from dissipation of excess pore pressure.The proposed solution is validated by comparing the measured excess pore pressure and the calculated results obtain from existing analytical solutions.The effects of initial void ratio and void ratio at liquid limit on the degree of deformation consolidation and the degree of pore pressure consolidation are also investigated.The results show that,when the initial void ratio remains constant,the dissipation of excess pore water pressure becomes slower with an increase in the void ratio at liquid limit,leading to an increase in consolidation time;when the void ratio at liquid limit remains constant,an increase in the initial void ratio leads to accelerated dissipation of excess pore water pressure,resulting in a shorter consolidation time.