An Incorporating Pore Water Pressure Constitutive Model for Overconsolidated Clay and Calibration of Transient FE Parameters

The simulation accuracy of triaxial tests for oversolidated clay in transient finite element analysis is affected by soil constitutive model, permeability coefficient, overconsolidation ratio, shear rate and mesh size. This study introduces the concepts of overconsolidation parameters, potential strength, and hardening parameters from the unified hardening model into the modified Cam-Clay model. By integrating the generation mechanism of pore water pressure, a constitutive model for overconsolidated clay incorporating pore water pressure was developed, and its accuracy was validated through triaxial tests. By invoking the UMAT subroutine, accurate simulation of the undrained triaxial tests of overconsolidated clay was achieved in the static/general analysis in Abaqus. Based on this, model parameters for simulating triaxial tests of overconsolidated clay in transient analysis (Soils) were calibrated. The relationships between shear rate, mesh size, and soil parameters were quantified, providing a reference for similar engineering numerical simulations.