Analysis of time-dependent bearing capacity of pile foundation in marine soft soil region considering non-Darcy flow

Abstract

Due to the deviation of pore water seepage in marine soft soils from Darcy flow under low hydraulic gradients, existing methods face challenges in accurately calculating the time-dependent bearing capacity of piles in such areas. This paper adopts the secondary development of Python to ABAQUS and employs a continuous coupling analysis method to establish a numerical model capable of simultaneously solving the large deformation of pile driving and non-Darcy flow. The model addresses issues such as mesh distortion during pile driving and the numerical implementation of three-dimensional non-Darcy flow. The accuracy of the model was verified through comparison with two experimental cases. Subsequently, the study analyzed how non-Darcy flow affects soil consolidation around the pile and the time-dependent bearing capacity of pile. Results indicate that when the permeability coefficient of the soil around the pile is less than 1 × 10−7 m/s, non-Darcy flow significantly delays the consolidation of soil within three times the pile diameter around the pile, thereby reducing the time-dependent bearing capacity of pile, with a greater impact observed for lower permeability coefficients of the soil. Once the soil around the pile reaches 90% consolidation, subsequent construction can proceed to shorten the project duration while maintaining safety.