Numerical Solution for Nonlinear Consolidation of Composite Foundations with Impervious Piles Based on Hansbo’s Flow

In composite foundations, impervious piles function as vertical reinforcement, significantly enhancing the bearing capacity of the foundation. However, compared to granular material piles, the drainage path in composite foundations with impervious piles remains a relatively long vertical path. Under these conditions, the consolidation behaviors are significantly influenced by the flow state of pore water in soils. Extensive data indicate that the flow of pore water in soft soils deviates from Darcy’s law at low hydraulic gradients. Applying traditional Darcy’s law to solve the consolidation problem of composite foundations with impervious piles is not appropriate. Therefore, the widely accepted Hansbo’s flow law is introduced to describe the flow state in soft soil, incorporating the nonlinear compressibility and permeability characteristics of the soil. A consolidation model for composite foundations with impervious piles is established, and its numerical solution is provided. Comparative analyses with existing solutions and engineering cases verify the reliability of the proposed consolidation model. The consolidation behavior of composite foundations under different conditions is analyzed, highlighting the impact of various combinations of Hansbo’s flow parameters m and i1 on consolidation. The differences in calculation results between the Darcy and the Hansbo’s flow model for different nonlinear soil behaviors are elucidated.