A 2D FDEM-based moisture diffusion-fracture coupling model for simulating soil desiccation cracking

Based on the combined finite-discrete element method (FDEM), this paper presents a moisture diffusion-fracture coupling model to simulate soil desiccation cracking. The coupling model, firstly, analyzes moisture content distribution within the soil according to a moisture diffusion model. Then, the shrinkage stress caused by the change of moisture content is calculated and applied to the system equation of FDEM. Finally, if a new crack is generated, the node sharing relationship and mesh of adjacent solid elements are updated for moisture diffusion calculation in the next time step. In this paper, examples of 1D moisture migration in the soil trip, shrinkage stress and deformation caused by the moisture reduce in the rectangular soil are studied. The simulation results agree well with analytical solutions, which verifies the correctness of the proposed model. Then, the model is used to simulate soil desiccation cracking process, and the crack evolution pattern in the numerical results is consistent with experimental results. Besides, several main factors affecting soil desiccation cracking are also investigated, including the elastic modulus, the moisture shrinkage coefficient, and the soil thickness. The moisture diffusion-fracture coupling model provides a new research tool for studying the mechanical mechanism of soil desiccation cracking.

Automated summary

This paper presents a moisture diffusion-fracture coupling model based on FDEM to simulate soil desiccation cracking. By studying examples and investigating main factors, the simulation results validate the correctness of the model and are consistent with experimental results. The model provides a new research tool for studying the mechanical mechanism of soil desiccation cracking.