A Two-Dimensional Moisture Diffusion Continuous Model for Simulating Dry Shrinkage and Cracking of Soil

Dry shrinkage cracking of soil is a common phenomenon in nature. The shrinking and cracking of soil have been linked to several geological disasters. To simulate dry shrinkage cracking in soil, we present a continuous 2D moisture diffusion model, which is implemented in a GPU parallel multiphysics finite-discrete element software, namely MultiFracS. In this model, the moisture distribution of the system is analyzed initially, then the shrinkage stress caused by the change of moisture is calculated. Finally, the shrinkage stress is applied to the governing equation of FDEM to calculate the mechanical fracture. By repeating the preceding procedures, the soil shrinkage cracking problem can be simulated and investigated. We first verify the correctness of the model in dealing with the moisture diffusion problem in a continuous medium. Then we study the soil dry shrinkage and cracking, and compare the simulation results with the experimental results. The simulation results are in good agreement with the analytical solution or the existing literature results, which verifies the effectiveness of the 2D moisture diffusion continuous model to simulate the dry shrinkage cracking of soil.