Soil desiccation cracking under a non-uniform temperature field: Experimental investigation and DEM modeling

Soil desiccation cracking significantly impacts the hydraulic and mechanical properties of soil. Although extensive research has been conducted on cracking under uniform conditions, the influence of non-uniform temperature fields remains poorly understood. This study combines laboratory experiments and discrete element method (DEM) simulations to investigate soil desiccation cracking under non-uniform temperature fields. Laboratory tests utilized a controlled heating setup to establish a temperature gradient, with digital image correlation (DIC) employed to analyze strain and displacement fields. DEM simulations incorporated a temperature-dependent evaporation model to capture the micromechanical behavior of soil particles under non-uniform thermal conditions. The results reveal that cracks initiate near the high-temperature region and propagate in a “fish-scale” pattern toward the low-temperature region, driven by differential evaporation and uneven shrinkage. A distinct dry/wet interface forms and migrates from the high-temperature to the low-temperature region as evaporation progresses. DEM simulations accurately reproduced the observed crack patterns, demonstrating the model's capability to capture the effects of non-uniform temperature fields on soil cracking. Furthermore, the simulations indicate that crack propagation is governed by the movement of tensile stress concentrations, which are more pronounced in high-temperature regions. This study highlights the critical role of temperature gradients in desiccation cracking, offering valuable insights for geotechnical engineering and enhancing predictive models under varying environmental conditions.