Exploring the Hysteresis Effects of Climate-Induced Desiccation Cracks on Slope Stability: New Insights From Experimental and Numerical Studies

Abstract

Climate-induced desiccation cracks exhibit a hysteresis behavior, referred to as crack dynamic hysteresis (CDH), where they display different geometric characteristics during the drying and wetting phases at constant soil water content. This phenomenon has a complex effect on slope stability, an aspect often overlooked in analytical and numerical methods. In this study, we conducted experimental and numerical analyses to provide new insights into the effects of the CDH on slope stability. A series of laboratory experiments on desiccation cracking under drying-wetting cycles were performed. The testing results were used to develop and validate an extended dynamic dual-permeability model. The proposed model was integrated into a set of slope stability analyses using the finite element method. The numerical model results show that CDH causes greater fluctuations in crack dynamics and increases soil water retention under drying-wetting cycles. Neglecting this phenomenon leads to underestimation of slope stability during dry conditions and overestimation during wet conditions, with these discrepancies becoming more pronounced as the cycles progress. Furthermore, CDH changes the mechanical properties of soil, transitioning relatively stable zones to regions prone to localized instability. These unstable zones present significant challenges for accurately analyzing and managing slopes with cracked soil layers. Monitoring groundwater fluctuations and local crack development after heavy rainfall events is essential for mitigating localized slope collapses.