Desiccation cracks can significantly increase permeability and reduce shear strength, which potentially results in shallow landslide occurrence. In this study, a full-scale model test was carried out on a cracked soil slope under rainfall-evaporation cycles. We quantified the crack characteristics at the slope crest (SC), around the slope shoulder (SS), and the slope foot (SF) by image processing techniques. The moisture content, matric suction, and pore water pressure at different depths under the crack areas were monitored by hydrologic sensors. The results indicate that patterns of desiccation cracks dynamically varied with their positions at the slope and rainfall-evaporation cycles. Using the indicator of lower hydrologic sensors responding to rainfall earlier than upper ones, preferential flow induced by desiccation cracks can be detected. It is shown that desiccation cracks can significantly increase the infiltration depth to four or five times deeper than the crack depth. Experiment evidence confirmed that preferential flow through desiccation cracks can trigger slope failure or even landslides by forming local perched water zones near the crack tips. Based on this investigation, the failure process of the cracked soil slope was separated into three stages in terms of the crack patterns and failure modes: (I) generation of desiccation cracks, with failure mode of surface erosion; (II) development and transformation of cracks, with failure modes of flow-slip and local failure; (III) rebirth and further development of cracks, with failure mode of overall failure. From the derived conclusions, we suggested that further modifications should consider the dynamic changes of desiccations cracks when simulating the seepage and stability of the cracked soil slope. Also, specific treatment measures to the slope failures in different stages were provided.

干燥裂纹会显着增加渗透率并降低剪切强度，这有可能导致浅层滑坡的发生。在这项研究中，在降雨-蒸发循环下，在裂隙土质边坡上进行了全面模型试验。我们通过图像处理技术量化了在坡顶（SC），坡肩（SS）和坡脚（SF）处的裂纹特征。通过水文传感器监测裂缝区域下不同深度的水分含量，基质吸力和孔隙水压力。结果表明，干燥裂纹的模式随其在坡度和降雨-蒸发循环中的位置而动态变化。使用下部水文传感器对降雨的响应要早于上部水文传感器的指示，可以检测到由干燥裂缝引起的优先流动。结果表明，干燥裂纹可将渗透深度显着增加到比裂纹深度大四到五倍。实验证据证实，通过干燥裂纹的优先流动可通过在裂纹尖端附近形成局部栖息的水带来触发边坡破坏，甚至引发滑坡。在此基础上，将开裂土质边坡的破坏过程从裂缝形式和破坏方式分为三个阶段：（1）干燥裂纹的产生，表面侵蚀的破坏方式；（二）裂纹的发展与转变，具有滑移和局部破坏的破坏方式；（三）裂纹的重生和进一步发展，具有整体失效的失效模式。根据得出的结论，我们建议在模拟裂隙土坡的渗流和稳定性时应进一步考虑干燥裂缝的动态变化。此外，还提供了针对不同阶段的边坡破坏的具体处理措施。