Red clay is prone to cracking in desiccating environments, with criss-cross cracks compromising soil structures and inducing slope instability. Under natural hygrothermal conditions, a desiccation test of red clay slurry was performed with a self-made device and digital image correlation (DIC) technology to study the crack evolution and quantitatively analyse the relationships between moisture content, displacement, strain and cracks. The results showed that cracks were usually initiated by subdividing and intersecting with other cracks at right angles. The main cracks were initiated first and had the longest duration; the stabilised main cracks were longer and wider than secondary cracks. DIC technology was used to monitor crack evolution dynamically. Based on the areas of strain concentration, the locations of early-initiated cracks and propagation trends could be preliminarily predicted. The failure strain in cracking was related to the moisture content, while crack evolution was related to the Atterberg limits of the red clay. The soil shrinkage exhibited anisotropic behaviour, with greater vertical shrinkage at the soil clod centre compared with the edges. In contrast, the horizontal displacement and maximum principal strain at the soil clod centre were smaller than those at the edges. These findings contribute to providing guidance for formulating engineering geological hazard control measures.

中文翻译：

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基于数字图像相关性的干燥裂纹演化定量分析

红粘土在干燥环境中容易开裂，纵横交错的裂缝会损害土壤结构并引起边坡失稳。在自然湿热条件下，利用自制装置和数字图像相关（DIC）技术对红粘土浆体进行干燥试验，研究裂纹演化过程，定量分析含水率、位移、应变与裂纹之间的关系。结果表明，裂缝通常是由细分并与其他裂缝成直角相交而引发的。主裂纹最先萌生，持续时间最长；稳定后的主裂纹比次裂纹更长、更宽。DIC 技术用于动态监测裂纹演化。根据应变集中区域，可以初步预测早期裂纹的位置和扩展趋势。开裂破坏应变与含水率有关，而裂纹演化与红粘土的阿特伯格极限有关。土壤收缩表现出各向异性行为，与边缘相比，土块中心的垂直收缩更大。相比之下，土块中心的水平位移和最大主应变均小于边缘。这些研究结果有助于为制定工程地质灾害防治措施提供指导。与边缘相比，土块中心的垂直收缩更大。相比之下，土块中心的水平位移和最大主应变均小于边缘。这些研究结果有助于为制定工程地质灾害防治措施提供指导。与边缘相比，土块中心的垂直收缩更大。相比之下，土块中心的水平位移和最大主应变均小于边缘。这些研究结果有助于为制定工程地质灾害防治措施提供指导。