关键词: 三趾马红土, 数字图像定量处理, 裂缝演化, 自愈机制

Abstract: The dewatering shrinkage cracking of clay has significant influence on human engineering activities. The dry dehumidification test was carried out on the remolded hipparion clay, and the dynamic quantitative data of cracks was obtained by digital image quantitative processing technology. It was found that the evolution law of cracks was different from the traditional law of cracks (the area and average width of cracks continuously increase during the drying process, and finally tend to be stable). For example, the crack of the sample shrunk during the middle of drying process, and the cracks showed the phenomenon of ‘self-healing’. Subsequently, the ‘split-block’ theory was put forward to analyze the mechanism of this phenomenon, and the concept of healing degree was also introduced to study the healing effect of cracks under different initial water contents. The results show that the initial water content has a significant effect on the crack healing degree of the sample. The lower the initial water content is, the earlier the healing occurs and the greater the degree of final healing is. The final healing degree of the sample with a dry density of 1.7 g/cm3 is in a good linear relationship with the initial water content under a temperature of 40℃.

Key words: hipparion red soil, digital image quantitative processing, crack evolution, self-healing mechanism