三趾马红土失水收缩裂缝演化规律研究

黏性土失水收缩开裂对人类工程活动影响显著。通过设计室内试验监测装置，对重塑三趾马红土开展干燥脱湿试验，并运用数字图像定量处理技术获得其干缩裂缝演化的动态定量数据，发现其裂缝演化规律与传统规律（裂缝面积、平均宽度在干燥过程中始终增长，最终趋于稳定）有所不同，表现为试样裂缝在干燥中期出现收缩现象，呈现裂缝的自愈性。随后提出裂块理论深入分析了此现象的产生机制，并引入愈合度概念，研究了不同初始含水率下试样裂缝的愈合规律，结果表明：（1）初始含水率对试样裂缝愈合度影响显著，初始含水率越低，试样裂缝越早开始愈合且最终愈合度越大；（2）干密度1.7 g/cm3的试样在40℃脱湿条件下，试样最终愈合度与初始含水率呈良好的线性关系。

The evolution of cracks in the dewatering shrinkage process of hipparion red soil

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℃.