Abstract: Computer image processing and programming technology were used to describe and analysis quantitatively features of expansive soil surface cracks under the different influence of compaction degree, the initial water content and dry wet cycles. The factors of dry wet cycles, degree of compaction and initial moisture content which have influence on expansive soil cracking rules were discussed. The results show that: the parameters such as node number, number of blocks, fracture rate, fractal dimension parameters can be characterized the degree of fracture cracking; with increase of expansion soil compaction degree, the degree of cracking decreases; expansive soil cracking extent under plastic limit water content of the initial water content is less than that of optimum water content; with the increase of cycle number, the degree of cracking increases, but change amplitude of the fracture parameters decreases, the first dry-wet cycle influence on cracking was maximum, and the fifth, or the sixth times have little effect on cracking.

Key words: road engineering, expansive soil, image processing, dry-wet cycling, cracking rules

摘要： 运用计算机图像处理和编程技术，对不同压实度、初始含水率和干湿循环次数影响下膨胀土的表面裂隙的特征进行了描述和定量分析，探讨了压实度、初始含水率和干湿循环次数对膨胀土开裂规律的影响。结果表明：节点个数、块区个数、裂隙率和分形维数可以用来表征表面裂隙的开裂程度；随着膨胀土压实度的增大，裂隙的开裂程度减小；膨胀土的初始含水率为塑限含水率时开裂程度小于最佳含水率时的开裂程度；裂隙的开裂程度随干湿循环次数的增加而增大，裂隙相关参数的变化率呈减小的趋势，第1次干湿循环对膨胀土开裂的影响最大，第5、第6次干湿循环对开裂的影响甚微。

关键词: 道路工程, 膨胀土, 图像处理, 干湿循环, 开裂规律