中文摘要：

为研究改良膨胀土的裂隙发育特征及其对抗剪强度的影响,对掺不同比例的石灰、风化砂的膨胀土进行饱和干湿循环,利用图像处理技术对土样表面裂隙图像进行裂隙参数提取,并进行饱和抗剪强度试验。研究表明：石灰和风化砂能够有效地限制裂隙的发育。裂隙率随着循环次数的增加呈线性增长,而改良膨胀土的黏聚力和内摩擦角随着循环次数的增加分别呈对数和幂函数衰减;裂隙率和黏聚力之间具有较好的指数函数关系,而改良土的内摩擦角和裂隙率之间存在对数函数关系;膨胀土的改良效果可考虑结合裂隙指标进行评价。

英文摘要：

To study the development characteristics of the improved expansive soil fissure and its effect on the shear strength,the saturated wet dry cycle is conducted for the expansive soil with different mix proportion of lime and weathered sand. The image processing technology is used to extract the surface crack fracture parameters from the soil images,and the saturated shear strength of soil is tested. The results show that the lime and weathered sand can effectively restrict the development of cracks. The crack rate increases linearly with the increasing number of cycles,and the cohesive force and internal friction angle of the modified expansive soil increase with the increasing number of cycles. There is a good exponential function relationship between the crack rate and the cohesive force,and the logarithmic function relationship exists between the internal friction angle and the crack rate of the modified soil. Combination of the fracture index is more reasonable to evaluate the improvement effect of the expansive soil.