压实膨胀土表面裂隙发育规律及与强度关系研究

Research on the relationship between fracture development rules and strength of the compacted expansive soil

利用PCAS裂隙图像处理软件对干湿循环条件下不同压实度膨胀土的表面裂隙发育变化进行动态、定量的测量,并对不同裂隙发育程度的膨胀土进行了直剪试验。试验结果表明:压实度越大,裂隙开裂程度越小;黏聚力随干湿循环次数的增加呈递减趋势,而内摩擦角则受干湿循环的影响小。循环次数相同时,压实度越大,黏聚力越大;黏聚力分别随裂隙条数、裂隙总长度、裂隙平均宽度变化的曲线具有明显的相似性,说明黏聚力与这三个参数存在一定的相关性;裂隙率和分形维数与黏聚力具有线性关系。

The fissure image processing software of PCAS is used to dynamically and quantitatively determinate the fracture change of different compaction of expansive soil under the dry-wet circulation, and with different fracture degree of expansive soil in the direct shear test. The experimental results show that ： （ 1 ） the greater the degree of compaction, the smaller the degree of fracture; （2） the cohesive force with the increasing number of dry-wet circulation shows a decreasing trend, and the internal friction angle is little affected by the dry-wet cycle. The greater the degree of compaction in the same cycles, the larger the cohesive force is ; （3） curves of cohesive force with the number of article fracture and the total length of the average width are quite similar, and the cohesive force and the three parameters have certain relevance; （4） the fissure rate and the fractal dimension have a linear relationship with the cohesive force.