论文部分内容阅读
红粘土的强度特性直接关系到路基的稳定和边坡坡度的选取,是红粘土地基工程、边坡工程和洞室工程设计计算的重要参数。直剪试验与三轴试验是室内测定土的抗剪强度指标最常用的两种试验方法。试验所用的土样取自贵州大学西校区某基坑,采用直剪试验与三轴试验测定红粘土抗剪强度,并进行了比较。结果表明,粘聚力随含水率的增大而减小,最佳含水率前,减小幅度较小,超过最佳含水率后,减小幅度较大;粘聚力随压实度的增大而增大,同一压实度下,最佳含水率前的粘聚力远远大于最佳含水率后的粘聚力。内摩擦角随含水率的增大而减小,随压实度的增大而增大;粘聚力随含水率、压实度的变化幅度远远大于内摩擦角的变化幅度。同一含水率同一压实度下,不固结不排水三轴试验得到的粘聚力和内摩擦角比直剪(快剪)试验的结果要大。
The strength characteristics of red clay is directly related to the stability of subgrade and the selection of slope, which is an important parameter for the calculation of red clay foundation engineering, slope engineering and cavern engineering. Direct shear test and triaxial test are the two most commonly used test methods for determining the shear strength of soil in the laboratory. Soil samples used in the experiment were taken from a foundation pit of West Campus of Guizhou University. The shear strength of red clay was measured by direct shear test and triaxial test, and compared. The results showed that the cohesion decreased with the increase of water content, and the decrease range was smaller before and after the optimum water content. When the water content exceeded the optimum moisture content, the decrease range was larger. The cohesion increased with the increase of compaction Large and increase, the same degree of compaction, the cohesion before the best moisture content is far greater than the cohesion after the best moisture content. The internal friction angle decreases with the increase of water content and increases with the increase of compaction degree. The variation range of cohesion with moisture content and compaction degree is much larger than the change range of internal friction angle. The same moisture content at the same degree of compaction, uncured undrained triaxial test cohesion and internal friction angle than the direct shear (quick shear) test results larger.