为了解冻融作用对黄土路用性能的影响,以Q2黄土为研究对象,采用增湿法配制不同含水率试样,并在不补水条件下进行不同温度冻融循环后,分别开展液限、塑限、单轴固结及直剪试验,得出了Q2黄土液限、塑限、压缩模量、粘聚力及内摩擦角等物理力学指标与含水率、测试温度的关系。研究结果表明:天然含水率试样冻融后,塑性指数随测试温度降低而略有增大,土样压缩模量及抗剪强度随含水率增大而降低;测试温度对黄土力学性能的影响取决于试样的含水率,其中压缩模量随测试温度降低而降低,且其降幅与饱和度之间存在近似二次函数关系;当含水率小于临界值时,粘聚力随测试温度降低而增大,含水率大于临界值时粘聚力则减小;试样内摩擦角随测试温度的降低呈增大趋势,且含水率越大,内摩擦角的增幅越大。
In order to find out the change rules of loess characteristics after freeze-thaw circle, Q2 loess samples with different moisture contents were prepared by moistening method. After freeze- thaw circle under different test temperatures and without water supply, tests of liquid and plastic limit, uniaxial consolidation and direct shear were conducted, and the relationships between physical and mechanical indexes of loess and moisture content and temperature were obtained. The results show that plastic index of samples after freeze-thaw circle with natural moisture content increases slightly with the decrease of temperature, compression modulus and shear strength decrease with the increase of moisture content; temperature influence on mechanical property of loess depends on the moisture content of samples, compression modulus decreases with the decrease of temperature, and the decreasing range changes with sample saturation in approximate quadratic function; when moisture content is less than critical value, cohesive force increases with the decrease of temperature, while cohesive force decreases when moisture content is more than critical value; internal friction angles of samples increase with the decrease oftemperature, and the increasing range of internal friction angle increases with the increase of moisture content.