含水量对晋西黄土抗剪强度影响的试验

Experiment study on relationship between water content and shear strength of loess in west Shanxi Province

以晋西黄土为研究对象，采用常规直剪试验和不排水不固结三轴试验，对不同含水量下土样的抗剪强度参数进行了测定，得出晋西黄土抗剪强度随含水量变化的规律。试验表明：直剪试验条件下，随着含水量的增加，土的抗剪强度降低。当含水量小于12%左右时，随着含水量的增大，黏聚力c降低迅速；当含水量在12%～23%时，随含水量的增大，黏聚力降低缓慢，降低幅度较小，当含水量大于23%左右时，随含水量的增大，黏聚力降低趋势再次变陡；抗剪强度参数内摩擦角φ随着含水量的增大，变化趋势不明显，其取值大致在14%～32%。三轴不固结不排水剪切试验中，随着含水量的增加，抗剪强度参数c降低，在小于12%含水量时，降低趋势陡，大于12%含水量后，降低趋势变缓；内摩擦角φ随着含水量的增大呈线性降低，且相关性较好。

Based on the direct-shear tests and unconsolidated-undrained triaxial tests, the authors study the relationship between shear strength and water content of loess in West Shanxi Province. The experimental results show that the value of shear strength decreases as the water content increases in direct shear test, when water content is smaller than about 12%, the value of cohesion decreases quickly as water content increases. And with water content between about 12% and 23%, it decreases slowly as the water content increases. When the water content is lager than about 23%, it decreases quickly again. The value of internal friction angle has no obvious change as water content increases. The value of internal friction angle ranges from 14% to 32%. In triaxial compression test, shear strength parameter “c” decreases when the water content increases. With the water content less than 12%, the decreasing tendency is steep, and it is slow as the water content is larger than about 12%. With the water content increasing, internal friction angle decreases linearly and has a good correlation.