吸力、含水率和干密度对重塑非饱和土抗剪强度影响研究

Research on effects of suction,water content and dry density on shear strength of remolded unsaturated soils

进行了一系列控制吸力、含水率和干密度的直剪试验,研究了重塑非饱和土的抗剪强度特性。试验结果表明,在试验研究的吸力范围内,非饱和土的黏聚力随吸力线性增加,而内摩擦角随吸力的变化则很小。对于控制含水率的试验,非饱和土的黏聚力和内摩擦角均随含水率增加而线性减小,且黏聚力减小的幅度更明显。干密度对非饱和土的内摩擦角几乎没有影响,黏聚力随干密度呈指数增加。对控制吸力和含水率的试验结果进行了比较,提出的考虑含水率影响的抗剪强度公式可供实际工程参考。

The direct shear tests with controlled suction, water content and dry density equaling constants were conducted to study the effects of suction,water content and dry density on the shear strength of remolded unsaturated soil. The test results show that the cohesion of unsaturated soil has a linear increase with the increasing of suction; but the friction angle has little change with the change of suction. The cohesion and friction angle of unsaturated soil have a linear decrease with the increasing of water content; but the cohesion decreases more. The cohesion of unsaturated soil has an exponent increase with the increasing of dry density; but the friction angle has little change with the increasing of dry density. The comparison of the test results with controlled suction and water content equaling constants is carried out. The shear strength formula including impact of water content is proposed, which can be for reference in engineering application.