非饱和红粘土三轴试验研究

Study on the triaxial tests of unsaturated lateritic soil

利用非饱和三轴系统进行不同围压和不同基质吸力的三轴剪切试验,求出了该典型红粘土的强度指标,并分析强度指标随基质吸力变化的规律;结果表明,强度指标在进气值前后差异很大,且基质吸力大于进气值后出现了非线性变化的趋势,其中表观凝聚力最为突出;最后,验证了用幂函数拟合表观凝聚力与基质吸力的关系是行之有效的。

Using the unsaturated triaxial apparatus, the unsaturated traxial tests were carried out under different confining pressures and different suction. The strength indexes were obtained, and the law of strength index changing with suction was analyzed The results show that the strength indexes were dramatically different around the fir-entry pressure. Moreover the strength indexes show a nonlinear trend as the suction exceeded the air-entry pressure,and the apparent cohesion was most notable. At last, it is validated that the power equation was good for fitting the relationship between apparent cohesion and suction.