不同含水率下滑带土抗剪强度特性研究

Research on Shear Strength of Slide Zone Soil in Different Water Content

利用环剪试验仪可以研究土体在较大剪切位移下抗剪强度的变化规律。试验以三峡库区黄土滑坡滑带土为研究对象,研究了在不同法向压力和含水率下该滑带土抗剪强度的特性。试验结果表明:滑带土的抗剪强度与轴向应力的大小呈现出较强的线性关系,并随有效轴向应力的增大而增大;试样在剪切过程中呈现出应变软化的特征,当轴向应力一致时,低含水率的滑带土其抗剪强度峰后软化现象表现的越明显;不同含水率滑带土试样之间的c、值降幅百分比基本一致,c、值减小范围比较同步,塑限含水率可作为影响滑带土抗剪强度增降百分比的重要分界点。

Ring shear apparatus can be used to study soil strength under large shear displacement. The experi- ment took the slide zone soil of Huangtupo landslide as the object of study, the shear strength characteristics of the slide zone soil under the different normal stress and water content was researched. The test results show that： shear strength and normal stress of slide zone soil show strong linear relationship, and increases with the increasing of ef- fective axial strength. Sample presented the characteristics of strain softening property in the shearing process, and the slide zone soil shear strength post-peak softening phenomenon under the low water content appears more obvious when the normal stress is consistent; reduce percent of the slide zone soil＇s c、φalmost the same, and the plastic limit water content can be used as important cut-off point in the slide zone soil shear strength.