非饱和黄土抗剪强度特性试验研究  

Experimental Study on Shear Strength Characteristics of Unsaturated Loess

作　　者：闫芙蓉[1] 胡雪源[1] 崔芳[1] 

机构地区：[1]河南理工大学土木工程学院,河南焦作454000

出　　处：《水利与建筑工程学报》2017年第5期100-104,227,共6页Journal of Water Resources and Architectural Engineering

基　　金：河南理工大学博士基金项目(72515/313);深部矿井建设重点学科开放实验室基金项目(60705/001/013)

摘　　要：为了研究黄土滑坡的发生机理及剪切破坏特征,用探井法在延安滑坡体取样,进行了室内控制吸力的固结排水剪切试验,本次试验共做了10组(Q3、古土壤各5组)。试验结果表明:两种黄土存在不同剪切破坏面,古土壤颗粒中由于黏粒含量比较高,所以没有明显的剪切面;而Q3黄土由于其大孔隙发育,结构疏松,没有黏滞性,所以剪切面上有擦痕,存在明显的剪切面;抗剪强度参数会随着实验过程中基质吸力的改变而改变,黏聚力随着基质吸力的增加而增加,二者为线性关系;而内摩擦角的变化很小,几乎不随吸力的改变而改变;随着含水率的增加,吸力和黏聚力均呈现下降趋势,吸力的减小降低了土颗粒之间的有效应力,从而使土的抗剪强度降低。In order to analyze the mechanism of loess landslide and the shear failure features,we took samples by the exploratory method in Yan＇an landslides,and carried out the indoor control suction consolidated drained shear tests. This test made 10 groups（ Q3 and paleosol each 5 groups） with a total of 40 samples. The test results showed that the two types of loess have different shear failure surface,and ancient soil particles due to high clay content.There is no apparent shear plane,But Q3 loess for large pore development,loose structure,and no viscosity,there are obvious shear planes. Under the influence of a constant vertical stress,and within the scope of the test done by suction,with increasing matric suction increases,internal friction angle was almost unchanged and C value increased significantly. As the water content increases,viscous resistance combined with a water film is reduced,so that the friction between the particles decreases,and so the suction and cohesion show a downward trend,reducing the attraction of the effect between soil particles stress,and the shear strength of the soil is reduced.

关 键 词：非饱和土 黄土 基质吸力 抗剪强度 

分 类 号：TU43[建筑科学—岩土工程]