岩土力学Issue(1)：189-196,8.
南阳膨胀土渠道滑坡破坏特征与演化机制研究
Study of failure characteristics and evolution mechanism of canal slope of Nanyang expansive soil
摘要
Abstract
In order to understand the mechanism of expansive soil canal slope slide, a study is conducted based on the statistical results of 19 landslides at the Nanyang Section of Middle Route of South-to-North Water Transfer Project. The right bank landslide at TS105+400 is selected as typical landslide. Excavating trench exposes internal structure of landslide. A series of geological survey has been done to study the characteristics and evolution mechanism of expansive soil landslide in the area by excavating trench slides. The results show that, most landslides in the area occurred in the al+pl2Q strata. Slope stability is jointly controlled by vertical joints in the upper layer soil and the gently dipping big fissures at the toe of the slope, which are filled with highly expansive clay. Sliding surface is composed of the steep tilting cracks at the trailing edge of slope and big gently dipping fractures at the toe of slope. Excavation unloading effect causes the vertical joints’ opening. These joints can extend more than 3 meters into the slope, which destroys the integrity of the slope soil and serves as the main channel for water to go in and out of the slope;there is a high humidity area 4 to 8 meters below the surface of slope. Soil within the area is weak and the sliding surface develops in it. Wetting and drying cycles caused by climate and excavation unloading lead to the vertical crack to open and propagation deep into slope. This effect causes a dramatic attenuation of soil strength. The vertical cracks connected with the big gently dipping fissures at the toe of the slope eventually. The slope slides after these fissure and crack are filled with water after the occurrence of strong lasting precipitation.关键词
膨胀土/渠道边坡/滑坡/成因机制Key words
expansive soil/canal slope/landslide/genetic mechanism分类
建筑与水利引用本文复制引用
陆定杰,陈善雄,罗红明,戴张俊,李扬帆,陈平..南阳膨胀土渠道滑坡破坏特征与演化机制研究[J].岩土力学,2014,(1):189-196,8.基金项目
“十二五”国家科技支撑计划项目课题(No.2011BAB10B02)。 （No.2011BAB10B02）
