Stability Analysis on Shallow Layer Failure of Soil Slope Based on Unsaturated Soil Strength Theory

被引：0
|
作者：
Li X. [1 ,2 ]
Chen H. [1 ]
Li J. [1 ]
Yang C. [2 ]
机构：
[1] College of Traffic and Transportation, Chongqing Jiaotong Univ., Chongqing
[2] Key Lab. of Geological Hazards Controlling on Three Gorges Reservoir Area of Ministry of Education, Three Gorges Univ., Yichang
来源：
Gongcheng Kexue Yu Jishu/Advanced Engineering Sciences | 2019年 / 51卷 / 02期
关键词：
Logarithmic spiral; Shallow layer failure mode; Soil slope; Stability analysis; Unsaturated soil strength theory;
D O I：
10.15961/j.jsuese.201800359
中图分类号：
学科分类号：
摘要：
Based on unsaturated soil strength theory, a discriminant equation is established for the critical failure state of soil element in slope, and a combined failure mode of " upper and lower edge parallel slope curved surface" for soil slope is proposed, which includes three sliding regions composed of the tension zone at upper edge, the main slide zone in middle and the squeeze zone at lower edge. It is demonstrated that the failure surface morphology of the upper and lower edge sliding mass coincides with the logarithmic spiral. A new stability analysis method is established for unsaturated soil slope based on the limit equilibrium theory. The results shows that the relationships between landslide depth zw and main slide zone length L2 are better reflected using this combined failure mode of " upper and lower edge parallel slope curve". The stability of shallow soil slope decreases and tends gradually to the results of infinite slope stability with increase of the main slide zone length L2. For saturated soil slope, the effects of internal friction angle and slope angle on slope stability are very little, but the influence of cohesion is significant. For unsaturated soil slope, the slope stability is reduced apparently as cohesion and internal friction angle decreases and slope angle increases. As the soil slope is in critical state (i. e. safety factor FS=1.0), the sliding surface of potential landslide gradually migrates to the shallow layer with the increase of soil saturation. It indicates that the soil slope with rising saturation caused by rainfall is more prone to shallow failure. Compared with the traditional infinite length slope stability analysis method, for a finite length soil slope, this combined failure stability analysis method is more reasonability and accuracy because of the consideration of the mechanical effects of upper and lower edge zone. © 2019, Editorial Department of Advanced Engineering Sciences. All right reserved.
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页码：61 / 70
页数：9
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