scholarly journals Field Geological Investigations and Stability Analysis of Duanjiagou Landslide

2020 ◽  
Vol 9 (1) ◽  
pp. 23
Author(s):  
Wang ◽  
Xia ◽  
Zhang ◽  
Gao ◽  
Cheng
Keyword(s):  
Shear Strength ◽  
Shear Test ◽  
Unstable State ◽  
Force Transmission ◽  
Shear Strength Parameters ◽  
Strength Parameters ◽  
Transmission Method ◽  
Undisturbed Soil ◽  
The Stability ◽  
Sliding Zone

This paper analyses the stability of the Duanjiagou landslide on the Bazhong to Guangan Expressway K134–K135 segment in China. The Duanjiagou landslide took place on 4 November 2015. In order to discover the cause of the landslide, we carried out field geological investigations. The indoor physical property experiments were performed by taking the undisturbed soil sample from the borehole cores. To study the strength of the soil, we carried out a saturation direct shear test and saturation residual shear test on sliding zone soil samples. According to the physical properties of soil and the saturated shear strength parameters of sliding zone soil, the stability was analyzed by the landslide force transmission method and numerical simulation method. The results showed that in the initial sliding stage, the safety factor obtained by using the average value of saturated shear strength parameters was in good agreement with the field observation situation. The landslide was at an unstable state. The softening of soil and roadbed excavation at the foot of the slope are the main reasons for landslides.

scholarly journals Experimental Study on Variation Law and Mechanism of Soil Shear Strength Parameters along the Slope

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Yanhai Wang ◽  
Jianlin Li ◽  
Qiao Jiang ◽  
Yisheng Huang ◽  
Xinzhe Li
Keyword(s):  
Shear Strength ◽  
Direct Shear Test ◽  
Shear Test ◽  
Three Gorges Reservoir Area ◽  
Silty Clay ◽  
Direct Shear ◽  
Shear Strength Parameters ◽  
Strength Parameters ◽  
Undisturbed Soil ◽  
Soil Shear Strength

Under the action of rainwater seepage, geological origin, and human activities, the soil shear strength parameters will have spatial variability along the slope direction. After collecting samples of silty clay at a slope in the Three Gorges Reservoir area as the research object, not only the large-scale direct shear test was carried out on the site but also the direct shear test, water content test, density test, and particle grading analysis test were carried out in the laboratory with the undisturbed soil. The variation law and mechanism of soil shear strength parameters along slope were studied. The results indicate the following: (1) The coefficient of variation of shear strength parameters along the slope is relatively large. With the decrease of the elevation of the test location, the cohesion value tends to be strengthened, while the friction angle tends to degrade. (2) The mechanism of the variation law of soil shear strength parameters along the slope, which is mainly due to the decrease of the elevation, the decrease of the edges and angles between the particles, and the increase of the clay content is determined. (3) The variation model of shear strength parameters along the slope is proposed, which can provide a reference for relevant projects.

Slope Stability Analysis in Anisotropic Winnipeg Clays

1974 ◽  
Vol 11 (1) ◽  
pp. 59-71 ◽  
Author(s):  
W. S. Freeman ◽  
Hugh B. Sutherland
Keyword(s):  
Shear Strength ◽  
Cross Sections ◽  
Strength Properties ◽  
Shear Strength Parameters ◽  
Strength Parameters ◽  
Residual Shear Strength ◽  
Lower Shear ◽  
The Stability ◽  
Mechanism Of Failure ◽  
Cut Slopes

Two major aspects of an investigation dealing with the stability of natural and cut slopes in the Winnipeg area are described. The first concerns an experimental investigation of the anisotropic shear strength characteristics of the layered Lake Agassiz clays and the second is a study of the mechanism of failure for slopes in these layered clays.Four main types of clay were investigated and it was found that the effective shear strength parameters were greater for failure across the layers than for failure along the layers. Residual shear strength parameters were also determined.Stability analyses were carried out for representative slope cross sections using circular and noncircular failure surfaces, taking into account the anisotropic shear strength effects measured in the laboratory tests.Factors of safety were found for the conventional method of analysis assuming circular arc failure surfaces and isotropic shear strength properties. These factors of safety were found to be up to 0.5 greater than those obtained from noncircular failure surfaces which partially passed along the layers and so mobilized the lower shear strength properties of these layers.

scholarly journals Strength Characteristics and Slope Stability of Expansive Soil from Pingdingshan, China

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Ju-yun Zhai ◽  
Xiang-yong Cai
Keyword(s):  
Shear Strength ◽  
Slope Stability ◽  
Expansive Soil ◽  
Friction Angle ◽  
Natural Soil ◽  
Soil Slope ◽  
The Finite Element Method ◽  
Shear Strength Parameters ◽  
Strength Parameters ◽  
The Stability

By analyzing the characteristics of expansive soil from Pingdingshan, China, the shear strength parameters at different water contents, dry densities, and dry-wet cycles of expansive soil are obtained. It is found that, at higher soil-water content, the internal friction angle is 0° and the shallow layer of expansive soil slope will collapse and destroy; this has nothing to do with the height of the slope and the size of the slope. The parameters of soil influenced by atmosphere are the ones which have gone through dry-wet cycles, and the parameters of soil without atmospheric influence are the same as those of natural soil. In the analysis of slope stability, the shear strength parameters of soil can be determined by using the finite element method, and the stability coefficient of the expansive soil slope can be calculated.

Application of the Complex Variable Differential Method in the Back Analysis of Geotechnical Engineering

2010 ◽  
Vol 168-170 ◽  
pp. 2439-2444
Author(s):  
Ming Wei Liu ◽  
Ying Ren Zheng
Keyword(s):  
Shear Strength ◽  
Complex Variable ◽  
Back Analysis ◽  
Optimization Method ◽  
Differential Method ◽  
Analysis Method ◽  
Shear Strength Parameters ◽  
Strength Parameters ◽  
Measuring Point ◽  
The Stability

On the stability analysis of complex slope, the determination of rock-soil masses shear strength parameters is very important. It’s very necessary to use the back analysis method to verify experiment result of rock-soil masses parameters for the important slope engineering. Because the sensitivity of shear strength parameters to displacement parameters is very poor, so that we couldn’t get the satisfactory shear strength parameters result by traditional back analysis method. Aiming at the problems of traditional back analysis method, this paper puts forward a totally new method of back analysis, which is applicable to the shear strength parameters of rock-soil masses through the integration of complex variable differentiation method, optimization method and elastic-plasticity finite-element method. The method mathematically back calculates shear strength parameters of rock-soil masses on the basis of displacement of measuring point. The sample calculation result indicates that the method possesses high accuracy and searching efficiency, and is a method of back analysis of displacement deserving popularizing.

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