Back-Analysis Scheme of Shear Strength Parameters of Soil Slope Based on Strength Asynchronous Reduction Mode

Author(s):  
Gui Xu ◽  
Zhongda Chen ◽  
Kaiquan Xu ◽  
Yuanouyi Lei ◽  
Minrui Chen ◽  
...  
Géotechnique ◽  
2001 ◽  
Vol 51 (4) ◽  
pp. 373-374 ◽  
Author(s):  
L. D. Wesley ◽  
V. Leelaratnam

1985 ◽  
Vol 22 (2) ◽  
pp. 195-204 ◽  
Author(s):  
E. Karl Sauer ◽  
E. A. Christiansen

Little information is available about typical shear strength parameters of tills in southern Saskatchewan even though till is the most common earth material used for construction in this region. The Warman landslide in the South Saskatchewan River Valley provides some insight into the shear strength characteristics of a till, and the results are compared with laboratory tests. The till is from the Upper till of the Sutherland Group, which has a high clay content relative to the underlying and overlying tills. A back analysis of the landslide produced [Formula: see text]′ = 27° assuming c′ = 0. Comparison with laboratory test data and results from a similar landslide near Lebret, Saskatchewan, suggests that [Formula: see text]′ = 22.5° with c′ = 7 kPa may be appropriate "residual" shear strength parameters. A rising water table appears to have been the main contributing factor to instability between 1969 and 1984. There is a possibility, however, that at the 1:50 return interval for flood levels on the river, erosion at the toe of the landslide debris may be a significant factor. Numerous slump scars in the form of small amphitheatres, presently inactive, can be observed in the aerial photographs of the adjacent area. These failures likely occurred intermittently, depending on fluctuating water table and river flood levels. Key words: landslide, till, correlation, stratigraphy, back analysis, shear strength, residual, aerial photographs.


2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Ju-yun Zhai ◽  
Xiang-yong Cai

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.


2013 ◽  
Vol 860-863 ◽  
pp. 1280-1283
Author(s):  
He Wu ◽  
Qi Ge ◽  
Jing Bo Tian

In seasonal frozen regions, shallow landslide hazards in soil slopes usually happen. The type of failure surface is always on the freezing and thawing surface in the soil slope. So the direct influence factor of soil slope failure is the soil shear strength of the freezing and thawing (F-T) surface. The shear strength of the soil is determined by the two parameters of Cohesion c and Friction angle φ. In this study model experiment of F-T soil interface with different aggregate materials is designed by alternating the F-T cycle times, then the parameters c and the φ were obtained. Finally the deterioration modal of the two shear strength parameters of soil interface was put forward. The results demonstrated when the slope stability in the seasonal frozen regions was analyzed using shear strength reduction method, the two deterioration modals can provide the data reference for the analysis.


2010 ◽  
Vol 168-170 ◽  
pp. 2439-2444
Author(s):  
Ming Wei Liu ◽  
Ying Ren Zheng

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.


1979 ◽  
Vol 16 (1) ◽  
pp. 140-151 ◽  
Author(s):  
R. A. Widger ◽  
D. G. Fredlund

A common occurrence in cuts or fills of swelling soils is their reduction in strength with time. At the time of compaction, the clay generally has a high matrix suction. Correspondingly, it has a high strength and will stand at relatively steep side slopes. With time, the soil generally tends towards saturation and the matrix suction reduces towards zero. There is a reduction in total strength and if the gravitational forces are too large, the slope fails.During the past several years, numerous cut and fill slopes have been observed in the Regina area of Saskatchewan. Many of these slopes have remained stable for 4–6 years and then failed. There has been a 20 year history of observations on the Belle Plaine overpass west of Regina. Field and laboratory investigations have been conducted.With a knowledge of the geometry of the slope and failure plane, the simplified Bishop method of stability analysis was used to perform a 'back-analysis' to assess the shear strength parameters. The shear strength parameters from the laboratory program are compared with those calculated from the stability analyses. The analyses indicate that the peak shear strength parameters from triaxial tests on the softened Regina clay (i.e., c' = 5 kPa and [Formula: see text]), with the appropriate pore water pressures, give a factor of safety of 1 for the failed surface. The effect of spring thawing appears to be to produce the condition of most serious pore water pressures.


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