scholarly journals Surficial Failure of Expansive Soil Cutting Slope and Its Flexible Support Treatment Technology

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Jie Xiao ◽  
He-ping Yang ◽  
Jun-hui Zhang ◽  
Xian-yuan Tang

The surficial failure of most expansive soil cutting slopes, subjected to the repeated wet-dry cycles, often occurs during or after rainfall following a long drought. The reason for this, however, is still unclear. Therefore, the laboratory tests were conducted to gain the saturated drained shear strength of the natural Nanning expansive soil considering the combined effects of swelling with loading and wet-dry cycles. The findings indicate that the envelope of shear strength, which significantly drops close or equal to zero, can be well fitted by the generalized power function. At the same time, the effect of shear strength parameters on the stability of the expansive soil cutting slope was investigated. The reasons for the shear strength attenuation of the natural expansive soil and the surficial failure of the expansive soil cutting slopes were analyzed. It is evident that the effective cohesion being small is a vital factor influencing the occurrence of surficial failure of an expansion soil slope. Moreover, an effective flexible support treatment measure was provided.

2015 ◽  
Vol 744-746 ◽  
pp. 547-550
Author(s):  
Hong Zhang ◽  
Guo Jun Sheng ◽  
Wen Qing Wu

The reinforcement of expansive soil cutting slope has been a difficulty for the construction industry. This study selected Wanyi Expressway as the construction background and used finite difference method for the numerical simulation and design optimization of expansive soil cutting slope reinforced by sash girder anchor bolts. Calculation results show that the cutting slope ratio is closely related to the stability of the expansive soil cutting slope and that the length, set angle, and vertical spacing of the anchor bolts significantly influence the deformation of the cutting slope. The original design plan was optimized according to the calculation results, and a positive effect in plan execution was achieved. This study may serve as a reference for other similar construction designs.


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 405-408 ◽  
pp. 299-303
Author(s):  
Bo Tan ◽  
Rui Zhang ◽  
Yan Ting Lai

Landslide of expansive soil slope is a serious disease and difficult to correct in highway construction. And the mechanism of landslide of expensive soil cutting slope is complex, so the traditional slope analysis method is unable to analyze it to obtain the reasonable explanation. But the numeric analytic method can obtain the stress, strain and plastic zone of side slope analysis the distortion process of earth slope and the latent sliding plane reasonably, adopt the safety factors to evaluate the slope stability, The paper based on ANSYS and adopts the nonlinear and elastoplasticity model of soil, and use the theory of the shear strength reduction method with FEM to analysis the rule of NanYou road expansive soil landslide. Keywords:Expensive soil landslide of cutting slope swelling force FEM


1970 ◽  
Vol 7 (3) ◽  
pp. 285-296 ◽  
Author(s):  
W. J. Eden ◽  
R. J. Mitchell

An appraisal of the drained shear strength of Leda clay under low effective normal stresses has resulted in a new appreciation of its behavior in this stress range which can be applied to consideration of the stability of slopes. Closely spaced planes of weakness existing in the apparently intact clay give rise to dilatant behavior and predominantly frictional shearing resistance. This mode of failure is consistent with field observations that have been compiled from numerous landslides; three of these landslides are analyzed in this paper.


2012 ◽  
Vol 204-208 ◽  
pp. 241-245
Author(s):  
Yang Jin

The stability of soil slope under seepage is calculated and analyzed by using finite element method based on the technique of shear strength reduction. When the condition of seepage or not is considered respectively, the critical failure state of slopes and corresponding safety coefficients can be determined by the numerical analysis and calculation. Besides, through analyzing and comparing the calculation results, it shows that seepage has a negative impact on slope stability.


2000 ◽  
Vol 37 (2) ◽  
pp. 449-462 ◽  
Author(s):  
Charles Harris ◽  
Antoni G Lewkowicz

Active-layer detachment slides are locally common on Fosheim Peninsula, Ellesmere Island, where permafrost is continuous, the active layer is 0.5-0.75 m thick, and summer temperatures are unusually high in comparison with much of the Canadian High Arctic. In this paper we report pore-water pressures at the base of the active layer, recorded in situ on two slopes in late July and early August 1995. These data form the basis for slope stability analyses based on effective stress conditions. During fieldwork, the factor of safety within an old detachment slide on a slope at Hot Weather Creek was slightly greater than unity. At "Big Slide Creek," on a slope showing no evidence of earlier detachment failures, the factor of safety was less than unity on a steep basal slope section but greater than unity elsewhere. In the upper slope, pore-water pressures were only just subcritical. Sensitivity analyses demonstrate that the stability of the shallow active layer is strongly influenced by changes in soil shear strength. Possible mechanisms for reduction in shear strength through time include weathering of soils and gradual increases in basal active layer ice content. However, we suggest here that soil shearing during annual gelifluction movements is most likely to progressively reduce shear strengths at the base of the active layer from peak values to close to residual, facilitating the triggering of active-layer detachment failures.Key words: detachment slides, Ellesmere Island, pore-water pressures, gelifluction.


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