scholarly journals Slope Stability of a Scree Slope Based on Integrated Characterisation and Monitoring

Water ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 447 ◽  
Author(s):  
Daisy Lucas ◽  
Kerstin Fankhauser ◽  
Hansruedi Maurer ◽  
Brian McArdell ◽  
Reto Grob ◽  
...  

Three years of geotechnical seasonal field monitoring including soil temperature, suction and volumetric water content plus geophysical measurements, lead to a preliminary ground model and assessment of slope stability for a steep scree slope in the Meretschibach catchment, near Agarn village in the Swiss Alps. Building on data reported in a previous paper, which focused on preliminary ground characterisation and seasonal field monitoring, this current research aims to understand whether a surficial failure in the scree slope, triggered by rainfall and depending on bedrock conditions, would represent a relevant natural hazard for Agarn village. A final year of field data is included as well as site-specific sensor calibration, a Ground Penetrating Radar (GPR) profile, and laboratory triaxial testing to provide strength parameters. A bedrock map is presented, based on GPR, with a realistic ground model of the entire scree slope. Furthermore, a preliminary numerical analysis, performed using SEEP-SLOPE/W, shows the influence of a bedrock outcrop observed in the field, for a specific soil thickness, strength parameters and rain intensity. The stability of a gravelly slope decreases with groundwater flow over a step in the bedrock, and the location of the failure will tend to move uphill of a bedrock outcrop at a shallow depth as groundwater flow increases.

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.


2019 ◽  
Vol 92 ◽  
pp. 18009
Author(s):  
Yukun Wei ◽  
Anders B. Lundberg ◽  
Fredrik Resare

Field monitoring is frequently carried out during excavations and other geotechnical activities and provides additional information during the execution of a construction project. The interpretation of field monitoring data is often obscured by measurement noise and disturbance, and a systematic approach to assess both the quality and implications of the field monitoring data is very helpful in geotechnical practice. The possibility to infer practical conclusions from the field monitoring data depends on the type of field measurements, especially in monitoring of the stability of slopes. Pore pressure measurements can serve as a direct measurement of utilized soil strength for a slope, while deformation measurements are significantly more ambiguous and complicates the interpretation. The assessment of slope stability through field monitoring of deformations requires inverse or back analysis of the soil properties, followed by a forward analysis of the resulting slope stability. Such an inverse or back analysis is frequently influenced by non-uniqueness of the material properties and the stability of the measurement data. Systematic approaches to inverse or back analysis have been demonstrated in the scientific literature, but the practical use of these methods is not entirely straight-forward. The current paper presents a case study of systematic slope stability assessment through field measurements of deformations with a review of the field monitoring programme, numerical simulations of deformations, and a simplified approach to back analysis of the soil parameters. The excavation of a slope in an urban environment including layers of organic clay covered with highly heterogeneous gravel fill is used as an example of geotechnical back analysis. The aim is to elucidate some of the challenges in geotechnical back analysis while providing some practical solutions for practice.


1977 ◽  
Vol 14 (4) ◽  
pp. 466-476 ◽  
Author(s):  
Robert A. L. Hodge ◽  
R. Allan Freeze

Slope stability analyses carried out in terms of effective stress require an understanding of the distribution of pore-water pressures in a slope. This understanding must be based on a knowledge of the groundwater flow system, which is in turn dependent on the regional geologic environment and the configuration of hydraulic conductivity contrasts. This paper presents several computer simulations of flow systems in a variety of hypothetical slopes. Results show that the presence of low-conductivity units at the surface or at depth can be extremely detrimental to stability, particularly if they confine units of higher conductivity. The contrast in conductivity need not be more than two orders of magnitude. Such situations are common in thrust blocks, interbedded sedimentary rocks, weathering profiles, and deformed metamorphic rocks. Groundwater conditions critical to stability arise in anisotropic formations, where the axis of maximum conductivity is parallel to the dip of the slope. Fluctuations in regional flow systems can be critical to the stability of unconsolidated, terraced sediments.


2020 ◽  
Author(s):  
Brett Carr ◽  
Einat Lev ◽  
Loÿc Vanderkluysen ◽  
Danielle Moyer ◽  
Gayatri Marliyani ◽  
...  

KURVATEK ◽  
2018 ◽  
Vol 3 (1) ◽  
pp. 21-34
Author(s):  
Untung Wahyudi ◽  
Excelsior T P ◽  
Luthfi Wahyudi

PT. Putera Bara Mitra used open mining system for mining operation, Yet the completion of study on the end wall slope stability that  undertaken by geotechnical PT. Putera Bara Mitra in Northwest Pit and the occured a failure in the low wall on the 1st June 2012 led to the need for analysis and design the overall slope at the mine site. To analyze and design the overall slope, used value of the recommended minimum safety. The value was based on company for single slope SF ≥ 1.2 and SF ≥ 1.3 for overall slope. The calculation used Bichop method with the help of software slide v 5.0. Geometry improvements was done at the low slopes that originally single wall with a 30 m bench height and a slope 70° with SF = 0.781, into 4 levels with SF = 1.305. The analysis explained the factors that affect the stability of the low wall included the mining slope geometry, unfavorable drainase system, material stockpiles and seismicity factors. It was necessary to do prevention efforts to maintain the stability of the slope included the redesign to slope geometry, handling surface and subsurface water in a way to control slopes draining groundwater, vegetation stabilization using and monitoring slope using Total Station with Prism and Crackmeter to determine the movement of cracks visible on the surface. 


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.


2012 ◽  
Vol 170-173 ◽  
pp. 847-852
Author(s):  
Peng Ming Jiang ◽  
Zhong Lei Yan ◽  
Peng Li

As the complexity of unsaturated soil theory, and it must have a long test period when we study the unsaturated soils, so the conventional design analysis software does not provide such analysis, so we can imagine that such a slope stability analysis does not accurately reflect the actual state of the slope. Based on the known soil moisture content,this paper use the soil water characteristic curve and strength theory of unsaturated soil to calculate the strength reduction parameters of soil which can calculate the stability of the soil slope when using the common calculation method. It is noticeable that this method can be extended and applied if we establish regional databases for this simple method, and these databases can improve the accuracy of the calculation of slope stability.


1983 ◽  
Vol 20 (4) ◽  
pp. 661-672 ◽  
Author(s):  
R. K. H. Ching ◽  
D. G. Fredlund

Several commonly encountered problems associated with the limit equilibrium methods of slices are discussed. These problems are primarily related to the assumptions used to render the inherently indeterminate analysis determinate. When these problems occur in the stability computations, unreasonable solutions are often obtained. It appears that problems occur mainly in situations where the assumption to render the analysis determinate seriously departs from realistic soil conditions. These problems should not, in general, discourage the use of the method of slices. Example problems are presented to illustrate these difficulties and suggestions are proposed to resolve these problems. Keywords: slope stability, limit equilibrium, method of slices, factor of safety, side force function.


2001 ◽  
Author(s):  
Steven J. DeTeresa ◽  
Gregory J. Larsen

Abstract It is shown that the two interactive strength parameters in the Tsai-Wu tensor polynomial strength criterion for fiber composites can be derived in terms of the uniaxial or non-interacting strength parameters if the composite does not fail under practical levels of hydrostatic pressure or equal transverse compression. Thus the required number of parameters is reduced from seven to five and all five of the remaining strength terms are easily determined using standard test methods. The derived interactive parameters fall within the stability limits of the theory, yet they lead to open failure surfaces in the compressive stress quadrant. The assumptions used to derive the interactive parameters were supported by measurements for the effect of hydrostatic pressure and unequal transverse compression on the behavior of a typical carbon fiber composite.


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