scholarly journals Slope Stability Calculation Method of Highwall Mining with Open Cut Mines as an Example

2021 ◽  
Author(s):  
Juyu Jiang ◽  
Ye Lu ◽  
Dong Wang ◽  
Xinping Han
Keyword(s):  
Slope Stability ◽  
Recovery Rate ◽  
Limit Equilibrium ◽  
Coal Pillar ◽  
Time Dependent ◽  
Universal Method ◽  
Stability Calculation ◽  
Target Time ◽  
Highwall Mining ◽  
Overlying Strata

Abstract Highwall mining machines have been used to recover retained coal at the toe of highwalls and endwalls over the past few decades. However, there has not been a universal method to evaluate the slope stability using highwall mining while maximizing the recovery rate. Based on the required service time of coal pillars, this study proposes the concept of the target time pillar strength. To obtain time-dependent parameters for the coal, time-dependent shear tests were performed on specimens from an open-cut mine in Inner Mongolia. The highwall mining length was divided into three categories based on discontinuous structural plane theory: goaf, yielding, and elastic zones. The three zones were considered to all have resistances against shear stress. The basal coal seam is likely to become weak due to weight from the overlying strata, which may change the slope failure mode from circular to sliding along the weak layer. Numerical modeling was used to study the influence of the overlying strata and target time strength on the yielding zone development at the coal pillar ribs. The coefficients of the three zones were determined and substituted into the Mohr-Coulomb equation to obtain the time-dependent shear strength parameters. Subsequently, the influence of highwall mining on the slope stability was evaluated using the rigid body-limit equilibrium method (LEM). The optimized coal pillar width is determined to maximize the recovery rate without compromising the slope stability.

scholarly journals Slope stability calculation method for highwall mining with open-cut mines

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Juyu Jiang ◽  
Ye Lu ◽  
Dong Wang ◽  
Xinping Han
Keyword(s):  
Shear Strength ◽  
Slope Stability ◽  
Calculation Method ◽  
Coal Pillar ◽  
Time Varying ◽  
Shear Strength Parameters ◽  
Strength Parameters ◽  
Stability Calculation ◽  
Target Time ◽  
Highwall Mining

AbstractSlope stability is a prominent problem for the efficient application and promotion of highwall mining technology, especially when mining residual coal under high and steep end-slope conditions. This study proposes the concept of target time pillar strength based on the required coal pillar service time. Creep tests were performed to measure the time-varying properties of coal shear strength parameters under different loads, and a time-varying function was established by regression. The highwall mining length is divided into three categories based on discontinuous structural plane theory, including goaf, yielding, and elastic zones, all of which are considered to have resistances against shear stress. The basal coal seam is prone to weakening owing to the weight of overlying strata, which may shift the slope failure mode from circular to sliding along the weak layer. Numerical modeling was used to study the influence of the bearing stress and target time strength on the development of the yielding zone at the coal pillar ribs. The coefficients of the three zones were determined, and the temporal and spatial evolution patterns of the shear strength parameters of the weak layer were acquired. A slope stability calculation method is proposed based on rigid body-limit equilibrium theory that can quantify the influence of highwall mining operations on slope stability, which is significant for popularizing highwall mining technology.

scholarly journals Slope stability analysis under rainfall conditions considering unsaturated characteristics of materials

2020 ◽  
Vol 165 ◽  
pp. 03030
Author(s):  
Sha Wang ◽  
Guodong Mei ◽  
Xuyang Xie ◽  
Li Yaoxuan ◽  
Lu Yao
Keyword(s):  
Slope Stability ◽  
Safety Management ◽  
Limit Equilibrium ◽  
Extreme Rainfall ◽  
Calculation Model ◽  
Mine Safety ◽  
Stability Calculation ◽  
Safety Coefficient ◽  
Practical Engineering ◽  
Seepage Theory

As one of the important facilities in mines, the dump has become one of the major hidden dangers of mine safety management due to its large volume and loose structure. In this paper, based on unsaturated seepage theory of soil and practical engineering slope cases, the slope stability calculation model based on Bishop limit equilibrium method is established. This paper analyzes and calculates the evolution law of slope stability under extreme rainfall, obtains the law of slope stability safety coefficient changing with rainfall under unsaturated characteristics, and puts forward the corresponding countermeasures.

Influence of Underground Mining on Failure Mode and Stability of Counter-Tilt Slope in Surface Mines

2012 ◽  
Vol 594-597 ◽  
pp. 80-85
Author(s):  
Dong Wang ◽  
Lan Zhu Cao ◽  
Chun De Piao ◽  
Run Cai Bai
Keyword(s):  
Failure Mode ◽  
Failure Modes ◽  
Underground Mining ◽  
Limit Equilibrium ◽  
Surface Mining ◽  
Stability Calculation ◽  
Deformation And Failure ◽  
Surface Mines ◽  
The Stability ◽  
Overlying Strata

How to demonstrate the deformation and failure mode of the slope under combine surface and underground mining and evaluate its stability scientifically is one of the problems that need urgent solutions in mining engineering. First, the deformation and failure mode of the slope under simple surface mining, the deformation and failure mechanism of the overlying strata affected by underground mining and deformation mechanism of the slope under combined surface and underground mining were analyzed, then the failure mode and the stability calculation method of the slope under combined surface and underground mining was studied. The results show that the failure modes of the slope under combined surface and underground mining involve three patterns: slipping failure, subsiding failure and slipping-subsiding combined failure, that the failure modes and the stability of the slope under combined surface and underground mining be significantly affected by the underground mining positions and the influence be mainly controlled by the length of the latent slide plane of the slope and the weakening degree of the rock masses in the subsidence range. Finally, a limit equilibrium method to calculate the slope stability under combined surface and underground mining was put forward.

scholarly journals The Hydromechanical Interplay in the Simplified Three-Dimensional Limit Equilibrium Analyses of Unsaturated Slope Stability

Geosciences ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 73
Author(s):  
Panagiotis Sitarenios ◽  
Francesca Casini
Keyword(s):  
Analytical Solution ◽  
Slope Stability ◽  
Slope Failure ◽  
Failure Modes ◽  
Pore Water Pressure ◽  
Limit Equilibrium ◽  
Water Pressure ◽  
Three Dimensional ◽  
Stability Limit ◽  
Smooth Transition

This paper presents a three-dimensional slope stability limit equilibrium solution for translational planar failure modes. The proposed solution uses Bishop’s average skeleton stress combined with the Mohr–Coulomb failure criterion to describe soil strength evolution under unsaturated conditions while its formulation ensures a natural and smooth transition from the unsaturated to the saturated regime and vice versa. The proposed analytical solution is evaluated by comparing its predictions with the results of the Ruedlingen slope failure experiment. The comparison suggests that, despite its relative simplicity, the analytical solution can capture the experimentally observed behaviour well and highlights the importance of considering lateral resistance together with a realistic interplay between mechanical parameters (cohesion) and hydraulic (pore water pressure) conditions.

Slope Stability Analysis of Elastic Limit Equilibrium Method

2013 ◽  
Vol 275-277 ◽  
pp. 1423-1426
Author(s):  
Lin Kuang ◽  
Ai Zhong Lv ◽  
Yu Zhou
Keyword(s):  
Stability Analysis ◽  
Slope Stability ◽  
Safety Factor ◽  
Slip Surface ◽  
Limit Equilibrium ◽  
Limit Equilibrium Method ◽  
Slope Stability Analysis ◽  
Sliding Surface ◽  
Tangential Stresses ◽  
Equilibrium Method

Based on finite element analysis software ANSYS, slope stability analysis is carried out by Elastic limiting equilibrium method proposed in this paper. A series of sliding surface of the slope can be assumed firstly, and then stress field along the sliding surface is analyzed as the slope is in elastic state. The normal and tangential stresses along each sliding surface can be obtained, respectively. Then the safety factor for each slip surface can be calculated, the slip surface which the safety factor is smallest is the most dangerous sliding surface. This method is different from the previous limit equilibrium method. For the previous limit equilibrium method, the normal and tangential stresses along the sliding surface are calculated based on many assumptions. While, the limit equilibrium method proposed in this paper has fewer assumptions and clear physical meaning.

Some difficulties associated with the limit equilibrium method of slices

1983 ◽  
Vol 20 (4) ◽  
pp. 661-672 ◽  
Author(s):  
R. K. H. Ching ◽  
D. G. Fredlund
Keyword(s):  
Slope Stability ◽  
Factor Of Safety ◽  
Limit Equilibrium ◽  
Stability Limit ◽  
Limit Equilibrium Method ◽  
Soil Conditions ◽  
Side Force ◽  
Limit Equilibrium Methods ◽  
Equilibrium Method ◽  
The Stability

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.

scholarly journals Physical Modeling of the Controlled Water-Flowing Fracture Development during Short-Wall Block Backfill Mining

Lithosphere ◽  
2021 ◽  
Vol 2021 (Special 4) ◽  
Author(s):  
Yun Zhang ◽  
Yongzi Liu ◽  
Xingping Lai ◽  
Jianming Gao
Keyword(s):  
Coal Pillar ◽  
Similarity Criterion ◽  
Test Results ◽  
Control Effect ◽  
Physical Similarity ◽  
Wall Block ◽  
Fracture Development ◽  
Backfill Mining ◽  
Backfill Materials ◽  
Overlying Strata

Abstract Short-wall block backfill mining (SBBM) technology is an effective method to solve the environmental problems in the mining process. Based on the technical characteristics of SBBM technology and the physical similarity criterion, the physical similarity models for comparing the control effects of water-flowing fracture (WFF) development using short-wall block cave mining (SBCM) and SBBM were established, and the deformation and the WFF development of overlying strata above gob were monitored. The test results determined that the composite materials of 5 mm thick pearl sponge+5 mm thick sponge+10 mm thick paper+6 mm thick board were adopted as the similar backfill materials by comparing the stress-strain curves between the similar backfill materials and the original gangue sample. When the backfilling body was filled into the gob, it would be the permanent bearing body, which bore the load of the overlying strata accompanied with the protective coal pillar. At the same time, the backfilling body also filled the collapse space of overlying strata, which was equivalent to reduce the mining height, and effectively reduced the subsidence and failure height of the overlying strata. Compared with SBCM, the test results showed that the maximum vertical deformation, the height of water-flowing fractured zone, and activity range of overlying strata using SBBM were reduced by 91.4%, 82.5%, and 64.9%, respectively. SBBM had a significant control effect on strata damage and WFF development, which could realize the purpose of water resource protection in coal mines.

scholarly journals Renormalization Group Approach to Pandemics as a Time-Dependent SIR Model

2021 ◽  
Vol 8 ◽  
Author(s):  
Michele Della Morte ◽  
Francesco Sannino
Keyword(s):  
Renormalization Group ◽  
Time Dependence ◽  
Recovery Rate ◽  
Sir Model ◽  
Time Dependent ◽  
Cumulative Number ◽  
Group Approach ◽  
Renormalization Group Approach

We generalise the epidemic Renormalization Group framework while connecting it to a SIR model with time-dependent coefficients. We then confront the model with COVID-19 in Denmark, Germany, Italy and France and show that the approach works rather well in reproducing the data. We also show that a better understanding of the time dependence of the recovery rate would require extending the model to take into account the number of deaths whenever these are over 15% of the cumulative number of infected cases.

scholarly journals Application of Harmony Search Algorithm to Slope Stability Analysis

Land ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1250
Author(s):  
Sina Shaffiee Haghshenas ◽  
Sami Shaffiee Haghshenas ◽  
Zong Woo Geem ◽  
Tae-Hyung Kim ◽  
Reza Mikaeil ◽  
...  
Keyword(s):  
Stability Analysis ◽  
Slope Stability ◽  
Safety Factor ◽  
Search Algorithm ◽  
Limit Equilibrium ◽  
Harmony Search ◽  
Harmony Search Algorithm ◽  
Slope Stability Analysis ◽  
Unit Weight ◽  
Slope Safety

Slope stability analysis is undoubtedly one of the most complex problems in geotechnical engineering and its study plays a paramount role in mitigating the risk associated with the occurrence of a landslide. This problem is commonly tackled by using limit equilibrium methods or advanced numerical techniques to assess the slope safety factor or, sometimes, even the displacement field of the slope. In this study, as an alternative approach, an attempt to assess the stability condition of homogeneous slopes was made using a machine learning (ML) technique. Specifically, a meta-heuristic algorithm (Harmony Search (HS) algorithm) and K-means algorithm were employed to perform a clustering analysis by considering two different classes, depending on whether a slope was unstable or stable. To achieve the purpose of this study, a database made up of 19 case studies with 6 model inputs including unit weight, intercept cohesion, angle of shearing resistance, slope angle, slope height and pore pressure ratio and one output (i.e., the slope safety factor) was established. Referring to this database, 17 out of 19 slopes were categorized correctly. Moreover, the obtained results showed that, referring to the considered database, the intercept cohesion was the most significant parameter in defining the class of each slope, whereas the unit weight had the smallest influence. Finally, the obtained results showed that the Harmony Search algorithm is an efficient approach for training K-means algorithms.

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