scholarly journals Effect of Blast-induced Ground Vibration on Factor of Safety of Pit Wall Stability

2020 ◽  
Vol 1 (2) ◽  
Author(s):  
Pirat Jaroonpattanapong ◽  
Kittikun Pantachang ◽  
Thungfung S. ◽  
Petthong N.
Keyword(s):  
Slope Stability ◽  
Natural Condition ◽  
Factor Of Safety ◽  
Limit Equilibrium ◽  
Ground Vibration ◽  
Open Pit ◽  
Charge Weight ◽  
Plane Failure ◽  
Maximum Charge ◽  
The Stability

The regulated maximum peak particle velocity (PPV) from blasting operations of an open-pit coal mine is less than 2 mm/s to prevent mainly any public disturbance such as ground vibration and air blast. However, the blast-induce ground vibration can also decrease the stability of pit slope, which has not been intensively studied. A claystone pit wall, which is geotechnically investigated as having a plane failure type and the natural condition factor of safety (FS), has been selected for this study. The FS is selected to measure the effect of blast-induced ground vibration on the slope stability. The limit equilibrium, pseudo-static 1 (), and pseudo-static 2 () methods are used to determine the FS. The vibration results of blasting monitored at three slope positions: crest, middle, and toe, from two areas at the same pit wall, are recorded by blasting seismographs. Maximum charge weight per delay and the distance from blast areas to seismographs are collected to construct the scaled distance. The percentage change of FS of three methods from both areas compared to natural condition FS are all less than 4 percent considered that the slope stability is safe from blasting vibration (less than 15 percent). The relationship between the FS and maximum PPV from the limit equilibrium, pseudo-static 1 (), and pseudo-static 2 () methods indicate that the adverse maximum PPVs given the unity FS are 16.60 and 4.58, and 4.74 mm/s, respectively. The regulated PPV less than 2 mm/s at the mine is reasonable to prevent any possible plane failure. However, many impact parameters have not been included in this study, and their effects may disturb the pit wall stability.

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 AN EVALUATION OF ROCK SLOPE STABILITY USING LIMIT EQUILIBRIUM ANALYSES

2015 ◽  
Vol 6 (2) ◽  
Author(s):  
Faridha Aprilia ◽  
I Gde Budi Indrawan
Keyword(s):  
Slope Stability ◽  
Rock Slope ◽  
Limit Equilibrium ◽  
Rock Slope Stability ◽  
Rock Slopes ◽  
Plane Failure ◽  
General Limit ◽  
The Stability ◽  
Equilibrium Analyses ◽  
Limit Equilibrium Analyses

The stability of rock slopes is controlled by several factors, such as the intact rock strength, discontinuity characteristics, groundwater condition, and slope geometry. Limit equilibrium (LE) analyses have been commonly used in geotechnical practice to evaluate the stability of rock slopes. A number of methods of LE analyses, ranging from simple to sophisticated methods, have been developed. This paper presents stability analyses of rock slopes at the Batu Hijau open mine in Sumbawa Barat using various methods of LE analyses. The LE analyses were conducted at three cross sections of the northern wall of the open mine using the Bishop Simplified, Janbu Simplified, Janbu Generalised, and General Limit Equilibrium (GLE) methods in Slide slope stability package. In addition, a Plane Failure (PF) analysis was performed manually. Shear strength data of the discontinuity planes used in the LE analyses were obtained from back analyses of previous rock slope failures. The LE analysis results showed that the rock slopes were likely to have shallow non-circular critical failure surfaces. The factor of safety (Fs) values obtained from the Bishop Simplified, Janbu Simplified, Janbu Generalised, and GLE methods were found to be similar, while the Fs values obtained from the PF method were higher than those obtained from the more rigorous methods. Keywords: Batu Hijau mine, Bishop Simplified, Janbu Simplified, Janbu Generalised, limit equilibrium analyses, general limit equilibrium, rock slope stability, plane failure.

Comparing slope stability analysis using limit equilibrium and finite elements simulations of deep-seated landslides along the western margin of the Main Ethiopian Rift

2021 ◽  
Author(s):  
Tesfay Kiros Mebrahtu ◽  
Thomas Heinze ◽  
Stefan Wohnlich
Keyword(s):  
Slope Stability ◽  
Factor Of Safety ◽  
Limit Equilibrium ◽  
Limit Equilibrium Method ◽  
Strength Reduction ◽  
Ethiopian Rift ◽  
Seismic Load ◽  
Main Ethiopian Rift ◽  
Western Margin ◽  
The Stability

<p>Landslides and ground failures are among the common geo-environmental hazards in many of the tectonically active hilly and mountainous terrains of Ethiopia, such as in the western margin of the Main Ethiopian Rift in Debre Sina area. Besides the geological preconditioning, bi-modal monsoon and seismic events in the tectonically highly active region are usually suspected triggers. In order to minimize the damage caused by the slope failure events, a detailed investigation of landslide-prone areas using numerical modelling plays a crucial role. The aim of this study is to assess the stability of slopes, to understand the relevant failure mechanisms, and to evaluate and compare safety factors calculated by the different available numerical methods. The stability was assessed for slopes of complex geometry and heterogeneous material using the limit equilibrium method and the shear strength reduction method based on finite elements. Furthermore, numerical analysis was done under static and pseudo-static loading using the horizontal seismic coefficient to model their stability during a seismic event. The slope stability analysis indicates that the studied slopes are unstable, and any small scale disturbance will further reduce the factor of safety and probably causing failure. The critical strength reduction factors from the finite element method are significantly lower than the factor of safety from the limit equilibrium method in all studied scenarios, such as Bishop, Janbu Simplified, Spencer and Morgenstern-Price. The difference is especially evident for heterogeneous slopes with joints, which often are initiation points for the failure planes. The simulations show that slope stability of landslide prone hills in the study area strongly depends on the saturation conditions and the seismic load. The studied slopes are initially close to failure and increased pore-pressure or seismic load are very likely triggers.</p>

scholarly journals Vibration Management for Slope Stability with “Signature Hole Analysis” Method in Open Pit Blasting Activity

2019 ◽  
Vol 1 (1) ◽  
pp. 29-35
Author(s):  
Muhammad Syafiq Isnaya ◽  
Muhammad Fadil Bellico ◽  
Dwi Agung Priyanggoro
Keyword(s):  
Wave Propagation ◽  
Slope Stability ◽  
Ground Vibration ◽  
Open Pit ◽  
Analysis Method ◽  
Scaled Distance ◽  
The Stability ◽  
The Impact

One of the impact blasting activity is Ground Vibration which will affect the stability of the slope. Research and experiment conducted using Signature Hole Analysis (SHA) for monitoring wave propagation in each block-strip used to model and predict vibration which caused by the blasting activity. Signature Hole Analysis combined with Scaled Distance has succeeded in becoming the solution of ground vibration management.

scholarly journals Slope stability evaluation and monitoring of Tonglushan ancient copper mine relics

2018 ◽  
Vol 10 (8) ◽  
pp. 168781401879170 ◽  
Author(s):  
Zhigang Tao ◽  
Chun Zhu ◽  
Xiaohui Zheng ◽  
Manchao He
Keyword(s):  
Slope Stability ◽  
Limit Equilibrium ◽  
Warning System ◽  
Open Pit ◽  
Western Slope ◽  
Factors Affecting ◽  
Copper Mine ◽  
Limit Equilibrium Methods ◽  
The Stability ◽  
Major Factors

Due to natural environmental conditions and the effect of man, geological disasters (landslides, earthquakes, etc.) pose a serious threat to ancient relics distributed across China. In consideration of the current situation at the Tonglushan ancient copper mine relics, and on the basis of hydrology and geological engineering conditions of ancient relics, major factors affecting slope stability of ancient relics are analyzed. In light of major working condition types in the slopes of ancient relics, slope stability in relation to earthquakes and rainfall is analyzed using GeoStudio software with limit equilibrium methods. Results indicate that, with sustained rainfall, all slopes in the current reinforcement measure maintain a suitable stabilization status, but slope stability will sharply decline in response to an earthquake. Therefore, the influence of mining blasting activities on slope stability is analyzed. In view of the deformation characteristics of ancient copper mines, the sliding force remote monitoring and warning system based on the constant resistance and large deformation anchor bolt is adopted to continuously monitor the stability of the west slope of the relics. Monitoring results show that the application of “mechanical gun” instead of “explosive blasting” mining technique in the open-pit mine has effectively reduced the influence of mining disturbance on the stability of the western slope. As slope deformation of the relics can be effectively monitored and controlled, our findings provide a theoretical basis to analyze slope stability in other similar cultural relics.

Stability Analysis on High and Steep Slope of Open-Pit Based on Limit Equilibrium Method

2015 ◽  
Vol 777 ◽  
pp. 106-111 ◽  
Author(s):  
Zhen Hua Xie ◽  
Ran Yi Xie ◽  
Xiao Yue Lu
Keyword(s):  
Stability Analysis ◽  
Slope Stability ◽  
Limit Equilibrium ◽  
Limit Equilibrium Method ◽  
Slope Stability Analysis ◽  
Steep Slope ◽  
Open Pit ◽  
Safety Coefficient ◽  
The Stability ◽  
High And Steep Slope

The stability of slope in open-pit affects the economic benefits and safety production of mining enterprises. From the two aspects of internal factors and external factors, this paper analyses the factors affecting the slope stability of open-pit, discusses the basic theory of slope stability analysis, and puts forward the criterion of slope stability based on the safety coefficient. The limit equilibrium method is chosen to analyze the stability of the high and steep slope of open-pit in this paper, and the SLIDE software is used for numerical simulation according to the actual slope model of certain open-pit. The simulation results show that the slope safety coefficient of the instance is 1.01, which is unstable slope. When the number of the slope blocks is more than 40, the safety coefficient tend to be stable. Blasting vibration has a great influence on slope stability. The results of slope stability analysis provide a scientific guidance for the prevention and control of the slope instability.

scholarly journals Multi-level and Precise Evaluation of Slope Stability in Large Open-pit Mines: a Case Study at Dexing Copper Mine, China

2021 ◽  
Author(s):  
Shigui Du ◽  
Charalampos Saroglou ◽  
Yifan Chen ◽  
Hang Lin ◽  
Yong Rui
Keyword(s):  
Slope Stability ◽  
Limit Equilibrium ◽  
Equilibrium Analysis ◽  
Open Pit ◽  
Estimation Methods ◽  
Open Pit Mining ◽  
Copper Mine ◽  
Mine Slope ◽  
The Stability

Abstract As the mining industry developed significantly in the last decades and the depth of open-pit mining has increased, the stability of large open-pit slopes has become a major problem directly related to the safety production and development of a mine. However, the overall slope is indeed safer than the local slope based on the existing stability estimation methods. So the existing methods of directly analyzing the stability of the overall slope will produce some errors in the calculation results of the safety factor, and cannot comprehensively reflect the stability of the mine slope. Based on these problems, this paper adopted the idea of gradual analysis and the precise determination of discontinuity properties to perform a limit equilibrium analysis for the evaluation of mine slope stability. A case study slope, referred to as Yangtaowu Slope in Dexing Copper Mine, was selected for the demonstration of the accuracy of this approach. The results indicate that the adopted method can accurately reflect the actual stability of the slope, especially when the mine slope is near the critical state of stability.

scholarly journals SLOPE STABILITY ANALYSIS OF WASTE DUMP IN SANDSTONE OPEN PIT OSIELEC

2013 ◽  
Vol 35 (1) ◽  
pp. 3-17 ◽  
Author(s):  
Justyna Adamczyk ◽  
Marek Cała ◽  
Jerzy Flisiak ◽  
Malwina Kolano ◽  
Michał Kowalski
Keyword(s):  
Stability Analysis ◽  
Slope Stability ◽  
Limit Equilibrium ◽  
Slope Stability Analysis ◽  
Open Pit ◽  
Waste Dump ◽  
Limit Equilibrium Methods ◽  
Processing Wastes ◽  
The Stability

Abstract This paper presents the slope stability analysis for the current as well as projected (final) geometry of waste dump Sandstone Open Pit “Osielec”. For the stability analysis six sections were selected. Then, the final geometry of the waste dump was designed and the stability analysis was conducted. On the basis of the analysis results the opportunities to improve the stability of the object were identified. The next issue addressed in the paper was to determine the proportion of the mixture containing mining and processing wastes, for which the waste dump remains stable. Stability calculations were carried out using Janbu method, which belongs to the limit equilibrium methods.

A 3D slope stability analysis method assuming parallel lines of intersection and differential straining of block contacts

2002 ◽  
Vol 39 (4) ◽  
pp. 799-811 ◽  
Author(s):  
Muhsiung Chang
Keyword(s):  
Slope Stability ◽  
Factor Of Safety ◽  
Slip Surface ◽  
Limit Equilibrium ◽  
Three Dimensional ◽  
Shear Stresses ◽  
Block System ◽  
Stability Of Slopes ◽  
Sliding Mechanism ◽  
The Stability

A three-dimensional (3D) method of analysis of the stability of slopes was developed based on the sliding mechanism observed in the 1988 failure of the Kettleman Hills landfill slope (Kettleman City, California) and the associated model studies. By adopting a limit equilibrium concept, the method assumes the sliding mass as a block system in which the contacts between blocks are inclined. The lines of intersection of the block contacts are assumed to be parallel, which enables the sliding kinematics. In consideration of the differential straining between blocks, the shear stresses on the slip surface and the block contacts are evaluated based on the degree of shear strength mobilization on these contacts. The overall factor of safety is calculated based on the force equilibrium of the individual blocks and the entire block system as well. Based on comparisons with a series of hypothetical 3D and 2D problems with known solutions, the method was generally found to be accurate in predicting the stability of slopes involving a translational type of sliding failure. For rotational sliding failures in clays, however, the method appears to slightly overestimate the calculated factor of safety; up to as much as 10% in a typical problem examined in this study.Key words: slope stability, 3D method, limit equilibrium, block kinematics, strain incompatibility.

scholarly journals Modelling the effect of blast-induced vibrations on the stability of a faulted mine slope

2020 ◽  
Vol 120 (10) ◽  
Author(s):  
H. Bazzi ◽  
H. Noferesti ◽  
H. Farhadian
Keyword(s):  
Finite Element ◽  
Slope Stability ◽  
Water Pressure ◽  
Ground Vibration ◽  
Fe Analysis ◽  
Reference Points ◽  
Open Pit ◽  
Element Analysis ◽  
Fault Surface ◽  
The Stability

SYNOPSIS Blasting, which is carried out regularly in open-pit mines, causes considerable ground vibration in the vicinity of the blasting site. These vibrations may affect the stability of mine slopes, causing problems in safety and constituting a hazard to life and property. In this study, the effect of the blasting-induced vibrations on slope stability was investigated using finite element (FE) analysis. A pit slope containing a fault was examined under seismic loading caused by successive explosions with varying intensity. Some reference points were selected above/under the fault surface and their motions recorded during the FE analysis. The results show that the points above the fault surface have the greatest displacement, while below the fault surface, only minimal (negligible) motions occur. Also, the intensity of the explosion has the greatest impact on motions at the upper points, but below the fault surface, the effect of the blast intensity was minimal. Usually, each explosion causes only small displacements in the mine slopes, but the destabilizing effect of repeated weekly blasts is significant, as confirmed in the present study. A sensitivity analysis proved a direct relationship between both the shear stiffness and friction angle of the fault surface and the motions of upper reference points. Likewise, in the presence of underground water pressure, the blasting-induced movements increase sharply. Keywords: blasting, slope stability, finite element analysis, dynamic analysis.

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