Study of Slope Stability (Open Pit Mining, Algeria) (original) (raw)
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SME MineXchange 2022 Proceedings, 2022
This research is the result of a geotechnical study carried out in a natural slope in an Open Pit mine in Southern Peru, highlighting earthquakes as an important cause of instability within the case study presented. This leads to analyze the stability of a slope, according to the safety factor and thus consider a future construction in its environment according to the identified requirements. There are known disasters at national and international level that involve human lives because of the lack of analysis of slope stability conditions, which based on the results will allow to control and to take adequate corrective measures. These mass movements are classified whether they are soils or rocks, considering the mechanism and type of rupture, as well as the presence of water, the speed and magnitude of the movement. The movement problems are due to factors of inherent nature and constitute a reason to perform a calculation study to analyze and estimate the safety factor of each of the evaluated cases.
Back-analysis Study on Slope Instability In an Open Pit MIne (Algeria)
Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu, 2020
Purpose. To analyze the sliding from the geotechnical point of view and to identify the plausible causes that influence it. Methodology. To analyze the sliding from the geotechnical point of view and to identify the plausible causes that influence it, our study follows the following chronological order. Firstly, a feedback reconstructs the slip from the geotechnical point of view; a backanalysis is required to confirm the surface failure. Next, a check will be made of the surface failure through the finite differ ence method and using the shear strength reduction by finite difference method (SSRFD). A parametric study on the influence of the geometric parameters is performed to see the influence of the latter on the stability. The plausible cause that has directly influenced this sliding is shown. findings. This paper considers the application of three methods: limit equilibrium method (LEM), finite element method (FEM) and finite difference method (FDM) to perform back analysis and find out the layer of slope failure in an open pit mine. originality. Three different approaches LEM, FEM and FDM were used to perform the backanalysis the rock mass properties and to investigate the slope failure mechanism and the accuracy of this method in mining engineering field. Practical value. This study has illustrated that noncompliance with the art, open pit mining standards and early planning of the mining method can most often lead to critical situations and catastrophic results. The back analysis of the slip site allowed us to reconstruct the break already observed and to draw maximum lessons on the mode, location and mechanical parameters that triggered this break.
2016
Several types of instabilities can menace the personnel and equipment in the open cast mines. Their kinematicis dependent commonly on the nature, the structure, the fracturing and the strength of the rock mass. A scientific assessment vis-a-vis their equilibrium is suggested. For this task a considerable amount of field work must already carrying out to supply the necessary data ie: geometric, mecanic and geologic parameters. The main purpose of this research is identifying different modes of slope failures that may develop on the career “ENOF” of Jebel Gustar, by a multi-step analysis. For this task, i) a structural analysis; ii) an estimation of the rock mass and discontinuity mechanical properties, iii) a rating of the rock mass quality, iv) and a numerical simulation of the stability are procedurally used. The results matched well with the field observations. They proved the poor stability of the career, showing a typical example of a bad slope-design. The application of such ap...
Slope Stability Study in Quarries by Different Approaches: Case Chouf Amar Quarry, Algeria
IOP Publishing, 2020
The Lafarge-M'sila group's cement plant (Algeria) is supplied by the Chouf Amar limestone quarry, which allows great quarrying at the national level with annual productions of 4.2 mt / year, since several sliding in previous years have disrupted the exploitation and production of the quarry, and in the strategy of the Lafarge group increased its production up to 5mt / year in the medium term 2020-2030; a stability study is necessary to ensure production under the right conditions, the aim of our work is to study Chouf Amar stability and identify the important causes of the landslides that have influenced the site in question. We start with an empirical approach through a geomechanical characterization of the massif was put in place to highlight the instability at the level of the various rock formations. then, a stability analysis was carried out using two different approaches: the analytical approach using the limit equilibrium method (Slide 6) and the numerical approach using two methods: the finite element method (Phase 2) and the finite difference method (Flac) in the static and dynamic case considering the state of dry and wet marls. The results show an optimal state of stability on the scale of the full profile north flank of the quarry and bad stability on the scale of the bench's of the different levels and the main facies of the potential slide is that of the marls. 1. Introduction The stability of the slopes of surface mines during their exploitation is an equation with several variables (the geological conditions, the mechanical parameters and the characteristics of the networks of discontinuities), this problem imposes the continuous control of the geometrical, technological and safety parameters, the phenomenon of landslides in surface mining operations is quite frequent [1]. A landslide, if it were to occur, would cause significant damage and halt production. Before starting a stability analysis, it is important to collect the relevant information for this analysis, in sufficient quantity and precision to correctly use the chosen technique. Depending on the type of structure, the properties that most control the stability of the excavation vary. In the case of an open pit, these properties are the orientation, the dip, the spacing and the continuity of the discontinuities present in the rock mass [2] Several approaches, separated into three main categories, exist in order to analyse the stability of open slopes. Several of them make it possible to take into account many factors such as water,
Water
The purpose of this study is to identify the leading causes of slope instability along a local highway in Anhui, People’s Republic of China. As part of the east expansion project, the mountain range will be excavated to create a two-way, nearly 30 m wide highway. The site’s topography consists of a hill with palm-shaped faces carved from limestone running along its sides. The geological characteristics and slope stability of the research area highlight the possibility of slope failure along both sides of the roadway. Slope stability analysis was performed in order to determine the failure mechanism and create a stable slope. Initial slope characterization and shear properties of the rock were determined by means of fieldwork and laboratory analysis. By causing wedging failure and toppling collapse, the bedding joints and discontinuity orientations increase instability, as determined by a kinematic analysis performed with DIP.6 software. The Limit Equilibrium Method (LEM) of analysis...
Stability Analysis and Failure Mechanisms of Open Pit Rock Slope
Journal of the Civil Engineering Forum
Rock mass in nature tend to be unideal, for it is heterogeneous, anisotropic and has discontinuity. The discontinuity makes anisotropic strength and stress in the rock mass, and also controls the changing of the elastic properties of rock mass. This condition results to disruptions in the rock mass strength balance, and finally drives the slopes to collapse. This study aims to determine the slope failure mechanisms in the area of case study, as well as its variations based on the Rock Mass Rating (RMR), Geological Strength Index (GSI), Slope Mass Rating (SMR), kinematic analysis, numerical analysis and monitoring approach slope movement in a coal mine slope applications. The site investigations were implemented to obtain information about slope collapse. Prior to the collapse, the slope inclination was 38° with of 94 meters height, strike slope of N 245 E and direction of slope surface of 335°. After the collapse, the slope was became 25º; and after the collapse materials were clear...
The Influence of the Methodology for Slopes Forming in Open Pit Mines on their Stability
IOP conference series, 2019
Open pit mines are frequently accumulating significant amounts of material in the form of dumping grounds, landfills or forming land for reclamation. Often the form of emerging dumping grounds is determined by stability analysis of their slopes at the design stage. During the operation of the mining site and the collection of material on the pile, only the geometry of the slope is a subject of control. In many cases, after making slopes of a dozen or so meters height or even up to several tens of meters, and after a certain time has elapsed since their formation, deformation of the escarpments can be observed. At this stage, the only option is to change the geometry, i.e. inclination of a slope or, in the worst case, rebuilding of the dump. In the paper the analysis of the impact of the method of forming slopes and material quality on stability of formed slopes and their safe exploitation has been presented. It also presents a proposal to normalize the methodology of design and construction of slopes in a manner ensuring stability and taking into account the variability of the material parameters from which the slope is to be formed.
Journal of China University of Mining and Technology, 2008
One of the critical aspects in mine design is slope stability analysis and the determination of stable slopes. In the Chador-Malu iron ore mine, one of the most important iron ore mines in central Iran, it was considered vital to perform a comprehensive slope stability analysis. At first, we divided the existing rock hosting pit into six zones and a geotechnical map was prepared. Then, the value of MRMR (Mining Rock Mass Rating) was determined for each zone. Owing to the fact that the Chador-Malu iron ore mine is located in a highly tectonic area and the rock mass completely crushed, the Hoek-Brown failure criterion was found suitable to estimate geo-mechanical parameters. After that, the value of cohesion (c) and friction angle ( ) were calculated for different geotechnical zones and relative graphs and equations were derived as a function of slope height. The stability analyses using numerical and limit equilibrium methods showed that some instability problems might occur by increasing the slope height. Therefore, stable slopes for each geotechnical zone and prepared sections were calculated and presented as a function of slope height.
SLOPE STABILITY AND ROCKFALL HAZARD ANALYSIS IN OPEN PIT ZINC MINE
Rockfalls are a major safety hazard in open cut mines, particularly in large-scale deep pits. The geotechnical design relies on in-situ, site-specific, rock slope data to predict the trajectories and velocities of rockfalls that present a residual hazard in the mines. This paper presents slope stability analyses using both static general limit equilibrium methods and finite element stress analyses to estimate unstable areas and slope displacements in the mid-west slope at Glencore Zinc's Handlebar Hill Open Cut mine at Mt. Isa, Queensland, Australia. A conventional program-RocFall-was used for the slope rockfall risk assessment. Results indicate the possible slope benches involved in the initiation of rockfalls, and the maximum run-out distance, which could be defined as the pit's hazardous zone. A rockfall restraining system to absorb the impact energy of boulders and prevent them further falling was also modelled.
Geomechanical Stability of Slopes of the Surface Coal Mines of the Main
DergiPark (Istanbul University), 2016
The subject of this paper is the analysis of the geo-mechanical stability of slopes of the surface coal mines of the main geometry factors. Its main purpose is to define the interaction between the geological environment and the engineering activity. Therefore, in solving this problem all available documents from the previous researches and examinations for obtaining more credible and relevant data are used. Because of the above mentioned, the thesis shall obtain the following analyses: Description of the existing situation from geological aspect; Application of various numeric and graphical methods; Selection of most optimal geomethric parameters and stability analysis; In general, various methods are used for slope stability analysis. They can roughly be divided into two groups, such as: Border balance methods. In general, the slope stability analysis consists of the following components: Safety Factor Fs; Slope-Geometrical properties; Physical-mechanical properties of tested soil materials; Groundwater. The stability calculation shall be conducted by various methods with the software packages GGU Stability (BISHOP, JANBU). Discovering the right measure and the exact ratio between the advantage and the limitations of a given method is possible only through appropriate methodological approach, where aspects relevant to specific problems in geotechnical engineering shall be analyzed. Following significant results occurred from the work on this doctoral dissertation: 1) Analysis and sensitivity evaluation of the safety factor in the change of the values of certain geo-mechanical parameters. 2) Critical review of the selection of methods for geo-mechanical stability analysis;