scholarly journals Stability Analysis of Underground Multicavities in Bench Blasting Vibration

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Deqing Gan ◽  
Xi Yang ◽  
Yunpeng Zhang ◽  
Xinyu Wei
Keyword(s):  
Underground Mining ◽  
Open Pit ◽  
Open Pit Mining ◽  
Mining Activities ◽  
Potential Threat ◽  
Attenuation Relations ◽  
Bench Blasting ◽  
Iron Mine ◽  
Underground Cavities ◽  
The Stability

Underground cavities formed by underground mining activities are a potential threat to open-pit mining activities. Longtan Village Iron Mine is located in Chengde city, Hebei province, China. The open-pit mining and underground mining of Longtan Village Iron Mine are simultaneously performed. Cavities will remain after underground mining. When mining is performed on the top of the underground cavities in the open pit, concerns arise regarding the closest distance to prevent the collapse of the cavities. (The closest distance is the safe distance between the explosive and the cavities. If the distance between the explosive and the cavities is less than the closest distance, the stability of the cavities will be affected.) The collapse will endanger the safety of the workers and equipment in the open pit. Therefore, it is necessary to estimate the stability of the underground cavities near the bench blasting. In this paper, a series of bench blast tests was performed, and the site-specific attenuation relations of the PPV (Peak particle velocity) and principal frequency of Longtan Village Iron Mine were obtained. Then, an ANASYS three-dimensional numerical model was created, and the propagation of the blast wave and the response of the multicavities were calculated by LS-DYNA. The accuracy of the simulation was verified. However, the bench blast tests do not affect the stability of the cavities. The formula to calculate the closest distance was obtained, which can be used as an approximate guide when designing the bench explosion of Longtan Village Iron Mine. Workers can mine in a safe area of the open pit, and the stability of the cavities will not be affected.

scholarly journals Stability study of open mine slopes at pit 22 GN PT Kitadin Site Embalut, Kutai Kartanegara Regency, East Kalimantan Province

2021 ◽  
Vol 24 (1) ◽  
pp. 47-56
Author(s):  
Tandidatu Deny ◽  
◽  
Sundek Hariyadi ◽  
Keyword(s):  
Safety Factor ◽  
Stability Study ◽  
Open Pit ◽  
Open Pit Mining ◽  
Mining Activities ◽  
East Kalimantan ◽  
Stability Of Slope ◽  
The Stability ◽  
Excavation Site ◽  
Highwall Slope

The stability of slope, both on the slope of work and the final slope, is a very important aspect of slope stability, both on the slope of work and the final slope in open pit mining activities. The inconsistency of the slopes will result in the collapse of rocks around the excavation site. This happens because the condition of the rock when it has not been excavated is generally balanced. However, due to the discontinuous patterns that occur other than naturally and also due to the mining activities such as excavation, blasting and others, cause a reduction in the retaining force of the rock on the slope results in the equilibrium of the force tends to shift and is not balanced. Study of the stability of the open pit highwall slope at PIT 22 GN PT Kitadin Site Embalut, Kutai Kartanegara Regency, East Kalimantan Province was carried out with the aim to know the rock characteristics, to calculate slope geometry stable safety factors, and to recognize the type of landslide using a bishop method. The results of the modeling consist of several heights and slopes, as well as angles that is formed. Section AA’ has a safety factor value of 1.387, section BB has a safety factor of 1.482, section BB' has a safety factor value of 1.390, section DD' has a safety factor value of 1.318, section EE has a safety factor value of 2,381, section FF' has a safety factor value of 2.426, section GG' has a safety factor value of 2.424, section HH 'has a safety factor value of 2.339.

Calculation and Optimization of Soil Slope Stability on One Iron Mine

2014 ◽  
Vol 644-650 ◽  
pp. 1998-2002
Author(s):  
Shi Qing Nan ◽  
Juan Xia Zhang ◽  
Xian Zhang Guo ◽  
Tian Hong Yang
Keyword(s):  
Slope Stability ◽  
Slope Angle ◽  
Simulation Method ◽  
Open Pit ◽  
Open Pit Mining ◽  
Soil Slope ◽  
Deformation And Failure ◽  
Main Research ◽  
Iron Mine ◽  
The Stability

The purpose of slope stability evaluation was that, according to the slope engineering condition and constraints of mining technology, to study the deformation and failure rule of slope occurred by the change of stress field during the open-pit mining. The main research object of the paper was open-pit slope of one iron mine, for the mechanical parameters of the slope, it was obtained by physical experiments, and the numerical simulation method was used for the stability analysis and evaluation of quaternary soil slope angle and final slope angle. And some measures were proposed for slope stability during construction to ensure safety in production. The research of the paper has certain reference significance for optimization calculation of the soil slope stability

scholarly journals SAFETY IN SUBSTOPING-AND-CAVING IN TECTONICALLY STRESSED ROCK MASSES

2021 ◽  
Vol 2 (3) ◽  
pp. 311-321
Author(s):  
Sergey A. Neverov ◽  
Anton I. Konurin ◽  
Yuri N. Shaposhnik
Keyword(s):  
Mathematical Modeling ◽  
Underground Mining ◽  
Open Pit ◽  
Open Pit Mining ◽  
Variable Degree ◽  
Structural Elements ◽  
Mining System ◽  
Sublevel Caving ◽  
Mine Workings ◽  
The Stability

Mining of a thick steeply dipping deposit using sublevel caving with end-face ore drawing in transition from open pit excavation to underground mining is considered in conditions of developed tectonics. The technology was justifed by mathematical modeling of the stress state of the rock mass using finite element method. Safe parameters of the mining system were determined by solving a variational problem with a variable degree of geomedium disturbance in the existing mining and engineering structure when depleting reserves at an advanced stoping stage. The predicted areas of stability losses for main structural elements of the mining system have been determined. Safe parameters of ore breaking and drawing were calculated using the stability condition of mine workings. Recommendations are given for the excavation of thick steeply dipping deposits under open pit mining.

Research on 2D Limit Equilibrium Method of Slopes Considering the Effect of Horizontal In Situ Stress

2013 ◽  
Vol 671-674 ◽  
pp. 245-250
Author(s):  
Wen Hui Tan ◽  
Ya Liang Li ◽  
Cong Cong Li
Keyword(s):  
Limit Equilibrium ◽  
Limit Equilibrium Method ◽  
In Situ Stress ◽  
Open Pit ◽  
Open Pit Mines ◽  
Equilibrium Method ◽  
Iron Mine ◽  
The Stability ◽  
Slice Method

At present, in-situ stress was not considered in Limit Equilibrium Method (LEM) of slopes, the influence of in-situ stress is very small on the stability of conventional slopes, but in deep-depressed open-pit mines, the influence should not be neglected. Formula for calculating the Factor of Safety (FOS) under the effect of horizontal in-situ stress was deduced using General Slice Method (GSM) of two-dimensional (2D) limit equilibrium method in this paper，a corresponding program SSLOPE was built, and the software was used in a deep- depressed open-pit iron mine. The results show that the FOS of the slope decreased by 20% when horizontal in-situ stress is considered, some reinforcements must be taken. Therefore, the influence of in-situ stress on slope stability should be taken into account in deep open –pit mines.

Strategic mining options optimization: Open pit mining, underground mining or both

2016 ◽  
Vol 26 (6) ◽  
pp. 1065-1071 ◽  
Author(s):  
Eugene Ben-Awuah ◽  
Otto Richter ◽  
Tarrant Elkington ◽  
Yashar Pourrahimian
Keyword(s):  
Underground Mining ◽  
Open Pit ◽  
Open Pit Mining

Activities of Musan Mine observed by Sentinel-1 Coherence Imagery

2020 ◽  
Author(s):  
Jihyun Moon ◽  
Heejeong Seo ◽  
Hoonyol Lee
Keyword(s):  
Time Series ◽  
Satellite Images ◽  
European Space Agency ◽  
Open Pit Mine ◽  
Mining Activity ◽  
Open Pit ◽  
Open Pit Mining ◽  
Series Data ◽  
Mining Activities ◽  
Mining Site

<p>Musan mine in North Korea is the largest open-pit iron mine in Asia with the proved reserves of about 2.06 billion tons and more than 9 square kilometers. Open-pit mining is one of the surface mining technique extracting minerals from the surface. Vegetation is rarely distributed at the mining site because the topsoil is removed and the ore is mined directly from the surface. Therefore, it is effective to observe surface displacement at the mining site using Interferometric Synthetic Aperture Radar (InSAR) technology. InSAR coherence detects random surface change that measures the activity or stability of the interferometric phase of InSAR data. High coherence will be maintained on the surface where there is no movement and only surface scattering. On the other hand, the surface where there is a lot of movement and volumetric scattering has low coherence value. Therefore, using 12-days InSAR coherence images from Sentinel-1 satellites, for example, it is possible to analyze how active the open-pit mine is during the 12 days. Sentinel-1A satellite images were acquired from June 11, 2015 to May 24, 2016, followed by Sentine-1B satellite images from September 27, 2016 to April 21, 2019. A total of 102 SAR images were downloaded from European Space Agency (ESA) portal. There is a gap between May 24 and September 27, 2016 due to the transition of the data acquisition plan. Over 100 12-days coherence data were obtained by applying InSAR. Stable spots and target spots were selected through average and standard deviation of the entire coherence time series data. Coherence values include not only the mining activity but also the effects of perpendicular baseline, temporal baseline, and weather. Therefore, NDAI (Normalized Difference Activity Index) was newly defined to remove the noise and only the coherence value due to the influence of the mining activity was extracted. The degree of activities can be observed by the time series coherence and NDAI images. This study needs other references related to mining activities in order to analyze the mining activities in more detail. This method can be applied to other open-pit mine.</p>

Numerical Simulation Analysis on the Collapse of Slope in Iron Mine

2014 ◽  
Vol 926-930 ◽  
pp. 593-596
Author(s):  
Fang Wang ◽  
Chong Shi ◽  
Kai Hua Chen ◽  
De Jie Li ◽  
Ke Han
Keyword(s):  
Numerical Simulation ◽  
Shear Failure ◽  
Safety Management ◽  
Simulation Analysis ◽  
Underground Mining ◽  
Tensile Failure ◽  
Open Pit ◽  
Open Pit Mining ◽  
Roof Fall ◽  
Rock Movement

The process of open-pit mining can lead to high slopes in iron mines, and natural slopes should be rebuilt by the method of roof fall as the exploitation style turns from open-pit mining to the underground mining. So the slope can be steep, deep and may has the characteristics of collapse. It is difficult to describe the stabilization of the mining slope by a conventional safety factor method. Through the numerical simulation of underground mining process, this paper analyzes the result of distortion stress and rock movement rupture range. Studies have shown that the failure mode is dominated by tensile failure as a pattern of collapse and few is dominated by shear failure. The failure zone is controlled by rock mass parameters and structures. The results can be helpful for the proposition of exploitation program and safety management design.

scholarly journals Evaluating the Feasibility of Illegal Open-Pit Mining Identification Using Insar Coherence

2020 ◽  
Vol 12 (3) ◽  
pp. 367 ◽  
Author(s):  
Shunyao Wang ◽  
Xiaoping Lu ◽  
Zhenwei Chen ◽  
Guo Zhang ◽  
Taofeng Ma ◽  
...  
Keyword(s):  
Large Scale ◽  
Field Research ◽  
Open Pit ◽  
Open Pit Mining ◽  
Environmental Harm ◽  
Optical Remote Sensing ◽  
Mining Activities ◽  
Mining Sites ◽  
Illegal Mining ◽  
Adverse Weather

Illegal open-pit mining causes environmental harm and undermines sustainable development. Conventional monitoring approaches such as field research and unmanned aerial vehicle (UAV) imagery are time-consuming and labor-intensive, making large-scale monitoring difficult. In comparison, optical remote sensing imagery can cover large areas but is vulnerable to adverse weather conditions and is not sensitive to vertical ground changes. As open-pit excavation causes sudden changes in the scattering properties of ground objects along with dramatic vertical deformation, we evaluated the feasibility of using interferometric synthetic aperture radar (InSAR) coherence to identify illegal mining activities. Our method extracts the coherence coefficient from two SAR images taken on different dates, applies thresholding and filtering to extract a decorrelation map, and then overlays this with legal mining boundaries and optical satellite images to identify illegal mining activities. For three test cases in southwestern Inner Mongolia, China, 49 legal mining sites were correctly detected (with an accuracy of 90.74%) as well as six illegal mining sites. Ground truthing confirmed the presence of ongoing activity at one of these sites. Our study shows that InSAR coherence is suitable for the identification of mining activities, and our method provides a new approach for the detection and monitoring of illegal open-pit mining.

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