Prediction of failure of south slope caused by underground mining in the Yanqianshan open-pit iron mine

According to the problem of rock slope deformation, fracture and stability during the transform from open-pit to underground mining at Yanqianshan Iron Mine, using FLAC large deformation mode to analysis mine excavation characteristics about deformation and damage of open-pit slope in different depth. Excavation simulation displays that the softrock of north slope easily to backfall heavily, But unusually form rapid sliding, the influence to underground mining is small, but large number of small crushed stones fill the rock layer, that is unfavorable to control the dilution and loss index. South slope hardrock mass have not appeared large deformation and unitary sliding during primary mining.

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The Prediction of Northern Slope Deformation and Failure Caused by the Transformation of Open-Pit to Underground Mining in the Yanqianshan Iron Mine

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.580-583.364 ◽

2014 ◽

Vol 580-583 ◽

pp. 364-370

Author(s):

An Lin Shao ◽

Hai Long Feng

Keyword(s):

Slope Failure ◽

Underground Mining ◽

Limit Equilibrium ◽

Failure Process ◽

Open Pit ◽

Northern Slope ◽

Body Distribution ◽

Ore Bodies ◽

Sublevel Caving ◽

Iron Mine

The Yanqianshan<a name="OLE_LINK94"></a><a name="OLE_LINK93"></a> iron mine is preparing to transform from an open-pit mine to an underground mine. We adopt the <a name="OLE_LINK104"></a><a name="OLE_LINK103"></a>non-pillar sublevel caving approach to exploit the particularly thick steep ore bodies within the range from -183 m to -500 m from top to bottom. According to the features of ore body distribution and the approaches of exploitation, we expect that underground mining will result in <a name="OLE_LINK102"></a><a name="OLE_LINK101"></a>the loss of stability on the northern slope of the open pit, causing traction-type landslides. Moreover, along with increasing the depth of the mining operation, the range of slope failure will continue to expand and further affect the safety of drainage features and roads distributed on the north side of the open pit. For this purpose, we select four sections along the trending direction of ore bodies and apply the limit equilibrium method to predict the failure process and characteristics on the northern slope according to the stratified mining process.<o:p></o:p>

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A New Mining Scheme for Hanging-Wall Ore-Body during the Transition from Open Pit to Underground Mining: A Numerical Study

Advances in Civil Engineering ◽

10.1155/2018/1465672 ◽

2018 ◽

Vol 2018 ◽

pp. 1-17

Author(s):

Baohui Tan ◽

Fengyu Ren ◽

Youjun Ning ◽

Rongxing He ◽

Qiang Zhu

Keyword(s):

Underground Mining ◽

Numerical Study ◽

Hanging Wall ◽

Slope Instability ◽

Open Pit ◽

Ore Body ◽

Instability Development ◽

Induced Caving ◽

Iron Mine ◽

Mining Scheme

A new mining scheme by employing the induced caving mining method to exploit hanging-wall ore-body during the transition from open pit to underground mining is proposed. The basic idea is to use the mined-out area generated by the planned mining of the hanging-wall ore-body to absorb the collapsed slope body, so as to avoid the influence of the inner-slope mining to the normal open-pit mining and guarantee mining efficiency during the transition stage. Numerical simulation study on the process of induced caving mining of hanging-wall ore-body is carried out based on the practical engineering setting of the Hainan iron mine, China, by employing the numerical method of discontinuous deformation analysis (DDA). The impact of rock mass structure on the mechanism of slope instability development and the mining hazard assessment in the new mining scheme is investigated. The influence of mining sequence on slope instability development and mining safety is also analyzed by taking the hanging-wall ore-body mining under the southern anti-dip slope at the Hainan iron mine as an example, and eventually a reliable mining scheme via induced caving is obtained. The numerical study proves the feasibility of the proposed new mining scheme for hanging-wall ore-body and provides theoretical and technical support for its application in practical mining activities.

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Notice of Retraction: Rational depth of transferring open-pit into underground mining at Nanfen iron mine, China

2011 International Conference on E-Business and E-Government (ICEE) ◽

10.1109/icebeg.2011.5877046 ◽

2011 ◽

Author(s):

Li Youchen ◽

Cai Sijing

Keyword(s):

Underground Mining ◽

Open Pit ◽

Iron Mine

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Vibration Safety Criteria for Surficial Rock Mass of Open Pit Slope Affected by Underground Mining Blasting Operations

The Open Civil Engineering Journal ◽

10.2174/1874149501711010627 ◽

2017 ◽

Vol 11 (1) ◽

pp. 627-637 ◽

Cited By ~ 3

Author(s):

Nan Jiang ◽

Chang Xiong ◽

Chuanbo Zhou ◽

Xuedong Luo ◽

Shiwei Lu ◽

...

Keyword(s):

Rock Mass ◽

Underground Mining ◽

Ultimate Tensile Stress ◽

Stress Waves ◽

Open Pit ◽

Vibration Velocity ◽

Blasting Vibration ◽

Stress Criterion ◽

The North ◽

South Slope

Introduction: Blasting vibration velocity is an important index to evaluate the stability of mine slopes under blasting operations. Objective: In order to determine the blasting vibration safety criteria for slope rock mass scientifically and reasonably, the influence of stress waves on surficial rock mass of mine slopes was analyzed when stress waves propagate to the slope surface, and mathematical models for blasting vibration safety criteria are proposed based on the ultimate tensile stress criterion, the ultimate shear stress criterion and the Mohr-Coulomb criterion. Results and Conclusion: Combined with the field blasting operations during the open-pit to underground mining in Daye iron mine, the blasting vibration safety criteria is calculated. It is obtained that the blasting vibration safety criteria for the north slope and the south slope are 11.08cm/s and 10.20cm/s respectively. The results agree well with the Safety Regulations for Blasting in China and provide a reference to determine blasting vibration safety criteria for other similar projects.

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Stability Analysis of Underground Multicavities in Bench Blasting Vibration

Mathematical Problems in Engineering ◽

10.1155/2019/4014761 ◽

2019 ◽

Vol 2019 ◽

pp. 1-10 ◽

Cited By ~ 1

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.

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Study on the Process and Mechanism of Slope Failure Induced by Mining under Open Pit Slope: A Case Study from Yanqianshan Iron Mine, China

Advances in Civil Engineering ◽

10.1155/2019/6862936 ◽

2019 ◽

Vol 2019 ◽

pp. 1-26

Author(s):

Yingpeng Hu ◽

Fengyu Ren ◽

Hangxing Ding ◽

Yu Fu ◽

Baohui Tan

Keyword(s):

Slope Failure ◽

Underground Mining ◽

Ground Deformation ◽

Failure Process ◽

Google Earth ◽

Open Pit ◽

Mechanism Analysis ◽

Eastern Slope ◽

Rock Creep ◽

Iron Mine

Mining under an open pit slope results in the collapse and slide of the slope. In this paper, a combination of methods including Google Earth and field investigations is applied to investigate the process of eastern slope failure induced by underground mining in the Yanqianshan Iron Mine over five years. According to the observed ground deformation features, the geomorphic zone of the eastern slope can be divided into four regions (caved rock zone, cracking zone, toppling zone, and sliding zone). Break angles and fracture initiation angles at different times are counted separately. Based on the above work, the process of initiation and development of slope failure is studied. The analysis results show that the process of slope failure could be chronologically divided into three stages. First, a collapse pit, caused by the falling of the overlying strata above the goaf, appeared on the eastern slope. Then, the rock mass around the collapse pit slid into the pit to form a small landslide. Finally, because of mining disturbances and rock creep, a large landslide occurred on the northeastern phyllite slope. The control mechanisms of each failure stage are discussed separately. Finally, the RFPA3D code is employed to simulate the slope failure process under the influence of underground mining. The results are consistent with the field observations, which provided information on deformation failure and the mechanics of the slope that could not be directly observed in the field and deepened the mechanism analysis.

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Water inrush characteristics and hazard effects during the transition from open-pit to underground mining: a case study

Royal Society Open Science ◽

10.1098/rsos.181402 ◽

2019 ◽

Vol 6 (3) ◽

pp. 181402

Author(s):

Huijie Zhang ◽

Bin Zhang ◽

Nengxiong Xu ◽

Lei Shi ◽

Hanxun Wang ◽

...

Keyword(s):

Mine Water ◽

Underground Mining ◽

Water Inrush ◽

Mine Safety ◽

Liaoning Province ◽

Open Pit ◽

Comprehensive Method ◽

Iron Mine ◽

Mine Roadway

During the transition from open-pit to underground mining in iron ore mines, water inrush is a prominent problem for mine safety and production. In this paper, a comprehensive method that incorporates hydrochemical analysis and numerical simulation is proposed to analyse the characteristics of water inrush during the transition from open-pit to underground mining. The proposed method revealed the migration law of groundwater and analysed the source of mine water inrush in the Yanqianshan iron mine located in Liaoning province, China. The results show that the excavated mine roadway is the primary factor affecting groundwater migration and that the source of the mine water inrush is the groundwater in the aquifer around the mine roadway. Moreover, based on the results of the study, appropriate methods for prevention and treatment of mine water inrush were proposed. This approach provides a novel idea for the assessment of water inrush hazards and will serve as a valuable reference for analogous engineering cases.

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Extended Ultimate-Pit-Limit Methodology for Optimizing Surface-to-Underground Mining Transition in Metal Mines

Advances in Civil Engineering ◽

10.1155/2022/2753991 ◽

2022 ◽

Vol 2022 ◽

pp. 1-9

Author(s):

Si-Tong Ren ◽

Yang Liu ◽

Xin-Yi Yang ◽

Ding-Gui Tong ◽

Gao-Feng Ren

Keyword(s):

Underground Mining ◽

Surface Mining ◽

Critical Issue ◽

Practical Aspect ◽

Open Pit ◽

Optimization Approach ◽

Original Design ◽

Metal Mines ◽

Iron Mine ◽

Total Profit

The transition from surface mining to underground is a critical issue for metal mines. The commonly cited procedure cored by ultimate-pit-limit (UPL) methodology is restricted to maximize the profit from both surface and underground mining, due to the absence of the integration of the profit from either of them. Under the target for such maximization, this study proposes a new optimization approach, which directly relates the design of open-pit limit and underground stopes, by equalizing the marginal profit from either surface or underground mining. The variation of the crown pillar size is involved in this approach. The proposed approach is applied to the Dagushan iron mine, and results show the total profit increased from 3.79 billion CNYs (original design by conventional UPL methodology) to 4.17 billion CNYs (optimal design by the proposed approach), by 9.91%. Moreover, the marginal profit from surface and underground mining, as well as total profit, of all possible designs of surface-to-underground mining transition in Dagushan iron mine is calculated to validate the proposed approach. When the marginal profits satisfy the criterion of the proposed approach, the maximum value of the total profit appears, and this demonstrates the proposed approach is robust to maximize the total profit in surface-to-underground mining transition. This work contributes to existing literature studies primarily from practical aspect, by providing a unified approach to optimize the transition from surface to underground mining.

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Mining Plan Optimization Based on Linear Programming in Shirengou Iron Mine

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.429.206 ◽

2012 ◽

Vol 429 ◽

pp. 206-209

Author(s):

Ming Zhu ◽

Jin Long Sun ◽

Wen Sheng Liu ◽

Ai Xia Zhang ◽

Hui Zhi Zhou ◽

...

Keyword(s):

Mathematical Model ◽

Linear Programming ◽

Transition Period ◽

Underground Mining ◽

Economic Effect ◽

Mining Operation ◽

Open Pit ◽

Difficult Situation ◽

Iron Mine ◽

Project Optimization

Faced with the difficult situation of the joint operation of open pit and underground mining in transition period in Shirengou Iron Mine, a suitable linear programming mathematical model of mining plan was established and synthesis optimization results were obtained, which would increase the overall economic effect of the mining operation during the transition period, while the limited reserves and ore quality control were entirely considered. A pronounced economic benefit was achieved by the project optimization. This mathematical model can be widely used in mining process to control the quality and quantity equilibrium of ore output, comprehensive utilize some waste rock and optimize the mining plan.

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