scholarly journals Numerical Simulation of Surface Subsidence and Backfill Material Movement Induced by Underground Mining

2019 ◽  
Vol 2019 ◽  
pp. 1-17 ◽  
Author(s):  
Xibing Li ◽  
Dongyi Wang ◽  
Chongjin Li ◽  
Zhixiang Liu
Keyword(s):  
Underground Mining ◽  
Hanging Wall ◽  
Ground Surface ◽  
Surface Subsidence ◽  
Mining Method ◽  
Backfill Material ◽  
Ore Body ◽  
Sublevel Caving ◽  
Lead Zinc ◽  
Zinc Mine

Surface subsidence induced by underground mining is one of the challenging problems in mining engineering, which can destroy ground surface buildings and cause huge economic losses to the mine. In this study, a two-dimensional numerical model, established by the discrete element method code PFC2D, was adopted to investigate the mechanical mechanism of surface subsidence and backfill material movement induced by underground mining in the Hongling lead-zinc mine. In the first simulation case, the ore body was excavated from the ground surface to the mining level 705 m by the sublevel caving mining method, and the stress evolution during the mining process was analyzed to reveal the mechanical mechanism of surface subsidence. In the second and third simulation cases, the mined-out areas above 905 m were backfilled by the noncemented tailings and an insulating pillar was reserved beneath the backfill material, and then the deep ore body was excavated by two different mining methods to study the movement law of the backfill material and rock strata induced by underground mining. The numerical simulation results show that when the sublevel caving mining method is adopted, underground mining can induce toppling failures in the hanging wall and lead to a large collapse pit in the ground surface. After the toppling failures in the hanging wall, the collapsed waste rock in the mined-out area can provide support force for the surrounding rock and restrict the further collapse of the hanging wall. Furthermore, when the cut-and-fill mining method is adopted for the excavation of deep ore body, the insulating pillar can restrict the horizontal displacement of surrounding rock and maintain the stability of the backfill material. The cut-and-fill mining method can efficiently control the surface subsidence and prevent the occurrence of collapse pit in the ground surface and is recommended for the Hongling lead-zinc mine to solve the surface subsidence problem.

The Limit of Kirin Factory Ore Body by the Dynamic Multi-Plans in Huize Lead-Zinc Mine

2014 ◽  
Vol 644-650 ◽  
pp. 5231-5234
Author(s):  
Xiao Xia Yu ◽  
Jian Guo Gao ◽  
Yi Zheng Liu
Keyword(s):  
Service Life ◽  
Actual Situation ◽  
Typical Representative ◽  
Ore Body ◽  
Ferrous Metals ◽  
Economic Parameters ◽  
Lead Zinc ◽  
Zinc Mine ◽  
Non Ferrous Metals ◽  
Zinc Deposits

Huize lead-zinc mine is one of the typical representative of large rich lead-zinc deposits in the Sichuan-Yunnan-Guizhou lead-zinc mineralization district. It plays a key role in the development of Yunnan non-ferrous metals industry. In this paper, on the basis of enough analysis and research to Kirin factory Ore Body’s geologic feature in Huize lead-zinc mines, using reasonable economic parameters, combined with the actual situation of the orebody and break-even analysis, optimizing cut-off grade, it delineates the ore body by breakeven grade and comprehensive grade and achieves a dynamic multi-plans orebody for the purpose of the service life of mine.

Hierarchical fuzzy-AHP-based multi-criteria decision making approach for selection of underground metal mining method

2021 ◽  
Vol 15 (3) ◽  
pp. 405-420
Author(s):  
Bhanu Chander Balusa ◽  
Amit Kumar Gorai
Keyword(s):  
Decision Making ◽  
Underground Mining ◽  
Fuzzy Ahp ◽  
Hanging Wall ◽  
Ore Deposits ◽  
Mining Method ◽  
Metal Mining ◽  
Extrinsic Factors ◽  
Ore Deposit ◽  
Mining Methods

In the last few decades, many underground mining methods were proposed for extractions of ores. The decision-making for selecting the most suitable mining method for a typical ore depost depnds on various intrinsic and extrinsic factors (intrinsic – dip, shape, thickness, depth, grade distribution, RMR (rock mass rating) and RSS (rock substance strength) of ore, hanging wall, footwall, and extrinsic – recovery, dilution, safety, productivity, flexibility, capital). The present study aims to develop a hierarchical Fuzzy-AHP (FAHP) model for choosing the most suitable underground mining method for an ore deposit. The structure of the proposed hierarchical FAHP model consists of five levels. The level-1 of the hierarchy defines two variables (intrinsic factors and extrinsic factors). These are further classified into quantitative or qualitative nature of variable (listed in level-2). The criteria, sub-criteria, and mining method variables are listed respectively in Level 3, Level 4, and Level 5. For each level of the hierarchy, a fuzzy pair-wise comparison matrices are developed using the corresponding levels’ listed variables. These matrices at each level are subsequently used to determine the local and global weights of each variable. The global weights are used for prioritizing the different mining methods. The proposed hierarchical FAHP model was validated by considering the field data of two different ore deposits in India. The results showed that the most appropriate mining method predicted from the decision-making model and the adopted mining method for extracting the ore deposit are same in two case studied mines.

scholarly journals Study on the Rock Mass Caving and Surface Subsidence Mechanism Based on an In Situ Geological Investigation and Numerical Analysis

2018 ◽  
Vol 2018 ◽  
pp. 1-18 ◽  
Author(s):  
Fengyu Ren ◽  
Dongjie Zhang ◽  
Jianli Cao ◽  
Miao Yu ◽  
Shaohua Li
Keyword(s):  
Numerical Simulation ◽  
Rock Mass ◽  
Roof Rock ◽  
Rapid Development ◽  
Hanging Wall ◽  
Surface Subsidence ◽  
Engineering Project ◽  
Geological Investigation ◽  
Sublevel Caving

To deeply understand the mechanism of the rock mass caving and associated surface subsidence during sublevel caving mining, the Xiaowanggou iron mine was selected as an engineering project case study. The study area was analyzed by means of an in situ geological investigation and numerical simulation. First, a borehole television (BHTV) system and a GPS monitoring system were used to monitor the caving process of the roof rock mass and the development of the surface subsidence; the monitoring time was thirteen months. Then, a numerical simulation was used to analyze the damage evolution of the rock mass. Research shows the following: (1) in situ geological monitoring results indicate that the caving process of the roof rock mass presents intermittent characteristics, where slow caving and sudden caving are conducted alternatively and the arched-caving trend is more pronounced with continuous mining. The surface subsidence, horizontal displacement, and horizontal deformation of the hanging wall are higher than that of the footwall, and the subsidence center gradually deflects to the hanging wall in the late stage of the +45m sublevel mining. (2) Numerical simulation results indicate that the extension and penetration of the shear and tensile cracks along the joints and intact rock bridges are the main factors causing the rock mass caving and the existence of the stress arch and its evolution process is the fundamental reason for the intermittent caving of the rock mass. The rapid development of damage to the hanging wall (the damage angle reduced) is the main cause of the deflection of the subsidence center affected by joints and the mining size. (3) In the future of mining, large-scale subsidence will occur on the surface of the hanging wall.

Ground surface subsidence as effect of underground mining of the thick coal seams in the Jiu valley basin / Osiadanie gruntów wskutek wybierania pokładów o dużej miąższości w kopalniach zagłębia w dolinie Jiu

2012 ◽  
Vol 57 (3) ◽  
pp. 547-577 ◽  
Author(s):  
Ilie Onica ◽  
Dacian Marian
Keyword(s):  
Surface Deformation ◽  
Longwall Mining ◽  
Underground Mining ◽  
Ground Surface ◽  
Surface Subsidence ◽  
Coal Seams ◽  
Elasto Plasticity ◽  
Ground Surface Subsidence ◽  
Time Dependent Analysis

Abstract In the case of the thick and gentle coal seam no. 3 of the Jiu Valley Coal Basin (Romania), the mining methods are by use of the longwall mining technologies with roof control by caving or top coal caving. In this paper, it is presented the analysis of the complex deformations of the ground surface, over time, as a consequence of the coal mining in certain mining fields of the basin. Also, it is analysed the ground surface subsidence phenomenon using the CESAR-LCPC finite element code. The modelling is made in the elasticity and the elasto-plasticity behaviour hypothesis. Also, the time dependent analysis of the ground surface deformation was achieved with the aid of an especial profile function. The obtained results are compared with the in situ measurements data basis.

Development of Fuzzy Pattern Recognition Model for Underground Metal Mining Method Selection

2021 ◽  
Vol 12 (4) ◽  
pp. 64-78
Author(s):  
Bhanu Chander Balusa ◽  
Amit Kumar Gorai
Keyword(s):  
Pattern Recognition ◽  
Hanging Wall ◽  
Mining Method ◽  
Metal Mining ◽  
Ore Deposit ◽  
Recognition Model ◽  
Fuzzy Pattern Recognition ◽  
Sublevel Caving ◽  
Fuzzy Pattern ◽  
Deposit Characteristics

Selection of underground metal mining method is a crucial task for the mining industry to excavate the ore deposit with proper safety and economy. The objective of the proposed study is to demonstrate the application of a fuzzy pattern recognition model for the decision-making of the most favourable underground metal mining method for a typical ore deposit. The model considers eight factors (shape, depth, dip, rock mass rating [RMR] of ore zone, RMR of footwall, RMR of hanging wall, thickness of the ore body, grade distribution), which influence the mining method, as input variables. The weights of these factors were determined using the analytic hierarchy process (AHP). The study used the pair-wise comparison method to determine the relative membership degrees of qualitative and quantitative criteria as well as weights of the criteria set. The model validation was done with the deposit characteristics of Uranium Corporation of India Limited (UCIL), Tummalapalle mine selected. The weighted distances for easiest to adopt are found to be 0.1436, 0.0230, 0.0497, 0.2085, 0.0952, 0.1228, and 0.1274, respectively, for block caving, sublevel stoping, sublevel caving, room and pillar, shrinkage stoping, cut and fill stoping, and squares set stoping. The results indicate that the room and pillar mining method is having the maximum weighted distance value for the given ore deposit characteristics and thus assigned the first rank. It was observed that the mining method selected using fuzzy pattern recognition model and the actual mining method adopted to extract the ore deposit are the same.

Surface gravity and magnetic responses of mineralization, Mt. Isa, northwest Queensland, Australia

Geophysics ◽  
1991 ◽  
Vol 56 (4) ◽  
pp. 542-549 ◽  
Author(s):  
D. E. Leaman
Keyword(s):  
Hanging Wall ◽  
Gravity Anomalies ◽  
Surface Gravity ◽  
Depth Range ◽  
Copper Mineralization ◽  
Gravity And Magnetic ◽  
Lead Zinc ◽  
Zinc Mine ◽  
Host Rocks ◽  
Mt Isa

Surface gravity and magnetic surveys around the giant copper‐silver‐lead‐zinc mine at Mt. Isa in northwest Queensland have shown that each type of mineralization presents characteristic responses which are anomalous within the perspective of the host rocks. The responses reflect the entire mineralization‐alteration package and not simply the economic ore. Copper mineralization and associated alteration products, including “silica dolomite,” are not significantly magnetized, but the mineralization across a depth range of 1000 m produces a positive gravity anomaly of more than 2.5 mGal. The related alteration products are associated with large negative anomalies of up to 8 mGal in both hanging wall and footwall host rocks. Silver‐lead‐zinc mineralization is moderately magnetic (about 0.001 cgs). It is also denser and shallower and generates larger gravity anomalies. Negative secondary alteration effects, while significant, are equivalent in magnitude to the mineralization effect. Sites mineralized comparably to Mt. Isa would be located by semiregional surveys with a station spacing of 200 to 400 m and survey precision of better than 0.4 mGal, although there are limits to resolution of individual parts of the mineralization.

scholarly journals Analysis of the Surface Subsidence Induced by Mining Near-Surface Thick Lead-Zinc Deposit Based on Numerical Simulation

Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 717
Author(s):  
Yifan Zhao ◽  
Xingdong Zhao ◽  
Jiajia Dai ◽  
Wenlong Yu
Keyword(s):  
Large Scale ◽  
Surface Subsidence ◽  
Ecological Benefits ◽  
Near Surface ◽  
Economic Operation ◽  
Lead Zinc ◽  
Zinc Mine ◽  
Scale Surface ◽  
Good Agreement

This paper describes a case study of surface subsidence in the Hongling Lead-Zinc Mine. Hongling Lead-Zinc Mine is located in Inner Mongolia, China, about 240 km away from the border between China and Mongolia. There is a batch of outcrops of the near-surface thick steep-dip metamorphic orebody. The large-scale surface subsidence induced by underground excavation has brought some impact on the safety of herdsmen and their daily husbandry activities nearby. The requirements of reclamation for subsidence areas in the relevant laws and regulations, raise enormous pressure and risk on safe and economic operation. In this paper, a 3D numerical model of this mine was built by 3DMine and FLAC3D to analyse the excavation procedure and mechanism. The results of the simulation were in good agreement with the field subsidence data collected by satellites and unmanned aerial vehicles from 2009 to 2019. The analysis showed that the current mining method—an integrated underground method of stoping and caving—accelerated the surface subsidence, and some measures of monitoring, controlling and management were expected to take in order to improve economic and ecological benefits.

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

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.

scholarly journals Peculiarities of the underground mining of high-grade iron ores in anomalous geological conditions

2019 ◽  
Vol 28 (4) ◽  
pp. 706-716
Author(s):  
Mykhailo V. Petlovanyi ◽  
Vladislav V. Ruskykh
Keyword(s):  
Iron Content ◽  
Underground Mining ◽  
Hanging Wall ◽  
Slope Angle ◽  
High Grade ◽  
Ore Deposit ◽  
Ore Body ◽  
Subsequent Decrease ◽  
Geological Conditions ◽  
The Difference

This paper is dedicated to research into the geological peculiarities, shape of the ore body and the occurrence of the host rocks in the hanging wall of the Pivdenno-Biloz- erske deposit , as well as their influence on the degrees and quality of high-grade iron ore extraction. It is noted that in the interval of 480 – 840 m depths, a decrease is observed in the stability of the natural and technogenic massif, which is caused by the increase in rock pressure with depth, the influence of blast- ing operations on the massif and the difference in geological conditions. This has led to the collapse of hanging wall rocks and backfill into the mined-out space of chambers in certain areas of the deposit, the dilution of the ore and deterioration of the operational state of the underground mine workings. Attention is focused on the causes and peculiarities of consequences of the collapse of the hanging wall rocks during ore mining, which reduce the technical and-economic indexes of the ore extraction from the chambers. A 3D-model of an ore deposit with complex structural framework has been developed, which makes it possible to visually observe in axonometric projection the geological peculiarities and the shape of the ore body. The parameters have been studied of mining chambers in the 640 – 740 m floor under different changing geological conditions of the ore deposit and hanging wall rocks occurrence – the northern, central and southern parts. The difference in the iron content in the mined ore relative to the initial iron content in the massif has been defined as an indicative criterion of the influence of changing conditions on the production quality. The reasons have been revealed which contribute to the collapse of the rocks and the subsequent decrease in the iron content of the mined ore in ore deposit areas dif- fering by their characteristics. It has been determined that within the central and half of the southern ore deposit parts with a length of 600 m, an anomalous geological zone is formed, the manifestation of which will be increased with the depth of mining. It was noted that within this zone, with the highest intensity and density of collapse of hanging wall rocks, the influence of decrease in the slope angle and change in the strike direction are of greatest priority, and such geological factors as a decrease in hardness, rock morphology, deposit thickness increase this influence significantly. To solve the problems of the hanging wall rocks’ stability, it is recommended to study the nature and direction of action of gravity forces on the stope chambers in the northern, central and southern parts, as well to search for scientific solutions in regard to changes in the geometric shapes of stope chambers and their spatial location, improving the order of reserves mining in terms of the ore deposit area, the rational order of breaking-out ore reserves in the chambers with changing mining and geological conditions of the fields’ development.

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