scholarly journals Case Study of the Characteristics and Mechanism of Rock Burst near Fault in Yima Coalfield, China

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Zhenhua Jiao ◽  
Qiupeng Yuan ◽  
Peng Zou ◽  
Benjun Shi
Keyword(s):  
Rock Burst ◽  
Impact Damage ◽  
High Stress ◽  
Mining Area ◽  
Deep Mining ◽  
High Stress Concentration ◽  
Near Fault ◽  
Mining Depth ◽  
Time Space ◽  
Deep Rock

Deep mining near faults may easily cause rock bursts, which seriously threaten mining safety. Based on the engineering background of deep mining near fault in Yima coalfield, by collecting the rock burst events that happened near fault during deep mining, the correlation between fault structure and time-space features of rock burst was analyzed. The results show that the deep rock burst accounts for 84% in Yima coalfield at 600 m and 93% in the mining area within 1000 m from F16 fault. The risk of rock burst is positively correlated with mining depth and negatively correlated with the distance between mining area and F16 fault, and the frequency and intensity of rock burst near F16 fault increase significantly. Rock burst occurs in high stress concentration area, mainly in roadway, releasing energy level of 1.1 × 104 J–3.5 × 108 J, with impact damage range of 60–500 m. The mechanism of rock burst was explained from the view of the distribution of mining stress in surrounding rock. The stress of coal seam in deep mining near fault increases, and the disturbance effect of fault is obvious. Rock burst is easy to be induced under static and dynamic loads. The occurrence and mechanical characteristics of fault have different effects on rock burst and should be considered when evaluating the risk of rock burst.

scholarly journals Investigation of the Optimization of Unloading Mining Scheme in Large Deep Deposit Based on Vague Set Theory and Its Application

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Jia Sheng ◽  
Wen Wan ◽  
Dongrui Liu ◽  
Feifei Jiang ◽  
Xiangdong Li ◽  
...  
Keyword(s):  
Set Theory ◽  
Large Scale ◽  
High Stress ◽  
Mining Area ◽  
Technical Problems ◽  
Deep Mining ◽  
Vague Set ◽  
Mining Depth ◽  
Metal Mines ◽  
Selection Of

With the development of shallow surface mineral resources in metal mines, it is gradually turning to the stage of deep mining. According to the current mining depth and the average annual depth, during the period of “14th Five-Year Plan,” one-third of the underground metal mines will reach or exceed the mining depth of 1,000 m, with the deepest being 2,000 m. In the stage of deep mining, mines will face the conditions of high stress, high temperature, high well depth, and strong mining disturbance, which will greatly increase the difficulty of large-scale deep mining. Among them, the high ground stress environment is the principal problem of many technical problems in deep mining. The selection of mining method has become a prerequisite for solving the problem of efficient and safe mining of deep deposits. In this paper, the vague set theory was introduced into the selection of mining methods and a vague set model for deep unloading mining schemes was established. Taking the Jinchuan No. 2 mining area as the engineering background, four unloading schemes for deep mining were proposed, and the Vague set model was used for optimization. It is concluded that the mining approach with large-section unloading is the optimal unloading mining plan. The application shows that it has the advantages of high unloading efficiency, large production capacity, and low loss index. It has been fully promoted in the deep mining of the mining area. It is feasible and effective to use the vague set theory in the selection of deep unloading mining schemes, which provides a proper approach in the selection of deep unloading mining schemes.

scholarly journals Study on the Mechanism and Control of Rock Burst of Coal Pillar under Complex Conditions

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-19
Author(s):  
Xingping Lai ◽  
Huicong Xu ◽  
Jingdao Fan ◽  
Zeyang Wang ◽  
Zhenguo Yan ◽  
...  
Keyword(s):  
Stress Concentration ◽  
Rock Burst ◽  
Coal Mine ◽  
High Stress ◽  
Coal Pillar ◽  
Vertical Stress ◽  
Body Area ◽  
High Stress Concentration ◽  
Solid Coal ◽  
Working Face

In order to explore the mechanism of coal pillar rock burst in the overlying coal body area, taking W1123 working face of Kuangou Coal Mine as the engineering background, the full mining stage of W1123 is simulated by FLAC3D. It is found that the high stress concentration area has appeared on both sides of the coal pillar when W1123 does not start mining. With the advance of the working face, the high stress concentration area forms X-shaped overlap. There is an obvious difference in the stress state between the coal pillar under the solid coal and the coal pillar under the gob in W1123. The concrete manifestation is that the vertical stress of the coal pillar below the solid coal is greater than the vertical stress of the coal pillar below the gob. The position of the obvious increase of the stress of the coal pillar in the lower part of the solid coal is ahead of the advancing position of the working face, and the position of the obvious increase of the stress of the lower coal pillar in the gob lags behind the advancing position of the working face. At the same time, in order to accurately reflect the true stress environment of coal pillars, the author conducted a physical similarity simulation experiment in the laboratory to study the local mining process of the W1123 working face, and it is found that under the condition of extremely thick and hard roof, the roof will be formed in the gob, the mechanical model of roof hinged structurer is constructed and analyzed, and the results show that the horizontal thrust of roof structure increases with the increase of rotation angle. With the development of mining activities, the self-stable state of the high stress balance in the coal pillar is easily broken by the impact energy formed by the sudden collapse of the key strata. Therefore, the rock burst of coal pillar in the overlying coal body area is the result of both static load and dynamic load. In view of the actual situation of the Kuangou Coal Mine, the treatment measures of rock burst are put forward from the point of view of the coal body and rock mass.

Research on Surface Deformation with Increasing Mine Depth

2011 ◽  
Vol 243-249 ◽  
pp. 5890-5893
Author(s):  
Gang Chen ◽  
Qiong Wang
Keyword(s):  
Surface Deformation ◽  
Large Range ◽  
Reference Value ◽  
Mining Area ◽  
Deep Mining ◽  
Mining Depth ◽  
Practical Engineering ◽  
Original Rock ◽  
Mine Depth ◽  
The Relationship

After ore mined, the equilibrium state of original rock stress around mining area is damaged, causing surface deforming at large range. With the increasing resource needing and mining intensity, the mines all over the world are gradually in a stage of deep mining, so it is important to study the principle of surface deformation under the condition of deep mining. Finite element method is used to simulate mine process with increasing depth, and the relationship between mining depth and surface deformation is achieved. The result has important reference value to practical engineering.

Impact analysis of pressure-relief blasting on roadway stability in a deep mining area under high stress

2021 ◽  
Vol 110 ◽  
pp. 103781
Author(s):  
Yi Luo ◽  
Kun Xu ◽  
Junhong Huang ◽  
Xinping Li ◽  
Tingting Liu ◽  
...  
Keyword(s):  
Impact Analysis ◽  
High Stress ◽  
Mining Area ◽  
Pressure Relief ◽  
Deep Mining ◽  
Roadway Stability

Numerical Simulation of Preventing Rock Burst with Hydraulic Cutting

2012 ◽  
Vol 524-527 ◽  
pp. 637-641 ◽  
Author(s):  
Yao Cheng ◽  
Yu Lin Ma ◽  
Yong Li Zhang
Keyword(s):  
Numerical Simulation ◽  
Rock Burst ◽  
High Stress ◽  
Element Model ◽  
Pressure Relief ◽  
Deep Mining ◽  
Before And After ◽  
Mining Pressure ◽  
Slot Cutting ◽  
The Finite Element Model

Rock burst become increasingly serious in deep mining. Pressure relief will be realized with hydraulic cutting in the coal seam, and rock burst could be substantial prevented. The finite element model of hydraulic cutting is established, the variation of stresses around the slot before and after hydraulic cutting are found by Ansys software. The results of numerical simulation show: The influence circle of differential pressure with hydraulic cutting is about 5 meters. In the circle the stresses fall down 81%. The pressure relief is best when the pitch of holes is 8 meters with multi-slot cutting. The surface high stress area is significantly reduced after slotting and the stress concentration zone transferred to the deep. Reasonably direction of cutting travel determined pressure relief, and the cutting distance could influence directly the dimension and scope of pressure relief. The simulation results provide a theoretical foundation and technical reference for preventing rock burst with hydraulic cutting.

scholarly journals Ground Subsidence Evolution from 1000 m Deep Mining: A Case Study in Fengfeng Mining Area

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Yueguan Yan ◽  
Ming Li ◽  
Jibo Liu ◽  
Weitao Yan ◽  
Jinman Zhang ◽  
...  
Keyword(s):  
Eastern China ◽  
Mining Area ◽  
Ground Subsidence ◽  
Small Displacement ◽  
Deep Mining ◽  
Deep Mine ◽  
Surface Movement ◽  
Mining Depth ◽  
Movement And Deformation ◽  
Influence Radius

The mining of coal resources in eastern China has entered the stage of deep mining, and many mines have reached the depth of 1000 meters. Different from shallow and moderate depth mining, the temporal and spatial evolution regulation of surface movement and deformation under deep mining has its particularity. Combining with the geological and mining conditions of Fengfeng mining area, this paper systematically studies the characteristics of surface movement under the condition of shallow, moderate, and near kilometer mining depth. By means of field measurement, InSAR monitoring, we get the subsidence data under different mining depth and get the relevant subsidence parameters by inversion. Through comparative analysis, the special law of subsidence under the mining depth of 1000 meters is obtained. The results show that under the condition of nearly 1000 meters mining depth, the surface movement and deformation have the characteristics of large displacement angle, small displacement deformation value, and large main influence radius. The regulation of small proportion of active period of maximum subsidence point, gentle shape of surface movement basin, and low mining adequacy are obtained. The research results provide technical references for deep mining under buildings, railways, and water bodies and provide basis and reference for scientific mining and safe recovery of coal pillars in kilometer deep mine.

scholarly journals Rockburst Characteristics and Mechanisms during Steeply Inclined Thin Veins Mining: A Case Study in Zhazixi Antimony Mine, China

2018 ◽  
Vol 2018 ◽  
pp. 1-16
Author(s):  
Yuanjun Ma ◽  
Changwu Liu ◽  
Fan Wu ◽  
Xiaolong Li
Keyword(s):  
Numerical Simulation ◽  
Elastic Strain ◽  
Strain Energy ◽  
High Stress ◽  
Elastic Strain Energy ◽  
Compression Tests ◽  
High Stress Concentration ◽  
Mining Depth

With the increase of mining depth, rockbursts have become important safety problems in Zhazixi Antimony Mine, where overlying strata exceed 560 m. Due to the small spacing between the steeply inclined veins, mining activities have great influences on rockbursts of adjacent veins. In order to study rockburst characteristics and mechanisms in Zhazixi Antimony Mine, in situ measurement, field geological survey, uniaxial compression tests, and numerical simulation are conducted to analyze rockburst proneness and simulate the elastic strain energy accumulation characteristics. Consequently, rockburst proneness criteria are established on the basis of experimental results to propose the necessary lithologic conditions for rockburst aiming to Zhazixi Antimony Mine. Rockburst dangerous districts are defined based on high stress concentration and elastic strain energy distribution characteristics in mining process obtained by theory analysis and numerical simulation. Accordingly, it is suggested that thrown-type rockbursts mainly occur in massive stibnite of ventilation shafts and stopes where the elastic strain energy exceeds 300 kJ·m−3, spalling-type rockbursts generally appear in slate of roadways where the elastic strain energy exceeds 100 kJ·m−3, and ejection-type rockbursts arise in different rock masses under a certain condition. Last but not the least, prediction results are basically consistent with statistics data of rockburst events after comparative analysis.

scholarly journals Damage Evaluation for Rock Burst Proneness of Deep Hard Rock under Triaxial Cyclic Loading

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Shuang You ◽  
Hongguang Ji ◽  
Zijian Zhang ◽  
Chenghan Zhang
Keyword(s):  
Cyclic Loading ◽  
Rock Burst ◽  
Elastic Energy ◽  
Failure Process ◽  
Damage Zone ◽  
High Stress ◽  
Energy Index ◽  
Dissipation Energy ◽  
Deep Mining ◽  
Cyclic Loading And Unloading

High stress and strong excavation disturbance are the main causes of dynamic disasters, rock burst in deep hard rocks, and are more frequent and violent than those in shallow, which seriously restricts the deep mining. Given rock burst encountered in deep mining of Lingnan metal mines, the optimized triaxial cyclic loading and unloading tests are designed to characterize the performance of rock failure and to evaluate the rock burst proneness. The correlation between elastic energy index and damage evolution is built, and rock burst proneness in each status is analyzed; furthermore, the dissipation energy in the failure process of deep rocks is explicated. In this paper, the law that the elastic energy index via damage increases is drawn. In terms of the dynamic disaster conditions in the deep rock, the identification approach for the damage zone of the rock burst is established.

Rock Burst Analyse in Qirehataer Diversion Tunnel

2011 ◽  
Vol 138-139 ◽  
pp. 352-355
Author(s):  
Jian Feng Bian ◽  
Jian Jun Zhou ◽  
Guo Bin Zhao
Keyword(s):  
Rock Burst ◽  
High Stress ◽  
Horizontal Stress ◽  
Stress Conditions ◽  
Diversion Tunnel ◽  
Gneissic Granite ◽  
High Stress Concentration ◽  
Tunnel Section ◽  
The Right ◽  
Brittle Rock Mass

Rock burst is a geological hazard which occurs when hard and brittle rock mass is excavated under high in-situ stresses or high stress concentration. The Qirehataer diversion tunnel has 15.66 km long at a maximum depth of 1720 m. About 64.5% of the tunnel is located in gneissic granite. During excavation of the tunnel, light to moderate rock burst occurred in about 300 m length of the tunnel. This paper provides the analysis of the characteristics and stress conditions in the rock burst site using the stress conditions around the excavation, and provides an explanation on the reasons why rock burst occurred from the beginning to middle of the vault on the right side of the tunnel section, and the most serious situation is located at 60° with respect to horizontal. Stress release hole and bolt or bolt and net are used to prevent and manage rock burst which have been shown to be effective in this case.

Numerical Simulation of Factors on Zonal Disintegration in Surrounding Rocks of Deep Roadways

2012 ◽  
Vol 518-523 ◽  
pp. 5935-5938
Author(s):  
Jian Guo Ning ◽  
Xue Sheng Liu ◽  
Hai Tao Li
Keyword(s):  
Numerical Simulation ◽  
Rock Strength ◽  
High Stress ◽  
Mining Area ◽  
Simulation Software ◽  
Zonal Disintegration ◽  
Mining Depth ◽  
Damage Degree ◽  
Mining Conditions ◽  
Weak Structure

At the background of geological and mining conditions of typical roadways in Xinwen mining area, using numerical simulation software FLAC-3D, the effects of mining depth, weak structure and rock strength on the characteristics of zonal disintegration in Deep Roadway was studied. Results show that high stress is the premise to form the phenomenon of zonal disintegration; weak structure in surrounding rocks is the key and surrounding rock strength is the determinants of damage degree and scope of rupture zone in deep surrounding rocks. There are important theoretical and practical significances to explore the formation mechanism of zonal disintegration in surrounding rocks of deep roadways, and to ensure safe mining of deep resources.

Sign in / Sign up

Export Citation Format

Share Document