Prediction of Floor Failure Depth in Deep Coal Mines by Regression Analysis of the Multi-factor Influence Index

About under-group coal seams mining with the threat of high-pressure ordovician water, conventional mining technology by draining depressurization usually causes environmental issues such as soil erosion and ground subsidence etc.,By using grouting reinforcement technology, this paper changes floor direct charge layer into relatively separatedwater layer in the coal seam and achieves the goals of sealing the water inrush channel, moreover, on the basis of coal floor failure depth analysis and monitoring, the paper evaluates risk of water-inrush from seam floor when face length increases, On this basis, puts forward a reasonable working face length and mining technology, and has abtained good economic and social benefits in practice.

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The Effects of Backfill Mining on Strata Movement Rule and Water Inrush: A Case Study

Processes ◽

10.3390/pr7020066 ◽

2019 ◽

Vol 7 (2) ◽

pp. 66 ◽

Cited By ~ 4

Author(s):

Jian Hao ◽

Yongkui Shi ◽

Jiahui Lin ◽

Xin Wang ◽

Hongchun Xia

Keyword(s):

Longwall Mining ◽

Water Inrush ◽

Vertical Stress ◽

Strata Movement ◽

Ground Pressure ◽

In Situ Investigation ◽

Floor Failure ◽

Backfill Mining ◽

Failure Depth

Backfill mining is widely used to control strata movement and improve the stress environment in China’s coal mines. In the present study, the effects of backfill mining on strata movement and water inrush were studied based on a case study conducted in Caozhuang Coal Mine. The in-situ investigation measured abutment pressure distribution (APD), roof floor displacement (RFD), and vertical stress in the backfill area. Results are as follows: (i) The range and peak of APD, RFD, and vertical stress in the backfill area are smaller than in traditional longwall mining with the caving method. (ii) Backfill mining could change the movement form and amplitude of overburden and improve the ground pressure environment. (iii) Floor failure depth (FFD) is much smaller in backfill mining. Backfill mining can be an effective method for floor water inrush prevention.

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Sensitivity Analysis of the Main Factors Controlling Floor Failure Depth and a Risk Evaluation of Floor Water Inrush for an Inclined Coal Seam

Mine Water and the Environment ◽

10.1007/s10230-017-0497-6 ◽

2017 ◽

Vol 37 (3) ◽

pp. 636-648 ◽

Cited By ~ 17

Author(s):

Weitao Liu ◽

Dianrui Mu ◽

Xiangxiang Xie ◽

Li Yang ◽

Donghui Wang

Keyword(s):

Sensitivity Analysis ◽

Coal Seam ◽

Risk Evaluation ◽

Water Inrush ◽

Floor Failure ◽

Floor Water Inrush ◽

Main Factors ◽

Failure Depth

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Floor failure depth of upper coal seam during close coal seams mining and its novel detection method

Energy Exploration & Exploitation ◽

10.1177/0144598717747622 ◽

2017 ◽

Vol 36 (5) ◽

pp. 1265-1278 ◽

Cited By ~ 12

Author(s):

Wei Zhang ◽

Dongsheng Zhang ◽

Dahong Qi ◽

Wenmin Hu ◽

Ziming He ◽

...

Keyword(s):

Stress Distribution ◽

Coal Seam ◽

Mechanical Model ◽

Coal Pillar ◽

Coal Seams ◽

Geological Conditions ◽

Floor Failure ◽

Calculation Results ◽

Failure Depth ◽

Close Coal Seams

The primary problem needed to be solved in mining close coal seams is to understand quantitatively the floor failure depth of the upper coal seam. In this study, according to the mining and geological conditions of close coal seams (#10 and #11 coal seams) in the Second Mining Zone of Caocun Coal Mine, the mechanical model of floor failure of the upper coal seam was built. Calculation results show that the advanced abutment pressure caused by the mining of the upper coal seam, resulted in the floor failure depth with a maximum of 26.1 m, which is 2.8 times of the distance between two coal seams. On this basis, the mechanical model of the remaining protective coal pillar was established and the stress distribution status under the remaining protective coal pillar in the 10# coal seam was then theoretically analysed. Analysis results show that stress distribution under the remaining protective coal pillar was significantly heterogeneous. It was also determined that the interior staggering distance should be at least 4.6 m to arrange the gateways of the #209 island coalface in the lower coal seam. Taken into account a certain safety coefficient (1.6–1.7), as well as reducing the loss of coal resources, the reasonable interior staggering distance was finally determined as 7.5 m. Finally, a novel method using radon was initially proposed to detect the floor failure depth of the upper coal seam in mining close coal seams, which could overcome deficiencies of current research methods.

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Practical application of the method of regression analysis to assess the effectiveness of the execution conditions of collective agreements coal mines

On-line Journal Naukovedenie ◽

10.15862/67evn115 ◽

2015 ◽

Vol 7 (1) ◽

Cited By ~ 1

Author(s):

Kseniya Chashchina

Keyword(s):

Regression Analysis ◽

Coal Mines ◽

Practical Application ◽

Collective Agreements

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Investigation on Failure Characteristics of Coal Seam Floor in Paste Filling Working Face

Geofluids ◽

10.1155/2021/1808571 ◽

2021 ◽

Vol 2021 ◽

pp. 1-13

Author(s):

Qingliang Chang ◽

Xingjie Yao ◽

Chongliang Yuan ◽

Qiang Leng ◽

Hao Wu

Keyword(s):

Theoretical Model ◽

Coal Seam ◽

Water Inrush ◽

Failure Behavior ◽

Term Strength ◽

Failure Characteristics ◽

Working Face ◽

Floor Failure ◽

Failure Depth

Water inrush disasters are extremely prone to occur if the coal seam floor contains a confined aquifer. To find out the failure behavior of coal seam floor of paste filling working face, a beam-based theoretical model for the floor aquifuge was built, and then, the water inrush risk was evaluated based on the thickness of floor aquifuge. Next, the floor failure characteristics of the paste filling face was numerically studied and the effects of the filling interval and long-term strength of the filling body on the floor failure depth, stress and displacement distributions, and plastic zone were explored. The results showed that the theoretical model for evaluating the safety of the floor of the paste filling face based on the empty roof distance is proved to be consistent with that of the empirical formula judged based on the assumption that the paste filling working face was regarded as a cut hole with a certain width. The filling interval has a significant effect on the stress concentration of the surrounding rock, failure depth of floor, and roof-floor convergence. The smaller the filling interval is, the smaller their values are. When the filling rate is 98%, the long-term strength of the filling body is 5 MPa, and the floor failure depth is not more than 4 m. In contrast, the strength of the filling body has no obvious influence on the floor failure depth, but it has a certain impact on the roof-floor convergence. From the perspective of reducing floor failure depth, there is no need to increase the long-term strength of backfill, but it is necessary to increase the early strength of backfill so as to reduce the width of the equivalent roadway.

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Control of Water Inrush from Longwall Floor Aquifers Using a Division Paste Backfilling Method

Geofluids ◽

10.1155/2021/9374127 ◽

2021 ◽

Vol 2021 ◽

pp. 1-10

Author(s):

Qingliang Chang ◽

Xingjie Yao ◽

Shiguo Ge ◽

Ying Xu ◽

Yuantian Sun

Keyword(s):

Water Inrush ◽

Water Injection ◽

Field Measurements ◽

Mining Method ◽

Confined Water ◽

Working Face ◽

Floor Failure ◽

Site Water ◽

Failure Depth ◽

Theoretical Analyses

Aiming at the problem of the safety mining problems of longwall paste filling working face under buildings on high confined water in the Daizhuang Coal Mine, the paste filling mining method was used. A series of theoretical analyses, numerical simulations, and field measurements were applied. The results showed that when the filling interval of the working face increases from 1.2 m to 3.6 m, no significant change is found in the depth of the perforated plastic zone of the floor strata. According to the types of water-conducting cracks in the floor strata of the working face 11607, the floor strata are divided into the floor intact area, the structure developed area, and the floor weak area. Based on that, the measures for preventing and controlling the floor failure in the paste filling working face are proposed. Furthermore, the failure depth of the floor of the test working face was detected by the on-site water injection method, and the results showed that the maximum failure depth of the floor of the test working face was about 3 m.

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A multifactor coupling prediction model for the failure depth of floor rocks in fully mechanized caving mining: a numerical and in situ study

Royal Society Open Science ◽

10.1098/rsos.190528 ◽

2019 ◽

Vol 6 (8) ◽

pp. 190528

Author(s):

Yulong Jiang ◽

Tingting Cai ◽

Xiaoqiang Zhang

Keyword(s):

Coal Seam ◽

Prediction Model ◽

Shanxi Province ◽

Burial Depth ◽

Floor Failure ◽

Face Length ◽

Mining Face ◽

Failure Depth ◽

Multifactor Coupling

To study the mining-induced failure depth of floor rocks in a fully mechanized mining caving field affected by different coal seam pitches, mining face lengths, burial depths and aquifer water pressures, multifactor-coupled orthogonal numerical tests on the failure depth of floor rocks were conducted. The numerical results show that the failure depth of floor rocks increases with increasing mining face length, coal seam pitch and burial depth. According to the relationship between failure depth and these impact factors, a multifactor-coupled prediction model for the failure depth of floor rocks was established. In addition, the in situ measurement of the failure depth of floor rocks in the Yitang Coal Mine in Huoxi coal field in Shanxi Province, China, was performed, and the in situ failure depths of floor rocks in the 100 502 (80 m) and 100 502 (180 m) mining faces were approximately 12.50–14.65 m and 17.50–19.20 m, in good agreement with the results of the multifactor prediction model. Furthermore, the sensitivity of each impact factor in the prediction model of the floor failure depth was further analysed by F -test and range analysis, and the impact order of studied factors on the floor failure depth is coal seam pitch > mining face length > burial depth > aquifer water pressure.

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Microseismic Monitoring and Numerical Simulation Research of Floor Failure Depth in Extra-Thick Coal Seam

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.881-883.1799 ◽

2014 ◽

Vol 881-883 ◽

pp. 1799-1804 ◽

Cited By ~ 1

Author(s):

Ai Ping Cheng ◽

Yong Tao Gao ◽

Chao Liu ◽

Jin Fei Chai

Keyword(s):

Numerical Analysis ◽

Coal Mining ◽

Microseismic Monitoring ◽

Floor Rock ◽

Thick Coal Seam ◽

Floor Failure ◽

Mining Disturbance ◽

Microseismic Events ◽

Mining Face ◽

Failure Depth

Based on the condition of fully mechanized caving face in one mine, two methods of microseismic monitoring and numerical analysis were combined to study the evolution characteristics and development law of floor failure depth in extra-thick coal seam. Microseismic monitoring results show that the number of microseismic events partly reflects the influence of mining disturbance in the roof and floor rock mass. The distribution of microseismic events are intensive near the coal mining face, which show the floor rock mass is seriously damaged during the coal mining. The greatest floor failure depth estimated from mine microseismic monitoring is 31 meters. Numerical analysis indicate that the rock stress around the mine stope is redistributed during the coal mining, due to the effect of mining disturbance. The abutment pressure increases in front of the coal mining face and the stress reduces in the mined areas. The concentration and release of the stress makes contribution to the destroy of the floor rock. The maximum floor failure depth is up to 28 meters calculated from numerical simulation. The consistency of microseismic monitoring results and numerical analysis improve that it is effective and reliable to obtain floor failure depth and considerably possible to predict the water inrush using microseismic monitoring technology with its inherent ability to remotely monitor the progressive failure caused by mining. The research results have great popularization and application values for the similar mine.

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