Stress evolution and coal seam deformation through the mining of a remote upper protective layer

2018 ◽  
pp. 1-11
Author(s):  
Qingyi Tu ◽  
Yuanping Cheng
Keyword(s):  
Coal Seam ◽  
Protective Layer ◽  
Stress Evolution

scholarly journals Case study on the mining‐induced stress evolution of an extra‐thick coal seam under hard roof conditions

2020 ◽  
Vol 8 (9) ◽  
pp. 3174-3185 ◽  
Author(s):  
Cong Li ◽  
Heping Xie ◽  
Mingzhong Gao ◽  
Jing Xie ◽  
Guangdi Deng ◽  
...  
Keyword(s):  
Coal Seam ◽  
Stress Evolution ◽  
Thick Coal Seam ◽  
Hard Roof ◽  
Induced Stress

Study on the Terminal Line Reasonable Position of Two Coal Seam under the Down-Protective Layer Pressure-Relieved Mining

2013 ◽  
Vol 295-298 ◽  
pp. 2913-2917
Author(s):  
Xiang Yang Zhang ◽  
Min Tu
Keyword(s):  
Coal Seam ◽  
Coal Pillar ◽  
Protective Layer ◽  
Simulation Software ◽  
Surrounding Rock ◽  
Rock Properties ◽  
Engineering Practice ◽  
Working Face ◽  
Roadway Deformation ◽  
The Impact

In order to study the stress distribution and its dynamic influence law while the protective layer mining, based on the transfer law of mining-induced stress in the coal seam floor and in front of the working face, using numerical simulation software to simulate the surrounding rock stress under the different pillar width mining conditions, and carried through the roadway deformation engineering practice observations. It is shown that reserved 110m coal pillar could weaken the impact on the front of the floor tunnel under the protective layer mining process. When the top liberated layer mining to reduce the impact of mining stress superposition, it should avoid the terminal lines on the two coal seams at the same location and may be staggered at least about 30m ~ 50m. And it obtained that the roadway deformation not only by mining impact, but also considering the geological environment surrounding rock conditions, tunnel position in which layers of rock, rock properties and other factors. The research guided the engineering practice successfully.

scholarly journals Study on Numerical Simulation Test of Mining Surface Subsidence Law under Ultrathick Loose Layer

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Weiping Shi ◽  
Xiaocheng Qu ◽  
Chuntao Jiang ◽  
Kaixin Li
Keyword(s):  
Numerical Simulation ◽  
Numerical Model ◽  
Coal Seam ◽  
Crack Propagation ◽  
Research Process ◽  
Surface Subsidence ◽  
Stress Evolution ◽  
Seam Mining ◽  
Loose Layer ◽  
Similar Simulation

In the process of coal mining, the surface subsidence under ultrathick loose layer is abnormal (subsidence coefficient greater than 1.0), which will cause great damage to the surface ecological environment. The fracture propagation and stress evolution of bedrock are of great significance to the prevention of surface subsidence. Taking the 1305 working face of a mine as the background, this paper study the process of crack propagation and stress evolution of bedrock under the influence of ultrathick loose layer by methods of on-site measurement, similar simulation, and numerical simulation. During the research process, the physical model was verified by the measured data. Then, the numerical model was verified by the crack propagation angle and subsidence of bedrock, which were obtained in a similar simulation. Based on the verified numerical model, it was obtained that after the coal seam was mined out, the bedrock above the mined-out area was mainly damaged by tension, while the strata on both sides of the crack expansion angle were mainly damaged by shear and tension. During coal seam mining, for bedrock the process of fracture expansion, subsidence, and stress evolution all could be divided into four stages. This research provides a basis for the control of surface subsidence.

Coal Seam Group Protection Layer Face Causes and Characteristics Analysis of Dynamic Phenomenon

2012 ◽  
Vol 550-553 ◽  
pp. 502-505
Author(s):  
Yong Jiang Zhang ◽  
Xian Zheng Meng ◽  
Zun Yu Xu
Keyword(s):  
Coal Seam ◽  
Coal Mine ◽  
Protective Layer ◽  
Test Area ◽  
Mine Safety ◽  
Dynamic Phenomenon ◽  
Geological Conditions ◽  
Characteristics Analysis ◽  
Safety Production ◽  
Mining Face

In Xinji Coal Mine under complicated geological conditions, regional faults. Experimental zone for near coal seam group mining(6-1,7-1,7-2,8 seam), The objective conditions with protective layer . The minefield of soft broken coal seam, Soft layered coal firmness coefficient f = 0.18. In the test area of 210601,210603 6-1seam protective layer mining face during the period, there were 8 abnormal gas dynamic phenomenon, To the coal mine safety production brought hidden trouble. On the basis of dynamic phenomenon occurring phenomenon, analysis of the dynamic phenomena, combined with the test area actual situation, summed up the6-1coal power causes, for guiding the 6-1safety mining and provide a theoretical basis, has important significance.

Induced stress evolution of hydraulic fracturing in an inclined soft coal seam gas reservoir near a fault

2021 ◽  
Vol 88 ◽  
pp. 103794
Author(s):  
Qianting Hu ◽  
Zhizhong Jiang ◽  
Quangui Li ◽  
Wenbin Wu ◽  
Qingguo Wang ◽  
...  
Keyword(s):  
Coal Seam ◽  
Hydraulic Fracturing ◽  
Stress Evolution ◽  
Coal Seam Gas ◽  
Gas Reservoir ◽  
Soft Coal ◽  
Induced Stress ◽  
Soft Coal Seam

scholarly journals Geological evolution process, mechanism, and application of protective layer in semi-coal and rock face

2021 ◽  
Vol 24 (4) ◽  
pp. 499-506
Author(s):  
Xiaoping Xie ◽  
Xinqiu Fang ◽  
Minfu Liang ◽  
Dechun Ai
Keyword(s):  
Coal Seam ◽  
Protective Layer ◽  
Practical Significance ◽  
Low Permeability ◽  
Coal Seams ◽  
Pressure Relief ◽  
Rock Face ◽  
Geological Evolution ◽  
Pillar Mining ◽  
Gas Coal

Under the influence of geological structure, the surrounding rock of semi-coal seam is easy to be loose and fractured, and the repairing rate is high. Therefore, it is of great theoretical and practical significance to study semi-coal seam mining's mechanism and control technology. In this paper, the geological evolution principle of the semi-coal seam is analyzed theoretically. The mechanic's relationship between the mining height of the semi-coal face and the lower coal seam's pressure relief is interpreted. The mechanism of eliminating bad blind areas in non-pillar mining of upper protective seam is analyzed. Through numerical simulation analysis, it is concluded that the expansion deformation rate of a protective layer increases linearly with the increase of mining thickness of the protective layer, and the width of undesirable blind zone of coal seam increases linearly with the rise of protective layer thickness. This paper puts forward the technology of non-pillar mining in the protective seam's semi-coal and rock face. Field industrial test results show that the technology achieves the overall pressure relief and reflection reduction of low permeability and high gas coal seams. The underlying 3 + 4 protective layer achieves the general pressure relief and reflection reduction of low permeability and high gas coal seams. Coalbed methane can be pre-drained up to 18 m3/min with a concentration of 90%.

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