Rock strata failure and subsidence characteristics under the mining of short distance thick coal seams: a case in west China

2021 ◽  
Vol 43 (4) ◽  
pp. 356
Author(s):  
Jianghua Li ◽  
Hongjie Li ◽  
ng Li ◽  
Donghao Wang
Keyword(s):  
Short Distance ◽  
Coal Seams ◽  
West China ◽  
Rock Strata ◽  
Strata Failure

Assessment of rigid overlying strata failure in face mining

2010 ◽  
Vol 2 (4) ◽  
Author(s):  
Eva Jiránková
Keyword(s):  
Longwall Mining ◽  
Practical Importance ◽  
Assessment Method ◽  
Coal Seams ◽  
Deep Mine ◽  
Failure Assessment ◽  
Surface Measurements ◽  
Strata Failure ◽  
Simultaneous Assessment ◽  
Overlying Strata

AbstractThe method of overlying strata failure assessment of extracted seams is based upon the simultaneous assessment of surface subsidence and seismic activity, considering the spatiatemporal progress of mining, depending on the character of the rock mass. The rigid overlying strata failure assessment results in finding whether a failure of the firm overlying rocks occurred or whether a strutting arch was formed over the mined-out area. The practical importance of the overlying strata failure assessment consists in determining the size of the mined-out area at which the com-plete failure of the rigid overlying strata occurred and in the assessment of the current stress condition of the overlying strata failure. The assessment method is applicable in deep mine workings where thick coal seams are being mined by means of the method of longwall mining with controlled caving. The results of this method are used to amend contemporary known methods of rock-burst protection, namely (regarding the use of surface measurements for the evaluation) in overlying strata areas.

Mechanical Model and Analysis on Movement of Rock Strata between Coal Seams in Pillar Upward Mining of Left-Over Coal

2011 ◽  
Vol 58-60 ◽  
pp. 393-398
Author(s):  
Guo Rui Feng ◽  
Jing Zheng ◽  
Ya Feng Ren ◽  
Cong Ming Zhong ◽  
Li Xun Kang
Keyword(s):  
Differential Equation ◽  
Mechanical Properties ◽  
Partial Differential Equation ◽  
Mechanical Model ◽  
Theoretical Foundation ◽  
Control Measures ◽  
Coal Seams ◽  
Set Up ◽  
Rock Strata ◽  
Upward Mining

Work out control measures for pillar upward mining of left-over coal, in view of coal floor movement, this paper analyzes theoretical foundation and mechanical properties of mechanical model on coal floor movement of rock strata between coal seams in pillar upward mining of left-over coal and presents a simplified corresponding mechanical condition. Taking into the relation between layer movement and time consideration, the PTh model is used to show its rheological properties. By using a two-dimension model, mechanical model of coal floor movement is set up and both ends of cantilever beam are fixed. Finally, subsiding partial differential equation is induced at different districts in pillar upward mining of left-over coal. After solving the equation, prediction model about law of coal floor movement at different districts is gotten in pillar upward mining of left-over coal, which provides a theory basis for further study on upward mining.

scholarly journals Safety Mining Technology of Coal Seams in Weathered Zone Based on Ground J-Type Pregrouting Reinforcement

2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
Min Tu ◽  
Jinlong Cai ◽  
Hualei Zhang ◽  
Chuanxin Rong
Keyword(s):  
Industrial Test ◽  
Coal Seams ◽  
Strata Movement ◽  
Research Results ◽  
Weathered Zone ◽  
Working Face ◽  
Fracture Development ◽  
Seam Mining ◽  
Rock Strata ◽  
Overlying Strata

A thin basement coal seam mining model under different overlying strata conditions was developed using the discrete element software UDEC. This approach is used to discuss the safety mining of the thin basement coal seams. Fracture development in overlying and rock strata movement law in the stope was discussed. The relationship between support and surrounding rocks under different overlying strata conditions was analyzed. Lastly, a field industrial test was conducted based on the research results. A few major conclusions could be drawn. Under load transmission in loose water-bearing strata, causing a large-scaled rock strata movement to advance into the working face is easy when only one bearing stratum exists in the overlying strata. Meanwhile, the support bears strong loads, which can easily be collapsed. When two bearing strata exist in the overlying one, the upper bearing stratum can form a voussoir beam structure. Loads on the support decreased substantially compared with those under single bearing stratum, whilst the probability of pressing frame was reduced accordingly. A weathered zone above the stope was reinforced by ground J-type drilling pregrouting, thereby improving the physical and mechanical properties and increasing the bearing capacity of the rock strata in the grouting range and safety mining of the working face in the lower coal seams. Research results provide important references for the safety mining of thin basement coal seams under similar conditions.

Simulation of water resource loss in short-distance coal seams disturbed by repeated mining

2015 ◽  
Vol 74 (7) ◽  
pp. 5653-5662 ◽  
Author(s):  
Liqiang Ma ◽  
Zhiyuan Jin ◽  
Jimeng Liang ◽  
Hai Sun ◽  
Dongsheng Zhang ◽  
...  
Keyword(s):  
Water Resource ◽  
Short Distance ◽  
Resource Loss ◽  
Coal Seams

Research on Movement and Deformation of Rock Strata between Coal Seams in Pillar Upward Mining of Left-Over Coal with Numerical Simulation Method

2011 ◽  
Vol 225-226 ◽  
pp. 623-627
Author(s):  
Guo Rui Feng ◽  
Jing Zheng ◽  
Hong Fu Liu ◽  
Cong Ming Zhong
Keyword(s):  
Coal Seam ◽  
Control Function ◽  
Simulation Method ◽  
Vertical Displacement ◽  
Face Advance ◽  
Geological Condition ◽  
Coal Seams ◽  
Seam Mining ◽  
Rock Strata ◽  
Upward Mining

Based on the occurrence condition of coal seams and the geological condition on coal seam mining in Coal Mine Group Baijiazhuang, after pillar mining the 8th coal seam was well controlled, ascending mining the 6th coal seam, mining process was numerically simulated by FLAC3D,the variation law of displacements field on interlayer strata between the 6th coal seam and the 8th coal seam at different face advance were analyzed. Vertical displacement on rock strata increased gradually from below. A control stratum existed on rock strata and could play a control function for steady of strata movement, which provides a theory basis for further study on upward mining.

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