Numerical simulation of spatial distributions of mining-induced stress and fracture fields for three coal mining layouts
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摘要
In this study, the spatial distributions of stress and fracture fields for three typical underground coal mining layouts, i.e. non-pillar mining(NM), top-coal caving mining(TCM) and protective coal-seam mining(PCM), are modeled using discrete element software UDEC. The numerical results show that different mining layouts can lead to different mining-induced stress fields, resulting in diverse fracture fields. For the PCM, the mining influenced area in front of the mining faces is the largest, and the stress concentration factor in front of the mining faces is the lowest. The spatial shapes of the mining-induced fracture fields under NM, TCM and PCM differ, and they are characterized by trapezoidal, triangular and tower shapes, respectively. The fractal dimensions of mining-induced fractures of the three mining layouts decrease in the order of PCM, TCM and NM. It is also shown that the PCM can result in a better gas control effect in coal mines with high outburst potential. The numerical results are expected to provide a basis for understanding of mining-induced gas seepage fields and provide a reference for highefficiency coal mining.
In this study, the spatial distributions of stress and fracture fields for three typical underground coal mining layouts, i.e. non-pillar mining(NM), top-coal caving mining(TCM) and protective coal-seam mining(PCM), are modeled using discrete element software UDEC. The numerical results show that different mining layouts can lead to different mining-induced stress fields, resulting in diverse fracture fields. For the PCM, the mining influenced area in front of the mining faces is the largest, and the stress concentration factor in front of the mining faces is the lowest. The spatial shapes of the mining-induced fracture fields under NM, TCM and PCM differ, and they are characterized by trapezoidal, triangular and tower shapes, respectively. The fractal dimensions of mining-induced fractures of the three mining layouts decrease in the order of PCM, TCM and NM. It is also shown that the PCM can result in a better gas control effect in coal mines with high outburst potential. The numerical results are expected to provide a basis for understanding of mining-induced gas seepage fields and provide a reference for highefficiency coal mining.
In this study, the spatial distributions of stress and fracture fields for three typical underground coal mining layouts, i.e. non-pillar mining(NM), top-coal caving mining(TCM) and protective coal-seam mining(PCM), are modeled using discrete element software UDEC. The numerical results show that different mining layouts can lead to different mining-induced stress fields, resulting in diverse fracture fields. For the PCM, the mining influenced area in front of the mining faces is the largest, and the stress concentration factor in front of the mining faces is the lowest. The spatial shapes of the mining-induced fracture fields under NM, TCM and PCM differ, and they are characterized by trapezoidal, triangular and tower shapes, respectively. The fractal dimensions of mining-induced fractures of the three mining layouts decrease in the order of PCM, TCM and NM. It is also shown that the PCM can result in a better gas control effect in coal mines with high outburst potential. The numerical results are expected to provide a basis for understanding of mining-induced gas seepage fields and provide a reference for highefficiency coal mining.
引文
Alehossein H,Poulsen B.Stress analysis of longwall top coal caving.International Journal of Rock Mechanics and Mining Sciences 2010;47(1):30e41.
Chen H,Cheng Y,Ren T,Zhou H,Liu Q.Permeability distribution characteristics of protected coal seams during unloading of the coal body.International Journal of Rock Mechanics and Mining Sciences 2014;71:105e16.
Chen J,Lu B,Gu X,Fan J.Determining three-dimensional connectivity of rock mass discontinuity by projection.Chinese Journal of Rock Mechanics and Engineering2005;24(15):2617e21(in Chinese).
Falconer K.Fractal geometry:mathematical foundations and applications.Wiley;1990.
Gao M,Jin W,Dai Z,Xie J.Relevance between abutment pressure and fractal dimension of crack network induced by mining.International Journal of Mining Science and Technology 2013;23(6):925e30.
Guo H,Yuan L,Shen B,Qu Q,Xue J.Mining-induced strata stress changes,fractures and gas flow dynamics in multi-seam longwall mining.International Journal of Rock Mechanics and Mining Sciences 2012;54:129e39.
He M,Zhang G,Qi G,Li Q,Jia Q,Zhou J.Stability control of surrounding rocks in deep entry of Jiahe coal mine.Journal of Mining and Safety Engineering2007;24(1):27e31(in Chinese).
He M,Zhu G,Guo Z.Longwall mining“cutting cantilever beam theory”and 110mining method in China-the third mining science innovation.Journal of Rock Mechanics and Geotechnical Engineering 2015;7(5):483e92.
He M,Wang Y,Yang J,Zhou P,Gao Q,Gao Y.Comparative analysis on stress field distributions in roof cutting non-pillar mining method and conventional mining method.Journal of China Coal Society 2018;43(3):626e37(in Chinese).
Jiang Y,Wang H,Xue S,Zhao Y,Zhu J,Pang X.Assessment and mitigation of coal bump risk during extraction of an island longwall panel.International Journal of Coal Geology 2012;95:20e33.
Mark C,Gale W,Oyler D,Chen J.Case history of the response of a longwall entry subjected to concentrated horizontal stress.International Journal of Rock Mechanics and Mining Sciences 2007;44(2):210e21.
Qian M,Xu J.Study on the“O shape”circle distribution characteristics of mining induced fractures in the overlaying strata.Journal of China Coal Society1998;23(5):466e9(in Chinese).
Shabanimashcool M,Li CC.Numerical modelling of longwall mining and stability analysis of the gates in a coal mine.International Journal of Rock Mechanics and Mining Sciences 2012;51:24e34.
Shabanimashcool M,Li CC.A numerical study of stress changes in barrier pillars and a border area in a longwall coal mine.International Journal of Coal Geology2013;106:39e47.
Singh AK,Singh R,Maiti J,Kumar R,Mandal PK.Assessment of mining induced stress development over coal pillars during depillaring.International Journal of Rock Mechanics and Mining Sciences 2011a;48(5):805e18.
Singh R,Singh AK,Maiti J,Mandal PK,Singh R,Kumar R.An observational approach for assessment of dynamic loading during underground coal pillar extraction.International Journal of Rock Mechanics and Mining Sciences 2011b;48(5):794e804.
Song Z,Liu Y,Chen M.Discussion on the manifestation of abutment pressure before and after rock beam fracture and its application.Shandong Mining Institute Journal 1984;1:27e39(in Chinese).
Wang Z,Zhou H,Xie H.Research on fractal characterization of mined crack network evolution in overburden rock stratum under deep mining.Rock and Soil Mechanics 2009;30(8):2403e8(in Chinese).
Xie H,Chen Z,Wang J.Three-dimensional numerical analysis of deformation and failure during top coal caving.International Journal of Rock Mechanics and Mining Sciences 1999;36(5):651e8.
Xie H,Zhang Z,Gao F,Zhang R,Gao M,Liu J.Stress-fracture-seepage field behavior of coal under different mining layouts.Journal of China Coal Society2016;41(10):2405e17(in Chinese).
Xie H,Zhou H,Liu J,Xue D.Mining-induced mechanical behavior in coal seams under different mining layouts.Journal of China Coal Society 2011;36(7):1067e74(in Chinese).
Yang W,Lin BQ,Qu YA,Li ZW,Zhai C,Jia LL,Zhao WQ.Stress evolution with time and space during mining of a coal seam.International Journal of Rock Mechanics and Mining Sciences 2011;48(7):1145e52.
Yasitli N,Unver B.3D numerical modeling of longwall mining with top-coal caving.International Journal of Rock Mechanics and Mining Sciences2005;42(2):219e35.
Yu B,Zhang R,Gao M,Li G,Zhang Z,Liu Q.Numerical approach to the top coal caving process under different coal seam thicknesses.Thermal Science2015;19(4):1423e8.
Yuan L.Key technique of safe mining in low permeability and methane-rich seam group.Chinese Journal of Rock Mechanics and Engineering 2008;27(7):1370e9(in Chinese).
Zhang Z,Zhang R,Liu J,Liu X,Li J.Permeability evolution of unloaded coal samples at different loading rates.Thermal Science 2014;18(5):1497e504.
Zhang Z,Zhang R,Xie H,Gao M,Xie J.Mining-induced coal permeability change under different mining layouts.Rock Mechanics and Rock Engineering2016;49(9):3753e68.
Zhou H,Zhang T,Xue D,Xue J.Evolution of mining-crack network in overburden strata of longwall face.Journal of China Coal Society 2012;36(12):1957e62(in Chinese).
Chen H,Cheng Y,Ren T,Zhou H,Liu Q.Permeability distribution characteristics of protected coal seams during unloading of the coal body.International Journal of Rock Mechanics and Mining Sciences 2014;71:105e16.
Chen J,Lu B,Gu X,Fan J.Determining three-dimensional connectivity of rock mass discontinuity by projection.Chinese Journal of Rock Mechanics and Engineering2005;24(15):2617e21(in Chinese).
Falconer K.Fractal geometry:mathematical foundations and applications.Wiley;1990.
Gao M,Jin W,Dai Z,Xie J.Relevance between abutment pressure and fractal dimension of crack network induced by mining.International Journal of Mining Science and Technology 2013;23(6):925e30.
Guo H,Yuan L,Shen B,Qu Q,Xue J.Mining-induced strata stress changes,fractures and gas flow dynamics in multi-seam longwall mining.International Journal of Rock Mechanics and Mining Sciences 2012;54:129e39.
He M,Zhang G,Qi G,Li Q,Jia Q,Zhou J.Stability control of surrounding rocks in deep entry of Jiahe coal mine.Journal of Mining and Safety Engineering2007;24(1):27e31(in Chinese).
He M,Zhu G,Guo Z.Longwall mining“cutting cantilever beam theory”and 110mining method in China-the third mining science innovation.Journal of Rock Mechanics and Geotechnical Engineering 2015;7(5):483e92.
He M,Wang Y,Yang J,Zhou P,Gao Q,Gao Y.Comparative analysis on stress field distributions in roof cutting non-pillar mining method and conventional mining method.Journal of China Coal Society 2018;43(3):626e37(in Chinese).
Jiang Y,Wang H,Xue S,Zhao Y,Zhu J,Pang X.Assessment and mitigation of coal bump risk during extraction of an island longwall panel.International Journal of Coal Geology 2012;95:20e33.
Mark C,Gale W,Oyler D,Chen J.Case history of the response of a longwall entry subjected to concentrated horizontal stress.International Journal of Rock Mechanics and Mining Sciences 2007;44(2):210e21.
Qian M,Xu J.Study on the“O shape”circle distribution characteristics of mining induced fractures in the overlaying strata.Journal of China Coal Society1998;23(5):466e9(in Chinese).
Shabanimashcool M,Li CC.Numerical modelling of longwall mining and stability analysis of the gates in a coal mine.International Journal of Rock Mechanics and Mining Sciences 2012;51:24e34.
Shabanimashcool M,Li CC.A numerical study of stress changes in barrier pillars and a border area in a longwall coal mine.International Journal of Coal Geology2013;106:39e47.
Singh AK,Singh R,Maiti J,Kumar R,Mandal PK.Assessment of mining induced stress development over coal pillars during depillaring.International Journal of Rock Mechanics and Mining Sciences 2011a;48(5):805e18.
Singh R,Singh AK,Maiti J,Mandal PK,Singh R,Kumar R.An observational approach for assessment of dynamic loading during underground coal pillar extraction.International Journal of Rock Mechanics and Mining Sciences 2011b;48(5):794e804.
Song Z,Liu Y,Chen M.Discussion on the manifestation of abutment pressure before and after rock beam fracture and its application.Shandong Mining Institute Journal 1984;1:27e39(in Chinese).
Wang Z,Zhou H,Xie H.Research on fractal characterization of mined crack network evolution in overburden rock stratum under deep mining.Rock and Soil Mechanics 2009;30(8):2403e8(in Chinese).
Xie H,Chen Z,Wang J.Three-dimensional numerical analysis of deformation and failure during top coal caving.International Journal of Rock Mechanics and Mining Sciences 1999;36(5):651e8.
Xie H,Zhang Z,Gao F,Zhang R,Gao M,Liu J.Stress-fracture-seepage field behavior of coal under different mining layouts.Journal of China Coal Society2016;41(10):2405e17(in Chinese).
Xie H,Zhou H,Liu J,Xue D.Mining-induced mechanical behavior in coal seams under different mining layouts.Journal of China Coal Society 2011;36(7):1067e74(in Chinese).
Yang W,Lin BQ,Qu YA,Li ZW,Zhai C,Jia LL,Zhao WQ.Stress evolution with time and space during mining of a coal seam.International Journal of Rock Mechanics and Mining Sciences 2011;48(7):1145e52.
Yasitli N,Unver B.3D numerical modeling of longwall mining with top-coal caving.International Journal of Rock Mechanics and Mining Sciences2005;42(2):219e35.
Yu B,Zhang R,Gao M,Li G,Zhang Z,Liu Q.Numerical approach to the top coal caving process under different coal seam thicknesses.Thermal Science2015;19(4):1423e8.
Yuan L.Key technique of safe mining in low permeability and methane-rich seam group.Chinese Journal of Rock Mechanics and Engineering 2008;27(7):1370e9(in Chinese).
Zhang Z,Zhang R,Liu J,Liu X,Li J.Permeability evolution of unloaded coal samples at different loading rates.Thermal Science 2014;18(5):1497e504.
Zhang Z,Zhang R,Xie H,Gao M,Xie J.Mining-induced coal permeability change under different mining layouts.Rock Mechanics and Rock Engineering2016;49(9):3753e68.
Zhou H,Zhang T,Xue D,Xue J.Evolution of mining-crack network in overburden strata of longwall face.Journal of China Coal Society 2012;36(12):1957e62(in Chinese).