Abstract
Fractures in the overburden induced by mining disturbances provide channels for heat-mass exchange between the subsurface environment and ground surface. Void fraction is an important characterization parameter to determine the difficulty of fluid flow and heat transfer. The three-dimensional stochastic distribution characteristics of the void fraction in the longwall mining-disturbed overburden are proposed based on the theoretical expressions of stratum and ground settlements and combined with a stochastic law with a normal distribution of void fractions obtained from statistical analyses from similar physical simulation experiments. The deterministic and stochastic distribution models and the discrete element numerical simulations show that the void fraction distribution is U-shaped in the cave zone and M-shaped in the bed separation zone. In the ground subsidence zone, the void fraction distribution of the horizontal fracture is M-shaped in the strike direction and an inverted U-shaped in the dip direction, and the void fraction presents an M-shaped distribution for the vertical fracture. As the depth decreases, the void fraction gradually decreases. As longwall mining progresses, the subsidence amount of stratum changes from a V-shaped into a U-shaped distribution, and the total void fraction transforms from an inverted V-shaped distribution to M-shaped distribution. The fracture distribution of the disturbed overburden forms into a fractured arch, and the fracture density gradually decreases from the foot to the top of the arch. The void fraction as a determinant parameter for stochastic distribution of permeability can provide valuable information for coal bed methane drainage, water inrush prevention, and coal fire control.
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References
Adhikary DP, Guo H (2014) Modelling of Longwall Mining-Induced Strata Permeability Change. Rock Mech Rock Eng 48:345–359
Alehossein H, Poulsen BA (2010) Stress analysis of longwall top coal caving. Int J Rock Mech Min Sci 47:30–41
Alejano LR, Taboada J, García-Bastante F, Rodriguez P (2008) Multi-approach back-analysis of a roof bed collapse in a mining room excavated in stratified rock. Int J Rock Mech Min Sci 45:899–913
Bai Q-S, Tu S-H, Zhang C, Zhu D (2016) Discrete element modeling of progressive failure in a wide coal roadway from water-rich roofs. Int J Coal Geol 167:215–229
Bouzeran L, Furtney J, Pierce M, Hazzard J, Lemos J (2017) Simulation of ground support performance in highly fractured and bulked rock masses with advanced 3DEC bolt model. Proceedings of the Eighth International Conference on Deep and High Stress Mining 667–680
Cheng J, Liu F, Li S (2017a) Model for the prediction of subsurface strata movement due to underground mining. J Geophys Eng 14:1608–1623
Cheng J, Zhao G, Li S (2017b) Predicting Underground Strata Movements Model with Considering Key Strata Effects. Geotech Geol Eng 36:621–640
Dou L-M, He X-Q, He H, He J, Fan J (2014) Spatial structure evolution of overlying strata and inducing mechanism of rockburst in coal mine. Transactions of Nonferrous Metals Society of China 24:1255–1261
Earon R, Olofsson B (2018) Hydraulic heterogeneity and its impact on kinematic porosity in Swedish coastal terrains. Eng Geol 245:61–71
Gao B, Peng S, Gong H, Yue X (2005) Exploration of the criteria for the classification of flow units in oil and gas reservoirs. J China Univ Min Technol 34(1):82–86
Gao F, Stead D, Coggan J (2014) Evaluation of coal longwall caving characteristics using an innovative UDEC Trigon approach. Comput Geotech 55:448–460
Gong H, Kizil MS, Chen Z, Amanzadeh M, Yang B, Aminossadati SM (2019) Advances in fibre optic based geotechnical monitoring systems for underground excavations. Int J Min Sci Technol 29:229–238
He J-H, Li W-P, Liu Y, Yang Z, Liu S-L, Li L-F (2018) An improved method for determining the position of overlying separated strata in mining. Eng Fail Anal 83:17–29
He M, Zhu G, Guo Z (2015) Longwall mining “cutting cantilever beam theory” and 110 mining method in China—The third mining science innovation. J Rock Mech Geotech 7:483–492
Ju Y, Wang Y, Su C, Zhang D, Ren Z (2019) Numerical analysis of the dynamic evolution of mining-induced stresses and fractures in multilayered rock strata using continuum-based discrete element methods. Int J Rock Mech Min Sci 113:191–210
Karacan CÖ, Ruiz FA, Cotè M, Phipps S (2011) Coal mine methane: A review of capture and utilization practices with benefits to mining safety and to greenhouse gas reduction. Int J Coal Geol 86:121–156
Lai XP, Cai MF, Xie MW (2006) In situ monitoring and analysis of rock mass behavior prior to collapse of the main transport roadway in Linglong Gold Mine, China. Int J Rock Mech Min Sci 43:640–646
Ma L-Q, Zhang D-S, Jing S-G, Zhang W, Fan G-W (2008) Numerical simulation analysis by solid-liquid coupling with 3DEC of dynamic water crannies in overlying strata. J China Univ Min Technol 18:347–352
Majdi A, Hassani FP, Nasiri MY (2012) Prediction of the height of destressed zone above the mined panel roof in longwall coal mining. Int J Coal Geol 98:62–72
Meng Z, Shi X, Li G (2016) Deformation, failure and permeability of coal-bearing strata during longwall mining. Eng Geol 208:69–80
Ning J, Wang J, Tan Y, Xu Q (2020) Mechanical mechanism of overlying strata breaking and development of fractured zone during close-distance coal seam group mining. Int J Min Sci Technol 30:207–215
Palchik V (2003) Formation of fractured zones in overburden due to longwall mining. Environ Geol 44:28–38
Palchik V (2005) Localization of mining-induced horizontal fractures along rock layer interfaces in overburden: field measurements and prediction. Environ Geol 48:68–80
Palchik V (2010) Experimental investigation of apertures of mining-induced horizontal fractures. Int J Rock Mech Min Sci 47:502–508
Pan Z, Connell LD (2012) Modelling permeability for coal reservoirs: A review of analytical models and testing data. Int J Coal Geol 92:1–44
Shabanimashcool M, Li CC (2012) Numerical modelling of longwall mining and stability analysis of the gates in a coal mine. Int J Rock Mech Min Sci 51:24–34
Song Z, Kuenzer C (2014) Coal fires in China over the last decade: a comprehensive review. Int J Coal Geol 133:72–99
Tran VDH, Meguid MA, Chouinard LE (2014) Discrete Element and Experimental Investigations of the Earth Pressure Distribution on Cylindrical Shafts. Int J Geomech 14:80–91
Vallejos JA, McKinnon SD (2011) Correlations between mining and seismicity for re-entry protocol development. Int J Rock Mech Min Sci 48:616–625
van Dijk P, Zhang J, Jun W, Kuenzer C, Wolf K-H (2011) Assessment of the contribution of in-situ combustion of coal to greenhouse gas emission; based on a comparison of Chinese mining information to previous remote sensing estimates. Int J Coal Geol 86:108–119
Wang F, Zhang C, Zhang X, Song Q (2015a) Overlying strata movement rules and safety mining technology for the shallow depth seam proximity beneath a room mining goaf. Int J Min Sci Technol 25:139–143
Wang J, Li E, Chen L, Wang J, Tan Y, Duan J, Pu S, Gao L, Han Y, Wang C (2019) Measurement and analysis of the internal displacement and spatial effect due to tunnel excavation in hard rock. Tunn Undergr Space Technol 84:151–165
Wang JA, Park HD (2003) Coal mining above a confined aquifer. Int J Rock Mech Min Sci 40:537–551
Wang Q, He M, Yang J, Gao H, Jiang B, Yu H (2018) Study of a no-pillar mining technique with automatically formed gob-side entry retaining for longwall mining in coal mines. Int J Rock Mech Min Sci 110:1–8
Wang S, Elsworth D, Liu J (2011) Permeability evolution in fractured coal: The roles of fracture geometry and water-content. Int J Coal Geol 87:13–25
Wang S, Li X (2017) Dynamic Distribution of Longwall Mining-Induced Voids in Overlying Strata of a Coalbed. Int J Geomech 17
Wang S, Li X, Wang D (2016a) Mining-induced void distribution and application in the hydro-thermal investigation and control of an underground coal fire: A case study. Process Saf Environ Prot 102:734–756
Wang S, Li X, Wang D (2016b) Void fraction distribution in overburden disturbed by longwall mining of coal. Environ Earth Sci 75
Wang S, Li X, Wang D, Cao K (2015b) Stochastic distribution law of porosity in underground coal fire ignition void areas of fallen rock. Journal of Engineering Science 37(5):543–550
Wang S, Li X, Wang S (2017a) Separation and fracturing in overlying strata disturbed by longwall mining in a mineral deposit seam. Eng Geol 226:257–266
Wang T, Hu W, Elsworth D, Zhou W, Zhou W, Zhao X, Zhao L (2017b) The effect of natural fractures on hydraulic fracturing propagation in coal seams. J Petrol Sci Eng 150:180–190
Wong LNY, Peng J (2020) Numerical investigation of micro-cracking behavior of brittle rock containing a pore-like flaw under uniaxial compression. Int J Damage Mech 29(10):1543–1568
Wong LNY, Meng F, Guo T, Shi X (2020) The role of load control modes in determination of mechanical properties of granite. Rock Mech Rock Eng 53(2):539–552
Wu J-H, Hsieh P-H (2021) Simulating the postfailure behavior of the seismically- triggered Chiu-fen-erh-shan landslide using 3DEC. Eng Geology 287
Wu J-H, Lin W-K, Hu H-T (2017) Assessing the impacts of a large slope failure using 3DEC: The Chiu-fen-erh-shan residual slope. Comput Geotech 88:32–45
Xia K, Chen C, Liu X, Fu H, Pan Y, Deng Y (2016) Mining-induced ground movement in tectonic stress metal mines: a case study. Bull Eng Geol Env 75:1089–1115
Xu N, Zhang J, Tian H, Mei G, Ge Q (2016) Discrete element modeling of strata and surface movement induced by mining under open-pit final slope. Int J Rock Mech Min Sci 88:61–76
Xuan D, Xu J (2017) Longwall surface subsidence control by technology of isolated overburden grout injection. Int J Min Sci Technol 27:813–818
Zhang J (2005) Investigations of water inrushes from aquifers under coal seams. Int J Rock Mech Min Sci 42:350–360
Zhang J, Shen B (2004) Coal mining under aquifers in China: a case study. Int J Rock Mech Min Sci 41:629–639
Zhang S, Liu Y (2012) A Simple and Efficient Way to Detect the Mining Induced Water-conducting Fractured Zone in Overlying Strata. Energy Procedia 16:70–75
Zhou XP, Zhao XD, Wong LNY, Cheng H (2019) A modified Sarma method for stability analysis of layered slopes. Bull Eng Geol Env 78(3):1893–1909
Zhu H, Shen J, Zhang F (2019) A fracture conductivity model for channel fracturing and its implementation with Discrete Element Method. J Petrol Sci Eng 172:149–161
Acknowledgements
This research was supported by the National Natural Science Foundation of China (No. 52174229) and the Natural Science Foundation of Liaoning Province (No. 2021-KF-23-01), for which the authors are very thankful. We would also like to acknowledge the editors and reviewers for their invaluable comments.
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Wang, S., Liu, K., Wang, S. et al. Three-dimensional stochastic distribution characteristics of void fraction in longwall mining-disturbed overburden. Bull Eng Geol Environ 81, 414 (2022). https://doi.org/10.1007/s10064-022-02929-z
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DOI: https://doi.org/10.1007/s10064-022-02929-z