Abstract
The purpose of this paper is to provide scientific basis for the stability evaluation of overburden rock of repeated mining goaf under the expressway. The objectives of the present study are to reveal the development of overburden rock fractures under repeated mining and to identify the fractal characteristics of the overburden rock fractures. The results show that (1) the separation fracture and vertical fracture fissure are developed in the overburden rock under repeated mining; (2) after the mining of the lower coal seam, the fractures developed in the overburden rock of the goaf are obviously retained in general. The number of fractures on both sides of the goaf is relatively large, while in the central part, it is relatively small and the fractures in most areas are basically closed; (3) under the same advancing length of working face in the lower coal seam, the fractal dimension in the caving zone is larger than that of the fractured zone; (4) with the increase of the advancing length of working face in the lower coal seam, the variation trend of the fractal dimension appears from small to large and then to small and stable; (5) when the repeated mining is over and the overburden rock movement is basically stable, the ratio of the fractal dimension in the caving zone and the fractured zone is 1.067:1. The results have an important reference value for ensuring the safety of the expressways above the repeated mining goaf in Shanxi region and similar areas.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Babadagli T (2001) Fractal analysis of 2-D fracture networks of geothermal reservoirs in south-western Turkey. J Volcanol Geotherm Res 112(1):83–103
Cheng X, Zhao G, Li Y, Meng X, Dong C, Liu Z (2018) Researches of fracture evolution induced by soft rock protective seam mining and an omni-directional stereo pressure-relief gas extraction technical system: a case study. Arab J Geosci 11:326. https://doi.org/10.1007/s12517-018-3666-4
Fan G, Zhang D, Chen M, Zhang S (2019) Dissipative structure feature of mining fractured overburden system and threshold effect of catastrophic instability. J Min Saf Eng 36(6):1093–1101 (In Chinese)
Feng J, Liu X, Yu Z (2017) Numerical simulation study on the mining-induced fracture evolution of steep coal seam. J China Coal Soc 42:1971–1978 (In Chinese)
Li Z, Ding X, Cheng Z (2010) Research on fractal characteristics of overlying strata crack evolution in coal seam with thin bedrock. J Min Saf Eng 27:576–580 (In Chinese)
Li H, Wang W, Qi Q, Zhang L (2014) Study on fissure development rule of overlying strata influenced by mining based on fractal theory. J China Coal Soc 39(6):1023–1030 (In Chinese)
Li D, Zhou H, Xue D, Yi H, Gao H (2015) Relationship between percolation and fractal properties of mining-induced crack network in coal and rock masses. Rock Soil Mech 36:1135–1140 (In Chinese)
Li S, Ding Y, An Z, Li H, Wei X (2016) Experimental research on the shape and dynamic evolution of repeated mining-induced fractures in short-distance coal seams. J Min Saf Eng 33:904–910 (In Chinese)
Liang T, Liu X, Wang S (2019) Fractal study on the crack network evolution and permeability change in mining rock mass. J China Coal Soc 44(12):3729–3739 (In Chinese)
Liu J, Li J, Geng Q, Zheng X (2018) In-situ measurement and simulation of regional mining-induced fracture evolution. Journal of Liaoning Technical University (Natural Science) 37(1):49–55 (In Chinese)
Lu Y, Wang L (2015) Numerical simulation of mining-induced fracture evolution and water flow in coal seam floor above a confined aquifer. Comput Geotech 67:157–171
Mandelbrot BB (1983) The fractal geometry of nature. W. H. Freeman & Co., New York, 468p
Poulsen BA, Adhikary D, Guo H (2018) Simulating mining-induced strata permeability changes. Eng Geol 237:208–216
Sofianos AI (1996) Analysis and design of an underground hard rock Voussoir beam roof. Int J Rock Mech Min Sci Geomech Abstr 33:153–166
Song B, Chen L, Zhang F, Chen L, Li H (2017) Study on the evolution law of the fracture influenced by mining based on fractal theory. Geotechnical Investigation & Surveying (1):1–6 (In Chinese)
Wang J, Wang Z (2018) Propagating mechanism of top-coal fracture in longwall top-coal caving mining. J China Coal Soc 43(9):2376–2388 (In Chinese)
Wang G, Yu G, Yu Y, Lu S, Kang Y (2012) Study on cracks fractal evolution laws of mining rock mass. J Min Saf Eng 29:859–863 (In Chinese)
Wang C, Zhang Q, Li J, Liu W (2017) Similar simulation of overlying strata fracture development under repeated mining in shallow. Coal Mining Technol 22(6):78–81 (In Chinese)
Wang S, Zhao J, Zhang L (2019) Numerical simulation of mining-induced fracture development of roof of Shennanwa coal mine. Safety in Coal Mines 50(10):231–234 (In Chinese)
Xu G, Li H, Guan J (2018) Laws of overburden strata rupture and fissure evolution during mining under water body. Safety in Coal Mines 49(4):42–45 (In Chinese)
Zhang J (2017) Mining-induced stress characteristics and fracture evolution law of over one kilometer deep Pingdingshan coal mine. J China Univ Min Technol 46(5):1041–1049 (In Chinese)
Zhang Y, Liu X (2004) Testing study on fractal characteristics of cracks in mining rock masses. Ground Pressure and Strata Control 23:94–95 (In Chinese)
Zhang Y, Jin Z, Liu X (2004) Testing study on fractal correlation law of cracks in mined rock masses. Chin J Rock Mech Eng 23:3426–3429 (In Chinese)
Zhang Y, Zhang B, Zhang C, Zhao J, Liu J, Zhang S (2013) Study of the dynamic evolution rules and distribution pattern of mining-induced fractures of thick coal seam. J China Univ Min Technol 42:935–940 (In Chinese)
Zhang R, Ai T, Zhou H, Ju Y, Zhang Z (2015a) Fractal and volume characteristics of 3D mining-induced fractures under typical mining layouts. Environ Earth Sci 73:6069–6080
Zhang Y, Zhang C, Zhao F (2015b) Dynamic evolution rules of mining-induced fractures in different floor area of short-distance coal seams. J China Coal Soc 40(4):786–792 (In Chinese)
Zhang Y, Cao S, Guo S, Wan T, Wang J (2018a) Mechanisms of the development of water-conducting fracture zone in overlying strata during shortwall block backfill mining: a case study in Northwestern China. Environ Earth Sci 77:543
Zhang Y, Xu Y, Wang K, Chen P, Wang X, Zheng Q, Zhang Z (2018b) The fracturing characteristics of rock mass of coal mining and its effect on overlying unconsolidated aquifer in Shanxi, China. Arab J Geosci 11:666. https://doi.org/10.1007/s12517-018-4034-0
Zhou S, Lin B (1999) Theory of gas occurrence and flow in coal seam. Beijing: the Press of Coal Industry (In Chinese)
Zhou H, Zhang T, Xue D, Xue J (2011) Evolution of mining-induced crack network in overburden strata of longwall face. J China Coal Soc 36:1957–1962 (In Chinese)
Zhu W (2019) Developing rule and engineering application of mining fracture under thick unconsolidated layers and thin bedrock. Metal Mine 10:126–132 (In Chinese)
Acknowledgements
The authors gratefully appreciate all the valuable comments and suggestions from the anonymous reviewers and editors, which helped to improve the quality of the manuscript greatly.
Funding
This study was supported in part by the National Natural Science Foundation of China (No. 41572221) and the National Natural Science Foundation of China (No. 41807195).
Author information
Authors and Affiliations
Contributions
The work was coordinated by the corresponding author Zhixiang Zhang and Yongbo Zhang. Qiang Zheng, Zhaoliang Wang, Liangliang Guo performed the experiment. This paper was mainly written by Zhixiang Zhang and Yongbo Zhang. Yongxin Xu revised the manuscript.
Corresponding authors
Additional information
Responsible Editor: Longjun Dong
Rights and permissions
About this article
Cite this article
Zhang, Z., Zhang, Y., Xu, Y. et al. Fracture development and fractal characteristics of overburden rock under repeated mining. Arab J Geosci 14, 225 (2021). https://doi.org/10.1007/s12517-021-06524-6
Received:
Accepted:
Published:
DOI: https://doi.org/10.1007/s12517-021-06524-6