Abstract
Extracting the contiguous coal seams under the lowermost aquifer in the unconsolidated Cenozoic alluvium is apt to water and quicksand inrush. By using a series of investigation methods including empirical formulas, numerical simulation, theoretical analysis, etc., the study focused on the fracture and the excess pore water pressure in the overlying strata in the process of extracting no. 8 coal seam firstly and no. 9 coal seam (under no. 8 coal seam) subsequently in no. 8102 working face of Luling coal mine in the north of Anhui Province of China. When no. 8 coal seam was extracted, the water-conducting fractured zone penetrated into the lowermost aquifer and rapid dissipation of excess pore water pressure above the gob occurred, accompanied by relatively high seepage hydraulic gradient over the headgate and the tailgate. When no. 9 coal seam was extracted, failure did not obviously extend upwards and the excess pore water pressure decreased slowly and a relatively high seepage hydraulic gradient transferred downwards from the headgate to the tailgate in the inclined profile. The safe water head (H s) in the lowermost aquifer was confirmed to 15.6 m. Therefore, water and quicksand inrush was avoided effectively in the process of extracting the contiguous coal seams by dewatering, controlling mining height, and laying double resistance nets in the working face.
Similar content being viewed by others
References
Bear J (1972) Dynamics of fluids in porous media. Elsevier, Amsterdam
Booth CJ (1986) Strata-movement concepts and the hydrogeological impact of underground coal mining. Ground Water 24:507–515
Booth CJ, Bertsch L (1999) Groundwater geochemistry in shallow aquifers above longwall mines in Illinois, USA. Hydrogeology Journal 7:561–575
Booth CJ, Spande ED (1992) Potentiometric and aquifer property changes above subsiding longwall mine panels, Illinois basin coalfield. Ground Water 30:362–368
Booth CJ, Curtiss AM, Demaris PJ, Bauer RA (2000) Site-specific variation in the potentiometric response to subsidence above active longwall mining. Environmental & Engineering Geoscience 6:383–394
Gandhe A, Venkateswarlu V, Gupta RN (2005) Extraction of coal under surface water body—a strata control investigation. Rock Mechanics and Rock Engineering 38(5):399–410
Hill JG, Price DR (1983) The impact of deep mining on an overlying aquifer in western Pennsylvania. Ground Water Monitoring Review 3:138–143
Islam MR, Hayashi D, Kamruzzaman AB (2009) Finite element modeling of stress distributions and problems for multi-slice longwall mining in Bangladesh, with special reference to the Barapukuria coal mine. International Journal of Coal Geology 78:91–109
Jiang B, Qu ZH, Geoff GX, Wang ML (2010) Effects of structural deformation on formation of coalbed methane reservoirs in Huaibei coalfield, China. International Journal of Coal Geology 82:175–183
Kim JM, Parizek RR, Elsworth D (1997) Evaluation of fully-coupled strata deformation and groundwater flow in response to longwall mining. International Journal of Rock Mechanics & Mining Sciences 34:1187–1199
Liu TQ (1981) Surface movements, overburden failure and its application. Coal Industry Press, Beijing
Miao XX, Cui XM, Wang JA, Xu JL (2011) The height of fractured water-conducting zone in undermined rock strata. Engineering Geology 120:32–39
Sarkar TN, Singh TN, Verma AK (2012) A numerical simulation of landslide-prone slope in Himalayan region—a case study. Arabian Journal of Geosciences 5:73–81
Singh R, Singh TN (1999) Wide stall mining for optimal recovery of coal from a thick seam under surface features. International Journal of Rock Mechanics & Mining Sciences 36:155–1688
Singh R, Singh TN, Dhar BB (1996) Coal pillar loading for shallow mining conditions. International Journal of Rock Mechanics & Mining Sciences 33:757–68
Singh AK, Singh R, Maiti J, Kumar R, Mandal PK (2011) Assessment of mining induced stress development over coal pillars during depillaring. International Journal of Rock Mechanics & Mining Sciences 48(2):805–818
Tan JQ, Ju YW, Hou QL, Zhang WY, Tan YJ (2009) Distribution characteristics and influence factors of present geo-temperature field in Su-Lin mine area, Huaibei coalfield. Chinese Journal of Geophysics 52(3):732–739
Yavuz H (2004) An estimation method for cover pressure re-establishment distance and pressure distribution in the goaf of longwall mines. International Journal of Rock Mechanics & Mining Sciences 41(2):193–205
Zhang JC, Peng SP (2005) Water inrush and environmental impact of shallow seam mining. Engineering Geology 48:1068–1076
Zhang DS, Fan GW, Ma LQ, Wang XF (2011) Aquifer protection during longwall mining of shallow coal seams: a case study in the Shendong Coalfield of China. International Journal of Coal Geology 86:90–196
Zheng LG, Liu GJ, Qi CC, Zhang Y, Wong MH (2008) The use of sequential extraction to determine the distribution and modes of occurrence of mercury in Permian Huaibei coal, Anhui Province, China. International Journal of Coal Geology 73:139–155
Acknowledgments
This work was financially supported by the National Natural Science Foundation of China (no. 41173106) and the Science and Technology Project of Anhui Province, China (no. 12010402150). We also gratefully acknowledge the numerical analysis carried out by our research group.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Chen, L., Zhang, S. & Gui, H. Prevention of water and quicksand inrush during extracting contiguous coal seams under the lowermost aquifer in the unconsolidated Cenozoic alluvium—a case study. Arab J Geosci 7, 2139–2149 (2014). https://doi.org/10.1007/s12517-013-1029-8
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s12517-013-1029-8