Mode of overlying rock roofing structure in large mining height coal face and analysis of support resistance

Abstract

The mining space of large mining height coal face is large, the range of movement and caving of rock strata is large and the stability of supports at coal face is low and damage rate of supports is high, which significantly affects the safe and efficient production of coal mines. By similar simulation experiment and theoretical analysis, the mode of fractured roofing structure of large mining height coal face and the method of determination of reasonable support resistance of the support was evaluated. Analysis shows that the structural mode of “combined cantilever beam–non-hinged roofing–hinged roofing” of the large mining height coal face appears at the roofing of large mining height coal face. The supporting factor of caved gangue at the gob is introduced, the calculating equations of the fractured step distance of roofing were derived and conventional calculating method of caved height of roofing was corrected and the method of determination of the length and height of each structural area of the roofing was provided. With reference to the excavating conditions at Jinhuagong coal mine in Datong minefield, the dimensions of structural areas of the roofing of the coal face were determined and analyzed, and reasonable support resistance of the height coal face was acquired. By selecting Model ZZ13000/28/60 support and with procedures of advanced pre-cracking blasting, the safe production of large mining height coal face was assured.

Keywords

large mining height / roof structure / roof model / roof fracturing distance / support resistance

References

[1] ChenY-g, QianM-gaoStrata control around coal face in China [M], 1994XuzhouThe Publishing House of China University of Mining and Technology

[2] QianM-g, ShiP-w, XuJ-linMine pressure and strata control [M], 2010XuzhouThe Publishing House of China University of Mining and Technology

[3] QianM-g, XuJ-lin. Dominant stratum theory for control of strata movement [M]. The Publishing House of China University of Mining and Technology, 2000

[4] WangJ-hua. Present status and development tendency of fully mechanized coal mining technology and equipment with high cutting height in China[J]. Coal Science and Technology, 2006, 34(1): 4-7

[5] NinYuTechniques and instruments of large mining height mechanized excavation in China [M], 2012BeijingCoal Industry Press

[6] XuY-qiCoal mining technology [M], 1999XuzhouThe Publishing House of China University of Mining and Technology

[7] HeF-l, QianM-g, LiuC-youHigh production and efficiency support-surrounding rock protection system of coal face [M], 1997XuzhouThe Publishing House of China University of Mining and Technology

[8] YasitliN E, UnverB. 3D numberical modeling of long wall mining with top-coal caving [J]. International Journal of Rock Mechanics & Mining sciences, 2005, 42: 219-315

[9] MaoD-b, KangL-jun. Longwall top coal caving mining with higher mining height and its feasibility [J]. Coal Mining Technology, 2003, 1: 11-14

[10] LiuQ-m, MaoD-bing. Research on adaptability of full-mechanized caving mining with large [J]. Mining-height Original Research Article Procedia Engineering, 2011, 26: 652-658

[11] GongP-linTheory of surrounding rock control of large mining height stope and its application [M], 2006BeijingCoal Industry Press

[12] GongP-l, JinZ-m, HaoH-jin. Research on stability test for fully mechanized mining support with large mining height [C]. Proceedings of the Second International Symposium on Mining Technology, 2001Jixi, Heilongjiang, ChinaScience Press246-251

[13] HuangQ-x, LiuW-g, TianY-su. Observation on the law of strata behavior in shallow seam and high mining height face [J]. Ground Pressure and Strata Control, 2003, 3: 58-59

[14] LiH-changSimilar experiment of mining pressure [M], 1988XuzhouThe Publishing House of China University of Mining and Technology

[15] WuF-f, YangJ-x, LiuC-you. Determination of the roof caving heights of thick and extra thick coal seams [J]. Journal of China University of Mining & Technology, 2014, 43(5): 765-772

[16] WuF-fengStudy on the law of roof broken and instability and the control of large mining height fully mechanized mining in thick coal seam [D], 2014XuzhouChina University of Mining & Technology

[17] LiX-weiMechanical properties of rocks [M], 1983BeijingCoal Industry Press

[18] LiuC-y, CaoS-genRelationship between the support and surrounding rocks of the stope and the monitoring and control [M], 2003XuzhouThe Publishing House of China University of Mining and Technology

[19] ShiQ, ZengY-wuRock mechanics experiment [M], 2010WuhanWuhan University Press

[20] Yangj-x, LiuC-y, YangP-ju. Research on roadside packing technology for end zone of steep inclined coal seam face [J]. Rock and Soil Mechanics, 2014, 35(2): 543-550

[21] LiuC-y, YangJ-x, YuBin. Support resistance determination of fully mechanized top-coal caving face in extra thick seam under multi-layered hard strata [J]. Journal of Mining & Safety Engineering, 2015, 32(1): 7-13

[22] UnverB, YasitliN E. Modelling of strata movement with a special reference to caving mechanism in thick seam coal mining [J]. International Journal of Coal Geology, 2006, 66: 227-252

[23] SinghR. Staggered development of a thick coal seam for full height working in a single lift by the blasting gallery method [J]. International Journal of Rock Mechanics & Mining Sciences, 2004, 41: 745-759