Analysis on failure characteristics of coal seam floors and water inrush risks in mining under pressure

doi:10.16265/j.cnki.issn1003-3033.2022.05.1535

Abstract

Abstract:

In order to study characteristics of floor failure under mining conditions, with working face 10409 of Xinzhi Coal Mine as a research object, distribution characteristics of floor stress field and damage evolution of floor strata were studied in detail by using a combination of theoretical analysis and numerical simulation methods. Then, based on verification results of on-site pressurized water test, distribution law of bearing pressure in coal seam floor strata and damage range of floor strata during mining process were obtained. Finally, mining risks of No. 10 coal seam under pressure was analyzed and evaluated. The results show that under influence of mining, the floor of coal seam presents periodic failure of tension failure-compaction-tension failure, and the critical value of working face length that affects failure depth of floors is about 160 m. The maximum failure depth of floor strata can reach 9.50 m, while maximum water inrush risk point lag behind working face is about 2.6 m.

Key words: pressurized coal mining, floor failure, water inrush risk, theoretical calculation, numerical simulation, pressurized water test

LI Gang, LIU Haizhen, YANG Qinghe, NIU Weifeng. Analysis on failure characteristics of coal seam floors and water inrush risks in mining under pressure[J]. China Safety Science Journal, 2022, 32(5): 68-76.

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References 13

[1]	赵家巍, 周宏伟, 薛东杰, 等. 深部承压水上含隐伏构造煤层底板渗流路径扩展规律[J]. 煤炭学报, 2019, 44(6): 1836-1845.
	ZHAO Jiawei, ZHOU Hongwei, XUE Dongjie, et al. Expansion law of seepage path in the concealed structural floor of coal seam in deep confined water[J]. Journal of China Coal Society, 2019, 44(6): 1836-1845.
[2]	孟召平, 王睿, 汪元有, 等. 开滦范各庄井田12煤层底板突水危险性的地质评价[J]. 采矿与安全工程学报, 2010, 27(3): 310-315.
	MENG Zhaoping, WANG Rui, WANG Yuanyou, et al. Geologic evaluation of water inrush risk for No. 12 coal seam floor of Fan'gezhuang mine field in Kailuan[J]. Journal of Mining & Safety Engineering, 2010, 27(3): 310-315.
[3]	鲁海峰, 姚多喜, 胡友彪, 等. 水压影响下煤层底板采动破坏深度弹性力学解[J]. 采矿与安全工程学报, 2017, 34(3): 452-458.
	LU Haifeng, YAO Duoxi, HU Youbiao, et al. Elasticity solution for failure depth of mining floor under water pressure[J]. Journal of Mining & Safety Engineering, 2017, 34(3): 452-458.
[4]	杜伟升, 姜耀东, 高林涛. 带压开采底板破坏因素分析及突水预测研究[J]. 煤炭科学技术, 2017, 45(6): 112-117.
	DU Weisheng, JIANG Yaodong, GAO Lintao. Study on water inrush prediction and floor failure factors analysis in ressurized coal mining[J]. Journal of China Coal Society, 2017, 45(6): 112-117.
[5]	YU Xiaoge, HAN Jin, SHI Longqing, et al. Application of a BP neural network in predicting destroyed floor depth caused by underground pressure[J]. Environmental Earth Sciences, 2017, 76(15):1-12. doi: 10.1007/s12665-016-6304-z
[6]	HU Yanbo, LI Wenping, WANG Qiqing, et al. Study on failure depth of coal seam floor in deep mining[J]. Environmental Earth Sciences, 2019, 78(24):1-13. doi: 10.1007/s12665-018-7995-0
[7]	王朋朋, 赵毅鑫, 姜耀东, 等. 邢东矿深部带压开采底板突水特征及控制技术[J]. 煤炭学报, 2020, 45(7): 2444-2454.
	WANG Pengpeng, ZHAO Yixin, JIANG Yaodong, et al. Characteristics and control technology of water inrush from deep coal seam floor above confined aquifer in Xingdong coal Mine[J]. Journal of China Coal Society, 2020, 45(7): 2444-2454.
[8]	张平松, 刘畅, 欧元超, 等. 准格尔煤田特厚煤层开采底板破坏特征综合测试研究[J]. 煤田地质与勘探, 2021, 49(1):263-269.
	ZHANG Pingsong, LIU Chang, OU Yuanchao, et al. Com-prehensive testing research on floor damage characteristics of mining extra-thick seam in Jungar coalfield[J]. Coal Geology & Exploration, 2021, 49(1): 263-269.
[9]	郭文兵, 邹友峰, 邓喀中. 煤层底板采动导水破坏深度计算的神经网络方法[J]. 中国安全科学学报, 2003, 13(3):34-37.
	GUO Wenbing, ZOU Youfeng, DENG Kazhong. Prediction of the failure depth of coal seam floor by artificial neural network method[J]. China Safety Science Journal, 2003, 13(3):34-37.
[10]	廖巍, 周荣义, 李树清. 基于小波神经网络的煤层底板突水非线性预测方法研究[J]. 中国安全科学学报, 2006, 16(11):24-28.
	LIAO Wei, ZHOU Rongyi, LI Shuqing. Study on the non-linear forecast methods for water inrush from coal floor based on wavelet neural network[J]. China Safety Science Journal, 2006, 16(11):24-28.
[11]	代长青. 承压水体上开采底板突水规律的研究[D]. 淮南: 安徽理工大学, 2005.
	DAI Changqing. Study on the floor water invasion regularity mining on the top of water-pressured[D]. Huainan: Anhui University of Science and Technology, 2005.
[12]	李加祥, 张文泉, 李白英, 等. 煤层底板岩体导水破坏判据的探讨[C]. 水电与矿业工程中的岩石力学问题: 中国北方岩石力学与工程应用学术会议, 1991:303-306.
[13]	武强. 煤矿防治水细则解读[M]. 北京: 煤炭工业出版社, 2018:223.

岩层名称	体积模量/ GPa	剪切模量/ GPa	黏聚力/ MPa	内摩擦角/ (°)	抗拉强度/ MPa
细砂岩	4.8	3.1	4.2	41	1
煤层	1.9	0.95	1.2	35.1	0.429
砂质泥岩	2.2	1.152	1.5	32.5	0.586
泥岩	1.8	1.02	1.2	31.6	0.612
铝土泥岩	1.9	0.95	1.0	36	0.429
砂岩	3.5	2.12	4.3	43	1.618
页岩	1.8	0.86	1.2	37	0.303
石灰岩	5.6	3.89	5.7	42.5	0.48

孔号及特征	测试深度/m	K₁/(m·d^-1)	K₂/(m·d^-1)	K₂/ K₁	ΔK/(m·d^-1)
3号孔单栓塞压水	(7.51,12.37)	13.87	16.43	1.184 092	2.554 655
3号孔双栓塞压水	(8.98,9.03)	2.112	50.36	23.833 33	48.224
3号孔双栓塞压水	(9.45,9.50)	2.64	56.72	21.484 85	54.08
3号孔双栓塞压水	(9.96,10)	282.74	320.32	1.132 898	37.576
3号孔双栓塞压水	(10.94,11)	97.5	109.64	1.124 549	12.144

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