Cloud model identification of coal face stability in steeply inclined working faces

doi:10.16265/j.cnki.issn1003-3033.2022.03.020

Abstract

Abstract:

In order to ensure safe and efficient mining on steeply inclined working faces, a stability evaluation index system of steeply inclined coal faces was constructed with quantified grade intervals on the basis of AHP method. Then, a standard stability cloud model based on cloud theory was established. With working face 3402 as an example, its coal face stability evaluation cloud image was generated, and similarity between this image and grades of cloud model was calculated through Dice coefficient to effectively identify stability and verify scientificity and validity of the model. The results show that the main influencing factors of coal face stability in steeply inclined seams are roof pressure at the face of mildly inclined ones, coal body cohesion and mining height, as well as inclination angle of coal seam and pseudo-inclination angle of working face. According to cloud model's identification, similarity between evaluation cloud image and standard grades for general stability indexes of 3402 working face is 0, 0.345 3, 0.787 2 and 0 respectively. It can be concluded that its stability is at level III, an unstable state, which is basically consistent with actual situation, demonstrating that the proposed model is scientific and effective to some extent.

Key words: steeply inclined working face, coal face stability, cloud model, analytical hierarchy process(AHP), comprehensive evaluation

XIONG Yu, KONG Dezhong, YANG Shengli, WU Guiyi, ZUO Yujun, CHENG Zhanbo. Cloud model identification of coal face stability in steeply inclined working faces[J]. China Safety Science Journal, 2022, 32(3): 144-151.

Figures/Tables 11

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References 20

[1]	伍永平, 贠东风, 解盘石, 等. 大倾角煤层长壁综采:进展、实践、科学问题[J]. 煤炭学报, 2020, 45(1):24-34.
	WU Yongping, YUN Dongfeng, XIE Panshi, et al. Progress,practice and scientific issues in steeply dipping coal seams fully-mechanized mining[J]. Journal of China Coal Society, 2020, 45(1):24-34.
[2]	李立, 于雷, 张世青, 等. 大采高大倾角工作面煤壁片帮机理分析[J]. 煤炭工程, 2020, 52(12):102-107.
	LI Li, YU Lei, ZHANG Shiqing, et al. Spalling mechanism of coal wall in large-angle and high-cutting coal mining face[J]. Coal Engineering, 2020, 52(12):102-107.
[3]	LIU Shuai, YANG Ke, TANG Chunan, et al. Mechanism and integrated control of "rib spalling: roof collapse-support instability" hazard chains in steeply dipping soft coal seams[J]. Advances in Materials Science and Engineering, 2021, 2021:1-20.
[4]	王红伟, 伍永平, 焦建强, 等. 大倾角煤层大采高工作面倾角对煤壁片帮的影响机制[J]. 采矿与安全工程学报, 2019, 36(4):728-735,752.
	WANG Hongwei, WU Yongping, JIAO Jianqiang, et al. Study on effect of dip angle on coal wall spalling of working face with great mining height in steeply inclined coal seam[J]. Journal of Mining & Safety Engineering, 2019, 36(4):728-735,752.
[5]	王红伟, 伍永平, 解盘石, 等. 大倾角煤层长壁大采高工作面煤壁稳定性的采厚效应[J]. 采矿与安全工程学报, 2018, 35(1):64-70.
	WANG Hongwei, WU Yongping, XIE Panshi, et al. Coal rib stability effect of mining-thickness with large mining height of working face in steeply inclined seams[J]. Journal of Mining & Safety Engineering, 2018, 35(1):64-70.
[6]	YAO Qiangling, LI Xuehua, SUN Boyang, et al. Numerical investigation of the effects of coal seam dip angle on coal wall stability[J]. International Journal of Rock Mechanics and Mining Sciences, 2017, 100:298-309. doi: 10.1016/j.ijrmms.2017.10.002
[7]	杨敬轩, 刘长友, 吴锋锋, 等. 煤层硬夹矸对大采高工作面煤壁稳定性影响机理研究[J]. 采矿与安全工程学报, 2013, 30(6):856-862.
	YANG Jingxuan, LIU Changyou, WU Fengfeng, et al. The research on the coal wall stability mechanism in larger height coal seam with a stratum of gangue[J]. Journal of Mining & Safety Engineering, 2013, 30(6):856-862.
[8]	伍永平, 杨文斌, 解盘石, 等. 大倾角大采高工作面煤矸互层顶板漏冒规律研究[J]. 煤炭工程, 2020, 52(12):85-90.
	WU Yongping, YANG Wenbin, XIE Panshi, et al. Roof caving law of interbedded coal gangue roof in fully mechanized coal mining face with steeply dipping coal seam and large mining height[J]. Mining Engineering, 2020, 52(12):85-90.
[9]	张浩, 伍永平. 大倾角煤层长壁大采高采场煤壁片帮机制[J]. 采矿与安全工程学报, 2019, 36(2):331-337.
	ZHANG Hao, WU Yongping. Coal wall caving mechanism of longwall large mining height stope in steeply dipping coal seams[J]. Journal of Mining & Safety Engineering, 2019, 36(2):331-337.
[10]	KONG Dezhong, XIONG Yu, CHENG Zhanbo, et al. Stability analysis of coal face based on coal face-support-roof system in steeply inclined coal seam[J]. Geomechanics and Engineering, 2021, 25(3):233-243.
[11]	陈刘瑜, 李希建, 毕娟, 等. 基于AHP-TOPSIS的冲击型煤与瓦斯突出倾向性预测[J]. 中国安全科学学报, 2020, 30(4):47-52. doi: 10.16265/j.cnki.issn1003-3033.2020.04.008
	CHEN Liuyu, LI Xijian, BI Juan, et al. Prediction of coal-gas outburst induced by rock-burst tendency based on AHP-TOPSIS[J]. China Safety Science Journal, 2020, 30(4): 47-52. doi: 10.16265/j.cnki.issn1003-3033.2020.04.008
[12]	XIONG Yu, KONG Dezhong, CHENG Zhanbo, et al. The comprehensive identification of roof risk in a fully mechanized working face using the cloud model[J]. Mathematics, 2021, 9: DOI:10.3390/math9172072.
[13]	吴孟龙, 叶义成, 胡南燕, 等. RAGA-PPC云模型在边坡稳定性评价中的应用[J]. 中国安全科学学报, 2019, 29(9):57-63. doi: 10.16265/j.cnki.issn1003-3033.2019.09.009
	WU Menglong, YE Yicheng, HU Nanyan, et al. Application of RAGA-PPC cloud model in slope stability evaluation[J]. China Safety Science Journal, 2019, 29(9): 57-63. doi: 10.16265/j.cnki.issn1003-3033.2019.09.009
[14]	解盘石, 张颖异, 张艳丽, 等. 大倾角大采高煤矸互层顶板失稳规律及对支架的影响[J]. 煤炭学报, 2021, 46(2):344-356.
	XIE Panshi, ZHANG Yingyi, ZHANG Yanli, et al. Instability law of the coal-rock interbedded roof and its influence on supports in large mining height working face with steeply dipping coal seam[J]. Journal of China Coal Society, 2021, 46(2):344-356.
[15]	李海涛. 煤体强度对煤壁稳定性的影响研究[J]. 煤炭工程, 2020, 52(8):118-122.
	LI Haitao. Effect of coal strength on coal wall stability[J]. Coal Engineering, 2020, 52(8):118-122.
[16]	郭卫彬. 大采高工作面煤壁稳定性及其与支架的相互影响机制研究[D]. 徐州: 中国矿业大学, 2015.
	GUO Weibin. Stability of coal wall and interaction mechanism with support in fully mechanized working face with great mining height[D]. Xuzhou: China University of Mining and Technology, 2015.
[17]	张浩. 大倾角煤层长壁大采高综采工作面煤壁稳定性分析[D]. 西安: 西安科技大学,2016.
	ZHANG Hao. Coalface stability of longwall large mining height fully-mechanized panel in steeply dipping coal seam[D]. Xi'an: Xi'an University of Science and Technology, 2016.
[18]	冯长根, 李杰, 李生才. 层次分析法在中国安全科学研究中的应用[J]. 安全与环境学报, 2018, 18(6):2126-2130.
	FENG Changgen, LI Jie, LI Shengcai. Application of the analytical hierarchy process method to the safety science research in China[J]. Journal of Safety and Environment, 2018, 18(6):2126-2130.
[19]	张科学, 亢磊, 何满潮, 等. 矿井煤层冲击危险性多层次综合评价研究[J]. 煤炭科学技术, 2020, 48(8):82-89.
	ZHANG Kexue, KANG Lei, HE Manchao, et al. Research on multi-level comprehensive evaluation of coal seam rockburst risk in underground mine[J]. Coal Science and Technology, 2020, 48(8):82-89.
[20]	田睿, 孟海东, 陈世江, 等. RF-AHP-云模型下岩爆烈度分级预测模型[J]. 中国安全科学学报, 2020, 30(7):166-172. doi: 10.16265/j.cnki.issn1003-3033.2020.07.025
	TIAN Rui, MENG Haidong, CHEN Shijiang, et al. Prediction model of rockburst intensity classification based on RF-AHP-Cloud model[J]. China Safety Science Journal, 2020, 30 (7): 166-172. doi: 10.16265/j.cnki.issn1003-3033.2020.07.025

评价指标	评价等级
评价指标	I级	Ⅱ级	Ⅲ级	IV级
C₁	0.6~0.8	0.8~0.9	0.9~1	1~1.2
C₂/%	80~100	60~80	40~60	<40
C₃/%	80~100	60~80	40~60	<40
C₄/MPa	>1.5	1~1.5	0.5~1	<0.5
C₅/(°)	>35	30~35	25~30	<25
C₆(0~100)	0~20	20~40	40~60	60~100
C₇(0~100)	0~20	20~40	40~60	60~100
C₈/m	0.7~2	2~3.5	3.5~5	>5
C₉/(°)	0~20	20~35	35~45	45~55
C₁₀/(°)	3.5~5	5~6.5	6.5~8	>8
C₁₁/%	85~100	65~85	40~65	<40

判断矩阵	特征向量U_j	指标权重ω_j	一致性比率CR	一致性检验
M_A	(0.368 51, 0.341 74, 0.289 75)	0.368 5, 0.341 7, 0.289 8	0.002 913	通过
M_B1	(0.558 42, 0.319 62, 0.121 96)	0.558 4, 0.319 6, 0.122 0	0.015 771	通过
M_B2	(0.389 4, 0.377 44, 0.131 1, 0.102 06)	0.389 4, 0.377 4, 0.131 1, 0.102 1	0.030 33	通过
M_B3	(0.476 85, 0.269 65, 0.173 99, 0.079 511)	0.476 9, 0.269 6, 0.174 0, 0.079 5	0.021 975	通过

评价指标		评价标准等级
评价指标		Ⅰ级	Ⅱ级	Ⅲ级	Ⅳ级
一级指标	B₁	(0.136 3,0.045 3,0.05)	(0.364 2,0.030 2,0.05)	(0.547 5,0.030 2,0.05)	(0.819 5,0.060 3,0.05)
	B₂	(0.119 2,0.039 9,0.05)	(0.357 5,0.039 9,0.05)	(0.595 8,0.039 9,0.05)	(0.857 5,0.047 8,0.05)
	B₃	(0.124 6,0.041 5,0.05)	(0.369 7,0.040 0,0.05)	(0.601 7,0.037 1,0.05)	(0.853 9,0.047 7,0.05)
总指标		(0.127 1,0.042 4,0.05)	(0.363 5,0.036 4,0.05)	(0.579 7,0.035 5,0.05)	(0.842 5,0.052 4,0.05)

二级指标	评价指标值		E_x	E_n	H_e
二级指标	最大	最小	E_x	E_n	H_e
C₁	0.97	0.71	0.401 5	0.073	0.1
C₂	81	71.5	0.237 5	0.015 8	0.12
C₃	90	75	0.175	0.025	0.12
C₄	0.6	0.34	0.765	0.021 7	0.09
C₅	22	20	0.95	0.016 7	0.09
C₆	70	55	0.625	0.15	0.13
C₇	65	45	0.55	0.033	0.12
C₈	3.9	2.3	0.38	0.043 3	0.09
C₉	50	23	0.7	0.07	0.09
C₁₀	7	5	0.385	0.051 7	0.09
C₁₁	70	45	0.575	0.041 7	0.14

一级评价指标	E_x	E_n	H_e
B₁	0.321 5	0.048 9	0.108 8
B₂	0.794 5	0.037 8	0.098 3
B₃	0.473 2	0.055 0	0.094 0