Determination method of peak stress and plastic zone width of supporting coal pillar in end-slope mining field

doi:10.16265/j.cnki.issn1003-3033.2023.10.2329

Abstract

Abstract:

In order to realize the maximum recovery of end-slope coal under the premise of ensuring the safety of the slope, the whole process of end-slope coal mining was simulated by using discrete element simulation software. The stress and deformation characteristics of supporting coal pillars were monitored and analyzed, three vertical load distribution models of supporting coal pillars under different roadway depths were constructed, and the mechanical analysis model of roadway-surrounding rock in an end-slope mining field was established. The results show that the vertical force and deformation of the supporting coal pillar show typical segmentation characteristics along the direction of the roadway. From the roadway mouth to the inside, with the increase of roadway depth, the vertical stress increases linearly at first. After reaching the peak, it suddenly decreases to the initial stress of the slope and remains unchanged in the range of about 3 times the width of the roadway before and after the end of the roadway. Based on the principle of constant vertical stress of overlying rock mass before and after roadway construction, the determination method of peak stress of coal pillar under different mining depths is obtained. Based on the limit equilibrium theory and Mohr-Coulomb strength criterion, a formula for estimating the maximum width of the plastic zone on one side of the coal pillar under peak stress is derived.

Key words: end-slope mining field, supporting coal pillars, peak stress, plastic zone width, roadway group

DING Xinpin, BAI Guoliang, CAO Mingming, SANG Sheng, QI Heng. Determination method of peak stress and plastic zone width of supporting coal pillar in end-slope mining field[J]. China Safety Science Journal, 2023, 33(10): 111-119.

Figures/Tables 6

Fig.1

Fig.2

Fig.3

Fig.4

Tab.1

Comparison table of numerical simulation and theoretical calculation results of vertical peak stress of supporting coal pillar

$W d$ /m	D/m	H/m	$γ$ /(kN · m^-3)	L/m	$σ s m$ /MPa
$W d$ /m	D/m	H/m	$γ$ /(kN · m^-3)	L/m	计算值	分析值
3	148	108	23	128	3.94	4.08
				148	4.62	4.53
				200	4.92	4.94

Tab.1

Fig.5

References 28

[1]	赵浩, 毛开江, 曲业明, 等. 我国露天煤矿无人驾驶及新能源卡车发展现状与关键技术[J]. 中国煤炭, 2021, 47(4):45-50.
	ZHAO Hao, MAO Kaijiang, QU Yeming, et al. Development status and key technology of driverless and new energy trucks in open-pit coal mine in China[J]. China Coal, 2021, 47 (4):45-50.
[2]	李崇, 才庆祥, 袁迎菊, 等. 露天煤矿端帮“呆滞煤”回采技术经济评价[J]. 采矿与安全工程学报, 2011, 28(2):263-266.
	LI Chong, CAI Qingxiang, YUAN Yingju, et al. Assessment of feasibility of leftover coal mining in end-slope of surface mine[J]. Journal of Mining & Safety Engineering, 2011, 28(2):263-266.
[3]	张志, 刘闯, 薛应东, 等. 相邻露天矿境界重叠区边帮压煤协调开采技术[J]. 煤炭科学技术, 2013, 41(9):91-95.
	ZHANG Zhi, LIU Chuang, XUE Yingdong, et al. Coordination mining technology of coal under side slopes in crossed limit area of two adjacent open pits[J]. Coal Science and Technology, 2013, 41(9): 91-95.
[4]	白润才, 刘闯, 薛应东, 等. 相邻露天矿边帮压煤协调开采技术[J]. 煤炭学报, 2014, 39(10):2001-2006.
	BAI Runcai, LIU Chuang, XUE Yingdong, et al. Coordination mining technology for coal underlying the slopes between two adjacent open pits[J]. Journal of China Coal Society, 2014, 39 (10):2001-2006.
[5]	DING Xinpin, LI Fengming, WANG Zhenwei, et al. Physical model experimental study on the coal face overburden movement law on the end slope of an open-pit mine[J]. Geotechnical and Geological Engineering, 2022, 40:4859-4877. doi: 10.1007/s10706-022-02206-6
[6]	丁鑫品, 王振伟, 李伟. 采动边坡失稳的动力过程及典型变形破坏机理[J]. 煤炭学报, 2016, 41(10):2606-2611.
	DING Xinpin, WANG Zhenwei, LI Wei. Dynamic process and typical deformation-failure mechanism of mining slope[J]. Journal of China Coal Society, 2016, 41(10):2606-2611.
[7]	黄天爽, 赵铭芳, 轩峰, 等. 端帮开采技术在露天煤矿的应用[J]. 露天采矿技术, 2020, 35(5):69-71.
	HUANG Tianshuang, ZHAO Mingfang, XUAN Feng, et al. Application of end slope mining technology in open-pit mine[J]. Opencast Mining Technology, 2020, 35(5):69-71.
[8]	李涛, 肖双双. 露天矿端帮采煤机开采参数设计方法[J]. 煤炭工程, 2020, 52(11):23-27.
	LI Tao, XIAO Shuangshuang. Design method of mining parameters for end slope shearer in surface mine[J]. Coal Engineering, 2020, 52(11):23-27.
[9]	张帅, 张群涛, 岳霆, 等. 端帮采煤机在中国露天开采中的应用分析[J]. 煤炭技术, 2016, 35(6):233-235.
	ZHANG Shuai, ZHANG Quntao, YUE Ting, et al. Application analysis of highwall miner for surface mine mining in China[J]. Coal Technology, 2016, 35(6):233-235.
[10]	陈绍杰, 周辉, 郭惟嘉, 等. 条带煤柱长期受力变形特征研究[J]. 采矿与安全工程学报, 2012, 29(3):376-380.
	CHEN Shaojie, ZHOU Hui, GUO Weijia, et al. Study on long-term stress and deformation characteristics of strip pillar[J]. Journal of Mining & Safety Engineering, 2012, 29(3):376-380.
[11]	王春秋, 高立群, 陈绍杰, 等. 条带煤柱长期承载能力实测研究[J]. 采矿与安全工程学报, 2013, 30(6):799-804.
	WANG Chunqiu, GAO Liqun, CHEN Shaojie, et al. Field research on long-term bearing capacity of strip pillar[J]. Journal of Mining & Safety Engineering, 2013, 30(6):799-804.
[12]	POULSEN B A. Coal pillar load calculation by pressure arch theory and near field extraction ratio[J]. International Journal of Rock Mechanics and Mining Sciences, 2010, 47(7):1158-1165.
[13]	VAN DER MERWE J N. New pillar strength formula for South African coal[J]. Journal of the South African Institute of Mining and Metallurgy, 2003, 103(5):281-292.
[14]	邹友峰, 柴华彬. 我国条带煤柱稳定性研究现状及存在问题[J]. 采矿与安全工程学报, 2006, 23(2):141-145,150.
	ZOU Youfeng, CHAI Huabin. Research status of strip coal pillar stability and its main problems in China[J]. Journal of Mining & Safety Engineering, 2006, 23(2):141-145,150.
[15]	于洋, 邓喀中, 范洪冬. 条带开采煤柱长期稳定性评价及煤柱设计方法[J]. 煤炭学报, 2017, 42(12):3089-3095.
	YU Yang, DENG Kazhong, FAN Hongdong. Long-term stability evaluation and coal pillar design methods for strip mining[J]. Journal of China Coal Society, 2017, 42(12): 3089-3095.
[16]	郭力群, 彭兴黔, 蔡奇鹏. 基于统一强度理论的条带煤柱设计[J]. 煤炭学报, 2013, 38(9):1563-1567.
	GUO Liqun, PENG Xingqian, CAI Qipeng. Design of strip coal pillar based on the unified strength theory[J]. Journal of China Coal Society, 2013, 38(9):1563-1567.
[17]	索永录, 姬红英, 辛亚军, 等. 条带开采煤柱合理宽度的确定方法[J]. 西安科技大学学报, 2010, 30(2):132-135.
	SUO Yonglu, JI Hongying, XIN Yajun, et al. Determination and calculation of reasonable width for strip pillar[J]. Journal of Xi'an University of Science and Technology, 2010, 30(2):132-135.
[18]	王旭春, 黄福昌, 张怀新, 等. AH威尔逊煤柱设计公式探讨及改进[J]. 煤炭学报, 2002, 27(6):604-608.
	WANG Xuchun, HUANG Fuchang, ZHANG Huaixin, et al. Discussion and improvement for A.H.Wilson's coal pillar design[J]. Journal of China Coal Society, 2002, 27 (6):604-608.
[19]	魏东, 李文洲. A.H.威尔逊煤柱留设公式的改进及应用[J]. 煤矿开采, 2010, 15(6):15-16.
	WEI Dong, LI Wenzhou. Improvament and application of A.H.Wilson's coal pillar design formula[J]. Coal mining Technology, 2010, 15(6):15-16.
[20]	李文. 房采采空区失稳危险性评价[J]. 中国安全科学学报, 2011, 21(3):95-100.
	LI Wen. Risk assessment of room method goafs instability[J]. China Safety Science Journal, 2011, 21(3):95-100.
[21]	王东, 姜聚宇, 韩新平, 等. 褐煤露天矿端帮开采边坡支撑煤柱稳定性研究[J]. 中国安全科学学报, 2017, 27(12):62-67. doi: 10.16265/j.cnki.issn1003-3033.2017.12.011
	WANG Dong, JIANG Juyu, HAN Xinping, et al. Stability of supporting coal pillar for slope highwall mined in lignite surface mine[J]. China Safety Science Journal, 2017, 27(12):62-67. doi: 10.16265/j.cnki.issn1003-3033.2017.12.011
[22]	姜聚宇, 杨慧雯, 王东, 等. 端帮开采支撑煤柱失稳演化机制试验研究[J]. 中国安全科学学报, 2021, 31(10):89-96.
	JIANG Juyu, YANG Huiwen, WANG Dong, et al. Experimental study on instability evolution mechanism of rib pillars during highwall mining[J]. China Safety Science Journal, 2021, 31(10): 89-96. doi: 10.16265/j.cnki.issn1003-3033.2021.10.013
[23]	陈彦龙, 吴豪帅. 露天矿端帮开采下的支撑煤柱突变失稳机理研究[J]. 中国矿业大学学报, 2016, 45(5):859-865.
	CHEN Yanlong, WU Haoshuai. Catastrophe instability mechanism of rib pillar in open-pit highwall mining[J]. Journal of China University of Mining & Technology, 2016, 45(5):859-865.
[24]	吴琼, 唐辉明, 王亮清, 等. 基于三维离散元仿真试验的复杂节理岩体力学参数尺寸效应及空间各向异性研究[J]. 岩石力学与工程学报, 2014, 33(12):2419-2432.
	WU Qiong, TANG Huiming, WANG Liangqing, et al. Three-dimensional distinct element simulation of size effect and spatial anisotropy of mechanical parameters of jointed rock mass[J]. Chinese Journal of Rock Mechanics and Engineering, 2014, 33(12): 2419-2432.
[25]	王贺, 高永涛, 金爱兵, 等. 节理岩体刚度参数选取与三维离散元模拟[J]. 岩石力学与工程学报, 2014, 33(增1):2894-2900.
	WANG He, GAO Yongtao, JIN Aibing, et al. Determination of stiffness parameters of jointed rock masses with 3DEC simulations[J]. Chinese Journal of Rock Mechanics and Engineering, 2014, 33(S1):2894-2900.
[26]	丁鑫品, 李凤明, 付天光, 等. 端帮采场覆岩移动破坏规律及边坡稳定控制方法[J]. 煤炭学报, 2021, 46(9):2883-2894.
	DING Xinpin, LI Fengming, FU Tianguang, et al. Overburden movement and failure law of coalface in end slope and the slope stability control method[J]. Journal of China Coal Society, 2021, 46(9): 2883-2894.
[27]	王瑞, 闫帅, 柏建彪, 等. 端帮开采下煤柱破坏宽度计算及失稳机制研究[J]. 岩土力学, 2019, 40(8):3167-3180.
	WANG Rui, YAN Shuai, BAI Jianbiao, et al. Theoretical analysis of the destabilization mechanism and the damaged width of rib pillar in open-pit highwall mining[J]. Rock and Soil Mechanics, 2019, 40(8):3167-3180.
[28]	丁鑫品. 露天矿端帮采场边坡变形失稳特征与支撑煤柱稳定性判别方法[J]. 煤矿安全, 2022, 53(3):229-235.
	DING Xinpin. Deformation and instability characteristics of slope and stability discrimination method of sup-porting coal pillars about end-slope mining field in open-pit mine[J]. Safety in Coal Mines, 2022, 53(3):229-235.