采空区遗留煤柱下方回采巷道失稳特征及控制技术研究

曹金钟; 高乐; 闫鹏飞; 李猛; 陈雷; 杨华康

doi:10.13272/j.issn.1671-251x.2021110032

采空区遗留煤柱下方回采巷道失稳特征及控制技术研究

doi: 10.13272/j.issn.1671-251x.2021110032

1.
中煤大同能源有限责任公司塔山煤矿, 山西大同　037001
2.
北京科技大学土木与资源工程学院, 北京　100083

基金项目: 国家自然科学基金项目（52011530037）。

详细信息

作者简介:
曹金钟（1969-），男，山东枣庄人，高级工程师，主要从事煤矿生产技术与管理工作，E-mail：84206520@qq.com

中图分类号: TD322
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- 被引次数: 0
出版历程
- 收稿日期: 2021-11-14
- 修回日期: 2022-03-25
- 网络出版日期: 2022-03-05

Research on instability characteristics and control technology of the mining roadway below the remaining coal pillars in the goaf

1.
Tashan Coal Mine, China Coal Datong Energy Co., Ltd., Datong 037001, China
2.
School of Civil and Resource Engineering, University of Science and Technology Beijing, Beijing 100083, China

摘要

摘要: 采空区下特厚煤层开采时，上煤层遗留煤柱和相邻工作面回采将对回采巷道的稳定性产生重要影响。目前对回采巷道变形破坏机理及控制的研究未考虑近距离留煤柱开采条件下特厚煤层临空巷道这种复杂环境。针对该问题，以塔山煤矿30503修复巷为工程背景，采用现场监测、理论分析及数值模拟等方法，分析了该巷道的变形破坏机理，提出了相应的巷道围岩支护技术。在30503修复巷顶板布置顶板离层仪，实时监测记录顶板各位置岩层位移情况。监测结果表明：由于受相邻工作面回采的影响，且距上覆遗留煤柱距离较近，30503修复巷顶板内围岩已较为破碎，在巷道掘进后，顶板变形速度快、离层量不断增加且影响范围广。针对监测结果，从遗留煤柱对巷道变形破坏的影响及基本顶断裂位置对巷道变形破坏的影响2个方面进行分析：① 巷道的不合理布置是导致修复巷破坏的重要原因，同时为避开遗留煤柱的影响，将巷道布置在距煤柱中心35 m（煤柱边缘25 m）以外的范围。② 修复巷掘进位置受遗留煤柱影响严重，巷道掘进前已处于高应力集中区域；当相邻工作面回采后，基本顶破断位置位于修复巷顶板上方，这是导致巷道顶板破碎的直接原因。针对上述分析结果，对不同宽度煤柱偏应力分布演化规律进行数值模拟分析，并提出了针对性的围岩稳定性控制技术方案：① 在保证煤柱具有足够的安全性和避免资源浪费前提下，将30503修复巷区段煤柱宽度设为8 m。② 近距离特厚煤层临空巷道掘进时，采用水力致裂措施减弱上覆遗留煤柱对煤层的影响。③ 选用锚网索+喷浆+单体支柱的支护方案对新掘巷道进行联合支护。为验证围岩稳定性控制技术的应用效果，采用十字观测法对30503工作面新修复巷掘进过程中的巷道变形量进行连续监测，结果表明：回采期间两帮变形量为90 mm，顶底板变形量为331 mm，围岩变形量得到了有效控制。
- 近距离煤层留煤柱开采 /
- 特厚煤层临空巷道 /
- 修复巷 /
- 巷道变形破坏 /
- 偏应力 /
- 围岩稳定性 /
- 水力致裂
Abstract: When the extra thick coal seam is mined in the goaf, the remaining coal pillar of upper coal seam and adjacent working face will have an important impact on the stability of mining roadway. At present, the research on deformation and failure mechanism and control of mining roadway does not consider the complex environment of gob-side roadway in extra thick coal seam under the condition of short distance coal pillar mining. In order to solve the problem, taking the 30503 repaired roadway in Tashan Coal Mine as the engineering background, the deformation and failure mechanism of the roadway is analyzed by using the methods of field monitoring, theoretical analysis and numerical simulation. And the corresponding surrounding rock support technology is proposed. A roof separator is arranged on the roof of 30503 repaired roadway to monitor and record the rock displacement at each position of the roof in real time. The monitoring results show that the surrounding rock in the roof of 30503 repaired roadway has been broken due to the impact of adjacent working face and the short distance to the overlying remaining coal pillar. After the roadway excavation, the roof deformation speed is fast, the seperation volume increases continuously and the impact range is wide. According to the monitoring results, the impact of the remaining coal pillar on the deformation and failure of the roadway and the impact of the fracture position of the basic roof on the deformation and failure of the roadway are analyzed. The results show the following points. ① The unreasonable arrangement of the roadway is an important reason for the damage of the repaired roadway. At the same time, in order to avoid the impact of the remaining coal pillar, the roadway is arranged at a distance of more than 35 m from the center of the coal pillar (25 m from the edge of the coal pillar). ② The excavation position of repaired roadway is seriously affected by the remaining coal pillar, and the roadway is in the high stress concentration area before excavation. When the adjacent 30501 working face is mined, the basic roof breaking position is located above the roof of the repaired roadway, which is the direct cause of the broken roof of the roadway. According to the above analysis results, the numerical simulation analysis is carried out on the evolution law of deviatoric stress distribution of coal pillars with different widths, and the targeted technical scheme of surrounding rock stability control is proposed. ① On the premise of ensuring sufficient safety of the coal pillar and avoiding waste of resources, the width of the coal pillar in the 30503 repaired roadway section is set to 8 m. ② When excavating the gob-side roadway in the short distance extra thick coal seam, hydraulic fracturing measures are adopted to reduce the impact of the overlying coal pillars on the coal seam. ③ The support scheme of bolt-mesh-anchor+guniting+single pillar is selected to support the newly excavated roadway. In order to verify the application effect of the surrounding rock stability control technology, the cross observation method is used to continuously monitor the roadway deformation during the excavation of the new repaired roadway in 30503 working face. The results show that the deformation of the two sides is 90 mm, the deformation of the roof and floor is 331 mm, and the deformation of the surrounding rock is effectively controlled.
- coal pillar mining in short distance coal seam /
- extra thick coal seam gob-side roadway /
- repaired roadway /
- roadway deformation and failure /
- deviatoric stress /
- surrounding rock stability /
- hydraulic fracturing

HTML全文

图 1 30503工作面巷道布置

Figure 1. Roadway layout of 30503 working face

下载: 全尺寸图片幻灯片

图 2 修复巷顶板变形监测数据

Figure 2. Monitoring data of roof deformation of repaired roadway

下载: 全尺寸图片幻灯片

图 3 煤柱载荷估算模型

Figure 3. Coal pillar load estimation method

下载: 全尺寸图片幻灯片

图 4 煤柱下方偏应力分布规律

Figure 4. Distribution law of deviatoric stress under coal pillar

下载: 全尺寸图片幻灯片

图 5 沿空巷道关键块体破断位置

Figure 5. Break position of the key block along the gob-side roadway

下载: 全尺寸图片幻灯片

图 6 数值计算模型

Figure 6. Numerical calculation model

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图 7 不同宽度煤柱偏应力不变量分布

Figure 7. Distribution of deviatoic stress invariants of coal pillars with different widths

下载: 全尺寸图片幻灯片

图 8 上覆遗留煤柱水力致裂卸压设计

Figure 8. Design of hydraulic fracturing and pressure relief for overlying coal pillars

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图 9 30503修复巷支护方案

Figure 9. 30503 repaired roadway support plan

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图 10 30503新掘巷道变形量

Figure 10. Deformation amount of 30503 newly excavated roadway

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表 1 数值模拟物理力学参数

Table 1. Physical and mechanical parameters of numerical simulation

岩性	厚度/ m	密度/ （kg·m⁻³）	体积模量/ GPa	剪切模量/ GPa	黏聚力/ MPa	摩擦角/ (°)	抗拉强度/ MPa
砂质泥岩	51	2 400	5.08	3.50	2.78	32.21	1.32
碎屑岩	15	2 450	5.49	3.78	2.94	33.15	1.52
细砂岩	3	2 470	8.77	6.58	4.77	36.79	2.98
砂质泥岩	8	2 400	5.08	3.50	2.78	32.21	1.32
2号煤层	3	1 340	4.93	3.25	2.67	31.22	1.04
高岭质泥岩	5	2 500	7.8	7.63	2.95	38.74	3.57
3−5号煤层	14	1 340	4.93	3.25	2.67	31.22	1.04
高岭质泥岩	4	2 546	6.65	4.33	3.63	35.83	2.38
粉砂岩	5	2 470	7.81	5.62	4.24	35.93	2.71
7号煤层	2	1 340	4.93	3.25	2.67	31.22	1.04
砂质泥岩	21	2 400	5.08	3.50	2.78	32.21	1.32

下载: 导出CSV

参考文献(20)

[1]	戴文祥,潘卫东,李猛,等. 近距离煤层强扰动巷道布置与支护技术研究[J]. 煤炭科学技术,2020,48(12):61-67. DAI Wenxiang,PAN Weidong,LI Meng,et al. Study on layout and support technology of strongly disturbed roadway in contiguous coal seam[J]. Coal Science and Technology,2020,48(12):61-67.
[2]	张炜,张东升,陈建本,等. 极近距离煤层回采巷道合理位置确定[J]. 中国矿业大学学报,2012,41(2):182-188. ZHANG Wei,ZHANG Dongsheng,CHEN Jianben,et al. Determining the optimum gateway location for extremely close coal seams[J]. Journal of China University of Mining & Technology,2012,41(2):182-188.
[3]	张向阳,常聚才. 上下采空极近距离煤层开采围岩应力及破坏特征研究[J]. 采矿与安全工程学报,2014,31(4):506-511. ZHANG Xiangyang,CHANG Jucai. Stress and failure characteristics of surrounding rock in the extremely close distance coal seams group mining after the upper and lower coal seam mining[J]. Journal of Mining & Safety Engineering,2014,31(4):506-511.
[4]	岳喜占,涂敏,李迎富,等. 近距离煤层开采遗留边界煤柱下底板巷道采动附加应力计算[J]. 采矿与安全工程学报,2021,38(2):246-252,259. YUE Xizhan,TU Min,LI Yingfu,et al. Calculation of subsidiary mining stress in floor roadway under the remaining boundary pillar of close coal seam mining[J]. Journal of Mining & Safety Engineering,2021,38(2):246-252,259.
[5]	谷攀,李彦斌,韦庆亮,等. 极近距离煤层采空区煤柱下回采巷道支护技术[J]. 中国科技论文,2020,15(3):373-378. doi: 10.3969/j.issn.2095-2783.2020.03.019 GU Pan,LI Yanbin,WEI Qingliang,et al. Support technology for mining roadway under coal pillar in goaf of extremely close coal seam[J]. China Sciencepaper,2020,15(3):373-378. doi: 10.3969/j.issn.2095-2783.2020.03.019
[6]	谷攀,李彦斌,李立功,等. 极近距离煤层采空区下过煤柱回采巷道破坏特征及控制对策研究[J]. 太原理工大学学报,2020,51(4):587-593. GU Pan,LI Yanbin,LI Ligong,et al. Study on failure characteristics and control countermeasures of mining roadway in goaf of extremely close distance[J]. Journal of Taiyuan University of Technology,2020,51(4):587-593.
[7]	李春元,王泓博,石瑶玉. 上覆遗留区段煤柱对下伏煤层开采扰动影响研究[J]. 煤炭科学技术,2020,48(3):232-239. LI Chunyuan,WANG Hongbo,SHI Yaoyu. Study on disturbing influence of overlying remaining coal pillars on underlying coal seam mining[J]. Coal Science and Technology,2020,48(3):232-239.
[8]	刘霞,翟春佳,李常浩. 上煤层遗留煤柱影响段沿空掘巷围岩破坏特征及补强支护措施[J]. 矿业安全与环保,2021,48(1):101-107. LIU Xia,ZHAI Chunjia,LI Changhao. Failure characteristics and reinforcement support of surrounding rock in gob-side entry driving affected by residual coal pillar of upper coal seam[J]. Mining Safety & Environmental Protection,2021,48(1):101-107.
[9]	方新秋,郭敏江,吕志强. 近距离煤层群回采巷道失稳机制及其防治[J]. 岩石力学与工程学报,2009,28(10):2059-2067. doi: 10.3321/j.issn:1000-6915.2009.10.013 FANG Xinqiu,GUO Minjiang,LYU Zhiqiang. Instability mechanism and prevention of roadway under close distance seam group mining[J]. Chinese Journal of Rock Mechanics and Engineering,2009,28(10):2059-2067. doi: 10.3321/j.issn:1000-6915.2009.10.013
[10]	王志强, 石磊, 苏越, 等. 特厚煤层错层位外错巷道围岩控制技术研究[J]. 矿业科学学报, 2018, 3（5）: 470-476. WANG Zhiqiang, SHI Lei, SU Yue, et al. Research on surrounding rock control technology of external-misaligned stagger arrangement of roadway in ultra-thick seam[J]. Journal of Mining Science and Technology. 2018, 3（5）: 470-476.
[11]	柏建彪,王卫军,侯朝炯,等. 综放沿空掘巷围岩控制机理及支护技术研究[J]. 煤炭学报,2000,25(5):478-481. doi: 10.3321/j.issn:0253-9993.2000.05.007 BAI Jianbiao,WANG Weijun,HOU Chaojiong,et al. Control mechanism and support technique about gateway driven along goaf in fully mechanized top coal caving face[J]. Journal of China Coal Society,2000,25(5):478-481. doi: 10.3321/j.issn:0253-9993.2000.05.007
[12]	孙福玉. 综放开采窄煤柱沿空掘巷围岩失稳机理与控制技术[J]. 煤炭科学技术,2018,46(10):149-154. SUN Fuyu. Instability mechanism and control technology of surrounding rock in gob-side entry with narrow pillar by fully mechanized caving mining[J]. Coal Science and Technology,2018,46(10):149-154.
[13]	王卫军,侯朝炯. 回采巷道煤帮锚杆支护可靠性分析[J]. 岩石力学与工程学报,2001,20(6):813-816. doi: 10.3321/j.issn:1000-6915.2001.06.013 WANG Weijun,HOU Chaojiong. Reliability analysis on coal wall bolting of extraction gallery[J]. Chinese Journal of Rock Mechanics and Engineering,2001,20(6):813-816. doi: 10.3321/j.issn:1000-6915.2001.06.013
[14]	张剑. 西山矿区近距离煤层群开采巷道围岩控制技术研究及应用[D]. 北京: 煤炭科学研究总院, 2020. ZHANG Jian. Study and application of roadway surrounding rock control technology to close coal seam group mining in Xisan Mining area[D]. Beijing: China Coal Research Institute, 2020.
[15]	宁静. 深部大采高综采工作面区段煤柱宽度优化研究[J]. 煤炭工程,2019,51(3):13-17. NING Jing. Width optimization of section coal pillar of deep fully mechanized mining face[J]. Coal Engineering,2019,51(3):13-17.
[16]	刘洋. 长壁留煤柱支撑法开采煤柱设计流程[J]. 煤矿开采,2008,13(2):19-22. doi: 10.3969/j.issn.1006-6225.2008.02.006 LIU Yang. Design flow of coal pillar mining with long wall and pillar supporting method[J]. Coal Mining Technology,2008,13(2):19-22. doi: 10.3969/j.issn.1006-6225.2008.02.006
[17]	许磊. 近距离煤柱群底板偏应力不变量分布特征及应用[D]. 北京: 中国矿业大学（北京）, 2014. XU Lei. Distribution and application of floor deviatoric stress tensor invariants under close-distance multiple pillars[D]. Beijing: China University of Mining and Technology（Beijing）, 2014.
[18]	张广超. 综放松软窄煤柱沿空巷道顶板不对称破坏机制与调控系统[D]. 北京: 中国矿业大学（北京）, 2017. ZHANG Guangchao. Asymmetric failure mechanism and regulation system of gob-side entry roof with fully-mechanized caving mining and loose and weak coal pillar[J]. Beijing: China University of Mining and Technology（Beijing）, 2017.
[19]	何文瑞,何富连,陈冬冬,等. 坚硬厚基本顶特厚煤层综放沿空掘巷煤柱宽度与围岩控制[J]. 采矿与安全工程学报,2020,37(2):349-358,365. HE Wenrui,HE Fulian,CHEN Dongdong,et al. Pillar width and surrounding rock control of gob-side roadway with mechanical caved mining in extra-thick coal seams under hard-thick main roof[J]. Journal of Mining & Safety Engineering,2020,37(2):349-358,365.
[20]	董合祥. 特厚煤层综放开采沿空掘巷窄煤柱围岩控制[J]. 采矿与岩层控制工程学报,2021,3(3):32-42. DONG Hexiang. Ground control of narrow coal pillar in gob side entry driving with fully mechanized top coal caving mining in extra-thick coal seam[J]. Journal of Mining and Strata Control Engineering,2021,3(3):32-42.