Abstract
Gob-area roof rupture movement is a key disturbance factor for gob-side entry retaining. The characteristics of gob-area sequential roof collapse of overlying strata and superposed disturbance mechanism for gob-side entry retaining are obtained via physical simulation and theoretical analysis, in which the scope of disturbed strata is enlarged from main roof to fracture zone. The experiment reveals that as a working face advances, roof strata sequentially collapse from bottom to top and produce multiple disturbances to gob-side entry retaining. Key strata among the overlying strata control each collapse. Main roof subsidence is divided into three stages: flexure subsidence prior to rupture, rotational subsidence during rupture and compressive subsidence after rupture. The amounts of deformation evident in each of the three stages are 15%, 55% and 30%, respectively. After the master stratum collapses, main roof subsidence approaches its maximum value. The final span of the key stratum determines the moment and cycling of gob-side entry retaining disturbances. Main roof subsidence influences the load on the filling wall. The sequential roof collapse of overlying strata results in fluctuations in the gob-side entry retaining deformation. Calculation formulae for the final span of the key stratum and the filling wall load are obtained via theoretical analysis. A control method for the stability of the gob-side entry retaining’s surrounding rock is proposed, which includes 3 measures: a “dual-layer” proactive anchorage support, roadside filling with dynamic strength matching and auxiliary support during disturbance. Finally, the gob-side entry retaining of the Xiaoqing mine E1403 working face is presented as an engineering case capable of verifying the validity of the research conclusions.
摘要
采空区顶板断裂运动是沿空留巷的关键扰动因素。 本文阐述了采空区覆岩的分次垮落特征及其对沿空留巷的叠加扰动机理, 将扰动岩层由过去的老顶扩大到了裂隙带。 物理模拟实验揭示, 顶板各岩层随着工作面的推进而由下向上依次垮落, 并对沿空留巷造成多次扰动。 覆岩中的各个关键层控制着每一次垮落, 其中老顶下沉分为断裂前的挠曲下沉、 断裂时的旋转下沉以及断裂后的压缩下沉三个阶段, 实验中三部分变形量分别占 15%, 55% 和 30%, 主控关键层垮落后老顶接近最大下沉值。 关键层的极限跨距决定着沿空留巷的扰动时机和扰动周期, 老顶下沉量影响着充填墙体的载荷大小, 覆岩的分次垮落则使沿空留巷呈现出波动性变形。 采用理论分析, 得到了关键层极限跨距和充填墙体载荷的计算方法。 提出了沿空留巷围岩稳定性控制技术, 包括“双层”主动锚固支护、 强度动态匹配的巷旁充填以及扰动期间的辅助支护 3 项。 最后结合小青矿 E1403 工作面沿空留巷的工程案例, 验证了研究结论的合理性。
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
YUAN Liang. Theory and practice of integrated pillarless coal production and methane extraction in multiseams of low permeability [M]. Beijing: China Coal Industry Publishing House, 2008. (in Chinese)
XU Ying, CHEN Jin, BAI Jian-biao. Control of floor heaves with steel pile in gob-side entry retaining [J]. International Journal of Mining Science and Technology, 2016, 26(3): 527–534.
HUA Xin-zhu, LI Ying-fu. Mechanics analysis on floor deformation of gob-side entry retaining and prevention and control of floor heave [J]. Journal of China Coal Society, 2016, 41(7): 1624–1631. (in Chinese)
YE Gen-xi, ZHU Quan-jie, LI Shu-xia, YU Zheng-xing. Development and application of composite filling body in gob-side entry retaining with 1000 m-plus deep coal mine [J]. Journal of Mining & Safety Engineering, 2016, 33(5): 787–794. (in Chinese)
SUN Xiao-ming, LIU Xin, LIANG Guang-feng, WANG Dong, JIANG Yu-lin. Key parameters of gob-side entry retaining formed by roof cut and pressure releasing in thin coal seams [J]. Chinese Journal of Rock Mechanics and Engineering, 2014, 33(7): 1449–1456. (in Chinese)
YUAN Liang. The technique of coal mining and gas extraction by roadway retaining and borehole drilling [J]. Journal of China Coal Society, 2008, 33(8): 898–902. (in Chinese)
YUAN Liang, GUO Hua, SHEN Bao-tang, QU Qing-dong, XUE Jun-hua. Circular overlying zone at longwall panel for efficient methane capture of multiple coal seams with low permeability [J]. Journal of China Coal Society, 2011, 36(3): 357–365. (in Chinese)
ZHANG Nong, YUAN Liang, WANG Cheng, KAN Jia-guang, XU Xing-liang. Deformation characteristics and stability analysis of roof roadway in destressed mining [J]. Journal of China Coal Society, 2011, 36(11): 1784–1789. (in Chinese)
YANG Hong-yun, CAO Shu-gang, WANG Shou-quan, FAN Ying-chong, WANG Shuai, CHEN Xian-zhe. Adaptation assessment of gob-side entry retaining based on geological factors [J]. Engineering Geology, 2016, 209: 143–151.
KANG Hong-pu, WANG Jin-hua, LIN Jian. High pretensioned stress and intensive bolting system and its application in deep roadways [J]. Journal of China Coal Society, 2007, 32(12): 1233–1238. (in Chinese)
KANG Hong-pu, WU Yong-zheng, LI Jian-bo. Analysis on mechanical performances and supporting function of combination components for rock bolting [J]. Journal of China Coal Society, 2010, 35(7): 1057–1065. (in Chinese)
ZHANG Nong, YUAN Liang, HAN Chang-liang, XUE Jun-hua, KAN Jia-guang. Stability and deformation of surrounding rock in pillarless gob-side entry retaining [J]. Safety Science, 2012, 50(4): 593–599.
QI Tai-yue, GUO Yu-guang, HOU Chao-jiong. Study on the adaptability for the pack-fillings of the gob-side entry retaining [J]. Journal of China Coal Society, 1999, 24(3): 256–260. (in Chinese)
CHEN Yong, BAI Jian-biao, ZHU Tao-lei, YAN Shuai, ZHAO She-hui, LI Xue-chen. Mechanisms of roadside support in gob-side entry retaining and its application [J]. Rock and Soil Mechanics, 2012, 33(5): 1427–1432. (in Chinese)
XUE Jun-hua, HAN Chang-liang. Strata behavior and control countermeasures for the gob-side entry retaining in the condition of large mining height [J]. Journal of Mining & Safety Engineering, 2012, 29(4): 466–473. (in Chinese)
TAN Yun-liang, YU Feng-hai, NING Jian-guo, ZHAO Tong-bin. Design and construction of entry retaining wall along a gob side under hard roof stratum [J]. International Journal of Rock Mechanics and Mining Sciences, 2015, 77: 115–121.
TAN Yun-liang, YU Feng-hai, NING Jian-guo, ZHAO Tong-bin. Adaptability theory of roadside support in gob-side entry retaining and its supporting design [J]. Journal of China Coal Society, 2016, 41(2): 376–382. (in Chinese)
WANG Hong-sheng, ZHANG Dong-sheng, FAN Gang-wei. Structural effect of a soft-hard backfill wall in a gob-side roadway [J]. Mining Science and Technology (China), 2011, 21(3): 313–318.
ZHANG Dong-sheng, MIAO Xie-xing, FENG Guang-ming, SONG Zhao-qian. Stability control of packing body for gob-side entry retaining in fully-mechanized coal faces with top-coal caving [J]. Journal of China University of Mining & Technology, 2003, 32(3): 232–235. (in Chinese)
LI Xue-hua, JU Ming-he, YAO Qiang-ling, ZHOU Jian, CHONG Zhao-hui. Numerical investigation of the effect of the location of critical rock block fracture on crack evolution in a gob-side filling wall [J]. Rock Mechanics and Rock Engineering, 2016, 49(3): 1041–1058.
ZHANG Zi-zheng, BAI Jian-biao, CHEN Yong, YAN Shuai. An innovative approach for gob-side entry retaining in highly gassy fully-mechanized longwall top-coal caving [J]. International Journal of Rock Mechanics and Mining Sciences, 2015, 80: 1–11.
BAI Jian-biao, SHEN Wen-long, GUO Guan-long, WANG Xiang-yu, YU Yang. Roof deformation, failure characteristics, and preventive techniques of gob-side entry driving heading adjacent to the advancing working face [J]. Rock Mechanics and Rock Engineering, 2015, 48(6): 2447–2458.
HAN Chang-liang, ZHANG Nong, LI Gui-chen, LI Bao-yu, WU Hai. Stability analysis of compound bearing structure of gob-side entry retaining with large mining height [J]. Chinese Journal of Geotechnical Engineering, 2014, 36(5): 969–976. (in Chinese)
NING Jian-guo, WANG Jun, LIU Xue-sheng, QIAN Kun, SUN Bi. Soft-strong supporting mechanism of gob-side entry retaining in deep coal seams threatened by rockburst [J]. International Journal of Mining Science and Technology, 2014, 24(6): 805–810.
HAN Chang-liang, ZHANG Nong, LI Bao-yu, SI Guang-yao, ZHENG Xi-gui. Pressure relief and structure stability mechanism of hard roof for gob-side entry retaining [J]. Journal of Central South University, 2015, 22(11): 4445–4455.
SHEN Wen-long, BAI Jian-biao, WANG Xiang-yu, YU Yang. Response and control technology for entry loaded by mining abutment stress of a thick hard roof [J]. International Journal of Rock Mechanics and Mining Sciences, 2016, 90: 26–34.
QIAN Ming-gao, SHI Ping-wu, XU Jia-lin. Mine pressure and strata control [M]. Xuzhou: China University of Mining and Technology Press, 2010. (in Chinese)
QIAN Ming-gao, MIAO Xie-xing, XU Jia-lin, MAO Xian-biao. Theory of key strata in ground control [M]. Xuzhou: China University of Mining and Technology Press, 2003. (in Chinese)
ZHANG Peng, HEASLEY K A. Elimination of boundary effect for laminated overburden model in pillar stability analysis [J]. Journal of Central South University, 2016, 23(6): 1551–1559.
Author information
Authors and Affiliations
Corresponding author
Additional information
Foundation item: Project(51404251) supported by the National Natural Science Foundation of China; Project(BK20140198) supported by the Natural Science Foundation of Jiangsu Province, China; Project(PPZY2015A046) supported by the Top-notch Academic Programs Project of Jiangsu Higher Education Institutions, China; Project supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions, China
Rights and permissions
About this article
Cite this article
Han, Cl., Zhang, N., Ran, Z. et al. Superposed disturbance mechanism of sequential overlying strata collapse for gob-side entry retaining and corresponding control strategies. J. Cent. South Univ. 25, 2258–2271 (2018). https://doi.org/10.1007/s11771-018-3911-8
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11771-018-3911-8