Influencing Factors of the Rebreak of the Key Rock Block of the Main Roof in the Gob

Springer Science and Business Media LLC - Tập 40 - Trang 4345-4356 - 2022
Yang Li1, Yuqi Ren1, Yikun Liu, Nan Wang1, Xinghai Lei1
1School of Energy and Mining Engineering, China University of Mining and Technology (Beijing), Beijing, China

Tóm tắt

In view of the phenomenon that upright triangular zone and inverted triangular zone of the collapsed roof appeared alternately in the gob, a mechanical model of the rebreak of the key rock block (KRB) of the main roof in the gob was established by using theoretical analysis. The main reason for the rebreak of KRB was revealed and the bending moment expression at any point of KRB was obtained. So, a rebreak system of KRB of the main roof in gob was developed using Matlab software. The four influencing factors of length of KRB (l), rotation angle of KRB (α), friction coefficient (f), and load on KRB (q) were selected to study the influence on the rebreak of value and position of the maximum bending moment of KRB by using orthogonal and controlled experiment. The results show that: (1) the degree of influence on the KRB is in order: l > q > α > f; (2) The maximum bending moment is positively related to l and q, is negatively related to α and is unrelated to f. (3) The positions of the maximum bending moments of KRB are all located at 0.575 l, which is not affected by l, α, f, and q. The research on the influencing factors of the rebreak of KRB can control the formation of the collapsed roof form in gob and provide a certain reference for the upward mining of coal seams between a short distance and the mining of coal seams under water bodies.

Tài liệu tham khảo

Esterhuizen E, Mark C, Murphy M (2010) Numerical model calibration for simulation coal pillars, gob and overburden response. In: Proceedings of the 29th international conference on ground control in mining, Morgantown, WV. Feng GR, Li Z, Hu SY et al (2018) Distribution of gob empty space for methane drainage during the longwall mining: a case study. J Nat Gas Sci Eng 60:112–124. https://doi.org/10.1016/j.jngse.2018.09.026 Feng GR, Wang PF, Chugh YP (2019) Stability of gate roads next to an irregular yield pillar: a case study. Rock Mech Rock Eng 52(8):2741–2760. https://doi.org/10.1007/s00603-018-1533-y Guo GL, Miao XX, Zhang ZN (2002) Research on ruptured rock mass deformation characteristics of longwall goafs. Sci Technol and Eng 05:44–47 He JH, Li WP, Qiao W (2020) A rock mechanics calculation model for identifying bed separation position and analyzing overburden breakage in mining. Arab J Geosci 13(18):920. https://doi.org/10.1007/s12517-020-05912-8 Jiang YD, Wang HW, Xue S et al (2012) Assessment and mitigation of coal bump risk during extraction of an island longwall panel. Int J Coal Geol 95:20–33. https://doi.org/10.1016/j.coal.2012.02.003 Kong DZ, Li Q, Wu GY et al (2021) Characteristics and control technology of face-end roof leaks subjected to repeated mining in close-distance coal seams. Bull Eng Geol Environ 80:8363–8383. https://doi.org/10.1007/s10064-021-02438-5 Li Q, Wu G, Kong D et al (2022) Study on mechanism of end face roof leaks based on stope roof structure movement under repeated mining. Eng Fail Anal. https://doi.org/10.1016/J.ENGFAILANAL.2022.106162 Li Y, Wang JC, Chen YD et al (2019) Overlying strata movement with ground penetrating radar detection in close-multiple coal seams mining. Int J Distrib Sens Netw 15(08):1550147719869852. https://doi.org/10.1177/1550147719869852 Li Y, Ren YQ, Peng SS et al (2021a) Measurement of overburden failure zones in close-multiple coal seams mining. Int J Min Sci Technol 31(01):43–50. https://doi.org/10.1016/j.ijmst.2020.12.009 Li Y, Ren YQ, Wang N et al (2021b) Study on structure form and evolution characteristics of collapsed roof in goaf. J China Coal Soc 46(12):3771–3780. https://doi.org/10.13225/j.cnki.jccs.2021.0272 Li YY, Hu CR (2008) Experiment design and data processing. Chemical Industry Press, Beijing Ling CD (2014) Chemical inspector (intermediate). China Machine Press, Beijing Liu TQ (1995) Influence of mining activities on mine rockmass and control engineer. J China Coal Soc 20(01):1–5 Miao XX, Qian MG (1995) Solid structure and model of voussoir beam of face surrounding rock. Ground Pressure Strata Control Z1:3–12 Pan WD, Nie XD, Li XY (2019) Effect of premining on hard roof distress behavior: a case study. Rock Mech Rock Eng 52(6):1871–1885. https://doi.org/10.1007/s00603-018-1657-0 Qian MG, Shi PW, Xu JL (2010) Mine pressure and strata control. China University of Mining and Technology Press, Xuzhou Qian MG, Miao XX, He FL (1994) Analysis of key block in the structure of voussoir beam in longwall mining. J China Coal Soc 06:557–563 Qian MG, Miao XX, Xu JL (1996) Theoretical study of key stratum in ground control. J China Coal Soc 03:2–7 Qin ZC, Yu X, Li QH et al (2016) Study on the orthogonal numerical simulation experiment of the effect of surrounding rock mechanical parameters on roadway deformation and failure. J Min and Saf Eng 33(01):77–82. https://doi.org/10.13545/j.cnki.jmse.2016.01.012 Salamon M (1990) Mechanism of caving in longwall coal mining. Rock mechanics contributions and challenges In: Proceedings of the 31st US symposium on rock mechanics. CRC Press Shi LQ, Xu DJ, Wang Y et al (2019) A novel conceptual model of fracture evolution patterns in the overlying strata during horizontal coal seam mining. Arab J Geosci 12(10):326. https://doi.org/10.1007/s12517-019-4486-x Song ZQ (1992) Practical mine pressure control. China University of Mining and Technology Press, Xuzhou Sun XF, Fang XS, Guan LT (2009) Mechanics of materials (I). Higher Education Press, Beijing Sun YN, Zhang PS, Yan W et al (2020) Experimental study on overburden movement and stress variation of coal seam mining with associated step faults. Safety in Coal Mines 51(07):48–54. https://doi.org/10.13347/j.cnki.mkaq.2020.07.010 Wang HW, Jiang YD, Zhao YX et al (2013) Numerical investigation of the dynamic mechanical state of a coal pillar during longwall mining panel extraction. Rock Mech Rock Eng 46(5):1211–1221. https://doi.org/10.1007/s00603-012-0337-8 Wang JC, Wang ZH, Li Y (2020) Longwall top coal caving mechanisms in the fractured thick coal seam. Int J Geomech 20(8):06020017. https://doi.org/10.1061/(ASCE)GM.1943-5622.0001722 Xu JL, Qian MG (2001) Study and application of dominant stratum theory for control of strata movement. China Min Mag 06:56–58 Zhang GC, He FL, Jia HG et al (2017) Analysis of gateroad stability in relation to yield pillar Size: a case study. Rock Mech Rock Eng 50(5):1263–1278. https://doi.org/10.1007/s00603-016-1155-1 Zuo JP, Sun YJ, Qian MG (2017) Movement mechanism and analogous hyperbola model of overlying strata with thick alluvium. J China Coal Soc 42(06):1372–1379. https://doi.org/10.13225/j.cnki.jccs.2016.1164 Zuo JP, Wu GS, Sun YJ et al (2021) Investigation on the inner and outer analogous hyperbola model (AHM) of strata movement. J China Coal Soc 46(02):333–343. https://doi.org/10.13225/j.cnki.jccs.2020.125