Determination of the rock mass displacement zone by numerical modeling method when exploiting the longwall at the Nui Beo Coal Mine, Vietnam

Tien Trung Vu¹, Son Anh Do¹

¹Hanoi University of Mining and Geology, Hanoi, Vietnam

Min. miner. depos. 2023, 17(1):59-66

https://doi.org/10.33271/mining17.01.059

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      ABSTRACT

      Purpose. It is important to conduct a study to identify the displacement zone caused by mining operations. By numerical modeling the process of mining the longwall 31104 in Seam 11 at the Nui Beo Coal Mine, Vietnam, the authors have deter-mined the total height of the rock mass displacement zone and the boundary of the affected area on the topographic surface.

      Methods. In this study, the authors use a numerical modeling method. The models are developed based on the UDEC (Universal Distinct Element Code) software. In addition, field survey methods and statistical analysis methods are used.

      Findings. Based on the analysis of the numerical modeling results, it has been determined that the total height of the displacement zone, when exploiting the longwall 31104 in Seam 11, is about 63 m. The analysis of the numerical modeling results also shows that the roof collapse angle is 52°, which determines the area of influence on the topographic surface in the range of 160 m.

      Originality. Based on the UDEC software, the authors have developed a simulation model for the mining process of the longwall 31104 in Seam 11. Analysis of the model results has shown the state of the displacement zone of the surrounding rock mass. In this study, the numerical modeling method is applied to simulate the longwall displacement zone, which is consistent with the actual production of the underground mine.

      Practical implications. Based on the analysis of the surrounding rock mass displacements zone, when exploiting the longwall 31104 in Seam 11 at the Nui Beo Coal Mine, the affected boundary on the topographic surface has been determined. At the same time, the height of the rock mass displacement zone has also been calculated. Thus, the research results can be used as a basis for implementation in actual production at the Nui Beo Coal Mine.

      Keywords: mining, displacement, longwall, rock mass, numerical modeling

      REFERENCES

1. Sainoki, A., & Mitri, H.S. (2014). Dynamic behaviour of mining-induced fault slip. International Journal of Rock Mechanics and Mining Sciences, 66(1), 19-29. https://doi.org/10.1016/j.ijrmms.2013.12.003
2. Zhou, D.W., Wu, K., Cheng, G.L., & Li, L. (2015). Mechanism of mining subsidence in coal mining area with thick alluvium soil in China. Arabian Journal of Geosciences, (8), 1855-1867. https://doi.org/10.1007/s12517-014-1382-2
3. Ji, H.G., Ma, H.S., Wang, J.A., Zhang, Y.H., & Cao, H. (2012). Mining disturbance effect and mining arrangements analysis of near-fault mining in high tectonic stress region. Safety Science, 50(4), 649-654. https://doi.org/10.1016/j.ssci.2011.08.062
4. Jiang, Y.D., Lv, Y.K., Zhao, Y.X., & Cui, Z.J. (2012). Principal component analysis on electromagnetic radiation rules while fully mechanized coal face passing through fault. Environmental Sciences Proceedings, (12), 751-757. https://doi.org/10.1016/j.proenv.2012.01.344
5. Hofmann, G.F., & Scheepers, L.J. (2015). Simulating fault slip areas of mining induced seismic tremors using static boundary element numerical modeling. Transactions of the Institutions of Mining and Metallurgy, 120(1), 53-64. https://doi.org/10.1179/037178411X12942393517291
6. Ren, S.G., Wu, Y.P., & Yin, J.H. (2015). Research on stability of overburden structure around longwall mining face in steeply dipping seam group. Applied Mechanics and Materials, (724), 100-110. https://doi.org/10.4028/www.scientific.net/amm.724.100
7. Production plan. Nui Beo Coal Mine. (2021). Quang Ninh, Vietnam: Department of Production Planning.
8. Xie, W.B., Chen, X.X., & Zheng, B.S. (2005). Numerical simulation research and analysis of mining engineering problem. Xuzhou, China: China University of Mining and Technology Press.
9. Xie, G.X., Chang, J.C., & Yang, K. (2009). Investigations into stress shell characteristics of surrounding rock in fully mechanized top-coal caving face. International Journal of Rock Mechanics and Mining Sciences, 46(1), 172-181. https://doi.org/10.1016/j.ijrmms.2008.09.006
10. Hu, B., Zhang, Q., Li, S., Yu, H., Wang, X., & Wang, H. (2022). Application of numerical simulation methods in solving complex mining engineering problems in Dingxi mine, China. Minerals, (12), 123. https://doi.org/10.3390/min12020123
11. Sjöberg, J., Perman, F., Quinteiro, C., Malmgren, L., Dahnér-Lindkvist, C., & Boskovic, M. (2012). Numerical analysis of alternative mining sequences to minimise the potential for fault slip rockbursting. Deep Mining 2012: Proceedings of the Sixth International Seminar on Deep and High Stress Mining., 357-372. Australian Centre for Geomechanics. https://doi.org/10.36487/ACG_rep/1201_26_sjoberg
12. Durand, A.F., Eargas, J.E.A., & Vaz, L.E. (2006). Applications of numerical limit analysis (NLA) to stability problems of rock and soil masses. International Journal of Rock Mechanics and Mining Sciences, 43(3), 408-425. https://doi.org/10.1016/j.ijrmms.2005.07
13. Jia, L.G. (2014). Simulation experiment study of surrounding rock deformation and surface movement during paste filling mining. Advanced Materials Research, (1073-1076), 2135-2144. https://doi.org/10.4028/www.scientific.net/amr.1073-1076.2135
14. Lai, X.P., Shan, P.F., & Cao, J.T. (2016). Simulation of asymmetric destabilization of mine-void rock masses using a large 3D physical model. Rock Mechanics and Rock Engineering, (49), 487-502. https://doi.org/10.1007/s00603-015-0740-z
15. Sheng, Q.B., Hao, S.T., Cun, Z., & De, F.Z. (2016). Discrete element modeling of progressive failure in a wide coal roadway from water-rich roofs. International Journal of Coal Geology, (167), 215-229. https://doi.org/10.1016/j.coal.2016.10.010
16. Sheng, Q.Y., Miao, C., Hong, W.J., Kun, F.C., & Bo, M. (2017). A case study on large deformation failure mechanism of deep soft rock roadway in Xin’An coal mine, China. Engineering Geology, (217), 89-101. https://doi.org/10.1016/j.enggeo.2016.12.012
17. Liu, G. L., Fan, K. G., & Xiao, T. Q. (2011). Study on mountainous shallow-buried coal seam mining working face strata behaviors and overlying strata movement features. Applied Mechanics and Materials, (121-126), 2911-2916. https://doi.org/10.4028/www.scientific.net/amm.121-126.2911
18. Yan, Z.G. (2011). Study on deformation of tunnel with underlying coal mining. Applied Mechanics and Materials, (105-107), 1295-1298. https://doi.org/10.4028/www.scientific.net/amm.105-107.1295
19. Li, Y.J., Li, C., Sun, H., & Xu, H.T. (2015). Research on upper limit increased of mining in coal mining face. Applied Mechanics and Materials, (737), 846-850. https://doi.org/10.4028/www.scientific.net/amm.737.846
20. Arash, D., Mohammad, A., & Ramin, R. (2020). Investigating the effect of simultaneous extraction of two longwall panels on a maingate gateroad stability using numerical modeling. International Journal of Rock Mechanics and Mining Sciences, (126), 104172. https://doi.org/10.1016/j.ijrmms.2019.104172
21. Li, S.J., Pu, W., Pei, P.Z., Peng. Q.Z., & Bin, X. (2017). Numerical analysis of the effects induced by normal faults and dip angles on rock bursts. Comptes Rendus Mécanique, 345(10), 690-705. https://doi.org/10.1016/j.crme.2017.06.009
22. Jin, Q.J., Pu, W., Li, S.J., Peng, Q.Z., & Fan, F. (2018). Numerical simulation on mining effect influenced by a normal fault and its induced effect on rock burst. Geomechanics and Engineering, 14(4), 337-344. https://doi.org/10.12989/gae.2018.14.4.337
23. Wang, X.Q., Yin, D.F., Gao, Z.N., & Zhao, Q.F. (2013). Reasonable entry layout of lower seam in multi-seam mining based on numerical simulation. Applied Mechanics and Materials, (295-298), 2980-2984. https://doi.org/10.4028/www.scientific.net/amm.295-298.2980
24. Ma, F.H., Sun, L., & Li, D. (2011). Numerical simulation analysis of covering rock strata as mining steep-inclined coal seam under fault movement. Transactions of Nonferrous Metals Society of China, 21(3), 556-561. https://doi.org/10.1016/S1003-6326(12)61640-9
25. Shnorhokian, S., Mitri, H.S., & Thibodeau, D. (2014). Numerical simulation of pre-mining stress field in a heterogeneous rockmass. International Journal of Rock Mechanics and Mining Sciences, 66(9), 13-18. https://doi.org/10.1016/j.ijrmms.2013.12.002
26. Vu, T.T., & Dаo, V.D. (2022). Аssessing the impаct of underground working (tunneling) in the ii section of seаm 14 on surfаce construction works аt Hа Lаm coаl mine (Vietnаm). Nаukovyi Visnyk Nаtsionаlnoho Hirnychoho Universytetu, (4), 39-44. https://doi.org/10.33271/nvngu/2022-4/039
27. Tuo, C., & Mitri, H.S. (2021). Strategies for surface crown pillar design using numerical modelling – A case study. International Journal of Rock Mechanics and Mining Sciences, (138), 104599. https://doi.org/10.1016/j.ijrmms.2020.104599
28. Coggan, J., Gao, F.Q., Stead, D., & Elmo, D. (2012). Numerical modelling of the effects of weak immediate roof lithology on coal mine roadway stability. International Journal of Coal Geology, 90-91(1), 100-109. https://doi.org/10.1016/j.coal.2011.11.003
29. Shi, J.W., & Chen, Z.L. (2014). Based on numerical simulation study of rockburst in roadway induced by fault. Advanced Materials Research, (962-965), 370-374. https://doi.org/10.4028/www.scientific.net/amr.962-965.370
30. Report of geological conditions of Nui Beo coal mine. (2021). Nui Beo Coal Mine. Quang Ninh, Vietnam: Department of Geodesy and Geology.
31. Mining passport for longwall 31104 in Seam 11 at Nui Beo Coal Mine. (2021). Nui Beo Coal Mine. Quang Ninh, Vietnam: Department of Mining Technology.