Abstract
The present study reflects upon the results of substantial program of two-dimensional Finite Element Method (FEM) numerical analyses of the open pit that links to slope angle optimization associated with the safety factor of the pit slope of a coal mine in Bangladesh. In the present analyses, two types of models have been presented. The first model estimates safety factor without seismic effect on the overall pit slope of the model; the second model incorporates safety factor with seismic stability of the model. The calculated optimum slope angle of the first model is 31° with a rational safety factor of 1.51, prior to the seismic effect. However, the value is reduced to 0.93, 0.82, and 0.72, after we applies the seismic effect in the second model with M6, M6.5, and M7, respectively. Finally, our modeling results emphasize that for the case of the proposed Phulbari coalmine, there is extremely high prospect for causing massive slope failure along the optimum pit slope angle with 31° if the mine area felt seismic shaking, like the Sikkim (in northern India) earthquake with M6.9 on September 18, 2011.
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References
Daftaribesheli A, Ataei M, Sereshki F, et al. (2011) Assessment of rock slope stability using the Fuzzy Slope Mass Rating (FSMR) system, Applied Soft Computing 11(8): 4465–4473. DOI: 10.1016/j.asoc.2011.08.032.
Faruque MO, Islam MR, Akhter S, et al. (2011) An overview of geology, hydrogeology, and open pit mining perspective of the Phulbari Gondwana coal deposit, NW Bangladesh. Proceedings of the Conference on Engineering Research, Innovation and Education (CERIE), 11–13 January 2011, Sylhet, Bangladesh, pp.952–958.
GDH Technical Outline, 2004. Asia Energy Plc. Competent Person’s Report, Phulbari Energy Project. pp.1–29.
Hustrulid W, Kuchta M (2006) Open Pit Mine Planning and Design. Published by: Taylor & Francis/Balkema, The Netherlands. p 312.
Islam MR, Shinjo R (2009b) Mining-induced fault reactivation associated with the main conveyor belt roadway and safety of the Barapukuria Coal Mine in Bangladesh: Constraints from BEM simulations. International Journal of Coal Geology 79(4):115–130. DOI: 10.1016/j.coal.2009.06.007.
Islam MR, Shinjo R (2009a) Numerical simulation of stress distributions and displacements around an entry roadway with igneous intrusion and potential sources of seam gas emission of the Barapukuria coal mine, NW Bangladesh. International Journal of Coal Geology 78(4): 249–262. DOI: 10.1016/j.coal.2009.03.001.
Islam MR, Hayashi D, Kamruzzaman, ABM, et al. (2009) Finite element modeling of stress distributions and problems for multi-slice longwall mining in Bangladesh, with special reference to the Barapukuria coal mine. International Journal of Coal Geology 78(2): 91–109. DOI: 10.1016/j.coal.2008.10.006.
Islam MR, Hayashi D (2008) Geology and coal bed methane resource potential of the Gondwana Barapukuria Coal Basin, Dinajpur, Bangladesh. International Journal of Coal Geology 75(3): 127–143. DOI:10.1016/j.coal.2008.05.008.
Islam MR, Islam MS (2005) Water inrush hazard in Barapukuria coal mine, Dinajpur District, Bangladesh. Bangladesh Journal of Geology 24(1): 1–17.
Koner R, Chakravarty D (2010) Discrete element approach for mine dump stability analysis. Mining Science and Technology 20(6): 0809–0813. DOI: 10.1016/S1674-5264(09)60286-6.
Li AJ, Merifield RS, Lyamin AV, et al. (2011) Effect of rock mass disturbance on the stability of rock slopes using the Hoek-Brown failure criterion. Computers and Geotechnics 38(4): 546–558. DOI: 10.1016/j.compgeo.2011.03.003.
Mavrouli O, Corominas J, and Wartman J, et al. (2009) Methodology to evaluate rock slope stability under seismic conditions at Sol’a de Santa Coloma, Andorra. Natural Hazards and Earth System Sciences 9(6): 1763–1773. DOI: 10.5194/nhess-9-1763-2009.
Mukhopadhyay M (1984) Seismotectonics of traverse lineaments in the eastern Himalaya and its foredeep. Tectonophysics 109(3-4): 227–240. DOI: 10.1016/0040-1951(84)90142-2.
Ning YJ, An XM, Ma GW, et al. (2011). Footwall slope stability analysis with the numerical manifold method. International Journal of Rock Mechanics & Mining Sciences 48(5): 964–975. DOI: 10.1016/j.ijrmms.2011.06.011.
Stacey TR, Xianbin Y, Armstrong R, et al. (2003) New slope stability considerations for deep open pit mines. The Journal of the South African Institute of Mining and Metallurgy, July/August 103(6): 373–390.
Tapponier P, Monlar P (1976) Slip-line field theory and largescale continental tectonics. Nature 264: 319–324. DOI: 10.1038/264319a0
Wardell Armstrong (1991) Techno-Economic Feasibility Study of Barapukuria Coal Project (unpubl.), Dinajpur, Bangladesh.
Wyllie DC, Mah CW (2005) Rock Slope Engineering, Civil and Mining. Spon Press, 270 Madison Avenue, New York, NY 10016. pp. 109–151. Available online: http://www.rocscience.com (Accessed on 25 December 2012)
Zhang LL, Zhang J, Zhang LM, Tang WH (2010) Back analysis of slope failure with Markov chain Monte Carlo simulation. Computers and Geotechnics 37(7–8): 905–912. DOI: 10.1016/j.compgeo.2010.07.009
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Islam, M.R., Faruque, M.O. Optimization of slope angle and its seismic stability: A case study for the proposed open pit coalmine in Phulbari, NW Bangladesh. J. Mt. Sci. 10, 976–986 (2013). https://doi.org/10.1007/s11629-012-2483-6
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DOI: https://doi.org/10.1007/s11629-012-2483-6