PSI - Issue 48

Youcef Cheikhaoui et al. / Procedia Structural Integrity 48 (2023) 81–87 Cheikhaoui et al/ Structural Integrity Procedia 00 (2023) 000 – 000

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4. Conclusion One can conclude from the presented results that there is an intense dependence relation between the probability of failure and the slenderness ratio and the extraction rate. It is clear that there is an inverse relation between the variation of the probability of failure and the slenderness ratio W/H. In addition, the load and volume of the pillar are factors that must be considered when selecting the dimensions of pillar, since there is a certain value of W/H where the probability of survival stabilizes at 1, based on the applied load. Therefore, in order to conduct optimal mining and better extraction of ore, the choice of pillar size is necessary. The choice of the optimal critical size of the pillars enables their safe operation and good performance of the mining, even high recovery rate safely. Acknowledgements We would like to express our sincere gratitude to all the people and organizations in particular the ENOF Company of the Chaabet El Hamra mine who contributed to the publication of this research paper. References Brady, B.G.H., Brown, E.T., 2004. Rock Mechanics: For Underground Mining. Springer Science & Business Media. Brown, E.T., 1970. Strength of models of rock with intermittent joints. Journal of Soil Mechanics & Foundations. Brown, E.T., Brady, B.G.H., 1985. . Rock Mechanics for underground mining. Cheikhaoui, Y., Bensehamdi, S., Cheniti, H., Kanli, A.I., Benselhoub, A., 2021a. New formula for evaluation of strength pillar in the underground mine of Chaabet El-Hamra (Setif, Algeria). Mineralia Slovaca 53, 57 – 68. Cheikhaoui, Y., Deck, O., Omraci, K., Cheniti, H., 2021b. The Scale and Shape Effects on the Characteristic Strength of a Rock Mass: Application to Mining Pillars. Presented at the Proceedings of 1st International Conference on Structural Damage Modelling and Assessment, Lecture Notes in Civil Engineering.Springer, Singapore. https://doi.org/10.1007/978-981-15-9121-1_23. Diederichs, M.S., 2002. Stress induced damage accumulation and implications for hard rock engineering. Presented at the Proceedings of the North American Rock Mechanics Symposium, Toronto, pp. 3 – 12. Fan, L., Liu, S., 2017. A conceptual model to characterize and model compaction behavior and permeability evolution of broken rock mass in coal mine gobs. International Journal of Coal Geology 172, 60 – 70. https://doi.org/10.1016/j.coal.2017.01.017 GALVlN, j. M., HEBBLEWHITE, B.K., Salamon, M., n.d. Australian coal pillar performance. International Society of Rock Mechanics News Journal 4, 1996. Kumar, N., Verma, A.K., Sardana, S., Sarkar, K., Singh, T.N., 2018. Comparative analysis of limit equilibrium and numerical methods for prediction of a landslide. Bull Eng Geol Environ 77, 595 – 608. https://doi.org/10.1007/s10064-017-1183-4 Lunder, P.J., Pakalnis, R.C., 1997. Determination of the strength of hard-rock mine pillars. CIM Bulletin 90, 51 – 55. Ma, H., Wang, J., Wang, Y., 2012. Study on mechanics and domino effect of large-scale goaf cave-in. Safety Science 50, 689 – 694. Morlier, P., Amokrane, K., Duchamps, J.M., 1989. L’ Effet D’ Échelle En Mécanique Des Roches Recherche De Dimensions Caractéristiques. Revue francaise de géotechnique 5 – 13. Scholtès, L., Donzé, F.-V., 2012. Modelling progressive failure in fractured rock masses using a 3D discrete element method. International Journal of Rock Mechanics and Mining Sciences 52, 18 – 30. https://doi.org/10.1016/j.ijrmms.2012.02.009 Weibull, W., 1939. A statistical theory of the strength of material. Ingeniors vetenskaps akademiens, Handlingar. Yang, H., Cao, S., Li, Y., Sun, C., Guo, P., 2015. Soft Roof Failure Mechanism and Supporting Method for Gob-Side Entry Retaining. Minerals 5, 707 – 722. https://doi.org/10.3390/min5040519