Mining of Mineral Deposits

ISSN 2415-3443 (Online)

ISSN 2415-3435 (Print)

Flag Counter

Numerical modelling of the pit wall stability while optimizing its boundaries to ensure the ore mining completeness

Olena Sdvyzhkova1, Serik Moldabayev2, Dmytro Babets1, Atac Bascetin3, Gulnur Asylkhanova2, Assel Nurmanova2, Vira Prykhodko1

1Dnipro University of Technology, Dnipro, Ukraine

2Satbayev University, Almaty, Kazakhstan

3Istanbul Technical University, Istanbul, Turkey


Min. miner. depos. 2024, 18(2):1-10


https://doi.org/10.33271/mining18.02.001

Full text (PDF)


      ABSTRACT

      Purpose is to assess changes in the stress-strain state of walls along the whole periphery of a super-deep open pit while optimizing its current and final boundaries for the complete ore excavation.

      Methods. Finite element 3D analysis of stress-strain state (SSS) of the soil and rock mass relies upon the models varying in their scales. Macrolevel model includes the full pit helping perform initial evaluation of its stability depending upon changes in the general wall slope along the pit periphery. Then, the macromodel is separated into sectoral models with smaller scales oriented radially in such a way to include potentially unstable wall areas. The sectoral models make it possible to show the complex bench line in more detail after the peripheries were optimized in terms of economic factor and simulate layered structure of the rock mass. Elastoplastic model of the medium as well as Mohr-Coulomb strength criterion has been implemented using RS3 (Rocscience) program codes.

      Findings. An indicator of wall strength (safety factor) distribution along the pit periphery has been identified; potential sliding surfaces within each of the separated open pit sectors have been localized based upon the shear strength reduction (SSR) procedure. Influence by the general wall slope as well as by the indicator of the ore excavation completeness on the stripping ratio has been demonstrated.

      Originality. For the first time, two-level modelling has shown difference in a safety factor depending upon a model scale and a reflection degree of the soil-rock mass structure. In the context of the actual mining and geological conditions of Kacharsky open pit, changes in the safety factor along the pit periphery have been identified depending on the general slope of the wall.

      Practical implications. Based upon the pit wall stability along the whole periphery, the possibility has been substantiated to optimize its design boundaries for the excavation of those amenable ore reserves, occurred near them, inclusive of ore, occurring in a bottom, which mining is impossible due to inaccessibility.

      Keywords: ore excavation, deep open pit, numerical modelling, final boundary optimization


      REFERENCES

  1. Sobko, B., & Lozhnikov, O. (2018). Determination of cut-off wall cost efficiency at motronivskyi pit mining. Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu, 3, 44-49. https://doi.org/10.29202/nvngu/2018-3/1
  2. Hou, J., Wang, H., Li, G., Sheng, B., & Wang, Q. (2024). Multistage dynamic optimisation of ore flow for underground metal mines. International Journal of Mining, Reclamation and Environment, 38(5), 407-423. https://doi.org/10.1080/17480930.2024.2311455
  3. Yaqot, M., & Menezes, B.C. (2023). Integrating mineral mining and metallurgical supply chains: A qualogistics approach. Computer Aided Chemical Engineering, 52, 1759-1764. https://doi.org/10.1016/B978-0-443-15274-0.50279-1
  4. Cao, B., Wang, J., Guo, X., Li, W., & Liu, G. (2023). Research on boundary optimization of adjacent mining areas in open pit coal mine based on calculation of sectional stripping ratio. Scientific Reports, 13, 21286. https://doi.org/10.1038/s41598-023-48708-y
  5. Das, R., Topal, E., & Mardaneh, E. (2023). A review of open pit mine and waste dump schedule planning. Resources Policy, 85(A), 104064. https://doi.org/10.1016/j.resourpol
  6. MacNeil, J., Dimitrakopoulos, R., & Peattie, R. (2022). A stochastic mine planning approach to determine the optimal open pit to underground mining transition depth – case study at the Geita gold mine, Tanzania. Mining Technology: Transactions of the Institute of Mining and Metallurgy, 131(3), 181-190. https://doi.org/10.1080/25726668.2022.2072559
  7. Badakhshana, N., Shahriar, K., Afraei, S., & Bakhtavar, E. (2023). Evaluating the impacts of the transition from open-pit to underground mining on sustainable development indexes. Journal of Sustainable Mining, 22(2), 6. https://doi.org/10.46873/2300-3960.1382
  8. Khaboushan, A.S., Osanloo, M., & Esfahanipour, A. (2020). Optimization of open pit to underground transition depth: An idea for reducing waste rock contamination while maximizing economic benefits. Journal of Cleaner Production, 277, 123530. https://doi.org/10.1016/j.jclepro.2020.123530
  9. Das, R., Topal, E., & Mardaneh, E. (2022). Improved optimised scheduling in stratified deposits in open pit mines – using in-pit dumping. International Journal of Mining, Reclamation and Environment, 36(4), 287-304. https://doi.org/17480930.2022.2036559
  10. Hustrulid, W., Kuchta, M., & Martin, R. (2013). Open pit mine – planning & design. London, United Kingdom: CRC Press, 1308 p. https://doi.org/10.1201/b15068
  11. Geovia. (2024). Geovia whittle roles. [online]. Retrieved from: https://www.3ds.com/products/geovia/whittle
  12. Purevdavaa, T., & Khandelwal, M. (2022). Ultimate pit limit optimization by computerized and manual methods for Dadiin Khar Tolgoi – 2 Coal Mine – A case study. Proceedings of Geotechnical Challenges in Mining, Tunneling and Underground Infrastructures, 97-116. https://doi.org/10.1007/978-981-16-9770-8_5
  13. Ares, G., Castañón Fernández, C., Álvarez, I.D., Arias, D., & Díaz, A.B. (2022). Open pit optimization using the floating cone method: A New algorithm. Minerals, 12(4), 495. https://doi.org/10.3390/min12040495
  14. Morales, N., Nancel-Penard, P., & Espejo, N. (2019). Development and analysis of a methodology to generate operational open-pit mine ramp designs automatically. Optimization and Engineering, 24(2), 711-714. https://doi.org/10.35624/jminer2019.01.09
  15. Farkaš, B., & Hrastov, A. (2021). Multi-criteria analysis for the selection of the optimal mining design solution – A case study on quarry “Tambura”. Energies, 14(11), 3200. https://doi.org/10.3390/en14113200
  16. Rakhmangulov, A., Burmistrov, K., & Osintsev, N. (2022). Selection of open-pit mining and technical system’s sustainable development strategies based on MCDM. Sustainability, 14(13), 8003, https://doi.org/10.3390/su14138003
  17. Sedina, S., Altayeva, A., Shamganova, L., & Abdykarimova, G. (2022). Rock mass management to ensure safe deposit development based on comprehensive research within the framework of the geomechanical model development. Mining of Mineral Deposits, 16(2), 103-109. https://doi.org/10.33271/mining16.02.103
  18. Aitkazinova, Sh., Sdvyzhkova, O., Imansakipova, N., Babets, D., & Klymenko, D. (2022). Mathematical modeling the quarry wall stability under conditions of heavily jointed rocks. Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu, 6, 18-24. https://doi.org/10.33271/nvngu/2022-6/018
  19. Supandi, H. (2021). Engineering geology consideration for low-wall stability analysis in open-pit coal mine. Geotechnical and Geological Engineering, 39, 3815-3828. https://doi.org/10.1007/s10706-021-01729-8
  20. Moldabayev, S.K., Sdvyzhkova, O.O., Babets, D.V., Kovrov, O.S., & Adil, T.K. (2020). Numerical simulation of the open pit stability based on probabilistic approach. Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu, 6, 29-34. https://doi.org/10.33271/nvngu/2021-6/029
  21. Wijesinghe, D.R., Dyson, A., You, G., Song, C., & Ooi, E.T. (2022). Simultaneous slope design optimisation and stability assessment using a genetic algorithm and a fully automatic image-based analysis. International Journal for Numerical and Analytical Methods in Geomechanics, 46(15), 2868-2892. https://doi.org/10.1002/nag.3431
  22. Mahmoodzadeh, A., Alanazi, A., Mohammed, A.H., Elhag, A.B., Alqahtani, A., & Alsubai, S. (2024). An optimized model based on the gene expression programming method to estimate safety factor of rock slopes. Natural Hazards, 120, 1665-1688. https://doi.org/10.1007/s11069-023-06152-1
  23. Qin, H., Yin, X., Tang, H., & Cheng, X. (2024). Reliability analysis and geometric optimization method of cut slope in spatially variable soils with rotated anisotropy. Engineering Failure Analysis. Engineering Failure Analysis, 158, 108019. https://doi.org/10.1016/j.engfailanal.2024.108019
  24. Kang, J., Wan, D., Sheng, Q., Fu, X., Pang, X., Xia, L., & Li, D. (2022). Risk assessment and support design optimization of a high slope in an open pit mine using the jointed finite element method and discontinuous deformation analysis. Bulletin of Engineering Geology and the Environment, 81(6), 254. https://doi.org/10.1007/s10064-022-02759-z
  25. Liu, T., Ding, L., Meng, F., Li, X., & Zheng, Y. (2021). Stability analysis of anti-dip bedding rock slopes using a limit equilibrium model combined with bi-directional evolutionary structural optimization (BESO) method. Computers and Geotechnics, 134, 104116. https://doi.org/10.1016/j.compgeo.2021.104116
  26. Karthik, A.V.R., Manideep, R., & Chavda, J.T. (2022). Sensitivity analysis of slope stability using finite element method. Innovative Infrastructure Solutions, 7, 184. https://doi.org/10.1007/s41062-022-00782-3
  27. Torres, V.F.N., Dockendorff, R., Sotomayor, J.M.G., Castro, C., & da Silva, A.F. (2023). Calibration of a three-dimensional slope stability evaluation in Brazilian iron open pit mine. Geotechnical and Geological Engineering, 41(6), 3829-3846.
  28. Dehghan, A.N., & Yazdi, A. (2023). A geomechanical investigation for optimizing the ultimate slope design of Shadan open pit mine, Iran. Indian Geotechnical Journal, 53(4), 859-873. https://doi.org/10.1007/s40098-022-00709-w
  29. Wang, X., Wang, K., Deng, T., Wang, F., Zhao, Y., Li, J., Huang, Z., Wang, J., Duan, W. (2024). Contribution of soil matric suction on slope stability under different vegetation types. Journal of Soils and Sediments, 24, 575-588. https://doi.org/10.1007/s11368-023-03653-1
  30. Sun, Z., Wang, B., Li, Y., Xu, J., & Ji, J. (2023). 3D limit analysis of rock slopes based on equivalent linear failure criterion with tension cut-off. Journal of Rock Mechanics and Geotechnical Engineering, 15(12), 3118-3130. https://doi.org/10.1016/j.jrmge.2023.02.009
  31. Demirdogen, S., & Yildirim, S. (2024). The disturbance factor of Hoek-Brown failure criterion in dam foundations. Geotechnical and Geological Engineering, 42, 817-825. https://doi.org/10.1007/s10706-023-02576-5
  32. Sdvyzhkova, O., Babets, D., & Kravchenko, K. (2015). Rock state assessment at initial stage of longwall mining in terms of poor rocks of Western Donbass. New Developments in Mining Engineering: Theoretical and Practical Solutions of Mineral Resources Mining, 65-70. https://doi.org/10.1201/b19901-13
  33. Sdvizhkova, Ye.A., Kovrov, A.S., & Kiriiak, K.K. (2014). Geomechanical assessment of landslide slope stability by finite element method. Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu, 2, 86-92.
  34. SOU-N MPP 73.020-078-1:2007. (2007). Standards of technological design for mining enterprises using an open method of developing mineral deposits. Kyiv: Ministry of Industrial Policy of Ukraine, 288 p.
  35. Pilecka, E., Stanisz, J., Kaczmarczyk, R., & Gruchot, A. (2021). The setting of strength parameters in stability analysis of open-pit slope using the random set method in the bełchatów lignite mine, central Poland. Energies, 14(15), 46090. https://doi.org/10.3390/en14154609
  36. Abdulai, M., & Sharifzadeh, M. (2021). Probability methods for stability design of open pit rock slopes: An overview. Geosciences, 11(8), 319. https://doi.org/10.3390/geosciences11080319
  37. Shashenko, O.M., Hapieiev, S.M., Shapoval, V.G., & Khalymendyk, O.V. (2019). Analysis of calculation models while solving geomechanical problems in elastic approach. Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu, 1, 28-36. https://doi.org/10.29202/nvngu/2019-1/21
  38. Haupt, S., Engelbrecht, J., Sibolla, B., & Mdakane, L.W. (2023). Time series insar analysis for slope stability monitoring using sentinel-1 in open pit mining. The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, XLVIII-1/W2-2023, 945-951. https://doi.org/10.5194/isprs-archives-XLVIII-1-W2-2023-945-2023
  39. López-Vinielles, J., Fernández-Merodo, J.A., Ezquerro, P., Alvioli, M., & Herrera, G. (2021). Combining satellite insar, slope units and finite element modeling for stability analysis in mining waste disposal areas. Remote Sensing, 13(10), 2008. https://doi.org/10.3390/rs13102008
  40. Wang, S., Zhang, Z., & Wang, C. (2023). Prediction of stability coefficient of open-pit mine slope based on artificial intelligence deep learning algorithm. Scientific Reports, 13, 1201. https://doi.org/10.1038/s41598-023-38896-y
  41. Sdvyzhkova, O., Golovko, Y., & Klymenko, D. (2017). Effect of harmonic oscillations on a crack initiation in the rock mass. Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu, 4, 13-18.
  42. Sdvyzhkova, O., Golovko, Yu., Dubytska, M., & Klymenko, D. (2016). Studying a crack initiation in terms of elastic oscillations in stress strain rock mass. Mining of Mineral Deposits, 10(2), 72-77. https://doi.org/10.15407/mining10.02.072
  43. Shcherbakov, P., Tymchenko, S., Moldabayev, S., Amankulov, M., & Babets, D. (2023). Mathematical substantiation and creation of information tools for optimal control of drilling and blasting in open-pit mine. Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu, 6, 31-38. https://doi.org/10.33271/nvngu/2023-6/031
  44. Лицензия Creative Commons