Stability Analysis and Design of Support System for Adits of the Gold Deposits of Mazraeh-Shadi Using Numerical Modeling

نوع مقاله : مقاله پژوهشی

نویسندگان

1 Dept. of Mining Engineering, Sahand University of Technology, Tabriz, Iran

2 Dept. of Mining Engineering, Amirkabir University of Technology, Tehran, Iran

چکیده

The present study proposes a suitable support system for the underground tunnels of the gold deposits of Mazraeh-Shadi in the East Azerbaijan Province of Iran using numerical modeling. The stability of the tunnels was evaluated using the data obtained from the numerical modeling, the ground reaction curve (GRC), the longitudinal deformation profile (LDP), permissible displacements according to the Sakurai relationships, and the load imposed on the support system of the tunnels. Due to the very large dimensions and high computational costs, the adits were modeled at the depths of 1830 and 1870 meters. According to the results and the diagram of the proposed support system based on Q and the cross-section of the tunnel, a support system made from fiber shotcrete with a thickness of 90-120 mm, along with rock bolts regularly installed, is proposed. At the intersections and the tunnel portal, a stronger support system had to be used, and in the tunnel portal the reinforcement system, such as the implementation of shotcrete on the sloped surface, should be taken.  At the level of 1870 meters, implementing shotcrete with a thickness of 12 cm and a safety factor of 1.2 was sufficient. At the level of 1830 meters, the shotcrete required to be strengthened. For this purpose, a layer of steel mesh or a restraining lattice with a spacing of 2 meters was used. The proposed support system is sufficient and appropriate given the relatively small dimension of the tunnels and their temporary use and according to the Sakurai criterion, the experimental methods, and the engineering judgment.

کلیدواژه‌ها

موضوعات

عنوان مقاله [English]

Stability Analysis and Design of Support System for Adits of the Gold Deposits of Mazraeh-Shadi Using Numerical Modeling

نویسندگان [English]

  • Mohammad Darbor 1
  • Hamid Chakeri 1
  • Milad Manafi 2
  • Akbar Balani 1
1 Dept. of Mining Engineering, Sahand University of Technology, Tabriz, Iran
2 Dept. of Mining Engineering, Amirkabir University of Technology, Tehran, Iran
چکیده [English]

The present study proposes a suitable support system for the underground tunnels of the gold deposits of Mazraeh-Shadi in the East Azerbaijan Province of Iran using numerical modeling. The stability of the tunnels was evaluated using the data obtained from the numerical modeling, the ground reaction curve (GRC), the longitudinal deformation profile (LDP), permissible displacements according to the Sakurai relationships, and the load imposed on the support system of the tunnels. Due to the very large dimensions and high computational costs, the adits were modeled at the depths of 1830 and 1870 meters. According to the results and the diagram of the proposed support system based on Q and the cross-section of the tunnel, a support system made from fiber shotcrete with a thickness of 90-120 mm, along with rock bolts regularly installed, is proposed. At the intersections and the tunnel portal, a stronger support system had to be used, and in the tunnel portal the reinforcement system, such as the implementation of shotcrete on the sloped surface, should be taken.  At the level of 1870 meters, implementing shotcrete with a thickness of 12 cm and a safety factor of 1.2 was sufficient. At the level of 1830 meters, the shotcrete required to be strengthened. For this purpose, a layer of steel mesh or a restraining lattice with a spacing of 2 meters was used. The proposed support system is sufficient and appropriate given the relatively small dimension of the tunnels and their temporary use and according to the Sakurai criterion, the experimental methods, and the engineering judgment.

کلیدواژه‌ها [English]

  • Gold deposits
  • Tunnel
  • Support system
  • Rock bolt
  • GRC
  • Numerical modeling

مراجع

[1]       Chryssanthakis, P., Barton, N., Lorig, L. and Christianson, M. (1997). Numerical simulation of fiber reinforced shotcrete in a tunnel using the discrete element method. International Journal of Rock Mechanics and Mining Sciences, 34(3-4): 54-e1.
[2]       Bhasin, R. and Høeg, K. (1998). Parametric study for a large cavern in jointed rock using a distinct element model (UDEC-BB). International Journal of Rock Mechanics and Mining Sciences, 35(1): 17-29.
[3]       Shen, B. and Barton, N. (1997). The disturbed zone around tunnels in jointed rock masses. International Journal of Rock Mechanics and Mining Sciences, 34(1): 117-126.
[4]       Fekete, S. and Diederichs, M. (2013). Integration of three-dimensional laser scanning with discontinuum modelling for stability analysis of tunnels in blocky rockmasses. International Journal of Rock Mechanics and Mining Sciences, 57: 11-23.
[5]       Golpasand, M.B., Do, N.A., Dias, D. and Nikudel, M.R. (2018). Effect of the lateral earth pressure coefficient on settlements during mechanized tunneling. Geomechanics and Engineering, 16(6): 643-654.
[6]       Darbor, M., Chakeri, H. and Asgharzadeh Dizaj, M. (2021). Investigation of the effect of different parameters on the penetration rate of earth pressure balance boring machine using fuzzy and neuro-fuzzy methods, and metaheuristic algorithms (A case study: Tabriz metro line 2). Journal of Analytical and Numerical Methods in Mining Engineering, 10(25): 43-60.
[7]       Behzadi Nezhad, H., Faramarzi, L. and Darbor, M. (2017). Stability analysis and support system design of penstock tunnels bifurcation with headrace tunnel of Rudbare-Lorestan dam project. Journal of Analytical and Numerical Methods in Mining Engineering, 7(13): 113-123.
[8]       Palassi, M. and Qoreishi, S.M. (2006). Calculating the GRC for tunnels supported by grouted rockbolts. In Geotechnical aspects of underground construction in soft ground. Proc, 5th International Conference of TC 28 of the ISSMGE, Netherlands, 15-17 June, 645-649.
[9]       Sharifzadeh, M., Shahriar, K. and Ashrafi, E. (2008). Stability analysis and design of support system in main adit of Jajarm bauxite underground mines, Proc, 2nd Iranian Mining Engineering Conference, Tehran, 199-206.
[10]    Wang, S., Zheng, H., Li, C. and Ge, X. (2011). A finite element implementation of strain-softening rock mass. International Journal of Rock Mechanics and Mining Sciences, 48(1): 67-76.
[11]    Xing, Y., Kulatilake, P.H.S.W. and Sandbak, L.A. (2017). Rock mass stability investigation around tunnels in an underground mine in USA. Geotechnical and Geological Engineering, 35: 45-67.
[12]    Rahmannejad, R., Kargar, A.R., Maazallahi, V. and Ghotbi-Ravandi, E. (2015). Analytical analysis of ultimate ground pressure on tunnel support system. Journal of Mining and Environment, 6(2): 151-157.
[13]    Xu, C., Xia, C. and Han, C. (2021). Modified ground response curve (GRC) in strain-softening rock mass based on the generalized Zhang-Zhu strength criterion considering over-excavation. Underground Space, 6(5): 585-602.
[14]    Brown, E.T. and Hoek, E. (1980). Underground excavations in rock, CRC Press.
[15]    Brown, E.T. (1981). ISRM suggested methods. Rock characterization testing and monitoring, London: Royal School of Mines.
[16]    Hoek, E. and Brown, E.T. (1997). Practical estimates of rock mass strength. International Journal of Rock Mechanics and Mining Sciences, 34(8): 1165-1186.
[17]    Barton, N. (1988). Rock mass classification and tunnel reinforcement selection using the Q-system. In Symposium on Rock Classification Systems for Engineering Purposes, Cincinnati, Ohio, USA.
[18]    Terzaghi, K. (1946). Rock defects and loads on tunnel supports. Proc, Rock Tunneling with Steel Supports. Commercial Shearing and Stamping, Youngstown, p. 271.

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سابقه مقاله

  • تاریخ دریافت: 19 بهمن 1402
  • تاریخ بازنگری: 17 اردیبهشت 1403
  • تاریخ پذیرش: 17 اردیبهشت 1403

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