Investigating the effect of material stiffness contrast on the dynamic stability of upstream tailings dams (Case study: Esfordi tailings dam)

Document Type : Research Article

Authors

1 Dept. of Mining Engineering, Isfahan University of Technology, Isfahan, Iran

2 Dept. of Civil Engineering, Isfahan University of Technology, Isfahan, Iran

Abstract

The effect of mechanical properties of upstream tailings dams is investigated under seismic loads. For this, the finite-difference numerical method under the Finn-Byrne nonlinear elastoplastic constitutive model was implemented. Variations of elastic modulus and Poisson’s ratio in the typical range of tailings dam material were investigated in the phenomenon of liquefaction, horizontal displacement, and subsidence. The results showed that with increasing the elastic modulus of the dam body from 10 to 50 MPa, the maximum horizontal displacement, subsidence, and liquefaction coefficient in the dam body have increased 2.3, 3.5, and 2 times, respectively. Moreover, by increasing the Poisson’s ratio from 0.25 to 0.4, the maximum horizontal displacement, subsidence, and liquefaction coefficient in the dam body have raised 2.4, 2.3, and 1.75, respectively. The Poisson’s ratio of tailings had a significant effect on the liquefaction of the dam body. In which, increasing the Poisson’s ratio from 0.25 to 0.4, the maximum liquefaction coefficients were increased 1.75 times. Ultimately, it is concluded that despite the displacement which is not affected by the variation of tailings dam elastic modulus, the liquefaction coefficient is doubled by its variation, which may cause a serious threat to the stability of the dam.

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[1]                 K.Pitilakis, “Site effects,” In Recent advances in earthquake geotechnical engineering and microzonation, Springer, Dordrecht,( 2004) pp. 139-197.
[2]                 Pitilakis, K., O. J. Ktenidou, P. Apostolidis, D. Raptakis, M. Manakou, K. Makropoulos, and D. Diagourtas. “Experimental and theoretical studies of topographic effects,” Proc. 16th ICSMGE (2005), pp. 175-182.
[3]                 D. Assimaki, E. Kausel, and G. Gazetas, “Soil-dependent topographic effects: a case study from the 1999 Athens earthquake,” Earthquake Spectra 21, no. 4 (2005), pp. 929-966.
[4]                 G. D. Bouckovalas and A. G. Papadimitriou, “Numerical evaluation of slope topography effects on seismic ground motion,” Soil Dynamics and Earthquake Engineering 25, no. 7-10 (2005), pp. 547-558.
[5]                 H. Havenith, D. Jongmans, E. Faccioli, K. Abdrakhmatov, and P. Bard, “Site effect analysis around the seismically induced Ananevo rockslide, Kyrgyzstan,” Bulletin of the Seismological Society of America 92, no. 8 (2002), pp. 3190-3209.
[6]                 S. Wang and H. Hao, “Effects of random variations of soil properties on site amplification of seismic ground motions,” Soil Dynamics and Earthquake Engineering 22, no. 7 (2002), pp. 551-564.
[7]                 H. B Havenith, M.Vanini, D.Jongmans, & E. Faccioli, “Initiation of earthquake-induced slope failure: influence of topographical and other site specific amplification effects,” Journal of seismology 7, no. 3 (2003), pp. 397-412.
[8]                 P. N. Ã. Psarropoulos, Y. Tsompanakis, and Y. Karabatsos, “Effects of local site conditions on the seismic response of municipal solid waste landfills,” Soil Dynamics and Earthquake Engineering 27, no. 6 (2007), pp. 553-563.
[9]                 C. Bourdeau and H. B. Havenith, “Site effects modelling applied to the slope affected by the Suusamyr earthquake (Kyrgyzstan, 1992),” Engineering Geology 97, no. 3-4 (2008), pp. 126-145.
[10]             Y. Mitani, F. Wang, A.C. Okeke and W. Qi, “Dynamic analysis of earthquake amplification effect of slopes in different topographic and geological conditions by using ABAQUS,” In Progress of Geo-Disaster Mitigation Technology in Asia, Springer, Berlin, Heidelberg, (2013), pp. 469-490.
[11]             J. R. Moore, V. Gischig, F. Amann, M. Hunziker, and J. Burjanek, “Earthquake-triggered rock slope failures: Damage and site effects,” In Proceedings 11th International & 2nd North American Symposium on Landslides, vol. 1, Banff, Canada: CRC Press, (2012), pp. 869-875.
[12]             F. Gouveia, R. C. Gomes, I. F. Lopes, and A. B. Author, “Influence of stiffness contrast in non-horizontally layered ground on site effects,” In Proc. of the 15th world conference on earthquake engineering. 2012.
[13]             A. Azhari and U. Ozbay, “Role of geometry and stiffness contrast on stability of open pit mines struck by earthquakes,” Geotechnical and Geological Engineering 36, no. 2 (2018), pp. 1249-1266.
[14]             D. Solans, E. Skiada, S. Kontoe, and D. M. Potts, “Canyon topography effects on ground motion: Assessment of different soil stiffness profiles,” Obras y Proyectos, no. 25 (2019), pp. 51-58
[15]             A. Azhari, H. S. Isfahani, and K. E. Heydari, “Effect of geometry and material of municipal solid waste landfills on seismic response,” In Proceedings of the Institution of Civil Engineers-Waste and Resource Management, Thomas Telford Ltd, (2021), pp. 1-16.
[16]             M. Najafi and A. Yarahmadi Bafghi, “Analysis of sustainability and environmental management of tailings dam (Case study: tailings dam Esfordi Phosphate Mine Processing Factory),” 5th Iranian Conference on Engineering Geology and Environment, Tehran, 2007 (In Persian).
[17]             J. Luis, G. Diez, J. G. Galindo, and A. Soriano, “Adjustment of a numerical model for pore pressure generation during an earthquake,” Plos one 14, no. 9 (2019), e0222834.
[18]             M. P. Byrne, “A cyclic shear-volume coupling and pore pressure model for sand,” Second Int. Conf. Recent Adv. Geotech. Eng. soil Dynamic, (1991), pp. 47–55.
[19]             Itasca Consulting Group, Inc, FLAC version 7.0: Fast Lagrangian analysis of continua. User’s guide. ICG, Minneapolis, 2011.
[20]             O.Vargas, R.Ortiz, and F. Flores, “Liquefaction Analysis Using Pore Pressure Generation Models During Earthquakes,” In From Fundamentals to Applications in Geotechnics, IOS Press, (2015), pp. 1057-1064.
[21]             A.Asaadi, M. Sharifipour,  & K. Ghorbani, “Numerical simulation of piles subjected to lateral spreading and comparison with shaking table results,” Civil engineering infrastructures journal 50, no. 2 (2017), pp. 277-292.
[22]             “Earthquake Design Regulations (Standard 2800),” Fourth Edition, Building and Housing Research Center, Ministry of Housing and Urban Development of Iran, no. Standard 2800, 2014.