Numerical analysis of Westwood Mine tailings embankment stability during the restoration phase
Résumé
Stability analysis of Westwood Mine tailings embankment performed using SLOPE/W and SIGMA/W codes showed that the minimum factor of safety obtained is higher than the recommended value of 1.5 set by some authors and the Quebec Ministry of Natural Resources and Wildlife for static loading and steady flow conditions. Pore pressures that must be controlled are higher in bottom layers of the embankment and these pressures move toward the downstream side. In addition, low electrical resistivity values (by geophysical method) associated to the high water content tailings layer, suggest its susceptibility to internal erosion.
Références
Barbour, S. L., and Krahn, J. (2004). Numerical modelling – prediction or process? Geotechnical news, December 2004.
Denahan B. J., Smith D. L., (1984). Electrical resistivity investigation of potential cavities underlying a proposed ash disposal area. Environmental geology and water sciences. Volume 6, Issue 1, pp 45-49.
Eberhardt, E. (2003). Rock slope stability analysis - Utilization of advanced numerical techniques.
Ernstson, K., Kirsch, R., (2006). Geoelectrical methods. In: Kirsch, Reinhard (Ed.), groundwater geophysics. Springer. ISBN: 3-540-29383-3, pp. 85–117.
GEO-SLOPE International Ltd. (2007). Geo-Slope Office (Slope/W, Seep/W, Sigma/W, CTran/W, Temp/W, Quake/W, Air/W). Geo-Slope International Ltd., Calgary, Canada.
Mériaux P., Royet P., Folton C. (2001). Surveillance, entretien et diagnostic des digues de protection contre les inondations. Cemagref Editions, 191 p.
Ormann, L., Zardari, M.A., Mattsson, H., Bjelkevik, A., and Knutsson, S., (2010). Numerical analysis of strengthening by rockfill embankments on an upstream tailings dam.
