Deterministic and probabilistic stability analysis of a mining rock slope in the vicinity of a major public road — case study of the LAB Chrysotile mine in Canada

Abstract

In recent years, several large open-pit mines have started operating in the province of Quebec in Canada, and some of the largest planned pits are located close to public infrastructure. Historically, large open-pit mining has seldom been done in many mining regions, such as the Abitibi region, where underground mines are the norm. As an integral part of achieving social acceptability of openpit mining, the stability of mining slopes must be carefully analyzed during the design process and the presence of public infrastructure near the slopes must be adequately considered. The province of Quebec does not have specific guidelines regarding such design considerations. This paper provides a short overview of the literature on some current practices regarding mining slope design close to public infrastructure. To demonstrate its applicability in the Quebec provincial context, the paper then investigates the stability of the west wall of the LAB Chrysotile open-pit mine in Thetford Mines (Quebec) near the new Road 112. Deterministic and probabilistic analyses were conducted using finite element shear strength reduction and limit equilibrium methods to investigate slope stability. The impact of pit infilling and rapid dewatering as well as long-term stability of the slope were investigated. The results of all analyses reveal that the current mining slopes at LAB Chrysotile are within acceptable design criteria limits. KEYWORDS open-pit mining, slope stability, public infrastructure, deterministic and probabilistic analysis, case study. CITATIONAmoushahi S, Grenon M, Locat J, & Turmel D. Deterministic and probabilistic stability analysis of a mining rock slope in the vicinity of a major public road-case study of the LAB Chrysotile mine in Canada.

Lessons from Tailings Dam Failures—Where to Go from Here?

“…In engineering risk assessment, the plot showing the frequency of occurrence versus the magnitude of consequence becomes a plot of annual probability of up to N fatalities (F) versus the number of fatalities (N). Some examples of actual F-N data for different engineering infrastructures are shown in Figure 13, after [16]. Superimposed on Figure 13 are the ALARP limits recommended by the Canadian Dam Association [17], shaded in red for additional risk, orange for tolerable risk, and green for broadly acceptable risk.…”

Prediction analysis of slope stability due to soft and weak interlayers based on partial least squares method

“…A large number of engineering examples and data show that among rocky slopes, slopes containing weak interlayer of undesirable geology are more prone to damage because the mechanical properties of weak interlayer are poor, and when encountering external factors such as water, wind and vibration, it is very easy to show the nature of unfavorable slope stability [5][6]. With the increasing frequency of human engineering activities, several landslide disasters have occurred on slopes containing weak strata worldwide, causing large losses to people's lives and property safety [7][8]. Researching slope stability analysis of slopes containing soft and weak interlayers has become a key technical problem in the geotechnical engineering community and has important theoretical and practical significance for preventing landslide disasters [9][10].…”

“…With the increasing frequency of human engineering activities, several landslide disasters have occurred on slopes containing weak strata worldwide, causing large losses to people's lives and property safety [7][8]. Researching slope stability analysis of slopes containing soft and weak interlayers has become a key technical problem in the geotechnical engineering community and has important theoretical and practical significance for preventing landslide disasters [9][10].…”