Analysis of a complex slope failure in a quartzite slope

In this paper the authors analyse a slope failure occurred during the construction of a road cut in a fissured quartzite rock mass in 2009. Although the mechanism has been described in the technical literature (Stead & Eberhardt, 1997), a particular approach by the limit equilibrium method was carried out during the construction development, in order to solve the instability occurred. Furthermore, this approach is coherent with the physical models described two years after this first study by Alejano et al. (2011). Additionally, a numerical model by means of the DEM-based code UDEC (Itasca, 2008) is carried out to simulate the observed phenomena. This model is able to better explain the features of the failure mechanism observed in place which encompasses sliding in the upper part of the slope, and induces a toppling mechanism in the middle and lower part of the slope and block extrusion in the toe.