Stability analysis of rock slopes in the Taşönü (Trabzon-Arakli) limestone quarry

The Taşönü limestone quarry (Araklı-Trabzon) was mined in Late Campanien-Paleocene aged limestone of Kireçhane Formation in various facies. In this study, stability of the rock slopes which have been excavated in the south of landslide area, were examined in terms of the slope stability probability classification system (SSPC). Additionally the slopes were evaluated based on kinematic analysis and limit equilubrium analysis, and optimum bench was designed. For these studies two slopes were choosen to evaluate in the landslide area.The slopes excavated are not at risk along discontinuities with respect to SSPC in terms of sliding or toppling in the open pit area but there may be small failure with increasing slope angle and height for the orientation-independent stability analysis.Kinematical and limit equilibrium slope stability analysis were performed for both excavation of benches and landslide area. According to the kinematical and limit equilibrium analysis, the slopes are stable in the excavated area and unstable in the landslide area.From the limit equilibrium analysis, for a safe slope design, the magnitude of acceleration induced by blasting should be 0.1g, and lower. Finally, the safe bench slope angle was calculated as 75o and bench width and bench height was 8 meters whereas the safe overall slope angle was 40o during the excavation of newly opened pit area.