Slopes stability analysis from Rosia Poieni open pit mine, Romania

¹ University of Petrosani, Department of Mining Engineering, Surveying and Underground Constructions, 20, University Street, Petrosani, Romania
² Volodymyr Dahl East Ukrainian National University, Research Department, 919 Avenue de Bretagne, Severodonetsk, Ukraine

^* Corresponding author: toderasmihaela@yahoo.com

Abstract

In the case of Roşia Poieni open pit mine the level of +805 m was established as a daily operating limit; the division into benches was based on this level by dividing into horizontal slices with a thickness of 15 m, equal to the height of the bench. Thus, there were 27 benches in the Curmătura area and 23 benches in the Ruginiş area. The general slope angle was set at 35°, the angle for which the tailings volumes and implicitly the opening-up coefficient were calculated. The stability analysis was performed for individual bench, 2 benches system and the general slope of the quarry (consisting of 24 benches), using two methods (Fellenius and Janbu). A polygonal slip surface was also modelled; such potential landslide surfaces can appear in the slopes of the Roşia Poieni quarry due to the natural cracking systems of the massif but also due to the secondary cracking generated by the used drilling-blasting works (exploitation technology). The stability check was done by applying Hoek’s graphical-analytical method; the determined values for the safety factor satisfy the condition of being greater than 1.3. In these circumstances, no further measures are required to increase the stability reserve.