Application of rock mass classification methods for slope stability design in open pit of Otso Gold Oy (Laivan Kaivos)

Abstract

Rock Mass Classification systems are used in the mining industry to classify rock types based on their physical and mechanical properties. It is one of the basic requirements on which the development of the mine will be based. Previous geotechnical studies at the Otso Gold Laivan Mine employed the Rock Mass Quality Index (Q-system), Goelogical Strength Index (GSI), Mining Rock Mass Rating (M-RMR) and later Rock Quality Designation Index (RQD) to determine the quality of rocks at the mine for mine planning, designs, and development, including slope stability analysis and design. However, these were done at a time there was less or no pit development. This study aims to classify unexposed sections of the mine Rock Mass Rating (RMR) and perform a Slope Mass Ratings for the stability of rock slopes in the south pit of the mine. RMR results will be used to compare with previously used classification systems. Three slopes are selected for stability analysis. Field measurements and observations were conducted to obtain data for rock classification and kinematic analysis. Kinematic analysis with the information on rock quality and stability of slopes from calculated RMR and SMR, will be used to perform a slope stability analysis on the present slopes and for consideration in future development of the pit. This study will also suggest slope specifications for further development based on present performances of the slopes.