SLOPE STABILITY ASSESSMENT OF THE SOUTHWEST OVERALL SLOPE OF THE QAJARAN OPEN-PIT MINE BASED ON THE GSI ROCK MASS CLASSIFICATION SYSTEM

Abstract

The application of assessing the fracturing quality of rock masses based on the classification system for determining the boundary parameters of the Qajaran open-cast mine slope is substantiated. In the certain geomechanical environment, the long-term slope stability of the south-west wall of Qajaran open-pit mine based on the Geological Strength Index (GSI) classification system is estimated. A comparative analysis between the results with other well-known classification systems, such as MRMR, Q-system and RQD, and the outputs of the proposed GSI system is made. A good agreement between the results obtained from Barton’s Q-system and Hoek’s GSI classification systems is found. It is highly desirable to quantify the rock mass based on 2 and/or more classification systems (e.g. Hoek’s GSI and Barton’s Q-system) to provide much more reliable and reasonable estimates. The stability analysis of Qajaran open-pit overall slope at different scales based on the confirmed lower and upper bounds of the GSI classification system and compared with the results of the accepted stability criteria is performed. It has been shown that when there are limited input data of the jointed rock mass in the current geomechanical environment, it is expedient to use Hoek’s GSI classification system to determine the geometric parameters at different scales at the first development stage of the rock slope designs and estimate the stability of the overall slopes of deep open-pit mines based on Hoek-Brown failure criterion.