Abstract
Open pit mining, is a mining operation or excavation where a naturally occurring mineral located near the surface of the earth is extracted. The size and depth of this type of operation increase year after year.
Slope stability and mine planning constitute an integral part of the open pit mining operations. They are critical aspects of geotechnical engineering. Slopes in open pit mines are safe when the pit slope angle is well designed and adhered to. In order to obtain the main goals and to mine efficiently, pit slopes must be stable. Therefore, the stability of slopes depends on a number of factors that should be considered during the slope design phase of mine planning. By considering these factors, mining companies will be able to reduce the probability of pit slope failure occurrence. Achieving the correct design balance is the optimum goal, as the over design of the pit slope will increase the stripping ratio, thus increasing operating costs, while under design could lead to potential slope failure and the negative impacts associated with the failure.
In mining operations, safety has been considered as the first priority. For this reason, the acceptable pit slope angle, and factor of safety need to be achieved to avoid accidents and incidents associated with slope failure. Slope failure can affect the safety of workers, damage equipment, and result in the loss of mineral reserves.
An empirical technique was used in conjunction with laboratory data and the rock mass rating to evaluate the deformation, failure parameters and field strength required for the stability analysis. The ROCKLAB program from Rocscience Inc. is designed to calculate failure criteria for the rock mass, based on the input of representative’s intact rock and rock mass parameters for each rock type or geotechnical domain. For this purpose, ROCKLAB based in Pretoria (South Africa) was used.
The calculation of modulus of deformation, site specific rock mass strength, friction angle, cohesion and the Hoek-Brown failure criteria parameters (mi, mb, s and a) were also took into consideration during the design process. In order to develop proper failure criteria for estimating the strength and deformation of the rock mass present in the design area, three critical properties of each distinct geotechnical...
M.Tech. (Extraction Metallurgy)