Stability of Slopes in Iron Ore Mines

Abstract

Slope stability analysis is important in any opencast iron ore mine. A failure of slope in a working area of mine can give rise a significant economic losses and safety impact. The fundamental failure modes are varied and complex. Such mechanisms are governed by engineering geology condition of rock mass which are almost always unique to a particular site.
Using the FLAC/Slope software stability of slope is analysis. The work was aimed at study of stability of slopes using numerical modelling, at the same time study the different failure mechanism. The purpose of this project is to learn and assess this FLAC/Slope software. As the study of the software is easy, it can be concluded that it is user-friendly. Based on parametric studies it can be concluded that slope angle plays a major role on slope stability.
Safety factor varied from 0.63 to 1.37 for the depth of 10 m to 250 m for the slope angle of 45 degrees. It showed that with the increase in height of the bench or depth of the mine safety factor of the bench decreases indicating less stability of the concerned slope. At the depth of 100 m, the safety factor was found to be exceeding 1.2 for slope angle less than 35 degrees. Therefore, it is recommended to maintain the overall slope angle not steeper than 35 degrees, in the hypothetical mine conditions assumed in the project.
At the depth of 150m, factor of safety is 1.02, and 1.01 for the slope angles of 35 degree and 40 degrees, respectively. This indicated that the slope may be maintained with more than 1.0 safety factor at flatter than 40 degree, ensuring continuous monitoring of the stability of slope through observational approaches. It is recommended that for improving the reliability of model results, calibrations of models with actual field conditions may be taken of through piezometric monitoring and measurement of slope moments in varying geomining condition at different mine sites