Slpoe monitoring of an open pit mine and dump for prediction of instability

Abstract

The technical paper present a case study related to slope monitoring of a 110 m deep chromite mine and its 90m high dump of Odisha Mining Corporation. The long term slope monitoring study was conducted by Trimble Total Station on quarterly basis to detect any movement in and around the mine and dump. The monitoring stations were located on different benches of the pit and dump. Based on the slope monitoring data of four years presented in this paper, it can be said that the maximum change in positions of different monitoring stations installed in pit was 3.2 cm. Its cumulative change does not show any increasing trend (acceleration in movement). So, it is not of great concern from pit instability point of view. If the change of the movement monitoring data is regularly showing increasing trend then only it is of great concern. Otherwise the change is most likely due to external factor and not due to actual movement in the slope. But, the maximum cumulative change in the dump has been observed as 43 cm in four years period which helped in identification of unstable zone. The mine management was asked to be careful in this zone and should install monitoring stations at closer intervals. If the monitoring shows regularly increasing trend then it may fail in due course of time. So, this study was useful to detect movement in advance for the safety of men and material of the mine.