Dump design and remedial measure for stabilisation

Abstract

The paper deals with the geotechnical studies carried out for slope design of the dump slopes at chromite ore open cast mine, Orissa, M/s IMFA. The geotechnical properties of the dump materials were tested at the Rock & Soil Mechanics Laboratory of CSIR - CIMFR. The ground water condition was estimated. The slope stability analysis was done for optimum dump design. It was also aimed to know the influence of slope design parameters on the safety factor by sensitivity analysis, which tells the importance of the parameter for stability of the slope. A more justified and suitable remedial measure can be planned for any critical slope after sensitivity analysis. The most likely geomining condition of the dump was adjudged to be in drained condition because proper drainage has been provided at top and toe of the dump. The 75m high dump of limonite should be developed in four stages/ lifts. The height of lower three lifts should be 20m each and the top lift should be 15m high. The exposed width of berm should be equal to vertical height of lift. The sensitivity analysis shows that the influence of water is alarming, hence every attempt is being taken to keep the rain water away from the slope and proper drainage pattern is effectively maintained.