SLOPE STABILITY ANALYSIS OF BHANEGAON OPENCAST COAL MINE, NAGPUR AREA, WESTERN COALFIELDS LIMITED - USING NUMERICAL METHODS.

Abstract

Coal is a major source of raw material in power generation of the country and its contribution is about 90% for power generation. For last four decade we have been tapping easily mineable coal reserves in the country. Major part of India’s coal production comes from opencast coal mines. Though, coal deposits close to the surface are depleting fast in the country, but there is no way out other than mining coal deposits through opencast mining lying at greater depths. At greater depth problem of slope stability is prominent. Further, if, the deposit is located close to the water reservoir, then it aggravates the problem of slope stability due to ground water movement. It has been observed that irrespective of the type of slope, majority of the slope failures are due to ground water hydrostatic pressure built up. Bhanegaon opencast mine is 33 km from Nagpur which is close to the confluence of two rivers i.e. Kanhan and Pench on rise side of the deposit. In this mine, destabilization of benches on rise side of the property are being regularly experienced. Slope stability analysis shows that ground water seepage is the cause of such failures. In Bhanegaon Opencast Mine, analysis has been conducted to analyse the cause of slope destabilization. In the present scenario limit equilibrium method and two dimensional finite element and finite difference approach have been used to simulate and analyse the slopes.

In Present study rise side of the opencast have been analysed for slope stability. It has been analysed with Limit Equilibrium and Numerical Methods with overall slope angle and water saturation levels. Study shows that reduction of hydrostatic pressure by draining water improves the slope stability drastically as compared with other alternatives.