In this paper a Lignite opencast mine working in a very adverse geo-mining conditions and its solution architecture is discussed. This mine is advancing towards dip directionby dumping the overburden material in de-coaled area. During rainy season, internal dump fails, active slope washed away and water mixed with dump material flows towards the pit bottom lies in the dipper side of the seam. Mixing of water and loose dump material creates silt formation at working face. These problems compelled to stop the mining operations for about 3 to 4 months in a year. For this reason re-design of mining operation is envisaged by creating a water barrier between the working face and internal dump. Apart from the design of water barrier, slope profile of working faces, internal dump is established by Bishop's limit equilibrium method.
Extensive laboratory test has been carried out to establish the in-situ material properties. The devised scheme is now very successful in actual mining practices.
slope stability, internal dump, water barrier
