A SOLUTION TO DUMP SLOPE STABILITY PROBLEMS OF TADKESHWAR LIGNITE OPENCAST MINE Prof. Indrajit Roy 1 , D. Vyas 2 , Somesh Sengupta 3 ABSTRACT Lignite mining operation at Tadkeshwar (52 km from Surat, Gujarat) was started from 2006 by Gujarat Mineral Development Corporation (GMDC). Due to presence of very soft strata like alluvium, yellow clay, variegated clay, Fossiliferous clay, grey clay and dark grey clay overlying lignite strata, the mine was experiencing frequent external and internal dump failures. For solving the above problem, Birla Institute of Technology, Mesra (BIT) was requested to conduct a detailed study on external and internal dumps of Tadkeshwar lignite mine. A detailed investigation was carried out with recommendations of dump profile along with suggestions for dump stabilization. A monitoring programme was also suggested. With the implementation of above recommendation, frequency of dump failure has been reduced drastically. In case of unavoidable slope failure, detailed monitoring suggested by BIT Mesra will ensure that there will not be any damage to men and machinery within and outside mine. This paper presents the solution to problems of slope failures in both external and internal dumps of Tadkeshwar lignite mine. Keywords: Lignite mining, Slope Stability, Opencast Mining, Dump failure. 1. Birla Institute of Technology, Mesra, indrajitroy@bitmesra.ac.in 2. General Manager, GMDC, geo@gmdcltd.com 3. Birla Institute of Technology, Mesra, someshsengupta@rediffmail.com 1.0 BACKGROUND OF INVESTIGATION The external dump failure of this lignite mine(Fig1) occurred in 2010 (Fig 2&3) due to which slided material started moving towards human settlement. Failure of internal dumps was also reported from this mine (Fig 4 & 5). Few tension cracks (Fig 6) were also observed in both the internal and external dumps. To tackle the above problem, BIT, Mesra conducted detailed slope stability study which is presented here. Fig.1: Tadkeshwar mine with exposed diverse clay strata 5th ASIAN MINING CONGRESS 13 – 15 February 2014, Kolkata, India The Mining Geological and Metallurgical Institute of India (MGMI)