An approach to tackle the problems of floor heaving near toe of external dump in an opencast coal mine of India

摘要

India with a very high density of population is in a very disadvantageous position in acquiring large tracts of land for opencast coal mining with the concurrent problems of depletion of forest area, resettlement and rehabilitation of people affected by projects. Opencast coal mining involves handling of large volume of waste rock overburden (O.B), a portion of which is back-filled in the de-coaled area of the quarry. The balance O.B. has to be dumped outside the quarry in a convenient place considering the safety, environment and economical aspects. This waste material dumped outside the quarry is termed as external dump. This paper deals with a specific case study of a mine, (located in eastern part of India) which has experienced floor heaving near toe of 75metre high external dump standing above 20m soft soil strata fully saturated with water (Fig 1). The methodology to tackle the problem of floor heaving by undertaking detailed slope stability study and its recommendation is discussed in this paper.