Stability of the parting between coal pillar workings in level contiguous seams

The factors affecting parting or innerburden stability in level contiguous pillar workings in coal mines have been identified as depth of cover, parting thickness, lateral eccentricity between lower and upper pillar workings, horizontal in situ stresses, Rock Mass Rating and extraction ratio. A large number of two- and three-dimensional FLAC models were run covering all these variables to arrive at a suitable predictive equation to define parting stability and support requirement in contiguous seam workings. Four unstable and four stable cases of parting from Indian coalfields were modelled using FLAC 3D and the results have been satisfactorily compared with the predictive equation. (C) 2002 Elsevier Science Ltd. All rights reserved.