NUMERICAL-SIMULATION OF CAVED GOAF BEHAVIOR IN LONGWALL WORKINGS

Modifications of the Chamber of Mines formula, which defines stress-st rain behaviour of fills, were attempted to suit caved goaf material be haviour. The constants of this formula were varied to run 2-D displace ment discontinuity type boundary element models. This variation was ca rried out by trial and error to improve the stress distribution over t he goaf as per available field experience. It was seen that the consta nts in the formula must be varied across the goaf in order to obtain r ealistic normal stress distributions. Final values of these constants are recommended for different cover depths and seam thicknesses.