ABSTRACT
Numerical modeling has evolved as a popular tool for the design of underground structures over the years. This paper presents design of horizontal crown pillar in a hard rock mine where a steeply dipping orebody is being mined. Three-dimensional continuum elastic model was developed to compute the stresses around the underground openings using 3DEC. Deatiled geological mapping was done to estimate the rock mass quality. Intact rock strength parameters were scaled to get rock mass strength parameters. Empirical rock failure criterion was used for analyzing the stability of the pillars in the central galaxy area of Khetri mine. The planned extraction of all stopes below the crown pillar would result in huge excavation of 200m × 110m × 30m. One stope of 30m-strike length is left to be extracted and no instability is reported to date.
