-

Problems associated with conventional pillar design methods has led to the extensive use of numerical methods in pillar design. In this research work, the FLAC-2D code was employed to evaluate the rock pillar strength as a function of applied loads. The commonly used elasto-plastic Mohr-Coloumb model is not suitable for expressing pillar behaviour, and thus, more advanced material models such as various strain-softening models should be used.
In this study, in order to assess the pillar strength the modified Hoek-Brown parameters were used to determine the softening parameters of pillars of varying geometries. Comparing the obtained results with published field data, the analysis results show that the use of modified Hoek-Brown parameters enables a realistic evaluation of pillar strength