Abstract:
In this study we explore the use of a novel numerical modelling approach to study the effect of pillar
reinforcement on pillar stability. Case studies in the literature indicate that tendons, strapping of
the pillars, and shotcrete or thin spray-on liners are commonly used to reinforce pillars. No clear
methodology exists to select the type of support or to design the capacity of the support required,
however. This has led to ongoing collapses in some mines in spite of heavy support being used to
reinforce unstable pillars. A limit equilibrium model with confinement on the edge of the pillar
was used to simulate the interaction of the support with the failing pillar. The model correctly
predicts that an increase in confinement will lead to a decrease in the extent of pillar failure. As
the displacement discontinuity boundary element method allows for the efficient solution of largescale
bord-and-pillar layouts, the effect of pillar confinement can now be studied on a mine-wide
scale. Accurate calibration of the limit equilibrium model is, however, required before this method
can be used for the design of effective pillar support.
