Support Design Using the Ground Reaction Curve and Support Reaction Curves at Underground Limestone Mines

Support of underground openings is typically accomplished at the intersection of the ground reaction and support reaction curves which represents an equilibrium point between the driving and resisting forces. This point can be used to select appropriate support systems during entry development. Literature suggests that the pillar structures in underground mines can also be regarded as support structures and their reaction to tributary and additional (abutment) stress can be viewed with respect to the ground reaction curve at the pillar location. This paper presents a series of 2D and 3D finite element numerical models that were used to estimate the ground reaction curve and the support reaction curve for a production pillar at an underground limestone mine. Numerical models take into account the stages of development and benching around the pillar. The equilibrium point between the ground and support reaction curve was estimated for the pillar under investigation. The numerical models show that the pillars react to the overburden load during development and production by deforming in the vertical direction in the order of 7-10 mm.