NUMERICAL-SIMULATION OF DAMAGE ACCUMULATION AND SEISMIC ENERGY-RELEASE DURING BRITTLE ROCK FAILURE - PART II - RIB PILLAR COLLAPSE

This paper presents an application of the numerical model presented in the companion paper (Part I) in which, by using a newly developed num erical code, RFPA(2D) (Rock Failure Process Analysis), a fundamental a pproach for the simulation of damage initiation and propagation causin g seismic energy release during an unstable failure of brittle rock wa s presented. The influence of material and loading system properties i ncluding stiffness and strength on pillar failure and associated seism ic patterns is studied. The results confirm that soft loading systems promote unstable failure or collapse of pillars. Weak pillar foundatio ns and shear stresses on the pillar drastically reduce the pillar's lo ad bearing capacity, and the related seismic activity and seismic ener gy release is significantly altered by these factors. As expected, for a high strength pillar, shear failure occurs in the floor and roof cl ose to the edges of the pillar, whereas failure zones inside the pilla r are found for low strength pillars. It is demonstrated that the prop osed model properly simulates the pillar failure process. (C) 1998. Pu blished by Elsevier Science Ltd.