Numerical simulation of damage accumulation and seismic energy release during brittle rock failure-Part II: Rib pillar collapse

Abstract This paper presents an application of the numerical model presented in the companion paper (Part I) in which, by using a newly developed numerical code, RFPA2D (Rock Failure Process Analysis), a fundamental approach for the simulation of damage initiation and propagation causing seismic energy release during an unstable failure of brittle rock was presented. The influence of material and loading system properties including stiffness and strength on pillar failure and associated seismic patterns is studied. The results confirm that soft loading systems promote unstable failure or collapse of pillars. Weak pillar foundations and shear stresses on the pillar drastically reduce the pillar's load bearing capacity, and the related seismic activity and seismic energy release is significantly altered by these factors. As expected, for a high strength pillar, shear failure occurs in the floor and roof close to the edges of the pillar, whereas failure zones inside the pillar are found for low strength pillars. It is demonstrated that the proposed model properly simulates the pillar failure process.