A continuum grain-based model for intact and granulated Wombeyan marble

Abstract

The discontinuum numerical modeling approaches widely used to simulate brittle rock failure employ the Voronoi tessellation technique to generate polygonal grain-like structures. Using this approach, called the grain-based model (GBM), the progressive micro-cracking leading to macroscopic fracturing and failure of brittle rocks can be realistically simulated. In this paper, a GBM is developed using the continuum numerical program RS2 to reproduce the laboratory behavior of intact and heat-treated (granulated) Wombeyan marble. An iterative calibration procedure is utilized to match the macro-properties of RS2-GBM to those of marble. It is found that RS2-GBM captures some of the most important characteristics of brittle rocks, including the non-linear strength envelope and the change in the failure mode and post-peak response with increasing confinement. It is demonstrated that the peak strength and failure mode of RS2-GBM are comparable to those of previously calibrated discontinuum GBMs. The advantage of the continuum over the discontinuum GBM is its shorter computation time. It is discussed that since the granulated marble serves as an analogue for a highly interlocked jointed rock mass, its calibrated continuum GBM can be used as an alternative tool for stability analyses and design of excavations and mine pillars in jointed rock masses.