Characterizing damage mechanisms in rock using an integrated remote sensing-numerical modelling approach

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Damage is a fundamental component of rock failure from the micro-to the macro-scale. The proposed research seeks to develop new methods of characterizing rock damage applicable to laboratory samples, high rock slopes and underground excavations. A major focus of the research will be the extension of discrete fracture network engineering, DFNE concepts of crack intensity, crack connectivity, focused and distributed damage and critical connectivity relationships to practical rock engineering solutions. Laboratory compression and indirect tensile testing will be undertaken on a wide variety of rock types illustrating varying mineralogy and microstructure with monitoring using conventional methods and a wide range of NDT techniques including acoustic emission, acoustic velocity, high speed thermal imaging and photographic methods. The change in rock damage characteristics will be assessed in detail over the full stress-strain range. Combined brittle fracture numerical-modelling-experimental programs will be used to further our understanding of rock damage processes. Remote sensing methods combined with modified engineering geological/geomorphological mapping will be used at the full scale to characterise damage in major rock slides, large open pits, high quarry slopes and underground excavations. Research will attempt to develop face connectivity mapping methodologies suitable for damage change detection studies. DFNE methods will be applied to pre-processing of input data for brittle fracture models (FDEM, Lattice Spring) and subsequent post-processing of brittle fracture models in order to show changes in damage with stress during simulations. Case studies will be selected to allow optimal development of new methods of mapping stress-induced and blast damage including non - explosive use environments such as high natural slopes and wire saw cut high rock slopes in marble/slate quarries. Research will aim to characterize blast damage to allow improved input into geomechanical models. External and internal damage in rock slopes and landslides will be characterized where possible into damage domains and the factors influencing damage evaluated using a damage interaction matrix approach. Damage encountered due to geologic processes in highly altered natural and open pit rock slopes will be investigated using a combined remote sensing-modelling-experimental methodology. All components of the proposed research will use multi-dataset visualization platforms to allow optimal interpretation of remote sensing and modelling results. The importance of improved methods of measuring, characterizing and modelling damage in rock at varied scales has major potential impacts in improving our fundamental understanding of rock mass strength, its progressive degradation and the implications for ensuring safe and economic natural and engineered rock structures. **