Efficient and numerically stable anisotropic failure criterion for micro layered rock

The paper deals with formulation and numerical implementation of anisotropic strength condition for micro layered rock. Periodically layered two-constituent microstructure is considered. The failure criterion of the constituents is assumed to be governed by Drucker-Prager strength condition. The macroscopic criterion is derived based on the micro-mechanics approach. It appears that a microstructure failure function can be satisfactory described by the conjunction of Jaeger critical plane condition and Pariseau anisotropic criterion. The formulation derived is then implemented into the commercial codes FLAC and FLAC3D. Numerical integration scheme, i.e. an elastic predictor and a plastic corrector of the failure function proposed are discussed in details, in the paper. Efficiency and numerical stability of the model proposed are verified against a series of numerical examples. The proposed model is also compared with "Ubiquitous Joints": a classical Jaeger critical plane approach available in FLAC environment. The presented results show that the model in some cases provides more precise description of micro-layered rock then Jaeger criterion.