Effect of Stress Path on the Failure Envelope of Intact Crystalline Rock at Low Confining Stress

Abstract

Numerical modelling is playing an increasing role in the interpretation of geological observations. A similar phenomenon is occurring with respect to the interpretation of the stress–strain response of intact rock measured in laboratory tests. In this research, the three-dimensional (3D) bonded particle model (BPM) with flat-jointed (FJ) contact was used to investigate the impact of stress paths on rock failure. The modified FJ contact model used for these studies numerically captured most of the intact rock behavior of Lac du Bonnet granite observed in the laboratory. A numerical simulation was used to track the behavior of this rock for different stress paths, starting with uniaxial tension and compression loading conditions. The migration from uniaxial tension to triaxial compression is challenging to simulate in physical laboratory tests but commonly observed around underground excavations. The numerical modelling methodology developed for this research tracks this stress path and the impact of the intermediate stress on peak strength at low confinements, commonly found around underground excavations.

Use of Mohr Diagrams to Predict Fracturing in a Potential Geothermal Reservoir

“…where µ is the coefficient of (internal) friction and S 0 is the cohesion. These conditions are usually linked to produce a failure envelope (e.g., [66,67]), as in Figure 1a.…”

A New Shear Constitutive Model Characterized by the Pre-Peak Nonlinear Stage

“…Rock materials are a complex mineral aggregate formed under physical and chemical actions after a long geological process [10][11][12], which makes the link between stress and strain (or displacement) of rock materials has been one of the most pressing issues over the past decades [13]. Extensive theoretical analysis, experimental tests, and numerical simulation studies have been implemented at the laboratory scale on the shear deformation behavior of rock joints, and fruitful results have been obtained [14][15][16][17][18][19][20]. It mainly includes the research on shear strength [21,22], shear constitutive models [23,24], surface failure characteristics [25][26][27][28], as well as the influencing laws of rock type [29], boundary conditions [30] and loading mode [31], and other factors.…”