Stress-dependent instantaneous cohesion and friction angle for the Mohr–Coulomb criterion

• DOI: 10.1016/j.ijmecsci.2024.109652
• Publication Date: 2024-08-18T22:08:29Z
• Authors: Hao Li; Leo Pel; Zhenjiang You; David Smeulders
• Keywords: Mohr–Coulomb theory; Cohesion (chemistry); Friction angle; Coulomb friction

The strength criterion of rock is essential for stability control and safety design geotechnical engineering constructions. Due to its widespread adoption, the Mohr–Coulomb (M-C) prominent among criteria. However, M-C constrained by three significant limitations: it fails capture nonlinear response, overlooks critical state, disregards σ2. This study introduces a novel Stress-dependent Instantaneous Friction angle Cohesion (SIFC) model represent convex envelope intact rock, covering spectrum from non-critical states. In pursuit this objective, an innovative approach calculating these instantaneous shear parameters at each corresponding σ3 initially introduced. By examining confining pressure dependency friction cohesion, SIFC derived introduced criterion. SIFC-enhanced criterion, utilizing obtained triaxial tests under lower σ3, delineates complete non-linear in (σ1, σ3) space, brittle ductile behavior. then extended polyaxial stress conditions. Validation through test data confirms that accurately reflects characteristics tested rocks.