Finite Element Study of the Stress Field Near Pressurized and Non-Pressurized Flaws in Rock Specimens Subject to Uniaxial and Biaxial Loads

摘要

The finite element code ABAQUS is used to model a typical granite specimen subjected to either uniaxial or biaxial compression, with two pre-fabricated flaws with the geometry 2a-30-30 in which only one flaw is pressurized. The maximum and minimum principal stresses as well as the maximum shear stresses are analyzed around the flaw tips and along the bridge between the inner flaw tips of the pressurized and non-pressurized flaws. When the specimen is loaded uniaxially, the maximum principal stresses in the bridge between inner flaw tips are tensile near the pressurized flaw and decrease significantly as one moves towards the non-pressurized flaw. For the biaxial loading, mainly compressive principal stresses are observed for low hydraulic pressures; tensile stresses start to develop for larger hydraulic pressures, but only near the pressurized flaw. For both uniaxial and biaxial cases, tensile and shear cracks may occur near the pressurized flaw but are not theoretically possible near the non-pressurized flaw.