Simple Determination of the Effective Young's Modulus of Rock by the Compliance Method

Abstract

Abstract A simple procedure for the determination of the effective Young's modulus of rock is presented. The method uses the elastic compliance calibration of fracture toughness test specimen geometry. Specimen compliance is measured with various sized three-point bend and compact tension specimens of granite. The experimental results show that the deformation behavior of the granite is significantly nonlinear and the specimen compliance is dependent on the loading level. A sharply notched specimen is successfully used to determine the effective Young's modulus rather than a fatigue precracked one because of the strong effect of fatigue loading on the specimen compliance. The effective Young's modulus evaluated by the compliance method coincides well with the Young's modulus determined from uniaxial tension tests and shows no specimen size or geometry effects. The effect of water environment on the effective Young's modulus is also investigated by this method.