Effect of structural anisotropy on deformation properties of granite under cyclic loading
Kusumi Harushige; Mine Yukihisa; Nishida Kazuhiko
Abstract:The effects of structural anisotropy on the deformation properties of granite under cyclic loading have not been clarified. In this paper, four types of granite specimens are prepared with an angle q of the structural anisotropic plane to the loading axis of 0 degree , 30 degree , 60 degree and 90 degree respectively; and cyclic loading tests are performed under uniaxial compression. The stress amplitude levels used in this experiment are 0-30%, 20-50% and 40-70% of the uniaxial compressive strength of this granite. As the results, for the stress amplitude level of 0-30%, the elastic modulus under the cyclic loading is approximately constant. However, it is recognized that the increase of axial strain during the cyclic loading is largest for the specimen with q of 30 degree , and its value under ten thousands cyclic numbers corresponds to 1.27 times as much as the axial strain given by 20% stress for the uniaxial compressive strength, and that its uniaxial compressive strength after cyclic loading is lowest for the all stress amplitude conditions. Further more, it is clarified that its volumetric strain indicates only a negative value under 50% and 70% stress levels under cyclic loading. Key Words:grain, structural anisotropy, cyclic loading, stress amplitude level, Axial strain