To confirm applicability of a method of determining anisotropy of transversely isotropic elasticity via a single triaxial test for a sedimentary soft rock specimen in which bedding plane were not clearly observed, anisotropic deformation behavior of soft sedimentary mudstones, which were sampled in Sagamihara and were not sufficiently studied yet, was experimentally investigated by proposed triaxial test in this study. Non-coaxial anisotropic relationships of stresses and strains were evaluated by full three dimensional strain tensor of mudstone measured by nine strain gauges set on the lateral plane of cylindrical specimen. Orientations of principal strains during isotropic consolidation were agreed with that of bedding orientations observed in the outcrop. Anisotropic stiffness of the mudstone was finally determined by a method of determining anisotropy of transversely isotropic elasticity via a single triaxial test.
