... ABSTRACT: To investigate deformation characteristics under different stress states and loading paths, we conducted a true triaxial compression test using a rectangular specimen of 35×35×70 mm, a confined triaxial extension test and a confined triaxial compression test using a cylindrical...

..., and the relationship between the stress and the strain in tension is then no longer one by one. So the state of stress and strain of the rocks depends not only on the loading magnitude but also on the loading paths. So, / Figure 2. Plastic bimodular model. although the deformation of these rocks in pre-failure stage...

.... . p 2e -3 L L- ,~ u1 Figure 3 : Two different shear loading paths (mm) of a 3D joint The results obtained for the two shear stresses, in both cases, are presented on figure 4. In the first part of the response, the behaviour is purely bidimensional, but when the loading direction changes (points...