SOILS AND FOUNDATIONS, vol.53, no.5, pp.628-638, 2013 (SCI-Expanded)
Orientations during drained and undrained triaxial shear tests on an artilicially made clayey soil were studied. The results show that the orientation pattern before shearing is nearly random, although there may be some degree of preferred orientation caused by the overburden pressure. Becoming higher towards the failure plane, the degree of preferred orientation sharply increases in both tests as the compression increases until failure. It was discovered that in the consolidated undrained tests, failure occurs at higher levels of strain than previously believed, while in the consolidated drained tests, failure occurs at much lower levels of strain than previously believed.