Abstract
The influence of the friction between the sample and the internal peripheral surfaces of shear box on the direct shear test keeps the normal stress on the shear plane constant was examined on high-density sands by discrete element analysis. It was revealed that the normal (vertical) components of the frictional reaction forces on the internal peripheral surfaces of shear box decrease the shear strength and facilitate the positive-dilatancy. In contrast, the shear direction components on the internal peripheral surfaces of shear box increase the shear strength and hardly affect the dilatancy. Furthermore, the distribution charts of the stress on the internal surfaces of shear box were shown in with/without the internal peripheral surface friction, and the inducement mechanism was discussed. These efforts would give useful knowledge for an interpretation on the results of the constant pressure direct shear test on sands.
