We had developed a super large scale direct shear test apparatus (SL-DS) with the specimen of 160cm in diameter and 80cm in height to investigate the characteristics of stress-deformation relations and strength on coarse-grained soils contained large size particles.
This paper introduces the mechanical structure of SL-DS as well as tests results on sand and mass-soil (a coarse-grained gravely soil composed of weathered granite rock). The test results show the angle of internal friction obtained from the direct shear test is approximately equal to that obtained from triaxial compression test, which may prove the usefulness of this apparatus in practice.