ABSTRACT
A ring shear apparatus was used to evaluate the interface behaviour between sand and steel up to an interfacial critical state. Glass beads and sands having a different mean particle size and crushability were sheared along the steels with various surface roughness at a given normal stress level. Further, the individual particle strength tests are also conducted to clarify the degree of soil crushability. Based on the test results obtained, the characteristics of sand-steel interface friction are discussed paying attention to the normalized surface roughness and soil crushability index. In addition, it is indicated that the friction angle between sand and steel with rough surface can be evaluated from the internal friction angle at critical state by considering the direct shear mode as a failure mechanism.
