DEFORMATION CHARACTERISTICS OF HIGHLY COMPRESSIBLE SAND "SHIRASU"

Abstract

In order to clarify the deformation characteristics of volcanic deposits, "Shirasu", drained triaxial compression tests were performed on compacted specimens having several densities. Isotropic compressibility and deformation behaviour in the early stage of shearing were discussed, and on the some properties compared Shirasu with Toyoura standard sand. Here, the attention up to the point of minimum volume during shear was given. It is shown in the study that Shirasu has a higher compressibility than Toyoura sand, and that the relationships among stress ratio, volumetric strain, and shear strain are formulated by exponential and logarithmic functions. Also, the influence of stress path on the deformation of Shirasu is discussed on the basis of repeated loading test results.