ON THE PARTICLE CRUSHING FEATURES OF SANDY SOILS

Abstract

Previous studies have investigated particle crushing of sandy soils in high-pressure conditions. In practice, the volume shrinkage and decreasing shear strength due to particle crushing around the pile-foundation tip in crushable sandy soils may be more important. Therefore, this study aims to confirm the volume shrinkage of sandy soils, e.g., silica sand, weathered granite, and volcanic sand, under various stress paths with a combination of high principal stresses. High-pressure crushing tests were carried out using a true tri-axial compression apparatus under the planned stress paths. Isotropic compression tests and combined stress tests (mean stress p and deviatoric stress q) were employed for three types of sandy soil. The particle-crushing progress became active in combination with mean stress p and deviatoric stress q. In addition, the relationships between the plastic volumetric strain and relative breakage were found to be approximately linear. As expected, the silica sand was less crushable than the weathered granite sand and volcanic sand under the same stress conditions.