Study on the Effect of Fine Particle Content on Static Liquefaction Instability of Saturated Silty Sands by Triaxial Tests

Abstract:

The effects of initial relative density， fine particle content and consolidation mode on static liquefaction of sand were studied by using consolidated undrained triaxial shear test. For pure Toyoura sand， the stress-strain relationship of medium dense and dense samples shows continuous strain hardening characteristic， and the pore pressure first increases and then decreases to negative values. The continuously strain softening occurs only in the very loose sample （D_r=5 %）. The results indicate that when the content of fine particles is low， the sand is more prone to strain softening. Based on the test results and the calculated second-order work， the stress ratio corresponding to the triggering point of static liquefaction instability of sand is obtained. The stress ratio increases with the increase of initial compactness and decreases with the increase of fine-grained content， indicating that loose specimen with a high fine-grain content is apt to trigger static liquefaction instability.