State-Dependent Behavior of a Crushable Sand in Drained Triaxial Tests

Abstract

Abstract This article presents a laboratory experimental study on the state-dependent behavior of a crushable sand that was crushed progressively in a number of the drained triaxial tests. The critical state line of sand showed a straight line in the e-logp′ plane, in the e-p′α=0.7 plane and in the q-p′ plane despite of involving the progressive particle breakage. It showed a family of the relations between stress ratio and dilatancy factor rather than a unique stress-dilatancy relation. While increasing the initial void ratio or the initial confining pressure, the peak-state friction and maximum dilatancy angles of sand showed a decrease, but the peak-state basic friction angle of sand increased. Linear representation was revealed for the relations of the maximum dilatancy angle - the peak-state stress ratio and the peak-state basic friction angle - the peak-state stress ratio. An increase in the peak-state state parameter resulted in a linear decrease of the peak-state friction and dilatancy angles of sand, but a linear increase of the peak-state basic friction angle of sand. It revealed a unique linear friction-dilatancy relation of sand incorporating the progressive particle breakage. The peak-state volumetric strain and deviator strain of sand increased while increasing the initial void ratio or the initial confining pressure or the peak-state state parameter, but decreased with increasing the peak-state stress ratio. The peak-state dilatancy factor d incorporating the progressive particle breakage decreased linearly with increasing the peak-state stress ratio, but linearly increased along the increase of the peak-state state parameter. Dilatancy of sand should be dependence of the pressure and density of sand as well as the progressive particle breakage.