Effect of confining pressure and depositional method on the undrained shearing response of medium dense sand

Abstract

This study examines the effects of the confining pressure and sample preparation method on the shearing behavior shown by sand from the Chlef River (Algeria). Undrained monotonic triaxial compression tests were performed on samples with an initial relative density of 50% at initial confining pressures of 50 to 200 kPa. Samples were prepared using two depositional methods: dry funnel pluviation and wet deposition. Our results reveal marked differences in the undrained shearing responses produced under identical conditions of density and stress and therefore determined by the soil fabric. Thus, at low confining pressures, samples prepared by the wet deposition method showed complete static liquefaction (zero effective confining pressure and zero stress difference). For both sample types, as confining pressures increased, effective stress paths exhibited increasing resistance to liquefaction indicated by increasing dilatant tendencies.