Drained and Undrained Creep Characteristics of Loose Saturated Sand

Drained and undrained creep characteristics of saturated loose fine sand were compared and interpreted based on the yielding and viscous properties under general stress conditions. The viscous properties were evaluated by performing specially designed triaxial compression (TC) and extension (TE) tests. To quantify the yield loci for shear and compression yielding mechanisms on the p'-q plane, various loading histories consisting of pre-shearing and pre-isotropic compression were applied. Different developing rates of creep strain during drained and undrained sustained loading were interpreted based on the double yielding concept, by which the yielding soil is explained by two types of yielding (shear and compression), while referring to the viscous properties formulated in a non-linear three-component rheology model.