EXPERIMENTAL STUDY ON CREEP BEHAVIOR OF SATURATED SOFT CLAYS UNDER LOADING AND UNLOADING CONDITIONS

Creep test was conducted on Shanghai soft clays under both drained and undrained conditions by means of triaxial creep apparatus. The creep properties of Shanghai soft clays can be influenced by factors including confining pressures,loading and unloading stress ratios,which is analyzed accordingly. Experimental results show that the confining pressures,loading and unloading stress levels can affect the creep deformation of the soft clays. The creep behavior of the soft clays is closely related to the drainage conditions and the consolidation can help to cease the creep phenomenon. The creep and resilience deformations of the soft soils are larger under the undrained condition,compared with those under the drained condition. The history of build-up of pore water pressures is similar to the development of axial strains with time under the undrained condition. Consolidation deformation and creep deformation exist simultaneously in the drained tests,however,the volume of water discharge doesn't drop right after unloading.