Cyclic creep behavior of saturated soft clay

A study on the deformation behavior of a saturated soft clay under cyclic loading was presented.Considering the intrinsic anisotropy of the soil,a soil specimen was initially restored to the in-situ stress state under K0 consolidation in a triaxial cell,and then the specimen was sheared in the same triaxial cell under axial cyclic loading and tested in a drained or undrained creep condition.The test results showed that:(a) The cyclic creep process of the saturated clays could be divided into three stages if the cyclic axial stress was less than 50% of the initial confining pressure.(b) The cyclic strain could be divided into two parts,that is,a irreversible accumulated strain and a reversible strain.The magnitude of the there was approximately a linear relation between the reversible strain and the amplitude of the cyclic stress.(c) The increase of excess pore water pressure initially lagged behind that of stress.The stable excess pore pressure was about 50% of the stress amplitude for a undrained specimen,however the residual excess pore water pressure was approximately 20% of stress amplitude for a drained specimen.