Creep behavior of soft clayey soils under consolidation by vacuum

surcharge

combined vacuum-surcharge preloading is investigated by using a new improved triaxial apparatus. Influence of the duration of loading and the rate of loading

as well as loading magnitude etc on compressibility of soft clay are demonstrated; meanwhile

relationship between axial strain (rate)

volumetric strain (rate)

deviatoric strain (rate)

stress ratio amd time are analyzed; Results show: The relationships of lg and lg versus lgt are nonlinear

but part of the relationships may be approximately considered linear; A hyperbolic equation can be used to express the changes of the deviatoric strain with time for different stress ratios; The two hyperbolic equations for deviatoric strain and deviatoric strain rate with time have interesting features. The validation of it has been examined using results of creep tests of soft clayey soil samples of Wenzhou.