Abstract：Time-dependence is one of the most important deformation behaviors of soft soil. It brings on post-construction settlement of soft soil engineering. For the need of practical engineering，a series of laboratory tests were done with undisturbed samples and disturbed samples respectively. And the deformation mechanism of soft soil was investigated，including stress-strain behavior，consolidation effect，secondary consolidation characteristics，creep effect，and so on. Based on the results，some special properties are systematically analyzed： (1) the influence of initial consolidation on stress-strain curve；(2) the relationship between secondary consolidation coefficient and consolidation pressure，as well as the influence of stress history on secondary consolidation coefficient；(3) the relationship between secondary consolidation coefficient and compression index；(4) the deformation characteristics of drained shear creep and undrained shear creep；(5) influencing factors on creep and technology of decreasing creep deformation. The study results show that time-dependent deformation of soft soil issues from the coupling effect of consolidation characteristics and creep characteristics. The deformation course of soft soil is actually the process of consolidation and creep concurrently. The ratios of two deformations to total deformation depend on many factors，among which stress level and drainage condition are the most important.
