Research on creep and consolidation characteristics of soft soil

Based on the mass of contrast tests, creep consolidation characteristics and calculating models of typical soft soil from Guangdong are systematically studied. The test results show that the deformation proportion of consolidation and secondary consolidation is related to the factors including initial load and loading ration in test, consolidation degree, water content and void ratio of soil samples. The complications of affecting secondary consolidation coefficient are loading history, loading ration and current consolidation state of soft soil. Preloading can reduce secondary consolidation coefficient. The scale between second consolidation coefficient and compression index is constant, about 0.025-0.10. Direct shear-creep characteristic is related to vertical consolidation pressure; and the creep rule presents strain hardening characteristics. Consolidation action can play down the creep effect, so the creep characteristic in triaxial test is connected with drainage condition. In coordination loading addition, the relationship between deviator stress and axial strain is nearly straight-line in CD test; but in CU test, it assumes nonlinear and there is visible yield characteristics. When the continuous loading manner is adopted in UU test, the failure strength will be improved. Bases of above results, the models of creep and consolidation are analyzed considering respectively nonlinear constitutive relationship and shear drainage condition.