Consolidation Behavior of Ultra-Soft slurry and 1-D Consolidation Model Considering Viscosity

The ultra-soft slurry exhibits significant, initially viscous and subsequently elasto-plastic consolidation behavior. In order to investigate the different consolidation response at the viscous stage (VS) and elasto-plastic stage (EPS), a series of element consolidation tests were carried out in the modified light-capped oedometer. Test results show that the consolidation coefficient and permeability at VS and EPS vary significantly, which would bring in non-negligible error to the consolidation prediction with the ordinary assumptions. A simplified 1-D consolidation model considering the significant behavior difference in the VS and EPS was developed. The suction pressure proposed by Hong (2007, 2010) was employed to identify the consecutive stages in the model. Then, the consolidation tests for ultra-soft clay under different loadings were conducted in the small-scale consolidometer and the test results are simulated with the proposed model. The model can describe the progressive consolidation well from the VS to EPS. It provides an easily-accessible and reasonable alternative for the prediction of the consolidation behavior for the ultra-soft slurry.