Test study on properties of secondary consolidation of soft soil

Based on a series of consolidation tests for undisturbed samples in Guangzhou Nansha,the influence of stress history,load ratios and overload pre-pressure on secondary consolidation properties has been researched.The results show that the separation of primary consolidation and secondary consolidation is related to load ratios,which effect to secondary consolidation ratio Cα also.Secondary consolidation was mainly affected by preconsolidation pressure pc.As ppc or ppc,Cα presents different regularities.After preloading,the secondary consolidation ratio Cα and compression index Cc is a constant: Cα/Cc≈0.03.The test results indicate that character of secondary consolidation depends on preconsolidation pressure,which provides a perspicuity idea for reduce settlement after construction.