Modeling the Compression Behavior of Dredged Sandy Clays Considering the Effect of Initial Water Contents and Sand Fractions

Dredged sandy clays are widely utilized as fill material in geotechnical projects, and their compressibility is crucial to the engineering design. It is well recognized that the compression behavior of dredged sandy clays is significantly affected by the initial water content and sand fraction. Besides, these two physical properties are usually spatially dependent due to the process of hydraulic filling. In this study, an effective compression model is formulated based on the equivalent void ratio concept. The compression curve of pure clays is first established as a reference, which depends on the initial void ratio and liquid limit. Then, the effect of sand fraction has been incorporated by directly implementing the equivalent void ratio into the reference curve. A structural variable is introduced to describe the evolving intergranular structure with coarse content and stress level. Only one additional structural parameter is required, and it can be readily calibrated by one traditional compression test. Validation shows that the model is effective in reproducing the compression behavior of dredged sandy clays with a wide range of initial water content and sand fraction. The proposed equation can provide a reasonable reference for establishing the hardening law and the corresponding general constitutive model of dredged sandy clays.