Abstract: High-moisture dredger fill sites with significant clay content are prone to substantial deformation during operation due to the combined effects of large strain consolidation and creep, posing critical risks to engineering safety. This study focuses on the mechanical behavior of high-moisture dredger fill under these conditions. Through comprehensive laboratory testing, the large strain consolidation and creep characteristics of the soil were analyzed. A finite element equation for large strain consolidation was developed, and a creep constitutive model based on fractional derivatives was established. A finite element model was constructed to capture the overlying effects of both large strain consolidation and creep deformation. Validation through model box experiments demonstrated the accuracy of the numerical simulations, which were employed to analyze the impact of these combined effects on surface settlement under applied loads. The results indicate that the strain-time curve during large strain consolidation shows significant attenuation, with creep deformation becoming increasingly pronounced in the later stages. The creep behavior of the dredger fill soil is distinctly nonlinear, with the nonlinear viscoplastic deformation phase accounting for approximately 59% of the total creep deformation. As consolidation time progresses, drainage volume and surface settlement initially increase rapidly before reaching a stable phase. The numerical model successfully captures the coupled effects of large strain consolidation and creep, with simulation results closely matching the experimental observations. This research provides valuable technical insight for the rational design and safe management of high-moisture dredger fill projects.

Key words: high moisture dredger fill, large strain consolidation, creep, constitutive model, overlying effect