Laboratory Model Test Of Vacuum Preloading On Dredged Clays At High Initial Water Contents

Vacuum preloading method has been widely applied in the improvement of reclaimed land with dredged clays at high initial water contents. In the engineering practice, it turns out that the treatment often does not meet the design requierments. The phenomenon known as "soil pile" often occur, showing the decreasing in shear strength along the radical direction around the PVD. The strength at the middle zone among the PVDs is very low, almost equal to the strength of dredged clays before treatment. In this study, model tests of vacuum preloading on dredged clays were performed for investigating the main factors responsible for the phenomenon of "soil pile";(1) Model tests of vacuum preloading on dredged clays were conducted with different initial water content, vacuum load and dredged clays, to explore the effect of experimental factors on the vacuum treatment effect.(2) According to the results of the radical vacuum degree in the dredged clays, the attenuation of radical vacuum degree and its quantitative relationship equation is obtained. In addition, the influence law of different experimental factors is also discussed.(3) According to the results of the radical distribution of soil water content and vane strength, the influence law on the vacuum treatment of experimental factors is obtained.(4) According to the results of the change of radical clay content after test, we find out at what conditions the fine particles will move towards the PVD and its influence of different experimental factors.