Experimental study on dredged slurry improved by vacuum preloading with top and bottom drainage

Abstract

The conventional vacuum preloading method is widely used to treat dredged slurry. However, this method cannot fully meet engineering requirements due to the loss of vacuum pressure. To overcome this issue, a method of vacuum preloading with top and bottom drainage is proposed, and the consolidation behavior of this method and the influence of the time ratio (a ratio of bottom vacuum application time to top vacuum application time) on this method are studied through laboratory model experiments. The results demonstrated that compared with the conventional vacuum preloading method, the average vane shear strength of the dredged slurry treated by vacuum preloading with top and bottom drainage increased by 20.6%, and the water content reduced by 6.0%. The time ratio has a significant effect on the consolidation of the dredged slurry, and the optimum time ratio is 1:1. Thus, vacuum preloading with top and bottom drainage can better complete the consolidation of the dredged slurry. In addition, this method can be used to develop a design guide for engineering practice.