Application of Sediment Fluidization by High Frequent Mechanical Vibrations into Slurry Transport

Friction reduction of sediment-transporting pipeline is very important in dredging engineering. Because of the two rheological behaviors of cohesive sediments, shear-thinning and thixotropy, cohesive sediments can usually be fluidized by the shear load which enables easier transportation of cohesive sediments and produces greater mobility of the sedimentary bed. This paper investigated the effect of the application of sediment fluidization by high frequent mechanical vibrations on the viscosity and transportation property of sludge and slurry using the method of settling ball and capillary rheometer respectively. The experimental results indicate that the high frequent mechanical vibrations can greatly influence the viscosity and the transport velocity of slurry. The vibrations applied on the sludge induce the mutual collision of the sediment particles which can break the bond between particles, so that the fine sediment bulk or sludge of high viscosity becomes a kind of slurry fluid which has quite low viscosity and good flow ability. Moreover, the effect of the vibration on the sediments decreases with the increasing distance to the vibration source, i.e., the closer the sediments to the vibration source, the lower the viscosity are. Meanwhile, the slurry velocity increases with the vibration duration until it reaches a stable value. Finally, two applications of the technique of sediment liquefaction are introduced in shortly.