Abstract: To study the flow deformation characteristics of liquefied sand, the experiments on the fluid characteristics of liquefied sand were conducted. Based on the boundary layer theory, a test device for apparent viscosity of liquefied sand had been developed independently. The device, mainly composed of adjustable speed motor, motor speed regulator, cylindrical rotor, torque sensor and other components, can effectively measure the apparent viscosity of liquefied sand. The apparent viscosity of saturated sand, the friction torque of cylindrical rotor under different pore pressure ratios, and rotating speeds are studied, especially the apparent viscosity of liquefied sand. The results show that both in the pore pressure development before liquefaction and the pore pressure dissipation after liquefaction, the friction torque is affected by the pore pressure ratio and rotational speed. As the pore water pressure of liquefaction sand gradually dissipates, the strength recovers, and the flow capacity decreases as the apparent viscosity increases. There is a linear correlation between apparent viscosity and pore pressure ratio of the liquefaction sand. The apparent viscosity decreases as the shear strain rate increases. There is a power function relationship between the apparent viscosity and shear strain rate, showing that the liquefaction sand has the characteristics of typical power-law shear thinning non-Newtonian fluid.

Key words: liquefied sand, apparent viscosity, apparatus, pore pressure ratio, shear strain rate