Experimental study on fluid properties of slurry and its influence on slurry infiltration in sand stratum

摘要

In construction of slurry engineering, especially in sand stratum of high permeability, small size fine particles in slurry are likely to flow through the stratum and washed away. In this study, nine groups of slurry fluid property tests were performed using a NXS-11A rotary viscometer in order to investigate infiltration of slurry in sand stratum. Additionally, a series of penetration tests were also conducted by a self-designed infiltration device. Experimental results show the test slurry meet characteristics of Bingham fluid at a medium to high shear rate, while it conforms to the Herschel-Bulkley model at a low shear rate. Darcy's law is no longer applicable to infiltration of slurry in sand stratum, because of the initial hydraulic gradient. The infiltration rate (v(s)) is not strictly linearly related to the hydraulic gradient at small hydraulic gradient (i). It is also indicated that the yield stress of slurry is the fundamental cause of initial hydraulic gradient during the infiltration process of slurry in sand stratum. The yield stress has a positive correlation with the initial hydraulic gradient. Ideally, initial hydraulic gradient is proportional to the dynamic shear force of slurry.