Abstract: The influences of drop height, funnel diameter and fine particles’ contents on sand specimen preparation for indoor geotechnical triaxial test were studied through preparation test of Fujian standard sand with self-manufactured air pluviation device. Results showed that the relative density of sand specimens increased with the increasing of drop height, and the growth rate slowed down and tended to be stable. The relative density of sand specimens decreased along with the increase of funnel diameter under the same drop height. A wider range of relative density can be achieved with the decrease of funnel diameter. The relative density of sand specimens decreased with the increasing of fine particles’ contents. The influences of drop height, funnel diameter and fine particles’ contents on the relative density of sand specimens can be well explained by Newton’s second law and conservation of energy. The gray image scanned with the 225 kV micro-computerized tomography of sand specimens prepared by air pluviation was analyzed by ImageJ software. The spatial homogeneity of sand specimens can be verified by reconstructing the three-dimensional model of sand specimens and calculating the proportion of sand pore area along the height of sand specimen. Furthermore, reasonable suggestions on preparing triaxial sand specimens were proposed.

Key words: air pluviation, sand preparation, sand, CT scanning, homogeneity