Assessment of Air Pluviation Using Stationary and Movable Pluviators

摘要

Methods used for laboratory sample preparation should be able to produce uniform and highly repeatable sand beds of required density and to simulate field conditions. Air piuviation is a widely used method to prepare cohesionless soil samples in the laboratory. In the present study, two currently used air piuviation setups, viz, stationary/portable traveling pluviator (PTP) and movable/mechanized traveling pluviator (MTP), are investigated in terms of their ability to prepare uniform and repeatable sand beds of a wide range of relative densities. The PTP and MTP piuviation setups mainly comprise hopper, orifice, flexible hose, and rigid tube. Chain pulley and rail track are the additional features of MTP, which allow the hopper to travel smoothly in one direction. Piuviation studies are performed by using Indian standard sand (Grade II), and a California bearing ratio (CBR) mold is used to evaluate relative density (RD) and deposition intensity (DI) of samples. The effect of height of fall (HF), DI, and number of diffuser sieves on the RD of the sand sample is studied for both the PTP and MTP piuviation setups. A model tank is used to verify the uniformity of the sand samples with the help of miniature cone-penetrations tests. The test results reveal that a wide range of RD with uniform and repeatable sand samples can be prepared by using MTP compared with PTP.