Development of a portable traveling pluviator device and its performance to prepare uniform sand specimens

It is necessary to maintain uniform relative density of sand particles as it plays an important role in influencing the behavior of the geotechnical structures. There are many pluviation techniques to prepare large, homogenous and uniform sand beds of desired densities for laboratory testing. In this research, a portable traveling pluviator has been developed following air pluviation method. A portable traveling pluviator consists of a hopper, reducer, orifice plate, flexible pipe, rigid tube and diffuser sieves. It has been observed from previous researches that the diameter of orifice plate, the orientation, pattern and number of diffuser sieves and the height of fall of sand particles have a great influence on controlling relative density of sand beds. In this paper, an orifice plate of 6 mm diameter and three diffuser sieves of hexagon pattern have been used. Relative density of sand has been measured for ten different heights of fall from 5 to 50 cm at an interval of 5 cm. In this study, six types of sand sample based on sand type and gradation have been used to find out the effect of finer and coarser particles of sand sample on the pluviator performance. From the research, it has been found that coarser particles of sand attain higher relative density and lower deposition intensity due to their larger velocity and greater impact energy compared to finer particles in different gradations for a particular height of fall.