Improvement of rainer system with a porous plate

for preparing large granular specimens in the calibration chamber, most previous studies have used the pluviation technique adjusting the deposition intensity while maintaining a constant drop height. This study introduces a rainer system improved by adopting a porous plate. This system controls the relative density of the specimens by adjusting the drop height without changing the deposition intensity. From a series of laboratory tests, it is revealed that an improved rainer system with a porous plate is capable of reconstituting a granular specimen with a wider range of densities than a conventional rainer system. It is also observed that using the rainer system with a porous plate significantly improves the vertical and horizontal homogeneity of the specimen.