Abstract
Sand cushion materials laid on rock sheds present unresolved problems. An important solution to such issues is enabling a comprehensive understanding of the deformation mechanism of sand cushion. In this study, we analyzed a large-scale test and a drop test for a square block-type sand model by ground density examination, with focus on variations in sand cushion density. During the examination, the internal components of the sand cushion with 80% density loosened. By image processing, we visualized the density variations in a model test, through which we determined the range of impact force influence and the localization of expansion and compression. Finally, we visualized the stress distribution at the bottom of the sand cushion with a pressure-sensitive sheet.
