抄録
The use of sand layers for energy absorbing function in protection structures such as walls, embankments, and galleries is extensive in some countries. Full-scale experiments, prototype experiments, and numerical analyses by discrete element methods have been used to investigate the impact characteristics of the sand layers. This research utilized the finite element method (FEM) code LS-DYNA to investigate the dynamic behavior of a sand cushion subjected to impact loads. First, the sand analysis parameters were calibrated through a parametric study using sand tank data. The model was then validated using two previous sand tank and sand cell experiments. Two types of lateral boundary conditions were considered in the numerical model of the sand cell. A further investigation on the effect of the drop height on the impact phenomenon of the sand cell was performed. The simulated results indicated that the sand parameters had a large effect on the impact phenomenon. Comparisons between the simulated and experimental results for the sand tank and sand cell were in good agreement. The effects of the boundary conditions and drop height on the sand cell impact characteristics were analyzed. Above all, this research demonstrated that practical application of the FEM to the dynamic behavior of protection structures, including a sand-cushioning layer, is feasible and can aid in the development of protection technology against natural hazards.
