Computational Modeling of Energy Dissipation Characteristics of Expanded Polystyrene (EPS) Cushion of Reinforce Concrete (RC) Bridge Girder Under Rockfall Impact

摘要

As a part of rock sheds, reinforced concrete (RC) girder is usually covered by traditional soil cushion as a shock-absorbing device. In this paper, expanded polystyrene (EPS) has been numerically modeled using RC girder under impact load analysis. A numerical method was established in comparison with the proposed prototype experiment. Furthermore, expanded polystyrene (EPS) cushions of different thicknesses and densities as an energy dissipation device for rockfall impact were tested using the proposed numerical model. The dynamic analysis and modeling were performed using LS-DYNA. The impact forces and displacements of the RC girder were measured. The simulated results revealed a major increase in terms of energy dissipation after introducing the EPS cushion. The results obtained from this study are: (1) the displacement can be reduced by 25% as compared to sand cushion as absorbing material using an EPS layer, (2) a large decrease in contact force was observed using a layer of EPS cushion at the top of the RC girder having lesser density of 19 kg/m~3, and (3) EPS cushions with 0.5 m thicker layer and lower 19 kg/m~3 density showed more remarkable energy dissipation effect when all the other conditions were the same.