冲击荷载下EPS垫层棚洞耗能减震作用研究

通过在棚洞顶部铺设砂垫层能够达到一定的缓冲吸能目的，然而工程实践表明：砂垫层材料缓冲效果有限，且自重荷载较大，建设成本偏高，不利于大面积推广应用。为此，在传统棚洞砂垫层的基础上提出一种结合聚苯乙烯泡沫层（EPS）的复合垫层结构，依托丽江至攀枝花高速公路宝鼎棚洞工程，采用动力有限元方法对运煤缆车冲击棚洞过程动力响应进行研究，与传统砂垫层进行比较，从而揭示EPS垫层在棚洞结构设计中的耗能减震作用。结果表明：与传统垫层结构相比，结合EPS垫层的棚洞结构能够在一定程度上降低棚洞结构自重、冲击力、以及棚洞混凝土板的位移、应力响应，具有较高的工程应用价值。

Study on the Dissipating Effects of Shed with EPS Cushion Under Impact Load

Currently, it is popular to defend it passively by shed tunnel. However, although the rockfall impact can be buffered by cushion set on common shed tunnel, the effect is not good according to engineering practice. Furthermore, the high construction cost caused by huge weight of thick cushion also against its promoting application. Therefore, in the Baoding bridge of Li-jiang-Panzhihua highway, rockfall shelters are used to protect the bridge and traffic from the impact of cable cars. Traditional soil cushion layer has some shortages such as low energy absorbing ability and high self-weight. In this paper, a layer of low-density compressible EPS material is included in the soil cushion layers of rockfall shelters. Dynamic finite element method is used to analyze the process of the falling boulder impacting the shelter structure with the composite cushion layer presented. It is concluded that the cushion layer composed by soil and EPS can greatly reduce the impact force, the deformation and stress of the structure, and simultaneously has a low self-weight.