Study on Applicability of Cushion System with New Materials on Rock-Shed Structures

本研究以实验与分析的方式探讨新型材料组成的三层垫层系统在岩棚结构上的适用性。本文提出的垫层体系是由砂作为顶层，钢筋混凝土板作为芯层，EPS（膨胀聚苯乙烯）作为底层。以钢筋和芳纶纤维增强塑料（AFRP）筋两种钢筋混凝土板为核心层，对4 m × 4 m的缓冲垫系统进行了3 tf重物从最大30 m高度自由下落的跌落冲击试验。采用DYNA-3D冲击分析通用程序和有限条法对带垫层的岩棚结构在冲击荷载作用下进行了数值分析。从这项研究中获得的结果如下：1）与单砂层情况相比，本文所提出的缓冲系统可以将最大传递冲击力减小到最大重量冲击力的一半，并显著改善冲击力的衰减。2）这些吸收效果可以从DYNA-3D和FSM的数值结果中得到证实。显然，所提出的三层垫体系可以实际用作岩棚结构的吸能体系之一。

In this study, applicability of three-layered cushion system made up from new materials on rock-shed structures, is discussed experimentally and analytically. The cushion system proposed here is composed of sand as top layer, RC slab as core layer and EPS (Expanded Poly-Styrol) as bottom layer. Two types of RC slabs are used as core layer which are reinforced with steel bars and AFRP (Aramid Fiber reinforced Plastic) rods.As an experimental approach, the weight-drop impact tests on the 4 m X 4 m cushion system are executed in which 3 tf weight is freely dropped from a maximum 30 m height. DYNA-3D code for general purpose of impact analysis and FSM (Finite Strip Method) are used for numerical analysis of rock-shed structure with cushion system under impact loads. The results obtained from this study are as follows ;1) The cushion system proposed here can reduce the maximum transmitted impact force to a half of the maximum weight impact force, and improve dispersibility of impact force drastically comparing with the results of the case using single sand layer.2) Those absorbing effects can be confirmed from the numerical results obtained using DYNA-3D and FSM.3) Therefore, it is clear that proposed three-layered cushion system can be practically used as one of absorbing systems of rock-shed structures.