落石冲击棚洞复合缓冲垫层动力响应研究

Study on Dynamic Response of Rockfall Impacting Composite Cushion Layer on Rock Shed

为探明棚洞聚乙烯泡沫、混凝土板复合垫层抗落石冲击性能,以框架型棚洞为研究对象,基于模型试验研究了不同高度落石冲击下落石冲击荷载及棚洞动力响应规律。结果表明:随着落石高度的增大,落石冲击力、冲击压力和棚洞顶板位移峰值、振动加速度峰值增大,线性关系明显。与纯砂垫层相比,聚乙烯泡沫和混凝土板复合垫层落石冲击力、冲击压应力、棚洞顶板位移、振动加速度峰值均显著减小;其中,混凝土板复合垫层落石冲击力、冲击压应力峰值最小,聚乙烯泡沫复合垫层棚洞顶板振动加速度峰值最小;落石冲击能量较大时,聚乙烯泡沫复合垫层棚洞顶板位移峰值最小。研究结果可为防落石棚洞复合垫层设计提供参考。

This study investigates the impact resistance of polyethylene(EPE)foam and concrete slab composite cushions in rock sheds,using a frame-type rock shed as the research object.The impact load and dynamic response of the rock shed under varying rockfall heights were analyzed through model testing.The results indicate that as rockfall height increases,the peak impact force,peak compressive stress,peak displacement,and peak vibration acceleration of the rock shed roof also increase,showing a clear linear relationship.Compared to pure sand cushions,both the EPE and concrete slab composite cushions significantly reduce the peak impact force,peak compressive stress,peak displacement,and peak vibration acceleration of the rock shed roof.Among these,the concrete slab composite cushion exhibits the smallest peak impact force and peak compressive stress,while the EPE composite cushion results in the smallest peak vibration acceleration.Additionally,under higher rockfall impact energy,the EPE composite cushion minimizes the peak displacement of the rock shed roof.These findings provide valuable insights for the design of composite cushion layers in rock sheds.