Study on Dynamic Response of Rockfall Impact Height to Concrete Hollow Thin Wall Ultra-High Pier Bridge Structure System

空心薄壁超高墩在山区、河谷桥梁中十分常见，但有关其抗撞性能的研究成果相对匮乏。因此，本文以某山区现浇式超高墩连续刚构桥为原型桥，基于Ls-dyna有限元软件建立了落石冲击条件下1:20缩尺两联钢筋混凝土空心薄壁超高墩分析模型，并基于既有试验成果验证，进而探究了落石冲击高度对空心薄壁超高墩的撞击响应和损伤失效模式的影响。结果表明：空心薄壁超高墩受落石冲击的局部损伤模式与中矮墩相似。撞击高度对撞击力影响较小，但对结构位移响应影响较大。Hollow thin-walled ultra-high piers are very common in bridges in mountainous areas and river valleys, but the research results on their collision resistance are relatively scarce. Therefore, in this paper, a continuous rigid frame bridge with cast-in-place ultra-high piers in a mountain area is taken as the prototype bridge. Based on Ls-dyna finite element software, an analysis model of the impact of rock fall on two reinforced concrete hollow thin-wall ultra-high piers with a scale ratio of 1:20 is established, and verified by the existing test results. The effect of rockfall impact height on the impact response and damage failure mode of the hollow thin-walled ultra-high pier is investigated by using the verification model. The results show that the local damage mode of the hollow thin-walled ultra-high pier under rockfall impact is similar to that of the medium-low pier. The impact height has little effect on the impact force, but a great effect on the displacement response of the structure.