强震作用下大跨度连续梁桥的倒塌破坏研究

Study on the Collapse and Failure of Long-span Continuous Beam Bridge under Strong Earthquake

近年来,大量的连续梁桥在强烈地震中出现了构件破坏甚至发生了整体倒塌的现象,因此需要对大跨度连续梁桥的倒塌破坏机理进行研究。结合一座大跨度连续钢箱梁桥,本文首先通过LS-DYNA建立了其动力显式有限元模型,然后通过倒塌仿真分析得到该连续梁桥在强震作用下的破坏模式,重点对比分析了不同地震波及其输入作用下的破坏特征。结果表明,在强震作用下,该连续梁桥的桥墩最先发生破坏,且边主跨间的桥墩尤应引起关注;考虑竖向地震后,桥梁的破坏模式发生了改变。

Recently, the failure phenomenon of the component in many continuous beam bridges have appeared even the whole structure collapse under the frequency strong earthquakes. Therefore, it is necessary to research the mechanism of the collapse and failure of long-span continuous beam bridge. Based on a long-span continuous steel-box beam bridge, a dynamic explicit finite model is established through the software of LS-DYNA in this paper at first. Subsequently, the failure modes of the bridge under strong earthquake are conducted by the analysis of collapse simulation, and the failure features of the bridges under difierent seismic waves and their inputs are compared emphatically. The results show that the failure piers are firstly happened of the continuous beam bridge and the piers between the main span and the side span should be pain attention. The failure modes of the bridge have a change after considering the vertical seismic wave.