大质量落物冲击下PC箱梁桥破坏效应分析  

Analysis on Damage Effect of PC Box Beam Bridge under Impact of Large Mass Falling Objects

作　　者：陈显涛 徐丰 CHEN Xiantao;XU Feng

机构地区：[1]武汉工程大学土木工程与建筑学院,湖北武汉430074

出　　处：《城市道桥与防洪》2024年第7期266-270,M0023,共6页Urban Roads Bridges & Flood Control

摘　　要：为研究大质量落物对桥梁的破环效应,以某公路跨铁路桥施工过程中公路桥梁体跌落事故为依托,使用显示动力分析软件LS_DYNA进行数值模拟,以跨径32 m铁路箱梁为研究对象,建立精细化模型,通过试算给出了详细的仿真相关参数,如材料类型、钢筋混凝土耦合方式、单元尺寸等;较为详细地还原了整个事故发生的过程,分析了箱梁的损伤状态和跨中位移,以及钢筋应力状体数据。结果表明,相较于货物抛洒等小质量冲击,箱梁在大质量落物冲击下除了接触区域的的混凝土脱落等局部损伤外,还出现了顺桥向裂缝、翼缘板网状裂缝等整体损伤,少部分普通钢筋达到屈服应力,预应力束都未屈服。In order to study the damage effect of large mass falling objects on bridges,based on the drop accident of highway bridge body during the construction process of a railway bridge crossing a highway,the display dynamic analysis software LS_DYNA is used to conduct the numerical simulation.Taking a 32 m-span railway box girder as the research object,a refined model is established to calculate and give the detailed simulating parameters,such as the material type,reinforced concrete coupling mode and element size,which restores the whole accident process in more detail.The damage status and mid span displacement of the box girder,as well as the stress state data of steel bars are analyzed.The results show that compared with small mass impacts such as cargo throwing,the box girder is not only locally damaged such as concrete falling off in the contact zone,but also overall damaged such as cracks along the bridge direction and mesh cracks in the flange plate under the large mass falling impact.And a small portion of ordinary steel bars reaches the yield stress,and the prestressed tendons have not yielded.

关 键 词：装配式预应力混凝土箱梁 数值仿真 冲击荷载 损伤分布 

分 类 号：U441.5[建筑科学—桥梁与隧道工程]