北方地区某三孔乱石拱桥坍塌原因分析

The Cause Analysis of a Three-hole Snecked Arch Bridge Collapse In The Northern Region

众所周知,多数圬工拱桥结构的破坏都是由于其下部基础的沉降、变位等原因引发的。但具体的基础变形量计算方法及其对上部结构的影响程度并没有被人们详细研究,这里对发生垮塌事故的北方地区某三跨乱石拱桥进行分析。根据现场勘测数据进行桥位处水文、冲刷计算,确定1#桥墩基础的沉降量及变形量,并借助MIDAS/CIVIL有限元计算软件模拟这种基础变位对上部主拱圈结构的影响程度,得出了导致该桥坍塌的根本原因。可为类似桥梁工程的养护管理及事故鉴定等提供思路和参考。

It is well known that most structural damage of the masonry arch bridge is due to the settlement and displacement in its lower base. But the specific foundation deformation calculation method and its influence of the upper structure has not been researched in detail. Here is the cause analysis of collapse accident of a three span bridge in the northern region. Based on the field survey data,we do hy- drology and erosion calculation at the bridge site, determine the foundation settlement and deformation of the first bridge pier. And with the help of MIDAS/CIVIL finite element software, we simulate the effect of the foundation displacement on the upper main arch ring structure and conclude the primary cause of the collapsed bridge. It provides ideas for the maintenance management and accident identification of similar bridges.