Abstract: Half-through or through arch bridges , whose suspenders ruptured , were analyzed , and it was discovered that bridge deck structure of half-through or through bridge were both f1oating systems. Numerical simulation was used to analyze the inf1uence of the bridge deck system stmcture form on suspenders stress. Through a simple model of the vehicle , the inf1uence of the vehicle speed on suspender stress was discussed. The results show that half-through or through arch bridge deck structure form has a huge inf1uence on the suspender stress under live load; secondly , floating bridge deck system has the advantage of simple construction , but it has the birth disadvantage on its poor integration , which is unfavorable to suspender stress and prone to suspender fatigue failure. Finally , fatigue failure is the main cause of the half-through or through arch bridge suspenders' fracture.

Key words: bridge deck structure, half-through or through bridge, suspender stress

摘要： 分析吊杆断裂的中F承式拱桥，发现其桥面系均为漂浮体系;运用数值模拟，分析桥面系结构形式对吊杆受力 的影响;基于简单车辆'模型，讨论车速对吊杆受力的影响。结果表明:桥面系结构形式对吊杆活载受力影响较大;漂 浮式桥面系虽然具有施工简便的优点，但其整体性差，存在先天缺陷，对吊杆受力不利，易引起吊杆疲劳破坏，是导 致中下承式拱桥吊杆断裂的主要原因。

关键词: 桥面系, 中下承式拱桥, 吊杆受力