Abstract: Taking Jiuqu Ｒiver Bridge reinforcement project as the research background，the main diseases of transverse deck arch bridge were summarized，and the main causes of the disease were analyzed deeply． According to main diseases and defects of the structure，three kinds of different reinforcement schemes were put forward． Through the comparison of the schemes，the scheme“strengthening construction on the arch structure and changing horizontal spread the carriageway plate into longitudinal laying by use of the arch rib”was considered to be more economic and safer，which improved fundamentally the defects of transverse deck． According to“as soon as possible”requirements of construction side，a construction method of demolition and reconstruction span by span was put forward． Comparing with the disposable demolition construction on the arch reconstruction，the demolition and reconstruction span by span can effectively shorten the construction period and reduce construction risk; meanwhile，the forcing system of the structure has little change．

Key words: transverse deck, arch bridge, reinforcement, research method

摘要： 以九曲河大桥加固改造工程为研究背景，归纳总结横置行车道板拱桥的主要病害，并深入分析得出病害产生 的主要原因;针对桥梁结构的主要病害及缺陷，提出3种不同的加固改造方案，进行方案比选，认为“利用原主拱肋， 加固改造拱上建筑结构，改横铺行车道板为纵铺”的方案更经济，安全性更高，且从根本上改善了横置行车道板的受 力缺陷;在建设方“尽早完工”的要求下，笔者提出一种逐跨拆除改造的施工方法，与一次性拆除拱上建筑改造的施 工方法相比，采用逐跨拆除改造施工方法能够有效缩短工期，且基本不改变结构受力体系，施工风险性低。

关键词: 横置行车道板, 拱桥, 加固改造, 方法研究