跨运河大跨度双层钢桁拱桥安装施工技术研究

Research on Erection and Construction Technology of Long-span Double-layer Steel Truss Arch Bridge Spanning Canal

摘要:

跨运河钢桁架拱桥由于结构刚度大、跨越能力强，且具有较好的城市景观效应，未来修建跨运河大跨度双层钢桁架拱桥具有较好的应用前景。为了进一步研究大跨度双层钢桁架拱桥的施工技术，以余杭运河大桥主桥为工程研究背景，建立了主桥的有限元三维模型，分析典型工况下的受力情况，详细介绍了双层钢桁架拱桥的结构特点，并对大桥的安装施工方法进行比较判别，最终选择了大跨度双层钢桁架拱桥支架法+跨中浮吊起重结合的安装施工方法。结果表明：依托桥梁为空间桁架结构，具有良好的刚度和强度，计算结果满足规范要求，主梁合龙后可拆除主梁的临时支架，可有效降低支架受力，便于水中支架拔除，节约成本。

Abstract:

Due to its high structural stiffness, strong spanning capacity and good urban landscape effect, the steel truss arch bridge spanning canal has a good prospect for future construction of long-span double-layer steel truss arch bridges spanning canal. In order to further study the construction technology of long-span double-layer steel truss arch bridge,taking the main bridge of Yuhang Canal Bridge as the engineering research background, a finite element three-dimensional model of the main bridge is established to analyze the stress situation under the typical working conditions. The structural characteristics of double-layer steel truss arch bridge are introduced in detail, and the erection and construction methods of the bridge are compared and judged. Finally, the erection and construction method of long-span double-layer steel truss arch bridge combined with mid-span floating crane is selected. The results show that as a spatial truss structure， the bridge has good stiffness and strength， and the calculation results meet the requirements of the specifications. After the main girder is closed, the temporary support of the main girder can be removed, which can effectively reduce the stress on the support, facilitate the removal of the underwater support, and save costs.