分阶段施工中钢箱梁制造参数的通用计算方法

General calculation method for manufacturing parameters of steel box girder in staged construction

为了精确计算分阶段施工中钢箱梁制造参数,形成简便统一的求解思路,基于安装时节段间交界面实现平顺对接的思想,直接根据结构累计位移确定已安装、待安装节段桥位现场的相对位置关系,以设计成桥状态下节段形心处梁长为基准,提出分阶段施工钢箱梁桥节段间制造夹角、顶底板长度制造参数的通用计算方法.将该方法应用于三跨钢箱连续梁桥大节段吊装施工,准确计算各小节段钢箱梁制造参数,并精准修正大节段接缝处顶底板加工长度.结果表明:制造完成后各小节段钢箱梁交界面焊缝宽度均匀一致,现场安装时大节段钢箱梁端面实现精准匹配,合龙后主梁线形与设计线形吻合良好,验证了所提方法的正确性.

In order to accurately calculate the manufacturing parameters of steel box girder in staged construction and form a simple and unified solution idea,a general calculation method for manufacturing parameters of the steel box girder bridge such as the manufacturing angle between the segments and the length of the top and bottom plates was proposed,based on the idea of achieving smooth butt joints at the interface of the sections during installation.This method determines the relative positional relationship between the installed section and the section to be installed at the bridge site directly according to the cumulative displacement of the structure,and takes the girder length at the centroid of the segment under design finished bridge state as the datum length.It was applied to a three-span steel box continuous girder bridge constructed by large-segment hoisting method.The manufacturing parameters of each small-segment steel box girder were accurately calculated,and the processing length of the top and bottom plates at the joints of the large-segment steel box girder was accurately corrected.The results show that the welding seam width at the interface of small-segment steel box girder is uniform and consistent after manufacturing,the end faces of the large-segment steel box girder were accurately matched during on-site installation,and the alignment of main girder after closuring is in good agreement with the design alignment,which verify the correctness of the proposed method.