温州瓯江大桥钢箱梁整体提升安装施工技术

Construction Techniques for Integral Lifting and Installation of Steel Box Girder of Wenzhou Oujian River Bridge

浙江温州瓯江大桥主桥为主跨200m的钢-混凝土混合梁刚构桥,按双幅布置,主梁采用单箱单室斜腹板截面,中跨跨中80m范围采用钢箱梁结构,钢箱梁重约660t。根据该桥结构特点,钢箱梁吊装采用桥面吊机整体提升的方法施工;采用两端同时焊接的方法焊接合龙口,温差控制在±5℃以内,所需要的切口量在20mm以内;钢箱梁合龙口焊接时,首先按底板、腹板、顶板的顺序焊接环形接头对接焊缝,检测合格后再组焊嵌补件。该桥钢箱梁的吊装和连接已顺利完成,施工中各项工序进展顺利。

The main bridge of Wenzhou Oujiang River Bridge in Zhejiang is a steel and con- crete hybrid girder rigid-frame bridge with a main span 200 m and is arranged in two separated decks. The main girder of the bridge is of the section of the single cell single box and inclined webs and in the 80 m range of the midspan of the central span, the steel box girder structure, weighing about 660 t, is applied. In the light of the structural characteristics of the bridge, the steel box main girder was constructed by the integral lifting and installation method by the deck cranes. The closure gap of the girder was welded by the method of simultaneous welding at both ends of the closure gap with the temperature difference controlled within ＋ 5 ℃ and the needed cutting amount controlled within 20 ram. When the closure gap was welded, the butt seams of the ring joints were firstly welded in the sequence from the bottom plates, webs and to the top plates and after the welding was checked to be qualified, the built-in components for the closure gap were then welded. The installation and jointing of the steel box girder of the bridge were suc- cessfully completed and the various working procedures proceeded smoothly in the construction.