既有桥梁下部结构加固施工技术

Construction technology of reinforcing existing bridge structures

结合国贸桥的工程实例,介绍了对国贸桥的补桩、新建承台及中横梁加固三个方面的施工工艺和施工技术。国贸桥的桥墩基础采用补桩加固,即在原承台的南、北两侧面各加一根直径为1.5 m的灌注桩。新建承台的基坑开挖之后,基坑侧壁挂网喷混凝土并打设锚杆加强支护。在原承台下吊装工字钢梁,然后在既有承台底部绑扎钢筋、浇筑混凝土。中横梁加固是在既有桥梁墩柱两侧增设两个钢墩柱,钢墩柱支撑钢盖梁,盖梁上设置"测力可调盆式橡胶固定支座"对横梁进行支顶,并对横梁进行粘贴钢板加固,增强其抗剪能力。

This paper introduced the construction technology of pile patching, caps and middle cross beam reinforcement of the International Trade Bridge in Beijing. The pile patching method is applying pile reinforcement to bridge pier foundation, which means building a 1.5 m diameter pile in each north and south side of the bridge original cap. Building new caps is to spray concrete in steel net, set bolt anchor on the wall of foundation pit based on slope excavation, lift and install the girder for flanged beam lifting, and band reinforcement bar and cast concrete at the bottom of original cap. Reinforcing middle cross beam is to add two steel piles on both sides of the bridge piers in order to support steel cap beam which can support cross beams with adjustable force basin rubber pedestal and convert single-point-support to three-points-support so as to improve the beam force condition, and reinforce the steel beams by pasting the steel plates so as to enhance the beam shear capacity.