高速公路钢箱梁高精度顶推关键技术研究

Research on key technologies for high precision jacking of steel box girders on highways

顶推施工方法的思路来源于钢桥,主要应用于高墩大跨度的斜拉桥中。随着我国公路工程建设的不断发展,我国钢结构桥梁不断增加。由于顶推施工方法用于钢箱梁施工具有安全可靠、施工速度快、不影响交通等优点,已成为钢箱梁施工的首选方案。文章以马场坪互通匝F桥为施工案例,对钢箱梁采用顶推施工方法,将已浇筑完成的第一联(1~3跨)的箱梁梁体作为顶推平台,与传统的顶推相比,节约了钢箱梁顶推平台的搭设费用,与支架法吊装拼接相比减少了满堂支架搭设费用。该施工方法摆脱了以往钢箱梁跨越高速搭设临时支墩、占用高速公路车道,以及平面、立体交叉作业的施工安全隐患较多的局面,有力保障了施工人员的安全,降低了施工安全风险。

The idea of incremental construction method originates from steel bridges,mainly applied to cable-stayed bridges with high piers and large spans.With the continuous development of highway engineering construction in China and the increasingly widespread use of steel,the number of steel structure bridges in China continues to increase.Due to the advantages of safe and reliable construction,fast construction speed,and no impact on traffic,the top push construction method has become the preferred solution for steel box girder construction.This article takes the Machangping Interchange Ramp F Bridge as the actual case,and adopts the top push construction method.The steel box girder is constructed using the first poured(1-3 spans)box girder body as the top push platform.Compared with traditional top push,it saves the installation cost of the steel box girder top push platform and reduces the cost of full support installation compared to the support method for lifting and splicing.This construction method breaks away from the situation where temporary piers were erected when steel box beams crossed highways,occupied highway lanes,and had many construction safety hazards in plane and grade crossing operations.It effectively ensures the safety of construction personnel and reduces construction safety risks.