大跨径悬臂浇筑拱桥施工期多重风险防御研究

Study on Multiple-risk Prevention of Long-span Cantilever Pouring Arch Bridge in Construction Period

大跨径钢筋混凝土拱桥的主拱圈采用悬臂浇筑法施工时,主拱圈节段施工时间长,悬臂跨径大,面临多重风险考验;为了确保主拱圈施工安全,需要对风险进行分析,并采取必要的防御措施。以净跨径182 m的攀枝花新密地大桥为例,分析了极端气温、洪水、强风、挂篮滑落、扣锚索断裂对主拱圈施工安全性的影响,针对性地采取了对策措施,有效防御了施工期多重风险。

The main arch ring is faced with the multiple risk tests because of long construction time of its node section and long cantilever span when the main arch ring of long-span reinforced concrete arch bridge is constructed by the cantilever pouring method. In order to ensure the construction safety of the main arch ring, it is required to analyze the risk and to take the necessary measures of risk prevention. Taking Xinmidi Bridge with a net span of 182 m in Panzhihua City as an example, this paper analyzes the influence of extreme temperature, flood, strong breeze, form traveler down and stayed anchored cable broken on the construction safety of the main arch ring. The targeted countermeasures are taken efficiently to prevent the multiple risks in construction period.