无应力状态法在大跨径拱桥施工中的应用

Application of Stress-Free State Method in Long-Span Arch Bridge Construction

为了实现大跨径拱桥经施工成桥后拱肋的受力状态逼近设计的合理成桥状态,以采用斜拉扣挂的缆索吊装、悬臂浇筑、转体施工等工法的大跨径拱桥为对象,讨论了无应力状态法的具体实施方法;推导了扣索索力的计算公式;提出了调索过程中拱肋位移和曲率约束条件的控制条件。将无应力状态法用于500 m级的钢管混凝土拱桥和200 m级悬臂浇筑拱桥施工计算,计算结果表明:成拱后的拱肋线形和内力与设计状态一致。

In order to realize the reasonable bridge state that the stress state of the arch rib of the long-span arch bridge will be the same as the design after the construction of the bridge,the specific implementation of the stress-free state method was discussed,taking the long-span arch bridge with cable hoisting,the cantilever casting,the rotation construction and etc. as the research object. The cable force calculation formula was derived,and the control conditions for the displacement and curvature constraint of the arch rib during the adjustment process were proposed. The stress-free state method was applied to the construction calculation of the 500 m concrete filled steel tube arch bridge and the 200 m cantilever casting arch bridge. The calculation results show that the alignment and internal force of the arch rib after arch are consistent with the design condition.