支架现浇的异型系杆拱桥合理施工状态的确定

Determination of Reasonable Construction States of Special-shaped Tied-arch Bridge Casting in Place with Full Framing

以支架现浇施工的长沙市黄柏浏阳河异型拱桥为工程背景,对异型拱桥施工全过程进行受力分析,给出了异型拱桥施工过程中各典型状态的受力性能和合理施工工序。异型系杆拱桥裸拱状态拱圈弯矩呈S形分布,拱圈支架分区卸落和成桥状态索力调整引起的弯矩增量分布可以用相应连续梁的弯矩来比拟。钢筋混凝土异型拱桥施工中不得出现裸拱状态;拱圈支架需按一定次序分区卸落,卸落过程中需按一定要求调整吊杆索力。

The Huangbo Liuyang River Bridge casting in place with full framing, which is a special-shaped tied-arch bridge, was taken as the object to study the structural behaviors for typical construction states and reasonable construction procedures. In the present study, the reasonable sequences of arch decentering, the sequences and amount of force adjustment of inclined cable tensile forces of each state were determined. Moment distribution of arch ring of special-shaped tied-arch bridge is at the shape of ＂S＂, and the distribution of moment increment caused by zonal decentering of arch ring scaffold and hanger force adjustment at the completion state can be assimilated to distribution of moment of continuous bridge. Reinforced concrete special-shaped tied-arch bridge only by self-weight in construction is not allowed. The decentering of arch ring scaffold in different zones should be in order. During the decentering, the hanger force adjustment should follow certain requirement.