嘉绍大桥主航道桥几何合龙控制

Geometry Closure Control of Main Channel Bridge of Jiaxing-Shaoxing Bridge

嘉绍大桥主航道桥是世界上首座六塔、双幅、空间四索面斜拉桥,全桥共有7个合龙口,合龙方案复杂。针对传统温度合龙工艺所存在的问题,基于几何控制法理论,首先给出了一种新的合龙工艺———几何合龙;其次介绍了合龙口姿态调整的计算方法及主航道桥选择几何合龙的原因;最后介绍了几何合龙工艺在嘉绍大桥实施时的操作要点。几何合龙技术可消除合龙时的温度附加效应,保证既定的合龙时间。实测数据表明采用几何合龙方式的嘉绍大桥主航道桥合龙后主梁线形平顺,误差较小,施工控制工作取得了较好的成果。

The main channel bridge of Jiaxing - Shaoxing bridge is the world＇s first 6-pylon seperate-deck, 4- cable-plane cable-stayed bridge, There are 7 closures and the closure scheme is complex. In the light of the problems of traditional temperature closure process, based on geometric construction control theory, first, we introduced a new closure process-geometry closure. Second, we introduced final closure attitude adjustment calculation method and the causes that selecting geometry closure for the main channel bridge. Finally, we introduced the operating details that implementing geometry closure process for Jiaxing - Shaoxing bridge. Geometric closure technique can eliminate the additional effect of temperature and ensure the established closure time. The measured data show that the profile of the main girder of Jiaxing - Shaoxing bridge is smoother and the error is smaller using geometry closure, the construction control work can achieve better result.