自锚式悬索桥吊杆安装及体系转换新技术

A New Way for Hanger Construction of Self-Anchored Auspension Bridge

长沙市湘江三汊矶大桥主桥为双塔双索面五跨自锚式悬索桥,上部结构采用钢箱梁。项目施工采用新技术,将钢箱梁按照控制线形标高顶推安装就位后用混凝土预制块进行压重,预抬高桥面,无应力安装吊杆后落梁完成体系转换,该法减少了吊杆反复张拉的繁琐程序,施工更简单、直观。通过合理确定钢箱梁的顶升量及顶升施工分级和落梁施工分级,确保了吊杆的顺利安装和吊杆索力的控制,保证了各构件和施工临时结构的安全,解决了新技术中的关键问题,项目取得成功。

Main bridge of the Changsha Xiangjiang River Sanchaji Bridge is a five span self-anchored suspension bridge with double tower and cable plane. Its superstructure is steel box girder. Steel box girder is burdened with concrete block after being installed by thrusting method, then it preformed camber. The steel box girder sinked to position after the unstressed hanger being assembled, then system transformation is accomplished. The construction could be simplified by this new technique. Through rationally determining the jack-up distance of steel box girder and hierarchically controlling the jacking up and falling down construction of steel box girder, the hanger is assembled successfully and the force in hanger is controlled, the safety in construction is ensured. The pivotal question in the new technique is solved, and the project is successful.