大跨度钢管砼拱桥拱肋预制与吊装的线形控制

钢管拱桥拱肋线形控制是全桥质量保证的重点之一,关系到全桥受力状态和使用寿命.以太平湖大桥为工程实例,首先阐述了拱肋在加工过程中的线形控制,对钢板下料、节段预拼以及焊接等方面的线形控制进行了简要的介绍;同时对吊装过程中的线形控制进行了深入的研究,在理论分析及现场测试基础上,根据控制测量原理及技术要求,动态调整扣索索力,可以保证拱的安装线形符合设计要求;最后分析了在拱肋吊装过程中,可能对拱轴线形产生影响的主要因素,如温度、塔架水平位移以及扣索张拉伸长量等等所造成的影响.工程实践表明,这种控制方法合理可行,实施方便,数据精度满足要求,达到了监测监控线形的目的.

The Line Shape Control of the Arch prefabricating and Hoisting of Long Span Arch Bridge with Concrete Filled Steel Tube

Based on the Taiping Lake extra large bridge,the paper sets forth the control technology of line shape during the course of arch ribs' machining and introduces briefly the line shape control on steel slab's machining,sects prefabrication and welding.At the same time,the line shape control in the process of cable hoisting is studied in depth.On the basis of theoretical analysis and site testing and according to the survey theory and technology requirement,the dynamic regulation of cable power can assure arch rib to achieve design requirements.Finally,the main effects in cable hoisting is analyzed,which may decide the rib shape,such as the effect of temperature,the plane excursion of the tower,the elongation of cable and so on.The project practice indicates this kind of control method is feasible and convenient to implement and the precision of the data meets the demands.Therefore,it has achieved the goal of monitoring and controlling line shape.