钢管混凝土劲性骨架拱桥拱肋施工控制研究

Research on the Construction Control of Arch Rib of Concrete-filled Steel Tube Stiff Skeleton Arch Bridge

研究目的:在大跨度钢管混凝土劲性骨架拱桥中,劲性骨架安装线形直接影响成拱线形。若控制不当,甚至会造成拱肋合龙困难。依托夜郎河大桥工程实例,通过仿真分析拱肋斜拉扣挂法悬臂拼装架设全过程,结合现场内力及线形实时监控,研究分析大跨径劲性骨架拱桥拱肋施工控制技术。研究结论:(1)在劲性骨架悬臂拼装时采取拱肋线形和索力双控,以控制拱肋线形为主;(2)在进行仿真分析时,采用节段竖向“0”位移控制索力大小,通过对扣索索力和控制点标高进行调整,竖向位移控制在1 mm误差范围内,得出此时扣索索力;(3)合龙前进行线形两岸联测以及全桥复测,根据拱肋内力及线形的监控结果,通过扣索、缆风索对拱肋进行全面线形、内力合理有效调整;(4)本文提出的拱肋施工控制方法,可有效保证成拱线形和结构应力满足设计和规范要求,对斜拉扣挂法悬臂拼装架设拱肋具有参考价值。

Research purposes:In the large-span CFST stiff skeleton arch bridge,the stiff skeleton installation alignment directly affects the arch alignment.And if it is not controlled properly,it may even cause difficulties in the arch rib closure.Based on the project example of Yelang River Bridge,by the simulation analysis of the whole process of cantilever erection of arch ribs with cable-stayed buckle-hanging method,combined with the on-site internal force and real-time monitoring of alignment,the arch rib construction control technology of large-span stiff skeleton arch bridge is studied and analyzed.Research conclusions:(1)In the cantilever assembly of the stiff skeleton,the arch rib alignment and the cable force were controlled,with the arch rib alignment being the main control.(2)In the simulation analysis,the vertical"0"displacement of the section was used to control the size of the cable force,and the vertical displacement was controlled within 1 mm error by adjusting the cable force and the elevation of the control point to obtain the cable force at this time.(3)Before the closure of the bridge,the joint test of the linear both sides and the whole bridge re-test were carried out.According to the monitoring results of the internal force and alignment of the arch ribs,the alignment and internal force of arch ribs were adjusted reasonably and effectively through the buckling cable and cable wind rope.(4)The construction control method of the arch rib proposed in this paper can effectively ensure that the arch alignment and structural stress meet the design and specification requirements,and it has reference value for the cantilever assembly and erection of the arch rib by the cable-stayed buckle-hanging method.