小半径大坡度转体梁施工关键技术研究

Research on Key Technologies for Construction of Small radius and Large Slope Swivel Beams

针对目前既是小曲线半径又是大坡度的桥梁转体施工研究不多现状,依托新建广州至湛江高速铁路工程广珠京广联络线特大桥(52+52)m转体梁施工项目,结合该桥为目前国内最小曲率半径(仅310 m)、坡度最大(纵坡达20‰)的T构转体桥,梁体上跨环镇东路、京广三线联4线、机走线等多条城市道路和铁路线路,转体过程中梁底与接触网立柱柱顶隔离开关距离仅有30 cm等不利条件,阐述了该转体桥的称重、配重、转体结构施工、BIM技术应用、定位监控等施工关键技术;通过转体结构的精准施工、BIM技术建模对施工方案进行优化、梁体二次配重方案进行预演、实时定位监控技术进行精度控制,历经50 min安全顺利完成转体施工,相关经验可为小半径大坡度转体梁施工提供参考。

In response to the current lack of research on the construction of swivel bridge with both small curve radii and large slopes,relying on the construction project of the Guangzhou Zhuhai Beijing Guangzhou connecting line super large bridge(52+52)m swivel beam of the newly built Guangzhou-Zhanjiang high-speed railway project,combined with the fact that this bridge is currently a T-shaped rotatable bridge with the smallest curvature radius(only 310 m)and the largest slope(longitudinal slope up to 20‰)in China,spanning Huanzhen East Road and connecting the Beijing-Guangzhou Third Line with Line 4 multiple urban roads and railway lines,such as machine running lines,there are unfavorable conditions such as a distance of only 30 cm between the bottom of the beam and the top of the overhead contact system column isolation switch during the rotation process.The key construction technologies of the rotation bridge,such as weighing,balancing,swivel structure construction,BIM technology application,positioning monitoring,are elaborated.Through precise construction of the swivel structure,BIM technology modeling to optimize the construction plan,rehearsal of the secondary weight scheme of the beam body,and real-time positioning monitoring technology to control accuracy,the swivel construction is safely and smoothly completed after 50 minutes.The relevant experience can provide reference for the construction of small radius and large slope swivel beams.