高原山区大跨度悬索桥关键施工方案研究

Study of Key Construction Scheme for Long-Span Suspension Bridge in Harsh Mountainous Region of Plateau

高原山区气候恶劣、交通不便、施工场地狭小,大跨度悬索桥施工工效低、施工控制难度大,需对其关键施工方案进行研究。结合国内部分已建及在建山区大跨度悬索桥的施工实例,分析该类桥梁的主要构件施工方法、智能化控制和施工监控。结果表明:桥塔可采用塔梁异步施工、钢筋可采用分片安装;重力锚可推广应用无冷却水管温控技术;隧道锚推荐采用钻爆法机械化开挖,可采用提斗式矿车出渣;猫道先导索推荐采用无人机飞行器架设;结合实际情况,主缆可选择循环式或往复式牵引系统架设;钢梁推荐采用两侧缆索吊装;施工推荐采用智能化控制;施工监控中需重点控制日照、温差等对主缆施工的影响。

The mountainous region of plateau features harsh climate conditions and poor transport facilities,and the spaces for construction are very limited,which not only makes the construction of the long-span suspension bridge with low efficiency,but also increase the complexities in construction control.Therefore,the key construction schemes should be studied.Based on the engineering practices of the long-span suspension bridges that are under construction or have already been in service in China,the construction methods,intelligent control and construction monitoring and control for the main components of the bridge of such type are analyzed.The results demonstrate that the construction of the tower can be carried out independently from the construction of the girder and the reinforcement at different locations can also be installed independently.The temperature of the gravity anchor block during the construction process can be controlled without using the cooling water pipes.The tunnel anchorage can be excavated by drilling and blasting and cleared by the bucket tipping mine cars.The UAVs are recommended to erect the pilot cables of the catwalk.In accordance with the actual construction conditions,the main cables can be erected by the cyclical or to-and-fro traction systems.The steel girder segments can be installed with the aid of main cables from the two sides towards the midspan.The construction can be intelligently controlled.The construction monitoring and control should focus on the influence of solar radiation and temperature difference.