桅杆柱撑索膜结构张拉前施工技术

Construction Technology of Mast Column Support Cable Membrane Structure Before Tensioning

大兴新机场北线(S3300)高速公路廊坊段出入口收费站罩棚,采用空间柔性结构体系,通过桅杆柱、钢桁架和钢索膜相结合的设计理念,使张拉工作变得操作简单、受力明确,但钢桁架和桅杆柱结构的安装以及张拉前设计受力状态的实现变得尤为重要。依据钢索张拉前基本状态的要求,论述了结构体系施工阶段的受力变化,分析了柔性结构体系从初始状态、平衡状态到设计状态的转化,总结了钢桁架、桅杆柱拼装、安装的操作要点以及结构卸载的具体要求。

The entrance and exit toll station canopy of the Langfang section of the Daxing New Airport North Line(S3300)expressway adopts a spatial flexible structural system.The design concept of combining mast columns,steel trusses and steel cable membranes makes the tensioning work simple to operate and the stress is clear.However,the installation of steel trusses and mast column structures and the realization of the designed stress state before tensioning become particularly important.According to the requirements for the basic state of steel cable before tensioning,the force changes during the construction stage of the structural system are discussed,the transformation of the flexible structural system from the initial state,equilibrium state to the design state is analyzed,and the operational points for the assembly and installation of steel trusses and mast columns,as well as the specific requirements for structural unloading,are summarized.