Multi-span bailey beam and cast-in-place support platform are closely related in bridge construction and other fields, mainly reflected in the following aspects:
In terms of composition and structure, multi-span bailey beams are often used as the main load-bearing structural components of cast-in-place support platforms. In the construction of cast-in-place beams, especially in the complex environment of cross-line, cross-river, etc., steel pipe columns and Bailey beams are often used to construct support platforms. Bailey beam has the characteristics of simple structure, convenient transportation, fast erection, large load capacity, good interchangeability and strong adaptability. It can form a multi-span beam structure system through reasonable arrangement and combination, and provide a stable and reliable support platform for the cast-in-place operation above.
Construction application: Multi-span bailey beam support platform provides working space and supporting foundation for cast-in-place construction. During the cast-in-place construction of bridge box beams and other structures, the construction personnel install formwork, tie steel bars, and pour concrete on the support platform composed of Bailey beams. For example, in the construction of some bridge beams, the use of multi-span Bailey beam support can effectively alleviate the impact on road traffic, and meet the requirements of cast-in-place beam construction.
In terms of force coordination: During the entire construction process, the multi-span Bailey beam and other components of the cast-in-place support platform bear the load together. The Bailey beam bears the main vertical load, including the weight of the cast-in-place concrete structure, the weight of construction equipment and personnel, etc., while the other parts of the support platform, such as the steel pipe columns and connecting systems, work together with the bailey beam to transfer the load to the foundation and ensure the overall stability of the structure. Taking the construction of cast-in-place box girder without floor support as an example, the cast-in-place bailey bracket consists of lower hoop, support rod, upper hoop, bearing beam, Bailey beam and full bracket from bottom to top. All parts cooperate with each other to jointly bear the construction load of cast-in-place box girder.
Deformation control: The deformation of multi-span Bailey beam directly affects the flatness and stability of cast-in-place support platform, and then affects the construction quality of cast-in-place structure. It is necessary to calculate and control the deformation of Bailey beam during construction. By reasonable setting of prearch and adjusting the arrangement and connection mode of Bailey beam, the deformation of Bailey beam under load can meet the requirements of castin construction and ensure the linear and dimensional accuracy of castin structure. For example, in the construction of the fourth span cast-in-place box girder of Yunxi Bridge, measures such as reducing the span of the Beret beam and strengthening the Beret beam are taken to control the deformation and ensure the construction quality of the cast-in-place box girder.
