As a load-bearing structural system, steel structure possesses many advantages such as lightweight, high strength, good plastic toughness, superior seismic performance, the high degree of industrial assembly, short construction period, significant comprehensive economic benefits, flexible structural system, pretty appearance, etc. Therefore, it is more and more widely used in industrial buildings, garages, shopping malls, and other large-span buildings. Corresponding to its construction process, it is necessary to build large reinforced concrete foundations or equipment foundations for these steel structure buildings, and bury structural bolts connecting the steel structure (column) and reinforced concrete foundation. Due to the large foundation of the steel structure (the upper part is mostly quadrangular prism-shaped), it is not easy to fix the bolt, and the quality requirement of steel structure installation is pretty high. Therefore, the embedding accuracy of the connecting bolt has become a key technology for the installation and construction of the metal building.
Use the independent bracket system and shaping mold to locate the embedded bolts, use theodolite or total station to adjust and calibrate accurately, and then complete the pouring of the concrete at one time to achieve the accuracy of the embedded position. Below are the characteristics of this process:
picture 1- process procedure
According to the engineering design positioning coordinates and elevation, the encrypted survey axis and elevation control network are used to facilitate accurate measurement for different parts.
According to the plane layout of the steel structure column, start from the corner column or side column firstly, and fix the embedded bolts along the longitudinal axis. If it is a multi-span steel structure, it should be constructed from the middle span’s longitudinal axis to both sides’ longitudinal axis to reduce the measurement and construction errors, and improve the overall installation accuracy.
The size of the steel structure concrete foundation is large with a maximum width of 3.8 m. The upper part is often designed as a quadrangular prism shape. The supporting mold’s height is much lower than the embedded height of the anchor bolt, and the steel mold has a certain degree of flexibility, which couldn’t meet the accuracy requirements of embedded bolts. Therefore, an independent bracket system is needed.
picture2 - installation diagram of the independent bracket system