Quality control of steel structure installation

① Before installation, the construction unit should inspect the product certificates, design documents, and pre-assembly records of the components, and re-verify and record the dimensions of the components. If the deformation or defects of the steel structure exceed the allowable tolerances, they should be addressed.
Before installation, a detailed measurement and correction process should be developed. For thick steel plates, process tests simulating the product structure should be conducted before welding and installation, and corresponding construction procedures should be prepared. A certain camber should be pre-set for the assembled roof trusses.

② After the steel structure is hoisted into place, the construction unit should measure and mark the design-required control points such as component positioning axes and elevations, and conduct pre-welding inspections of the hoisting and butt joints. Temporary supports and steel cables should be installed to ensure the safety and stability of the steel roof trusses during construction.

③ During steel structure installation, the construction unit should submit the elevation dimensions, welding, and painting of each component after hoisting to the supervisor for acceptance.

 

The Chinese steel structure industry is showing continuous and rapid growth. Steel structure production increased from 8.5 million tons in 2002 to 22.94 million tons in 2009, with an average annual compound growth rate of 15.24%. According to relevant data, steel structure production reached 26 million tons in 2010. In 2011, steel structure production was approximately 29 million tons. The Chinese steel structure industry is currently in a period of rapid development.

The overall concentration of the Chinese steel structure industry is relatively low. The number of steel structure enterprises with annual production of less than 10,000 tons, 10,000-50,000 tons, 50,000-300,000 tons, and more than 300,000 tons are 4000-5000, 100, 20, and 6-8 respectively; there are 51 enterprises with top-level steel structure manufacturing qualifications, 82 enterprises with Class A special design qualifications for light steel structure engineering, and even fewer enterprises that simultaneously possess the above qualifications and Class A professional contracting qualifications. As the industry continues to develop, mergers and acquisitions will become commonplace.