What are the main construction processes for building steel structure engineering?

Recently, with the transformation of urban construction towards high efficiency and green, steel structure engineering has been widely used in various engineering projects such as large venues, high-rise buildings, industrial parks, etc., relying on its advantages of lightweight and high strength, convenient construction, energy conservation and environmental protection. The construction quality of steel structure engineering is directly related to the safety, stability, and durability of buildings, and a scientifically standardized construction process is the core prerequisite for ensuring engineering quality.
The construction of building steel structure engineering is a systematic project that requires multiple core stages such as preliminary preparation, component processing, on-site installation, coating protection, and acceptance completion. Each link is closely connected and interlocked, and each step must strictly follow industry standards and design requirements to ensure that the entire construction process is orderly and controllable.

Pre construction preparation is the foundation for the smooth progress of steel structure engineering, mainly including drawing review, scheme preparation, personnel training, equipment preparation, and material acceptance. Before the project starts, the construction unit will organize multiple parties such as design and supervision to conduct a drawing review, carefully checking key information such as component dimensions, node methods, material specifications, etc., and promptly resolving any doubts in the drawings to ensure the accuracy and operability of the construction drawings. At the same time, a special construction organization design will be prepared based on the actual situation of the project, clarifying the construction plans, safety technical measures, and quality control standards for each link. After approval, it will be put into implementation. Construction personnel need to undergo professional training, and special operators such as welders and crane operators must hold valid work permits before they can work. In addition, construction equipment such as welding equipment, lifting equipment, and testing instruments need to be inspected on site to ensure their performance is qualified; Steel, welding materials, connecting materials and other raw materials need to be strictly inspected, and quality certificates and qualification certificates should be checked. If necessary, sampling and re inspection should be carried out. Only after passing the inspection can they be put into use to ensure the quality of the project from the source.

The processing and production of steel components in the factory is a key link in the construction of steel structures, and its quality directly determines the accuracy and efficiency of subsequent on-site installation. This stage mainly follows the core process of "layout → marking → cutting and cutting → straightening → edge and end processing → drilling → assembly → welding → friction surface treatment → painting". The layout process requires drawing component samples in proportion and accurately reserving welding shrinkage; Marking is to mark the cutting position on the steel and arrange the materials reasonably to save materials. Cutting and cutting can be done using high-temperature heat sources such as oxygen cutting and plasma cutting, as well as mechanical methods such as machine cutting and sawing, to ensure a smooth and crack free cut and timely removal of slag after cutting. For steel that undergoes deformation after cutting, it needs to be straightened through mechanical correction or flame correction using a steel straightening machine, and there should be no obvious damage after correction.

Edge and end processing can be carried out using methods such as scraping, planing, milling, etc., to ensure that the groove angle and blunt edge size meet the welding process requirements; Drilling is usually used for hole making, and punching can be used for thinner non critical components. The deviation of hole diameter and spacing should be controlled within the allowable range of the specifications. The assembly of components needs to be carried out on a flat and firm platform, using methods such as ground sampling and tire assembly to spot weld and fix them in sequence. After checking the assembly dimensions and gaps to ensure they are qualified, the welding process can proceed. Before welding, it is necessary to conduct welding process evaluation, develop reasonable welding operation procedures, strictly control parameters such as current, voltage, and speed during the welding process, remove welding slag in a timely manner after welding, conduct visual inspection and non-destructive testing on the weld seam, and repair unqualified welds as required, with a maximum of 2 repairs. After welding is completed, the friction surface of the component is treated with sandblasting, shot blasting and other methods, and finally painted. First, anti-corrosion coating is applied, and then fireproof coating is applied to ensure uniform coating thickness and good adhesion, effectively improving the corrosion resistance and fire resistance of the component.

The transportation and on-site stacking of steel components are important links connecting factory processing and on-site installation. Before transportation, a special transportation plan should be prepared, the transportation route should be surveyed, suitable transportation vehicles should be selected, and the components should be firmly fixed to prevent deformation and damage during transportation. After the components are transported to the site, they should be classified and stacked according to specifications and models, with proper labeling. The stacking area should be elevated to prevent moisture and prevent corrosion and deformation of the components. After the on-site stacking is completed, the quantity, appearance quality, and dimensions of the components need to be checked again to ensure consistency with the design requirements.

On site installation is the core stage of steel structure construction, which needs to be carried out in an orderly manner after the foundation acceptance is qualified. Before installation, a comprehensive inspection of the axis, elevation, and embedded parts of the building foundation is required. After meeting the requirements, a special installation plan is prepared, and qualified lifting equipment is equipped and debugged in place. According to the size, weight, and site conditions of the components, single machine lifting, double machine lifting, and other methods are used for component lifting. Large and complex components can be installed using segmented unit installation schemes. For example, in the construction of the steel structure roof of the Yellow River Sports Center Gymnasium, a segmented unit installation scheme of "multiple large crawler cranes+lattice column support" was adopted, effectively solving the problems of complex roof structure and difficult lifting.

During the lifting process, it is necessary to accurately control the position and elevation of the components, and use methods such as cable wind ropes for positioning and fixing to prevent the components from overturning. After the components are in place, they should be connected and fixed in a timely manner. The high-strength bolt connection pair should be initially tightened, re tightened, and finally tightened in the order of "from the part with higher joint stiffness to the part with lower constraint, and from the center of the bolt group to the surroundings". The connection nodes used for both bolts and welding should be constructed in the order of first tightening the bolts and then welding. During the entire installation process, it is necessary to monitor the verticality and levelness of the components in real time, adjust deviations in a timely manner, and ensure that the installation accuracy meets the specifications. For steel structures with complex shapes, BIM software can be used to model and cut materials, accurately control node positioning, and improve installation quality and efficiency.

The finishing and acceptance of coating protection is the final stage of steel structure construction, which directly affects the service life and safety performance of the building. After the on-site installation is completed, a comprehensive inspection of the coating layer of the components should be carried out, and any coating damage caused during transportation and installation should be repaired in a timely manner to ensure the integrity of the coating. The application of anti-corrosion and fireproof coatings should be carried out by professionals with corresponding qualifications, strictly following the construction process. Anti corrosion coatings should be applied in the order of "base treatment → primer coating → intermediate paint coating → topcoat coating → inspection and acceptance", while fireproof coatings should be applied in the order of "base treatment → coating preparation → coating construction → inspection and acceptance". Thick fireproof coatings need to be reinforced with steel wire mesh and other measures in specific situations.

After the painting is completed, the construction unit organizes self inspection. After passing the self inspection, it is submitted to the supervision unit for acceptance. The supervision unit conducts a comprehensive inspection of the project quality according to the specifications, focusing on key indicators such as component size, welding quality, painting thickness, and connection accuracy. After passing the acceptance inspection, the project can enter the completion stage, and the construction materials, including construction drawings, technical disclosure records, material inspection reports, welding process evaluation reports, weld seam inspection reports, etc., should be organized and improved to ensure that the materials are complete, authentic and effective, providing a basis for subsequent maintenance of the project.

Industry insiders say that the standardization and normalization of the construction process for building steel structures are key to ensuring project quality and construction safety. With the continuous advancement of technology, steel structure construction will pay more attention to refined control and green construction, further improving construction efficiency and engineering quality. In the future, with the implementation of more steel structure projects, scientific and reasonable construction processes will provide strong support for the high-quality development of urban construction.