The installation is the core process of steel structure projects, from component transportation to program completion. Through the arrangement of embedded parts, installation of steel columns and steel beams, connection reinforcement, and enclosure structure construction, the overall safety and stability of the structure are ensured. Scientific construction organization, safety measures, and on-site management ensure the progress and quality of construction. During the delivery stage, multiple inspections and customer acceptance are carried out to ensure that the project results meet the design and use requirements and complete the perfect closed loop from manufacturing to application.

1. Embedded Stage

Safety Measures Arrangement
This step involves the comprehensive deployment of safety protection facilities at the construction site and serves as the primary safeguard for personnel, equipment, and the working environment. Safety measures include the installation of safety fences, prominent warning signage, safety banners, demarcation of hazardous zones and restricted areas, and the provision of anti-fall devices for high-altitude operations. Fire extinguishers, protective nets, guardrails, emergency access routes, and first aid equipment must also be properly arranged to ensure rapid emergency response capability. Scientifically planned and rigorously implemented safety measures effectively prevent accidents such as falls from height, mechanical collisions, and falling objects, while maintaining on-site order and workforce well-being. This step is not only a mandatory legal requirement but also a reflection of the company’s commitment to construction quality, schedule control, and life safety management, forming a solid foundation for subsequent operations.

Equipment Arrival
This step represents the organized delivery of major mechanical equipment and auxiliary construction tools to the site according to the construction plan, marking the transition into active operational execution. Equipment includes hoisting machinery such as tower cranes and crawler cranes, welding machines, power tools, testing instruments, and temporary power supply systems. All equipment must be unloaded, positioned, assembled, and commissioned under professional supervision to ensure safe and reliable operation. Adequate equipment preparation significantly improves operational efficiency, reduces schedule delays, minimizes safety risks, and enhances construction stability. This phase demonstrates the contractor’s coordination capability, equipment management discipline, and technical strength, serving as a prerequisite for efficient hoisting, positioning, and welding operations.

Component Arrival
This step involves the sequential transportation and organized placement of prefabricated steel structure components at the construction site in accordance with the project schedule and spatial planning. Upon arrival, components must undergo verification of identification numbers, dimensions, and appearance quality to prevent installation delays caused by misplacement or errors. Scientific stacking optimizes site space utilization, reduces repeated lifting and handling, and enhances overall efficiency. Protective measures must also be implemented to prevent moisture exposure, corrosion, or mechanical damage. Component arrival functions as the logistical bridge between factory production and on-site installation, reflecting project schedule control and refined site management.

Layout Marking
This step consists of precise measurement and marking operations at the construction site to ensure installation accuracy. Using total stations, laser rangefinders, and levels, key control points such as axes, centerlines, elevation benchmarks, and reference coordinates are accurately transferred from design drawings to the site. High-precision layout control prevents cumulative deviations during installation and ensures geometric accuracy of the structural system. Cross-verification and repeated review are essential to guarantee data consistency and marking clarity. Accurate layout marking provides the technical basis for hoisting, splicing, welding, and node assembly operations.

Embedded Part Positioning
This step involves the accurate positioning of embedded parts within the concrete foundation or slab in strict accordance with structural design drawings and specifications. Embedded parts serve as the connection interface between steel components and the foundation; therefore, any deviation directly affects structural stability and load transfer performance. During positioning, centerlines, elevations, horizontality, and verticality must be precisely measured and adjusted. Fixation methods such as reinforcement positioning, support bracing, and temporary welding are typically employed to prevent displacement during concrete pouring. Accurate positioning enhances installation efficiency, minimizes rework, and ensures structural reliability.

Embedded Part Installation
This step secures the positioned embedded parts firmly within the foundation structure, forming the structural connection basis for subsequent steel installation. Elevation, alignment, horizontality, and verticality must strictly comply with design requirements. Welding, bolting, and temporary supports are applied to maintain stability during concrete pouring and vibration. Proper installation ensures load-bearing reliability and precise alignment with steel components, reducing adjustment work and preventing construction delays.

Dimensional Recheck
This step involves comprehensive measurement and verification of installed embedded parts to confirm compliance with design tolerances. Inspection items include center position, elevation, planar alignment, horizontality, and verticality. Using total stations, laser rangefinders, and precision levels, deviations are identified and corrected promptly to prevent downstream installation complications. This recheck forms a critical quality control checkpoint ensuring smooth hoisting, accurate splicing, and long-term structural stability.

2. Installation Stage

Steel Column Installation
This step involves hoisting prefabricated steel columns onto embedded parts using heavy lifting equipment and securing them accurately in position. As the primary vertical load-bearing elements, steel columns form the structural skeleton of the building. Strict control of verticality, elevation, and centerline deviation is required to maintain geometric accuracy. Temporary supports or guy cables are applied prior to final bolting or welding to ensure stability. Installation quality directly affects overall frame stability, seismic performance, and subsequent beam alignment.

Steel Beam Installation
This step entails lifting transverse steel beams into position and completing bolted or welded connections to establish the primary horizontal load-bearing system. Beam-end gaps, elevation differences, and node stability must be precisely controlled in accordance with layout references. Real-time adjustment of horizontality and straightness is necessary to maintain structural integrity. Proper beam installation enhances overall rigidity and supports roof and floor system construction.

Bolt Fixing
This step secures steel columns, steel beams, and key structural components using high-strength bolts to form a stable structural system. Bolt specifications, quantity, preload force, and installation sequence must strictly follow design standards. Torque wrenches or tensioning devices are employed to ensure accurate preload application and prevent insufficient tightening or overstressing. Standardized bolt fixing ensures load transfer reliability, structural safety, and long-term performance.

Secondary Structure Installation
This step installs purlins, support rods, secondary beams, ceiling frames, and floor decking to complete the structural system and enable spatial functionality. Although secondary structures do not serve as primary load-bearing members, they enhance overall stiffness, wind resistance, and seismic performance. Accurate installation prevents error accumulation and provides support for enclosure systems and building services.

Overall Structural Adjustment
This step integrates the main structure and secondary structure into a complete spatial system. Systematic verification of node connections, geometric tolerances, verticality, and flatness is performed using synchronized measurement equipment. Comprehensive structural acceptance and stability checks confirm compliance with design requirements. This stage establishes the structural foundation for enclosure, electromechanical, and finishing works.

Surface Treatment
This step includes detailed inspection, deviation correction, and surface repair of the installed steel structure. Verticality, flatness, coating integrity, node condition, and potential mechanical damage are examined. Required corrective measures such as welding repair, grinding, or re-spraying are implemented to ensure uniform appearance and corrosion resistance. High-quality surface treatment enhances durability, aesthetics, and long-term performance.

Cladding Installation
This step installs enclosure systems including exterior wall panels, roof panels, doors, windows, and curtain walls onto the main steel structure. The enclosure system ensures environmental protection performance, including waterproofing, wind resistance, insulation, and energy efficiency. Strict control of panel dimensions, joint density, and sealing performance is essential to achieve functional integrity and aesthetic quality. This phase marks the transition from structural framework to functional building space.

3. Delivery Stage

Structural Inspection
This step involves systematic inspection of dimensional accuracy, node quality, weld performance, and bolt strength to ensure structural safety and compliance. Laser measuring instruments, total stations, and ultrasonic flaw detectors are utilized for verification. Identified issues are documented and rectified promptly. Structural inspection ensures long-term safety, stability, and durability.

Appearance Inspection
This step evaluates coating uniformity, anti-corrosion quality, flatness, color consistency, weld appearance, and surface integrity. Any defects such as rust, sagging, or mechanical damage must be repaired prior to delivery. Appearance inspection enhances visual quality, protective performance, and brand image.

Supervisor Re-inspection
This step involves independent verification by a third-party supervision unit to confirm compliance with contractual and technical standards. Structural parameters, weld quality, and process execution are re-evaluated, and corrective measures are supervised. This ensures transparency and quality assurance prior to final acceptance.

Client Acceptance
This step invites the owner’s representatives to conduct comprehensive on-site inspection and confirmation. Quality, dimensional accuracy, appearance, functionality, and documentation are reviewed. Upon successful acceptance and rectification of any issues, the project proceeds to formal handover. This stage strengthens customer trust and brand credibility.

Document Handover
This step systematically organizes and transfers project documentation, including design drawings, inspection reports, construction records, weld inspection reports, hidden works records, change orders, as-built drawings, and quality certificates. Proper documentation supports lifecycle management, maintenance, and legal compliance.

Document Filing
This step archives all project-related documents, inspection records, contracts, supervision reports, and photographic evidence for long-term retention. A comprehensive archiving system supports traceability, quality improvement, and enterprise knowledge accumulation.

Project Completion
This step signifies the formal completion of the steel structure project from design through acceptance. Site demobilization, final cleanup, documentation confirmation, and dual approval by supervisor and client are completed. The project transitions into the operational and warranty phase. Project completion represents contractual fulfillment, technical capability, and corporate reputation, marking both the conclusion of construction and the beginning of long-term cooperation and service commitment.