1. Structural System and Computational Analysis
The primary task in designing a steel frame structure is selecting a rational structural system and performing precise calculations using specialized software. Professor Li from the Department of Civil Engineering at Tsinghua University points out: "It is essential to fully consider wind loads, seismic actions, snow loads, and imposed live loads. For high-rise or long-span buildings, nonlinear analysis, dynamic time-history analysis, etc., are also required to ensure the structure possesses sufficient load-bearing capacity and ductility under extreme conditions."

2. Connection Design: The Lifeline of Safety
Connections are critical components for force transfer in a steel frame, making their design paramount. The detailing of connections should adhere to the principle of "strong connections, weak members" to ensure connection reliability and toughness. Particularly for beam-column connections, rigid, pinned, or semi-rigid connections must be adopted based on seismic requirements, and detailed finite element analysis should be conducted to avoid stress concentration.

3. Fire Protection and Corrosion Protection Design
The inherent weaknesses of steel are its fire resistance and corrosion resistance. During design, fire protection measures for steel members (such as fire-resistant coatings, encasement, etc.) must be specified according to the building's function and required fire resistance rating. Simultaneously, appropriate anti-corrosion coating systems should be selected based on the environmental corrosivity category, with detailed protection design for vulnerable areas like connections and welds.

4. Coordination with Other Disciplines
Steel structure design must closely coordinate with architectural, mechanical & electrical (M&E), curtain wall, and other disciplines. Space for equipment and piping penetrations needs to be reserved in advance. Considerations include supports for curtain walls, the connection between floor slabs (commonly composite decks with profiled steel sheeting) and steel beams, and controlling structural deformation to meet building comfort requirements.

Construction Phase: Precise Craftsmanship and Strict Management

1. Material and Component Quality Control
All incoming steel materials must have certified quality documentation and be sampled for re-inspection as regulations require. The machining accuracy of components directly affects on-site installation, necessitating strict control over dimensional tolerances in cutting, welding, and hole-making. As a primary connection method, welding must be performed by certified welders, with visual inspection and non-destructive testing conducted on welds.

2. Installation Accuracy and Surveying Alignment
"The precision of embedded foundation anchor bolts is the first step, with errors strictly controlled to the millimeter level," emphasized a project manager from China Construction Steel Engineering Corporation. During installation, vertical alignment of columns, elevation, and levelness of beams must be corrected section by section. Subsequent installation can only proceed after a stable spatial unit is formed. Temperature effects on structural dimensions must be considered for high-altitude work.

3. High-Strength Bolt Construction
High-strength bolted connections are another core aspect of frame installation. Construction must strictly follow the procedures of initial tightening and final tightening, using specialized torque wrenches to ensure the design pre-tension is achieved. Faying surfaces must be kept clean and dry, strictly free from paint, oil stains, or contaminants.

4. Construction Safety and Temporary Bracing
Steel structure installation involves high-risk operations, requiring the development of specialized safety plans. Lifting operations need dedicated personnel for command, with safety警戒 zones established. Reliable temporary bracing systems must be installed before the structure becomes integral to prevent collapse.

5. Fire Protection and Anti-Corrosion Coating Application
Coating application has stringent requirements on environmental conditions (temperature, humidity) and should be avoided during rain, snow, or strong wind. Coating thickness must be inspected using thickness gauges to ensure compliance with design values. After applying fire-resistant coatings, performance tests such as bond strength tests are required.