| Design basis | Project location, building use, service life, importance category, governing authority, and design responsibility. | Industrial building, warehouse, commercial building, platform, pipe rack, or multi-storey frame; intended design service life stated in the project brief. | AISC 360 EN 1990 GB 50017 | Written design-basis document identifying the adopted code edition, load combinations, material standards, analysis method, and design assumptions. | Must be confirmed before pricing. |
| Dead loads | Self-weight of steel, slabs, decking, roofing, cladding, finishes, ceilings, permanent equipment, piping, and fixed services. | Use measured or specified component weights. Include allowance for permanent attachments and account for the structural model’s self-weight calculation method. | AISC 360 EN 1991-1-1 GB 50009 | Load take-off, member self-weight settings, permanent-load schedule, and calculation assumptions. | Check that equipment and non-structural permanent loads are not omitted. |
| Imposed and occupancy loads | Occupancy type, floor access, storage arrangement, maintenance zones, partition loads, and concentrated loads. | Loads depend on use and national annex or local requirements; storage and industrial areas commonly require higher or special load cases than ordinary office areas. | ASCE 7 with AISC 360 EN 1991-1-1 GB 50009 | Floor-load plan, distributed and concentrated load cases, and explanation of load categories used in combinations. | Verify use-specific loads with the project engineer. |
| Roof loads | Roof access, maintenance loading, roof-mounted equipment, drainage arrangement, finishes, and suspended services. | Separate permanent roof weight, maintenance or access load, snow load, ponding or water accumulation risk, and equipment reactions. | ASCE 7 / AISC 360 EN 1991-1-3 GB 50009 | Roof load map, local equipment reactions, ponding assessment where applicable, and design combinations. | Confirm whether the roof is accessible and whether snow drift zones apply. |
| Snow and ice | Ground snow data, roof shape, exposure, thermal condition, drifting geometry, parapets, and adjacent higher structures. | Snow actions may include uniform snow, asymmetric snow, drifted snow, and exceptional snow where required by the governing standard. | ASCE 7 EN 1991-1-3 GB 50009 | Source of climatic data, roof snow diagrams, drift cases, and governing snow combination. | Do not use a generic snow value without location and roof geometry. |
| Wind actions | Basic wind data, terrain category, topography, building height, enclosure classification, openings, internal pressure, and façade zones. | Check external pressure, internal pressure, local cladding pressures, overall frame effects, uplift, and serviceability drift. | ASCE 7 with AISC 360 EN 1991-1-4 GB 50009 | Wind criteria, pressure coefficients, wind load cases, façade-zone pressures, and drift results. | Confirm local wind parameters and enclosure assumptions. |
| Seismic actions | Seismic hazard, site class, importance, response spectrum, structural system, ductility level, irregularities, and non-structural restraints. | Define base-shear method, modal analysis requirements, accidental torsion, drift limits, diaphragm behavior, and connection ductility requirements. | ASCE 7 / AISC 341 EN 1998-1 GB 50011 / GB 50017 | Seismic design category or equivalent, response spectrum, system classification, drift checks, and connection design basis. | AISC 360 alone does not replace seismic provisions where AISC 341 is required. |
| Temperature effects | Building length, temperature range, solar exposure, restraint conditions, expansion joints, and connection detailing. | Consider expansion, contraction, thermal gradients, restraint forces, and temperature-sensitive equipment or façades. | AISC 360 EN 1991-1-5 GB 50009 | Temperature load cases, movement calculations, expansion-joint locations, and sliding or fixed support strategy. | Check compatibility between steel movement and cladding or services. |
| Crane and material-handling loads | Crane capacity, wheel loads, trolley position, impact factors, lateral surge, longitudinal forces, duty class, and fatigue cycles. | Include vertical wheel loads, transverse surge, longitudinal traction or braking, accidental skewing where applicable, and fatigue effects. | AISC 360 EN 1991-3 GB 50017 | Crane data sheet, runway-beam reactions, wheel-load envelopes, fatigue assessment, and rail alignment tolerances. | Supplier must demonstrate experience with dynamic and fatigue design. |
| Operational and equipment loads | Machine reactions, vibration, rotating equipment, pressure vessels, silos, tanks, pipes, cable trays, and maintenance operations. | Static reactions may need to be supplemented by dynamic amplification, harmonic forces, vibration limits, or accidental operating cases. | Project specifications AISC 360 EN 1993 GB 50017 | Equipment interface schedule, support reactions, vibration criteria, load envelopes, and coordination drawings. | Require certified equipment reactions rather than preliminary estimates where possible. |
| Accidental and robustness actions | Vehicle impact, blast basis if applicable, dropped objects, fire scenario, progressive-collapse strategy, and abnormal operating events. | Project-specific accidental actions may govern local members, ties, connections, barriers, or alternate-load-path checks. | ASCE 7 / AISC 360 EN 1991-1-7 GB 50009 / GB 50017 | Accidental-load register, robustness concept, fire design interface, and local protection requirements. | Confirm these requirements before selecting member sizes or connection types. |
| Load combinations | Strength, stability, serviceability, fatigue, fire, seismic, and accidental combinations applicable to the project. | Use combinations from the adopted jurisdictional framework; do not mix factors from different standards without engineering justification. | AISC 360 LRFD / ASD EN 1990 GB 50009 / GB 50017 | Complete combination table, governing combinations by limit state, and software load-combination export. | The supplier must identify the governing case for each critical member and connection. |
| Code selection: AISC route | Projects using United States-based or contractually specified American design provisions. | AISC 360 provides general requirements for structural steel buildings and includes both LRFD and ASD design methods. Seismic design may also require AISC 341 and AISC 358. | AISC 360 ASCE 7 AISC 341 AISC 358 | Design calculations, specification references, member and connection checks, and clearly stated LRFD or ASD basis. | Confirm engineer licensing, contract jurisdiction, and required material specifications. |
| Code selection: Eurocode route | Projects adopting European structural design standards or a national Eurocode implementation. | EN 1993 covers steel structures and is used with EN 1990 for basis of design, EN 1991 for actions, and EN 1998 where seismic design applies. National Annex parameters can modify design values. | EN 1990 EN 1991 EN 1993 EN 1998 | National Annex register, design situations, partial factors, buckling curves, connection checks, and execution-class assumptions. | The applicable National Annex must be identified, not assumed. |
| Code selection: China route | Projects designed, approved, or constructed under Mainland China requirements. | GB 50017 is the primary steel-structure design standard and is used with action, seismic, foundation, fire, and construction standards as applicable. | GB 50017 GB 50009 GB 50011 GB 50205 | Chinese-code calculation package, material and welding requirements, seismic assumptions, fabrication tolerances, and inspection plan. | Confirm the current mandatory edition and local approval requirements with the authority having jurisdiction. |
| Materials and traceability | Steel grade, plate and section availability, toughness, weldability, coating system, fastener grade, and delivery condition. | Typical specifications may include ASTM, EN, or GB material standards; the selected grade must match strength, toughness, welding, and temperature requirements. | AISC 360 Chapter A EN 10025 GB/T 1591 | Mill certificates, heat-number traceability, material substitution procedure, welding procedure specifications, and inspection records. | Reject undocumented substitutions or incomplete mill certification. |
| Connections and fabrication | Bolt type, weld category, slip-critical requirements, erection sequence, access, tolerances, and site-welding limitations. | Connection design must address strength, stiffness, ductility, fatigue where relevant, erection forces, and inspection requirements. | AISC 360 / RCSC EN 1993-1-8 GB 50017 / GB 50661 | Shop drawings, connection calculations, weld procedures, bolt installation method, NDT plan, and erection method statement. | Evaluate engineering and fabrication as one coordinated capability. |
| Serviceability and durability | Deflection limits, vibration criteria, drift limits, corrosion environment, fire rating, drainage, and maintenance access. | Serviceability limits are project- and use-dependent; corrosion protection and fire protection must be compatible with the exposure and required rating. | AISC 360 EN 1993-1-1 / EN 1993-1-2 GB 50017 | Deflection and vibration report, corrosion category or exposure basis, coating specification, fire-protection design, and maintenance plan. | Do not compare suppliers using steel tonnage alone; compare whole-life performance. |
| Supplier evaluation evidence | Engineering competence, software capability, quality system, production capacity, inspection resources, schedule, and site support. | Evidence should cover calculation review, BIM or detailing workflow, welding qualifications, dimensional control, coating inspection, packing, and erection support. | Project specification Applicable code Quality plan | Anonymous capability matrix, sample calculation index, inspection and test plan, fabrication schedule, nonconformance process, and references to comparable project types without disclosing confidential company data. | Select based on verified technical evidence, not only quoted price. |
