Steel Structure Design, Procurement, Prefabrication & Site Installation

Project Description

1) Engineering & Design

• Basis of Design (BoD): Develop design criteria including loads (dead, live, wind, seismic, thermal), deflection limits, serviceability, corrosion category, and erection tolerances.

• Codes & Standards: Design to applicable standards (e.g., AISC/EN 1993, AWS D1.1 for welding, ISO 12944 for coatings, ASTM/EN for materials, ASCE/EN 1991 for loads).

• Detailed Design & Modeling:

o Create 3D models and general arrangement (GA) drawings.

o Produce fabrication drawings, weld maps, bolt lists, and connection details (moment, shear, braced).

o Provide anchor bolt layouts, base plate designs, and grout specifications.

• Design Deliverables: Calculations, GA drawings, shop drawings, connection design notes, bill of materials (BoM), erection sequence drawings, lifting plans, and method statements.

• Design Reviews: Conduct interdisciplinary checks (civil, mechanical, electrical), clash detection, constructability review, and HAZID/HAZOP (as applicable).

2) Material Procurement & Inspection

• Material Take-Off (MTO) & BoM

• Incoming Material Inspection

• Storage & Traceability

3) Prefabrication (Shop)

• Cutting & Edge Preparation: CNC/oxy-fuel/plasma cutting; bevels per weld procedure; control heat input and prevent distortion.

• Fit-up & Assembly: Conformance to shop drawings; use jigs/fixtures; maintain camber and sweep control; check flange/web alignment.

• Welding:

o Qualified WPS/PQR and welder qualifications per AWS/EN ISO.

o Interpass temperature control, preheat as required.

o Weld visual inspection, dimensional checks, and NDT (VT, MT/PT, UT/RT) per ITP and hold points.

• Bolting (Pre-Assembly): Verify hole quality, bolt fit, threads; mock-up critical connections where needed.

• Dimensional Control: Check squareness, diagonals, hole alignment, base plate flatness; document with inspection records.

• Surface Preparation & Coating:

o Blast cleaning (e.g., Sa 2½ / SSPC-SP10) to specified profile.

o Apply primer/intermediate/top coats per ISO 12944 system; measure DFT, adhesion, and holiday tests for coatings.

o For galvanising: Dip per ISO/ASTM standards; verify coating thickness and appearance.

• Marking & Packing: Mark member IDs matching erection drawings; protect edges and coatings; prepare packing lists.

4) Logistics & Handling

• Transport Planning

• Lifting Plans

5) Site Installation & Erection

• Foundations Interface

• Erection Sequence

• Bolting

• Site Welding (If Applicable)

• Tolerances & Survey

• Interfaces & Accessories

• Final Coating Touch-Up

6) Inspection, Testing & Quality Records

• Quality Plan & ITP

• NDT & Tests

• Documentation

• Non-Conformance Control

7) HSE & Risk Management

• Construction HSE

• Environmental Controls

• Emergency Preparedness

8) Deliverables (Typical)

• Design basis, calculations, GA & shop drawings, BoM/MTO

• Quality Plan, ITP, WPS/PQR, welder and bolting procedure qualifications

• Coating system specification and inspection reports

• Lifting plans, erection methodology, sequence & temporary works drawings

• Survey records, NDT reports, bolt tension records, grout test results

• As-built drawings and MDR; handover dossier with O&M where applicable