Infrastructure Steel Structures

On bridges and utility structures, savings come from choosing the right girder or truss form early, then refining plate thicknesses along the span instead of carrying a single heavy section throughout. We rationalize splice positions to suit transport lengths and crane capacities, reduce the number of distinct fatigue details that need inspection, and standardize bracing and cross-frame members. Designing for inspection and maintenance access from the outset also avoids costly retrofits of walkways and access hatches later in the asset life.

Infrastructure members are typically welded plate girders, box sections, tubular trusses and fabricated cross-frames. Welding procedures are qualified to the AWS D1.1 or EN 1090 execution class requirements specified for the project, with full-penetration butt welds in flanges and webs prepared and sequenced to control distortion. Camber and sweep are built in according to the camber diagram, and girder segments are trial-assembled at the shop where splice fit-up or deck geometry is critical.

Bolted splices are drilled from templates or CNC data so that field joints match the trial-assembled geometry, and faying surfaces are prepared to the slip class assumed in design. Every piece carries durable marking tied to the erection drawings and to its material records, so splice partners, bearing ends and orientation are clear when components arrive at site.

Quality is managed through a project inspection and test plan agreed with the client and authority inspector before fabrication starts. Plates and sections are traced from mill certificates to individual cut parts, and fatigue-sensitive welds receive the ultrasonic, magnetic particle or radiographic testing the specification calls for. Camber, sweep, splice hole patterns and bearing seat flatness are dimensionally checked and recorded, and all records are compiled into a QC dossier that supports handover and future asset inspections.

Infrastructure steel is exposed for decades, often near de-icing salts, rivers or coastal air, so protection is selected for a long durability range in ISO 12944 categories such as C4, C5 or CX. Typical systems combine abrasive blast cleaning, zinc-rich primers and high-build intermediate and finish coats, or hot-dip galvanizing for secondary steelwork, handrails and utility members. We detail drainage paths, sealed box interiors and accessible surfaces so coatings can be inspected and maintained without major intervention.

Long girders and truss segments are planned around road, port and vessel constraints from the design stage. Components are packed and sequenced by span and erection stage, with lifting points, center of gravity and weights shown on each shipping drawing. Large members typically move as break-bulk with engineered supports to protect coatings and camber, while bolts, bearings hardware and small parts ship in containers. Export documentation, packing lists and marking schedules accompany every consignment.

Bridge and infrastructure erection is often constrained by possessions, road closures or river access, so we support the erection contractor with erection drawings, temporary condition checks for partially completed spans and input to the method statement. Our engineers can review lifting arrangements, splice bolting sequences and bearing setting procedures, and where agreed we provide technical supervision or advisory visits during critical lifts and final alignment.