Lusail Multi-Purpose Hall

A 105 m clear span over 16,000 seats.

The arena's signature is the column-free floor — nothing inside the seating bowl, no obstructed sightlines. Holding that clear span at 105 m demanded primary trusses of unusual depth and a secondary structure tuned for stage-rig point loads.

• Clear span105 m
• Roof area28,400 m²
• Seating capacity16,000
• Primary trusses14 deep-section trusses
• Suspended rig load120 t distributed
• Erection programme14 weeks

S460 deep trusses, S355 secondary, fully galvanised + painted.

The primary roof trusses are S460 NL high-strength plate to keep section depth manageable at 105 m clear span. Secondary purlins, bracings and catwalks step down to S355.

• Primary trussesS460 NL plate
• Secondary & purlinsS355 J2H sections
• Catwalks & rig gridS355 hot-rolled
• Surface treatmentHDG + 200µm intumescent
• Fabrication classEN 1090 EXC4
• Weld procedureAWS D1.1 + ISO 3834-2

Hold the clear span without a deflection that bothers the rigging.

An arena roof deflects under wind, snow and live load — that's expected. What this brief wouldn't tolerate was deflection that wandered the suspended rig grid, where a few millimetres translate into off-target lighting and audio aim during a live show.

The solution required a tighter deflection envelope than code minimum, plus a cambered fabrication so the roof reads flat at full live-load.

Cambered trusses, sequenced lift, in-place verification.

Each primary truss was fabricated with a built-in upward camber matched to its predicted full-load deflection. On site, trusses were lifted in pre-bolted segments with a 600 t crane, then field-welded along match-marked seams.

Once the roof was structurally complete, we ran a controlled water-bag load test that applied 110% of design live load. Measured deflection came in at L/780 — inside the L/600 spec.