Engineers Optimize Largespan Steel Truss Roofs for Modern Stadiums

Roof system comparison

The venue covers about 14,907 square meters and carries a Grade II structural safety rating with Category B seismic design. Its roof must balance appearance, structural performance and cost, so the design team initially evaluated three mainstream steel systems.

Because the roof has no suspended ceiling, the dense members of a grid structure would have disrupted the building’s warship-like appearance. A cable-strut system offered a lighter look, but its wind sensitivity raised the risk of bottom chord instability under wind suction, and adding self-weight to balance those loads would have reduced economic efficiency. The space truss ultimately prevailed because of its stiffness and simple lines.

Transfer trusses resolve irregular load paths

The arena’s substructure uses an irregular column grid, which creates uneven main truss spans across the roof. To smooth the flow of forces, the design team introduced a transfer truss concept.

• Rigid boundary configuration: A transfer truss made of double inverted-triangle space trusses separates the training hall from the competition hall and divides the irregular roof area into two zones.
• Load transfer: Main trusses run along the short-span direction and deliver loads to the transfer truss, which then carries them to the concrete substructure. The resulting load path is clear and direct.

This arrangement allows the roof to handle varying span conditions without forcing a single structural pattern across the entire arena. It also keeps the primary force flow predictable as the roof meets the lower concrete structure.

Lightweight design and member optimization

To maintain a light visual profile, the design team limited the truss height to 3.2 meters, producing a maximum depth-to-span ratio of about 1/16. The member sections were also refined in detail, with nine different specifications used across the roof.

Chord sections were reduced from 245×16 mm to 121×6 mm, while web members range from 76×4 mm to 219×16 mm. Those choices support structural safety while making efficient use of material and keeping the roof form visually lean.