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Arman vehicle service station in Atyrau

An insulated service station hangar measuring 18.0 × 42.0 metres — 756 m² of working floor. The 18-metre span is carried by trusses made of cold-formed profiles: there is not a single column inside, across the full width and the full length of the building. The profiles in the truss are only 100, 150 and 200 mm high.

Atyrau756 m²2018

Project at a glance

Dimensions on axes: 18.0 × 42.0 m
Area: 756 m²
Truss span: 18 m
Height to truss underside: 5.2 m
Truss spacing: 3.0 m
City: Atyrau

Detailed design: SP-0429-KM, ProfilStroyProekt LLC, St Petersburg, 2018

Structural solution

The structure consists of steel columns, trusses, purlins and bracing. Spatial rigidity is achieved through rigid connections between all elements.

A truss instead of a portal frame

Eighteen metres is too much for a solid beam made of light profile. So the span is carried by a truss: chords and a lattice in which every member works purely in tension or compression. It uses several times less material than a solid section of the same capacity.

The truss was designed for this building

The FS truss was engineered specifically for this building rather than taken off the shelf. Its depth varies along the span: 800 mm at the support and 1,745 mm at the ridge, where the bending moment peaks. Six 3-metre panels, ten types of lattice member and ten node details — each with its own sheet in the project.

Profiles of 100–200 mm

The whole truss is assembled from galvanized cold-formed profiles 100, 150 and 200 mm high to TU 1121-001-87370346-2015. The columns are paired 200 × 2.0 mm C-profiles. Steel grade S245 to GOST 27772-88. A 200 mm profile carrying an eighteen-metre span is exactly what a truss is for.

Ties along the bottom chord

The bottom chords of the trusses are tied together along the full length of the building. They stop the chord buckling out of plane and turn forty-two metres of separate trusses into a single spatial system.

Load calculation

Static analysis was performed in the SCAD software suite. Loads were taken to SP 20.13330.2011: nominal wind pressure 0.38 kPa, design load on the roof frame 1.78 kPa. The total design roof load is 181.1 kg/m², of which 120 kg/m² is snow.

Screw-fixed assembly

Frame members are connected with Ø6.3 self-drilling screws, bolted joints use bolts to GOST 7798-70, and the fixing to the foundation is by 12 × 120 mm wedge anchors. Welding and gas cutting of galvanized profile were not permitted.

Insulated envelope

Roof and walls are clad in sandwich panels — the roof panel is accounted for in the load calculation at 24.0 kg/m². The frame is made of galvanized profile, with areas damaged on site restored to SP 28.13330.2012.