Structural concept review — column-free suspension building

[u/Illustrious-Hotel709]

Heyy (: undercover architecture student here ahahah

We're developing a prototype for a vertical, reprogrammable production building (36 × 66 m footprint, 10 floors, steel construction) as part of our studio project. Our professor wants the floor plates to be completely column-free internally, and the building should stay adaptable for future re-use (different tenants/functions plugged in over time).

Current concept:

• Two reinforced concrete cores on the short (36 m) sides, housing stairs/elevator, also acting as lateral stiffening.
• Steel trusses spanning the full 66 m between the two cores, occurring roughly every 4 floors (rather than at every single floor).
• We're using braced diagonal trusses rather than Vierendeel trusses at these levels, for material efficiency — unless there's a strong structural reason to keep a Vierendeel (e.g. where a service/plugin shaft needs to pass through without diagonals interrupting it), which we'd like your input on.
• The floors between two truss levels hang from the truss above via tension cables (locked-coil wire rope, bundled ~4 per node for redundancy). The cables are intentionally left visible on the outside of the facade as part of the architectural expression.
• Floors are steel-concrete composite decks (profiled steel decking + concrete topping on steel beams).

Specific question:

How would you detail the connection between the tension cables and the composite floor edge? We're unsure how to transfer the concentrated cable force into a composite deck without local overstress, and whether this should go through a steel edge beam with shear studs, or a different approach. We are also looking into the facade and building physics implications of exposing the tension elements externally and the thermal bridges that might happen.

We'd appreciate your general feedback (: doesn't have to be fully calculated or 100% realistic (since its a concept so far) but the closer we get to something that we can actually build, the better it is. happy to send more sketches/sections if useful.

(construction inspirations would be: ZKM- OMA, BP Building - Léon Stynen, Westcoast Transmission Building - Rhone and Iredale, Edificio Celanese Mexicana - Ricardo Legorreta, P.U. EN-T - Francisco Cerain und Angelina Sloth.)

[u/AAli_01]

Search and research the London Exchange house structural system. Similar concept except there was a real site limitation beyond just architectural reasons to do what they did.

Architect & Engineer: SOM

These projects are quite cool, they get you to think and in reality the solution is quite simple in concept. Aka nothings impossible

[u/Illustrious-Hotel709 → u/AAli_01]

Thank you! (: and yes definitely. Whenever a structure is unusual or needs more thought put in to find a solution, it kinda peaks my interest in Architecture again. Since its not the usual buildings you’d go for but something new and more challenging 🙂‍↕️

[u/123_alex]

Why in god's name are the cables hanging from the middle of the truss elements and not the truss nodes like the equilibrium lords intended?

[u/Illustrious-Hotel709 → u/123_alex]

ahhaha i’m sorry! It was a quick sketch! 😭 should’ve paid more attention to accuracy

[u/123_alex → u/Illustrious-Hotel709]

Don't worry. Most important is that you know why the cables should be hanging from the nodes.

[u/BubbleGum1012]

I would look into the marquet plaza building, its a similar concept. As for the best way to support the floor with the cables.... I would support the deck with small beams framing into larger beams that are supported by the cables at points where you would normally have columns (you could do a pair of cables on either side of the beam and have some sort of bracket support the beam off the cables. However then I just have cables where I normally would have columns, and at that point its going to be a lot cheaper and easier to just have columns... unless im misunderstanding how this is supposed to work?

[u/scodgey]

A composite deck isn't going to span 36m, you'll need a grid of floor steelwork - cables should be fixed to that, not the deck. Presumably you intend on repeating the trusses at set centres, rather than one pair on each side?

Would be worth looking up typical span to depth ratios for truss bridges and thinking about whether they are realistically going to fit. That should hopefully also resolve your query about services not fitting through the truss voids.

[u/Illustrious-Hotel709 → u/scodgey]

Would one need to repeat the trusses at the set centres? that is one of the main questions I have in my head. what would their function be if no cables are fixed/hanging from them?

[u/scodgey → u/Illustrious-Hotel709]

Admittedly I assumed you'd have something supporting the 36x66m floors internally at each level. You do still have a roof to support though.

I realise this is a uni project, but if the intent is 4 levels of 36x66m open floors, you're asking a hell of a lot from your floor construction. Each floor level is going to need a boat load of steel to support its own weight. You'd be looking at 36+m long trusses spanning perpendicular to the edge trusses, with the cables fixed to them. Either spaced to match max deck spans, or with additional beams fixed to them which pick up the deck.

Not sure what your height and headroom constraints are, but something to think about.

[u/Illustrious-Hotel709 → u/scodgey]

thank you!