I chose to use a steel framing system to allow for longer spans and more open space in parts of the building. I tried to place columns where they wouldn’t interrupt the rooms/walkways too much, while still providing columns in the necessary places for framing openings and reducing beam spans. In the middle of the building, I utilized structural walls to help reduce the number of extra columns. I kept the structure exposed inside to create a more expansive feel.
At ground level, there is a concrete slab on grade, and isolated footings and wall footings. The second level floor is 3” LW concrete on a 2” deck.
The steel columns are typically W12x40. The girders are typically W12x26 or W21x48, depending on the span/number of elements framing into it/cantilever condition. The purlins are typically W10x19.
Structural Challenges
The main challenge was finding a way to support the curved roof. In the middle of the building, I utilized structural walls that extend all the way to the roof. In the exhibit/cafe spaces at either end of the building, I used trusses. I ran into issues with modeling the trusses. I was unable to copy-monitor the roof to the structural model, and so I couldn’t “attach top/bottom” the truss to the roof in the structural model. So, the trusses are currently in the architectural model. I intended to have a couple more trusses, but received errors when trying to attach them to the roof.
Also, sometimes it seemed unavoidable to place columns in somewhat inconvenient places, in order to frame openings or to keep a somewhat regular framing plan.