Hey Archinect i have got a question. I am a student engineer and i have to design a structure on a square that is 34x34 meters large, whit a large span without intermediate support. And on each side you have 34 columns with in each case 1 meter in between and +-3 to 4 meter high. With this span as thin as possible. See the image for more clarity.
You'll get the thinnest roof assembly using steel I-beams (technically "W" sections) spaced fairly closely together. That's not very exciting, but it's the most efficient shape of the most efficient framing material.
If you just want the appearance of a thin structure, you could use open web trusses or space frames (3-D trusses) as the other guys said. The total structure would have to be deeper, but if you keep the trusses or space frames exposed, the look would be thin.
If you want to try more exotic materials, you could use a diaphragm roof with steel cables in tension below. Again, the actual roof structure will be somewhat deeper than necessary, but the look would be very open. The diaphragm would have to be reinforced concrete, cross-laminated timber or something else good in both tension and compression.
Nov 20, 16 3:10 pm ·
·
BulgarBlogger
I
have a feeling you will have too much deflections
you could make the entire thing a very shallow dome and do it in concrete or another primarily compressive system. Problem then is resolving the thrust forces at the edge of the roof, but not impossible. Does it have to be flat?
Have you done research into other large buildings with column-free interior spaces? It would probably be informative.
Look at covered sports stadiums for examples of building whose interiors are column-free. Don't think the flat roof is going to work to well with snow or heavy rain loads. That said here is the McCormick Place in Chicago with the truss roof.
large spans without intermediate supports 34x34 meters
Hey Archinect i have got a question. I am a student engineer and i have to design a structure on a square that is 34x34 meters large, whit a large span without intermediate support. And on each side you have 34 columns with in each case 1 meter in between and +-3 to 4 meter high. With this span as thin as possible. See the image for more clarity.
Sorry for my Englisch.
or go 4 columns and space frame?
You'll get the thinnest roof assembly using steel I-beams (technically "W" sections) spaced fairly closely together. That's not very exciting, but it's the most efficient shape of the most efficient framing material.
If you just want the appearance of a thin structure, you could use open web trusses or space frames (3-D trusses) as the other guys said. The total structure would have to be deeper, but if you keep the trusses or space frames exposed, the look would be thin.
If you want to try more exotic materials, you could use a diaphragm roof with steel cables in tension below. Again, the actual roof structure will be somewhat deeper than necessary, but the look would be very open. The diaphragm would have to be reinforced concrete, cross-laminated timber or something else good in both tension and compression.
I
have a feeling you will have too much deflections
you could make the entire thing a very shallow dome and do it in concrete or another primarily compressive system. Problem then is resolving the thrust forces at the edge of the roof, but not impossible. Does it have to be flat?
Have you done research into other large buildings with column-free interior spaces? It would probably be informative.
Look at covered sports stadiums for examples of building whose interiors are column-free. Don't think the flat roof is going to work to well with snow or heavy rain loads. That said here is the McCormick Place in Chicago with the truss roof.
Nice to see an Archinect thread on the basics.
Columns? We don't need no stinking columns.
^ Holy cow, ArchA! That second one makes me both aroused and a little nauseated at the same time.
Can you make the roof sag a little?
the problem is not well defined. you could limit the depth to almost zero by using a sheet material that is sufficiently tensioned to cover the span.
Suspension or inflatable.
Its called a truss...
skyhooks.
Magnets
As for the topic at hand, has anyone suggested invisible flying unicorns? I spec the blue type over pink for reliability.
^ blue over pink? That is so sexist.
blue is what the engineers pick.
No one ever wants to do gluelams anymore.
Glulam unicorns?
Citizen - that's Museo de Arte Sao Paulo by Lina Bo bardi. Pretty cool building
Nobody suggested double tees either. They are all on anti-depressants because of that.
Check out the The Grandview Heights Aquatic Centre that just won the 2016 Structural Awards.
^ Agreed, archanonymous.
which type of roof is suitable for column free structure of span having 34 meters
magic
used the pipe truss
I still can’t wrap my head at how this bridge was designed at Lincoln Center in Manhattan.
Portal frame? Look at aircraft hangars.
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