Holes in a roof beam. What is the purpose? 8

[edison123]

I recently saw this roof beam with circular holes in an airport. What is the reason to cut out those holes? Reduce weight? Make it stiff?

Muthu

http://www.edison.co.in

 

[lexpatrie]

Concur.

 

[Lomarandil]

Like SnT, knowing it's an airport, I believe this case is primarily an architectural choice to mimic the aesthetic of a wing spar.

Clearly it wasn't planned (or planned well enough) for MEP penetrations -- look at that fire line!

 

[campbelltc]

I have a couple of questions here:

1. I know in the days of cheap fabrication, castellation was used to save on material cost. With the cost of fabrication these days, might this just be holes cut in a beam instead of castellation? I can't see the picture well enough to see if the web is welded at mid-height.

2. Has anyone noticed the span direction of the ceiling? Must be a ceiling because it spans in the same direction of the beams (more likely girders). I'd love to see the framing plans for this one.

Just my input.

 

[hokie66]

Yes, there must be a series of purlins above that ceiling. But in the picture, I can't see fasteners.

 

[civeng80]

Like edesin123 says. They seem to me to be holes cut out of a beam and not castellated beams, hard to see from the photo.

 

[CJS1878]

A key advantage like some of you mention is to have space within the depth of the beam to run services through. This means there is no need to hang services below the beams and therefore you can have a larger open area or reduce the overall height of the building. The removal of the weight can in theory help achieve larger spans?

 

[hokie66]

Only in theory. Practically, it makes no difference.

 

[edison123]

It is circular holes cut in the web with no welding. It is just a roof with no superstructure. One more photo.

Muthu

http://www.edison.co.in

 

[hokie66]

Edison,
Those are properly called rafters. And they form the superstructure, along with the purlins which support the roofing. The purlins also support the ceiling which you see in your nice photos.

 

[edison123]

Thanks hokie. The design looked interesting and hence my photos.

Muthu

http://www.edison.co.in

 

[MintJulep]

Was this the Delhi airport?

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