Any data centre guys??

[MIStructE_IRE]

What are you typically allowing as a blanket load for services suspended from underside of floor slabs?

The M&E guys never have this info on time and I’m normally allowing 0.5kN/m sq for services alone. Is this in line with your experiences? For comparison I guess this is 21 psf!

 

[r13]

I don't think there is a straight forward answer to your question. It highly depends on the nature of the project, and type of M&E component anticipated. You can always make conservative ball park estimate for the object, such as cable tray, lighting, piping...etc, and apply the estimate to strategic locations.

 

[KootK]

Recent Data Centre Thread

Consider playing chess with me on the Social Chess app at iTunes. Same handle. Fear not, I suck.

 

[IRstuff]

I'm getting 10.4 lb/ft^2 from that number. It sounds plausible, assuming it's a combination of bracketry and Cat5/6 cabling, etc.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

https://www.youtube.com/watch?v=BKorP55Aqvg

faq731-376 forum1529 Entire Forum list

http://www.eng-tips.com/forumlist.cfm

 

[MIStructE_IRE]

Oops you’re right IRstuff! I’m not used to those units! Thanks

 

[dik]

Check the site... data centres can have a fairly high live loading when you consider the equipment, etc.
thread507-242619
thread507-464420

Dik

 

[MIStructE_IRE]

Thanks all,

Just to be clear - I have the live load defined. All I’m looking for is a comparison on loadings for services suspended from underside of slab.

 

[canwesteng]

I'm using 10 psf for M&E in industrial, so that sounds good to me. I would look at what might happen if it's 20 psf in one spot and 0 psf somewhere else. Usually doesn't matter much to me as I'm using simply supported steel beams, M&E never really creates moments equal to 10 psf over the whole tributary width, but it might with a slab if they fix all their stuff at the same location.

 

[Rabbit12]

A lot of industrial clients require 20 psf for cable tray dead load. If you have lots of cabling/cable tray 20 psf would probably be a safe number.

 

[strucbells]

I've usually seen 15-20 PSF for SDL/collateral load for heavier industrial type projects.

 

[Agent666]

Keep in mind in a data centre the loads from cable runs are not usually nice distributed loads spread out under the floors like you might have from HVAC/cable trays in a building, they will likely be concentrated runs of cables resulting in higher loads at specific regions. They will always add more as well. No harm in being a little heavy handed here to cover your butt.

 

[KootK]

Similar to Agent's comment, my one data centre had cable tray runs 6'-8' wide with all kinds of supported stuff. If I recall correctly, the weight of these things was getting well into the hundreds of pounds per linear foot. And the trouble with a data centre is that you have to design for these local effects not just where they are in the planning phase but, rather, where they might be in the next two decades. The only practical way to design for that is to use a monster blanket load to cover it. And, in that respect, the big live loads are your friend. 10 PSF, 20 PSF, and 450 lb/ft all tend to get buried the noise of a blanket 250 PSF live load.

 

[GC_Hopi]

I have used 10 lb/ft for a standard cable tray but it is all engineering judgement. You could ask for concentrated runs to be located sometimes the electrical will reserve the conduit space if the project is using BIM. Below is a reference.

 

[MIStructE_IRE]

Thanks All,

I think I’m going to beef up to 20psf. I’m working with an existing building so don’t want to over-egg it either!

 

[bones206]

I have used a 50 psf dead load allowance for suspended services on two data center projects. In some areas like mechanical rooms with large suspended piping, I used 150-200 psf. That being said, budget was not an issue for either project. Those numbers included consideration of future loads.

 

[MIStructE_IRE]

Thanks Bones - its definitely nothing like that in my case.