Parking Garage Live Load

[Mauleflyer]

What live load is being used on parking garage design today? 40 or 50 PSF?

 

[SteelPE]

Depends on which code you are using.

IBC 2006 = 40psf
ASCE 7-05 = 40psf
IBC 2003 = 50psf
ASCE 7-02 = I can’t find this code right now but I believe it is 50psf as well.

Note that you still have to consider all applicable point loads contained within your specific code.

 

[lkjh345]

Under IBC 2006:

- for garages with passenger vehicles only use 40 psf or the concentrated load noted in Footnote 'a' of Table 1607.1

- 50 psf for garages with bus or truck traffic.

 

[Mauleflyer]

For the engineers with garage design experience have you lowered your design live load criteria from 50 psf to 40 psf?

 

[tngolfer]

IBC 2000 was 50 psf UNreducible (1607.9.1.2)

IBC 2003/2006 is 40 psf UNreducible (1607.9.1.2) but the concentrated load requirements changed.

 

[Teguci]

Check out the "2nd Story Car Showroom" thread. There is an article about live loads on parking garages involving some thorough research for the States as well as vehicle weight trends.

To answer your question specifically, when I was designing parking garages all the time, I used the 40 psf and reduced the column loads as allowed by code. None of my garages have failed yet.

As for point loads, I have seen an unsupported corner of a precast Doubletee fail under the 3,000 lbs test load.

I usually added 2 psf for mechanical loads.

 

[lkjh345]

Mauleflyer:

Not yet, though we have only done a couple of garages since our local city adopted IBC 2006. It had been on IBC 2000 up until January of this year.

I'm sure, sooner or later, we will get called on this by the precast or post-tension supplier, then we will get pushed to go to 40 PSF.

 

[Teguci]

clarification - Alternate Live Load reduction under the old BOCA code allowed for load reductions down to 40 psf and I believe even below that. Something like a 40% max reduction off of the 50 psf live load based on tributary area. Not talking about the latest IBC.

 

[WillisV]

This is a good discussion on the progression of parking deck live loads and parking deck live load reduction requirements from IBC 2000, 2003, to IBC 2006:

http://www.gostructural.com/article.asp?id=342