Partition wall loading debate 2

[MNach]

ASCE 7-10 4.3.2 provisions for partitions
Exception: A partition live load is not required where the minimum specified live load exceeds 80psf.

For a second floor office if one were to use the office loading (50psf) the 15 psf load would need to be added. Where corridors are not defined and could possibly move, I tend to just use a blanket 80psf for the floor load. Technically 80 doesn't exceed 80 so does the partition live load of 15psf need to be added to this? Seems silly to bump it up to 95psf. To me if there is a corridor there isn't a possibility of a partition wall. The corridor walls would be the beginning of the "office space" so it would not be under the corridor load anymore. Thoughts?

 

[BridgeSmith]

Use 80.1 psf for the floor live load?

 

[JAE]

Use 81 psf?



Check out Eng-Tips Forum's Policies here:
faq731-376

 

[JAE]

Ha - you beat me to it.

Check out Eng-Tips Forum's Policies here:
faq731-376

 

[BridgeSmith]

I thought about suggesting 80.01 psf, but that was just a little too ridiculous.

 

[SlideRuleEra]

HotRod, JAE, beat me, too... but will post anyway (with no changes)... spent too much time checking this out.

Technically 80 doesn't exceed 80 so does the partition live load of 15psf need to be added to this? Seems silly to bump it up to 95psf.

Not just a technicality, 80 psf does not exceed 80 psf.
There are similar examples of this logic in ASCE 7-10, for example 4.7.3 for live loads that exceed 100 psf are not eligible for live load reduction. 100 psf is not included... but, of course, live load reduction is optional.
To me, the simple solution is use 81 psf (or 85 psf, if you want it to "look good") for the floor load... and be done with it.

http://www.SlideRuleEra.net

 

[MNach]

Yes, 80.1 psf would satisfy the code, I guess what I am trying to determine is the intent of this exception and the use of the word exceeds. Is the code really recommending that we add the 15psf to the corridor because of the potential for partitions, or is it that anything less than the corridor load of 80psf has potential for partitions therefore it should be added. Because if a corridor has potential for partition loads, bumping it up to 80.1 is exploiting a non conservative loophole. If a floor needed 75 psf live load and had the potential for partitions, just using 80.1 doesn't actually match the loading it would see which would be 90psf

in regard to the live load reduction the logic there is a bit different because I would agree with the intent of 100psf can be reduced but anything above cant (which is how the code words it). And typically you wouldn't exceed it by 1 psf. With a partition in a corridor, I don't agree with the intent of adding a partition load on top of a corridor load, it seems excessive.

 

[BridgeSmith]

To me it would seem use what is reasonable to assume for the usage, and the potential usage. If the expectation of loading for a corridor is 80 psf, and you're not expecting there to be any partition walls in the corridor, then 80psf would seem reasonable and 95 psf would seem excessive. For other areas, where 50 psf is expected to be the floor live load, but partitions could be in the mix anywhere, then 65psf would seem to be the reasonable value.

OTOH, is the location of anything in an office building ever really permanent? Could someone decide to reconfigure the space and relocate the corridor? Probably. Would there be partitions in the new corridor? Not likely.

 

[JLNJ]

If structural engineers get called to the carpet on this kind of minutiae, I'm in big trouble.

 

[MNach]

yes the corridor can move, so using 80psf across the entire floor covers that. But according to 4.3.2 it needs the partition provision because it does not exceed 80psf.

 

[Hokie93]

If you are using IBC 2015, you can avoid partition loading with live load equal to 80 psf. The language in Section 1607.5 of IBC 2015 has been revised to read "... unless the specified live load is 80 psf or greater".

 

[MNach]

thanks Hokie93. That is the language and the intent that I think the ASCE really means to use.

 

[MNach]

Just looked it up in the 7-16 and they have switched the wording to 80psf or greater.

 

[Hokie93]

I am glad to see common sense on a code-writing committee is not completely dead.

 

[BridgeSmith]

Code writers are not all-knowing. From what I've seen, some don't seem to be particularly bright. You still have to use some common sense and judgment. Could the corridor be moved? Yes. Is the whole floor going to become a corridor? Not likely. So is using 80psf for the whole floor conservative? You betcha. Is it worth figuring out the likely locations of corridors in the future? Probably not.

 

[MIStructE_IRE]

Its all nonsense anyway. Check this out!

https://static1.squarespace.com/sta...f121c/1550314026647/Load+Report+Online_E1.pdf

 

[bob33]

As shown in the above attachment by MIStructE, jamming people together can result in large live loads. That's why the early code writers used 100 psf for exit stairs. In office areas, people and furniture loads are not normally the main concern. Large areas for filing cabinets, drawings, office libraries and compact storage are usually much worse. Today, with most information being stored electronically, storage loads are becoming less of an issue for offices.