Lateral loads on structure inside of a warehouse

[structdtl]

I am designing a 25-ft tall structure for equipment inside of a warehouse. There are no windows or roll-up doors in the room where the structure will be located, therefore wind loading is not considered. Project is in SDC A, so seismic loads are very low. And no dynamic loads are expected from the equipment.

What would be the minimum lateral load to be applied to the structure for stability? I have found many opinions, from applying 10 psf wind to applying a lateral load ranging from 1% to 10% of the dead load - I am looking for a reference in IBC or ASCE 7-10

Also, if calculating the load as a percentage of the dead load - how would you apply it in the ASD load combinations? just replace "0.6WL" with "0.01DL or 0.1DL"?

 

[r13]

I think 10 psf wind load came from code specified minimum for interior partition walls. But I would go for 10% dead load, as the structure would subject to eccentric/unbalanced load condition during erection and maintenance of the equipment. 0.1DL is appropriate if it is greater than 0.6WL.

 

[msquared48]

Consider Seismic too... but the 10 psf will probably control.

Mike McCann, PE, SE (WA, HI)

 

[IDS]

Not my area, but surely impact from vehicles would be the controlling force for horizontal loads.

Doug Jenkins
Interactive Design Services

http://newtonexcelbach.wordpress.com/

 

[structdtl]

Thanks for all the input -

I found on ASCE 7-10 section 1.4.3 that the minimum lateral load applied to any structure is 1% of the dead load, which seems low for industrial applications.

I assume there will be forklifts in the vicinity of the platform, but as far as I know they will not be loading the platform with a forklift as everything is piped to the equipment.

I think using 10% dead load for lateral is the way to go. It will govern over seismic since my calculated Cs is 0.0046.

 

[Aesur]

I have typically used the 5 psf live load or as you mentioned in SDC A the 1% dead for interior partitions. I am curious what system you have as I suspect that in the end you will end up with much more capacity than you intend to design for since the lateral loads are so tiny.

 

[Lomarandil]

(my clients and) I would consider 10% DL to be pretty onerous, assuming your structure has any significant weight to it.

I'd consider 5% DL or the impact force of one of those forklifts (maybe 6k similar to ASCE 7 vehicular impact).

Yes, I would make it a straight substitution for a traditional service-level lateral load (0.6WL, 0.6E, etc)

----
just call me Lo.

 

[phamENG]

This one doesn't fit cleanly into any of the categories, so you need to to look closely at the plausible hazards and sources of loading. That 1% lateral load is notmeant to account for lateral impact or even applied lateral load. As I understand it, it's meant to ensure stability of the structure (not the last line in the section in 7-10: "Structures explicitly designed for stability...shall be deemed to comply..."). So, if your structure is steel and you design it using one of AISC's methods for designing for stability, you don't need to apply this one. Stability looks at induced lateral effects from fabrication and erection errors/tolerances - true lateral loads must be applied separately.

What is the general layout of the industrial space you're looking at? Do you have a lot of normally open overhead doors? If so, then wind design could be appropriate. Is it near an area with lots of vehicle traffic? Then take some of the advice already given and look at forklift impacts, or whatever vehicle is in the vicinity. Keep in mind: fork lifts are maneuverable and can get into tight spaces. And a low speed impact can cause a good bit of damage to a wide flange column's flange.