Frost protection for ground mount solar array

[Enginerd]

Would the foundations for a ground mount solar array need to go below frost, or have other means of frost protection? Based on the letter of the code, I do not meet all the exceptions of 1809.5 (IBC 2009); but i think I meet the intent.

As the engineer, I do not care if I place a 'dead man' anchor on top of the ground which is sufficient to keep the array from blowing over or sliding around. The electrical connections will be such that they allow for movement from heave and slump during freeze/thaw cycles.

Would I still have to meet the requirements of 1809.4 for minimum depth?

I guess it is up to the AHJ, but our client would like a design to be used somewhat universally.

Your thoughts?

 

[Enginerd]

Would the design even be regulated under the IBC? Use group U would be the only thing that makes sense, but it isn't accessory to another building. It is completely stand alone.

 

[jar546]

It is still a structure and if it does not meet the exceptions then it is required to be at frost depth

 

[Paul Sweet]

Could you use helical piles? http://www.abchance.com/helical/

Another possibility would be to request approval under 104.11 - Alternative materials, design and methods of construction and equipment. Just show that the array is designed to accommodate distortions resulting from frost heave with no damage.

 

[MarkRandall]

Hmmm...I really don't know the answer, but I do question Jar's statement. How is this any different than a condenser sitting on a precast slab or a mailbox bolted to the sidewalk. I typically see these examples without frost depth protection, nor do I see any reason to require it. Definition for structure is in IBC is not very specific:

STRUCTURE. That which is built or constructed.

 

[mtlogcabin]

I guess it is up to the AHJ, but our client would like a design to be used somewhat universally

Go to ASCE 32-01 Section 7.3 and engineer one.

 

[Mark K]

Believe that the building code regulates buildings and thus does not regulate structures seperate from buildings.

 

[jar546]

Hmmm...I really don't know the answer, but I do question Jar's statement. How is this any different than a condenser sitting on a precast slab or a mailbox bolted to the sidewalk. I typically see these examples without frost depth protection, nor do I see any reason to require it. Definition for structure is in IBC is not very specific:STRUCTURE. That which is built or constructed.

Yup, frost protection required. Like stated above, can be engineered under ASCE 32.

It is not up to the AHJ as he/she does not have the authority to waive code requirements.

 

[jar546]

Believe that the building code regulates buildings and thus does not regulate structures seperate from buildings.

Even though IBC 101.2 does not apply in PA, it would apply in other jurisdictions that utilize Chapter 1 of the IBC.

In PA, the language is in 403 of the PA-UCC

 

[brudgers]

NEC 110-13 (a) Mounting. Electrical Equipment shall be firmly secured to the surface on which it is mounted.

Deadmen are fine for your bird feeder or satellite dish, but them there's live electrical parts and the sun don't come with a disconnect.