×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Nonstructural component Ch 13 or Non building structure Ch 15 ASCE 7 (AHU)
2

Nonstructural component Ch 13 or Non building structure Ch 15 ASCE 7 (AHU)

Nonstructural component Ch 13 or Non building structure Ch 15 ASCE 7 (AHU)

(OP)
Fellow Engineers,

I came across an AHU I have to design the anchorage for. I am almost sure that this is a non structural component and that I have to use Ch 13 in ASCE 7 (seismic coefficents are clearly stated for "air handlers" in Ch 13 table), but this AHU is not inside a building or attached to the building, it is sitting outside on SOG. Reading CH 13, is states that any nonstructural component attached to a building is designed with Ch 13. Also, Ch 15, refers me back to Ch 13 for any architectural, mechanical, and electrical components supported by nonbuilding structures. Should I use Ch 13 requirements even though the AHU is not attached or supported by a nonbuilding structure or building? Or is Ch 15 what I have to use even though an AHU does not really fall into a nonbuilding structure not similar to building category?

I hope you guys could help me figure out which requirements I need to obey, Ch 13 or Ch 15.

Thank You

JO

RE: Nonstructural component Ch 13 or Non building structure Ch 15 ASCE 7 (AHU)

I'd use 13. It seems that 15 is more for structures (racks, air supported structures, etc.)and 13 is for equipment. Or pick the one that gives you the highest load and use that.

RE: Nonstructural component Ch 13 or Non building structure Ch 15 ASCE 7 (AHU)

(OP)
Thank for the suggestions,

jedclampett, yes I usually pick the highest load and use that, it is conservative. But it would be nice to know which one it is exactly.

prm06, that flow chart takes me to ch 15, just because it is not attached/supported by another structure.

This is so confusing :/

RE: Nonstructural component Ch 13 or Non building structure Ch 15 ASCE 7 (AHU)

Of the two, it looks like Ch. 15 would be the one applicable.

It is not actually all that clear if ASCE 7 would be applicable to it in the first place. Per IBC, a structure is "that which is built or constructed", which could be construed to include just about every physical object, but the definition is usually construed in a more narrow sense; otherwise, we'd all be analyzing our coffee cups and staplers for seismic stability.

RE: Nonstructural component Ch 13 or Non building structure Ch 15 ASCE 7 (AHU)

(OP)
Stephen,

Are you saying it does not even need to be check for seismic? But this is a 20'x20'x12'High AHU.

JO

RE: Nonstructural component Ch 13 or Non building structure Ch 15 ASCE 7 (AHU)

I'm saying it's not clear where the cutoff is, if there is one, between "structures" and "other stuff" in the codes.
There was another thread about anchors on a rectangular tank. That tank is about the size of a semi.
So why does the rectangular tank require seismic design but a semi parked next to it doesn't?
But for a 20'x20'x12' item, I'd include it under Chapter 15.

RE: Nonstructural component Ch 13 or Non building structure Ch 15 ASCE 7 (AHU)

(OP)
jstephen,

Thanks for the advice

JO

RE: Nonstructural component Ch 13 or Non building structure Ch 15 ASCE 7 (AHU)

(OP)
I guess at the end, if you are unsure, just do both ch 13 and ch 15 requirements. Whatever the worst loading is, use that.

RE: Nonstructural component Ch 13 or Non building structure Ch 15 ASCE 7 (AHU)

Whether it is right or wrong, chapter 12 is often used for outdoor equipment anchorage (switchgear, generators, etcetera). I don't think the earthquake cares if the equipment is on a slab-on-grade inside a building or slab-on-grade outside the building, the forces will be similar (the same).

RE: Nonstructural component Ch 13 or Non building structure Ch 15 ASCE 7 (AHU)

(OP)
WannabeSE,

You mean ch 13?

JO

RE: Nonstructural component Ch 13 or Non building structure Ch 15 ASCE 7 (AHU)

(OP)
Bendog01,

Thanks.

RE: Nonstructural component Ch 13 or Non building structure Ch 15 ASCE 7 (AHU)

Joe
Sorry - I should proof read before submitting. I meant chapter 13 - non-structural components.

RE: Nonstructural component Ch 13 or Non building structure Ch 15 ASCE 7 (AHU)

(OP)
WannabeSE,

Yes I agree with you. I feel like ch 13 is correct. But they should really add that not all equpment need to be attached/supported by a structure', it is a bit confussing.

JO

RE: Nonstructural component Ch 13 or Non building structure Ch 15 ASCE 7 (AHU)

I recently looked at a problem in sdc D where we were adding several equipment access platforms to an existing building.
It seemed strange that platforms placed on an elevated level fell into chapter 13, but the 25% weight rule, but that platforms on the ground floor fell into chapter 15.

I designed all of them per chapter 13.

RE: Nonstructural component Ch 13 or Non building structure Ch 15 ASCE 7 (AHU)

(OP)
Once20036,

Thanks for the feedback. I guess in cases like these we just have to use our engineering judgement.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources