Need a book? Engineering books recommendations...

Return to index: [Subject] [Thread] [Date] [Author]

Mechanical Equip. Support

[Subject Prev][Subject Next][Thread Prev][Thread Next]
I am designing the anchorage and concrete pad for an HVAC unit weighing 
about 15 kips and is outside, (not part of a building). I normally design 
such per ASCE 7-05, Chapter 13, (non-structural components), using Section 
13.3 and the seismic coefficients of Table 13.6-1. However, the plan check 
engineer is requiring it be designed per Chapter 15 as there was an errata 
to the ASCE requiring non-structural components where the weight of the 
component is greater than 25% of the structure, it be designed per Chapter 
15, (non-building structures). Obviously if the equipment is sitting 
outside then it’s weight is greater than 25% of the building, as there is 
 no building! I don’t want to do this as I then need to design the 
anchorage for brittle failure per the ACI, (there is an exception in the 
2010 CBC that anchorage designed per ASCE 7, Section 13.4.2, need not 
satisfy ACI Section D.3.3.4- See 2010 CBC 1908.1.9- page 241).

My contention is that this piece of equipment, whether outside on an 
equipment pad, or inside a building at the foundation level is going to 
react the same to seismic forces and can be designed per ASCE Chapter 13 
and using the exception of CBC Sec. 1908.1.9, but the plan check engineer 
is insisting that Chapter 15 be used in the design.

Any comments about this, or that the building codes have gotten way overly 

Thanks in Advance,

Larry Hauer, S.E.

Post your message to the list by sending it to: 

The email messages sent to the list will be saved in an archive on the World Wide Web.
These archives are located at:

To contact the list owner, send your message to:

Sponsored By: Pacific Structural & Forensic Engineers Group, Inc. (PSFEG)

To unsubscribe, switch to/from digest, get on/off vacation, or change your email address, click here.