UBC special seismic load combinations

[appliedse]

I have a two story wood frame house in seismic zone 4. It is supported on grade beam and pier foundation. Plan checker want the grade beam checked against special seismic load combinations with omega factor per UBC. Does special seismic apply to grade beam? I heard both stories. Can anyone clarify and refer me to a section of UBC? THanks!!

 

[AlohaBob]

Does the checker also require an SE stamp for this?

 

[yack]

AlohaBob,
That would be the end of it all--a structural stamp for a 2 story wood framed house. What a joke.
AdiosBob

 

[AlohaBob]

It's routine in California, which is mostly zone 4. There are prescriptive standards, but the most responsible efficient and cost effective method in my experience is the SE. The plans review are rigorous.

Pier and grade beam foundations are required for special foundation design. And usually comparatively expensive.

Your entire foundation requires special seismic design.

 

[whyun]

In California, Structural Engineer License is required for hospitals and schools (primary, secondary, junior college). All other structures may be designed by a licensed Civil Engineer.

 

[AlohaBob]

From the standpoint of relevance for the topic, I think appliedse would be served well to review his questions with a structural engineering professional whos expertise includes his relevent local site conditions and residential design practices. I don't know where he lives and what jurisdiction rules apply, but this professional ought to be able to steer him to properly, efficiently, safely and most economically address the issue.

It's been my experience that anyone who's gripped a hammer sees himself a qualified structural engineer, designer and construction expert. And this is true I suppose within the context of their experience. Appliedse however addresses a formal technical challenge from a building official. Respecting the depth of required specialized design expertise in high seismic areas with applicable peculiarities of specific site conditions, materials of construction, even basic structural systems, this is an altogether different matter.