Is Seismic Rho Factor use for foundation desgin 1

[PEFLWI]

ASCE 7 requires in certain circumstances that the seismic loads be modified by rho, thus Eh = rhoQe per 12.4-3. Is this amplification required to be transferred to the foundations?

 

[spats]

I can't find anything that says it doesn't apply to foundations. ASCE 7-10, Section 12.3.4.1, lists elements that can be designed using rho=1, but foundations aren't one of them. Rightly or wrongly, I have always assume rho=1.3 applies to foundations for seismic design categories D thru F when using the equivalent lateral force method.

 

[BUGGAR]

I hope this doesn't confuse but a previous discussion led to the conclusion that "Rho is only to be used where it is specifically stated that it is to be used". This may have been on a legal forum.

 

[KootK]

NEHRP's design guide for the seismic design of mat foundations (Link) instructs designers to apply rho. See the last paragraph below.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[JAE]

BUGGAR, aren't you thinking about Omega and not rho?



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[BUGGAR]

Probably it was Omega.

 

[sandman21]

See the last post in this thread. Link