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Re: FEMA 310

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Lynn Howard,

You are correct in your  conclusions concerning the application of FEMA 310,
Tier 1 Analysis in your October 28, 1998 posting.

The Project Team authors of  FEMA 310, (Mel Green, Chair, Chris Poland, Dan
Shapiro, Mike Mehrain, Jon Heintz, Darrick B. Hom, etc.) will quickly point
out that a FEMA 310, Tier 1 Analysis is to define and sort out the "Good"
buildings.  They will probably direct you to Table 3-1, Benchmark Buildings,
page 3-3, which points out that wood frame (Type W1) designed and constructed
according to the 1976 or later UBC are considered "Benchmark" buildings and do
not require FEMA 310 evaluations.

If a building does not pass FEMA 310, Tier 1 Analysis, FEMA 310 suggests that
you proceed and perform a  Tier 2 Analysis, starting on page 4-2.  If you
follow FEMA 310, Tier 2 Analysis, you should pay attention to how the
overturning forces are resolved at the foundation level so that there is a
complete load path is provided looking at the provisions of Section

If a building does not pass FEMA 310, Tier 1 and Tier 2 Analyses, FEMA 310
suggests that you proceed and perform a Tier 3 Analysis, starting on page 5-1.
Read the 'Side-bar Commentary' on page 5 -1.  You are already familar with the
FEMA 310, Tier 3 Analysis, which is the FEMA 273 analysis procedure, as
evidenced by your previous SEAOSC List Server posting concerning your findings
using FEMA 273 and the conservative conclusions that result from the
application of FEMA 273.

The application of FEMA 273, Linear Static Procedure (LSP) could result in
still conservative conclusions since you could be using "Pseudo Lateral
Design" (Base Shear) values (V =C1*C2*C3*Sa* W) that are many times greater
than the 1994 UBC Base Shear, particularly concerning the review for the
global overturning of the building and the need to provide some tension hold-
downs at the foundation level.

If the application of FEMA 273, Linear Static Procedure (LSP) is still
producing  too conservative conclusions, FEMA 273 suggests that you use the
FEMA 273 Nonlinear Static Procedures (NSP) which can be very costly to apply.

You are correct that application of the provisions of FEMA 310, Tier 1
procedures (excluding the Table 3-1 Benchmark provisons) will result in
"tagging" almost every 1994 UBC conforming single wood frame building for a
FEMA 310 tier 2 evaluation.

You are to be commended for raising questions concerning the application of
the provisions of  FEMA 310 and FEMA 273.  I served on the Project Steering
Committee for FEMA 310 and had and continue to have serious concerns about
FEMA 310.  It was never my understanding that FEMA would print FEMA 310 as a
"Prestandard" in a "Yellow" cover and distribute it so widely when I voted, as
a member of the FEMA 310 Project Steering Committee,  to only send the October
1997 Draft of  FEMA 310 document to ASCE for ASCE to send it through the ASCE
Standards process.  FEMA has explained to me that FEMA had the right to
publish FEMA 310 as a "Prestandard" according to FEMA's agreement with ASCE,
but that fact was not make known to me when I voted at the November 1997
meeting of the ASCE  FEMA 310 Project meeting  to send the October 1997 Draft
of FEMA 310 through the ASCE Standards process first and not to be sent out as
a FEMA  Yellow cover "Prestandard."

Please continuing to raise questions concerning these new  FEMA 273 and 310
"Guidelines" for the evaluation and rehabilitation of buildings.  Contact Mel
Green, Chair or Kimberly Brubaker, ASCE Standards Coordinator
(kbrubaker(--nospam--at) and see if you can be appointed to the ASCE Standards
Committee on Seismic Rehabilitation, which has the responsibility to respond
to and resolve the January 1998 FEMA 310 review comments and will be meeting
in Las Vegas on December 2-3, 1998 to discuss the review comments and
cooordinate the proposed resolutions.

Almost half of the original ASCE Standards Committee on Seismic Rehabilitation
had to be dropped, according to the ASCE Standards rules, because of lack of
participation in the First and Second Ballot FEMA 310 process.  Hence, it
would be reasonable to assume that there would be room for you on this ASCE
Standards Committee.

Thank you again for your thoughtful comments.

Frank E. McClure    FEMCCLURE(--nospam--at)     October 29, 1998