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Re: IBC "Oops" (Was Residential Design Discussion)

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One of Dennis Wish's core complaints in regard to this issue is the penalty
that the rho factor inflicts on short walls. This problem HAS been
addressed and is in the process of resolution. The Draft copy of ASCE 7-02
defines rho for walls essentially the same as in UBC 97, but then adds:
"... where the ratio 10/lw need not be taken greater than 1.0 for buildings
of light frame construction." Once ASCE 7-02 is formally approved, it will
be incorporated into the IBC.

If California would adopt the IBC, the problem that Dennis has addressed
would soon go away. But it is now a political matter, not a technical
matter: rather than directing your ire at volunteers who work on the
committees, contact your California State Assemblyman and State Senator.
They are the only ones now who can solve the problem (by getting the State
to adopt the IBC). There is not a mechanism in place to make changes to the
UBC (ICBO will soon be absorbed into the ICC), and I doubt the State has
the will to finance a replacement (it seems that the State was getting a
free ride on Code development). We can yell 'til we are blue in the face,
but it seems obvious to me that the UBC isn't ever going to be changed
again, no matter how outrageous it might be. As long as California chooses
to stay with the UBC, SEAOC is powerless - like eveyone else - to correct
the problems. So direct you energy to your Assemblyman and State Senator -
tell them to support adoption of the IBC (you are wasting your time telling
them to support changes to the UBC - it isn't going to happen). The UBC is
a dead horse. I'm not saying anything about how I thing things SHOULD be, I
am only telling it like I see it.

But somebody did address the issue of the rho factor, and they did push it
hard enough to get it approved in ASCE 7. Somebody worked within the system
to correct a problem. I don't know who on the ASCE committee was behind the
change; maybe it was even SEAOC members (my guess is that SEAOC had a hand
in it). Whoever it was, they should be thanked with as much energy as was
expended previously criticizing them.

Allen Adams, S.E.
RAM International

>From: "Dennis Wish" <dennis.wish(--nospam--at)>
>To: "SEAINT Listservice" <seaint(--nospam--at)>
>Subject: Residential Design Discussions
>There are issues that have not been resolved in residential design. I've
>been off this list since the end of June and am returning in hopes that
>I can resolve some of these conflicts.
>3. The issue of Rho may be covered in the opinions stated by the SEAOC
>Seismology Committee but unless the code is revised (which it will not
>be) the base shear will need to be increased by a Rho of 1.5. Most of
>the professionals I have spoken to disregard the Rho factor because of
>the work done by Gary Searer that discredits the interpretation of Rho.
>Since it is codified, the opinions of those who created the code are of
>no value in a court of law. The engineer of record is still responsible.

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