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

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I can tell you from experience that "yelling" at state legislatures does
nothing if you don't have the masses behind you to support your claims.
SEAOC is a strong lobbyist and has been for many years. Writing letters
to local congressmen do nothing more than attempt to balance a scale
strongly skewed in the direction of the code makers and code councils. 

Yelling at the code makers constantly, causes people to open their ears.
Offering a solution does little until these same people are affected by
the restrictions that the code makers imposed upon us. 

The 10/Lw issue was actually resolved many years ago as it was one of
two strong points which the volunteers on the code committees could not
dismiss so easily as it affected other structures. However, we are still
bound by the rigid diaphragm design requirements for low-rise structures
and Rho has not been changed for residential structures in the next CBC.

The majority of us have resorted to either ignoring the 10/Lw issues or
using proprietary shearwall systems with an R=4.5 for use of say Hardy
Frames as braced frames rather than plywood shear walls. 

Even the design by Simplified Static Design principles requries the
designer to first prove the diaphragm is flexible which is virtually
impossible in structures with aspect ratio's less than 4:1 and which do
not have the mass of a masonry wall to convert the diaprhagm deflection
so as to make for a flexible diaprhagm.

So, what do most engineers do - they ignore the code and place
themselves in potentially liable positions. I suppose you can say that
if they ignore the full compliance issues in the code, they are,
essentially, thumbing their nose at the Seismology Committee and saying
- "See you in Court". If anyone of you get sued over these issues I and
an score of others will be happy to come to your defense because we
don't have the individual financial resources to seek legislative change
in the state and unless we move our SEAOC dues (I no long pay them) from
membership to a litigation fund, we won't see laws changed until we are
in a position to challenge them in court. Based on the position of
current companies supplying E&O insurance, it will be less expensive to
settle than challenge the law.


-----Original Message-----
From: Allen Adams [mailto:aadams(--nospam--at)] 
Sent: Tuesday, October 01, 2002 11:38 AM
To: seaint(--nospam--at)
Subject: Re: IBC "Oops" (Was Residential Design Discussion)

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

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