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RE: Architects Doing Engineering -Enough

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Based on your comments, Frank, the only conclusion I can draw is that the
Code must be too conservative. Otherwise, an engineer attempting to apply
"Code" forces to a structure you have described *should* come up with the
same design as prescribed by the Conventional Framing Provisions.

My only point is that one or the other should be changed so that they are
consistent. As you are probably aware, we can look pretty silly trying to
apply "Code" loads and design to a structure and then compare that structure
to one that purportedly complies with the Conventional Framing Provisions.

BTW, I would be shocked if even you felt comfortable living in a two story
residence constructed completely according to the Conventional Framing
Provisons w/o any engineering where the glazing is much greater than 10% and
the shear piers adjacent to a two car garage opening were 2-'6" wide w/o
hold downs.

Certainly the architecture of 40 years ago was much more accommodating to
good seismic performance, but I doubt if that story line is as true today.

Regards,
Bill Allen

-----Original Message-----
From: FLew98 [mailto:FLew98(--nospam--at)aol.com]
Sent: Thursday, May 21, 1998 9:45 PM
To: seaoc(--nospam--at)seaoc.org
Subject: Re: Architects Doing Engineering -Enough


In a message dated 98-05-21 17:22:10 EDT, 73527.1356(--nospam--at)compuserve.com  write:

>  Could it be that houses built under the conventional framing provisions
have
>  not experienced widespread failures because they have never been
subjected
>  to  the loads for which they should have been designed?
>  Could it be that engineer designed houses are more conservative than
houses
>  built under the conventional framing provisions because they are designed
>  for code prescribed loads?

Roger is onto something, especially regarding seismic loading.  Reality
check
for readers of this listserv:  Think back to every detached single-family
house you have lived in the U.S.  It's likely that most of them were of the
non-engineered wood-frame variety.   To your knowledge, have any of them
ever
sustained any earthquake damage, before, during or after you lived in it?
It's unlikely.  The reality is that only a very small percentage of such
housing stock ever sustain any earthquake damage, even of the cosmetic
variety, during their service life.  This is true even in urbanized Zone 4
country like the Los Angeles and San Francisco areas.  My mother-in-law's
two-
story house in Oakland was one of many that were hastily built in 1907 to
help
meet the demand for housing after the '06 S.F. event.  It has a brick
foundation, no anchor bolts or hold downs, and wouldn't calc out or meet
today's codes.  Yet, in it's 91 years of existence, the only damage have
some
minor plaster cracks in one living wall, caused by the Loma Prieta event.
I've lived in five non-engineered houses, all located in the Bay Area and
within a few miles of the Hayward and San Andreas faults.  Those houses have
experienced several earthquakes that have caused damage in the region, but
none of those houses sustained any damage.

Readers who can answer yes to the question of damaged houses, please provide
a
short post to this thread.  I'd be surprised if more than a dozen responses
appear out of the six thousand members of this listserv.

Frank Lew, SE
Orinda, CA

(I'll skip the motto since Bill Allen referenced it earlier in this thread)