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RE: Architects Doing Engineering -Enough

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Frank,
I'm not sure I understand the point. Yes, the time and conditions must be
right for damage to occur. However, this did not stop California from
creating a Hazard Mitigation program for Unreinforced Masonry.
Before you jump on me for this, consider the parallel between your comments
and the thousands who lived in URM apartment buildings in Los Angeles and
never experienced damage - period. How many building did you see prior to
Loma Prieta or even Whittier Narrows that were undamaged from before 1933 to
this time and still were forced to be retrofit.
Santa Monica tried to use the same analogy that you did to prove that they
were unaffected by those earthquakes such as Whittier that damaged buildings
in Los Angeles. Their former mayor was an attorney who hired an engineer
from one of the Universities near San Diego to attest that Santa Monica was
on a different fault line and was, therefore, not at the same risk of the
other areas covered in the State plan.
They learned their lesson when Northridge hit and over 100 buildings were
seriously damaged or destroyed in Santa Monica.

How do you negate the thousands of homeowners and the tremendous payoff by
the insurance industries on damaged single family residences? Do you assume
that since you don't know any of the owners personally it must not have
happened?

Frank, I'm not about to criticize you because I believe I am missing your
point and have interpreted your comments the wrong way. Are you suggesting
that the weakness in the code is due to apathy or the fact that SFR's are
simply low risk or that there are very few structural failures and even
fewer that caused loss of life?

As a professional community, we have surveyed the damage caused by improper
construction quality as well as improper design. I have reported and
corrected hundreds of examples in Los Angeles County (and parts of Ventura
County) after Northridge - the majority of which were light framed wood
structure - both single and multiple family residential.

Bill Allen aptly stated: "keep in mind that Northridge was a 6 point
something E/Q. As you are in the Bay Area, we have this sleeping monster
near us called the San Andreas. From some of the documents I have read, the
southern section of the San Andreas is capable of something like an 8.5. I
realize that it is extremely difficult to develop a design document which
extrapolates data to an event that is 100 times more powerful than
Northridge, but most agree that it is a very probable event."
I practice my profession four to six miles from the Southern Edge of the San
Andreas fault. Most of those homes that are allowed to be constructed from
Conventional framing standards are the lower income housing in Indio,
Coachella, Thermal, Desert Center, and around the Salton Sea. This is also
one of the most populated area's surrounding the Coachella Valley. As a
point of interest - even the wealthy are not out of the woods since
virtually all of the major cities from Palm Springs, Rancho Mirage, Palm
Desert and Indian Wells lies within ten miles of the fault.
Where are the bodies? They are living in these homes believing they are safe
and the state government cares enough to insure their safety in buildings
passed by building permits and inspected by city workers. I doubt that any
of them are aware of the poor quality of construction or the short cuts that
the developers took to maximize their profits by designing to the most
minimal standard allowed in the code. AND a standard that most engineers do
not agree with!

Finally, one comment about non-engineered home. I can't attest to which
homes were non-engineered and which were damaged due to poor quality of
construction. I can only attest to the homes that were damaged that may have
been designed by either conventional framing standards or by none at all and
were damaged due to poor workmanship. Do we blame the building inspector for
not checking the quality of work in the process of construction? Do we blame
the code as insufficient or of ignoring single family dwellings (which the
code did for many years).
For the most part, no building will be damaged until the conditions present
themselves that attack the building - this includes many different physical
conditions that can damage on building and not the one next door. This is
true of earthquakes, tornado's, hurricanes and even a runaway train. It's
all by chance, but the fact is that there is enough evidence of damage.
Furthermore, there is evidence that enough money was paid out by the
insurance industry for natural disasters in many states to cause these
companies to back out and no longer provide coverage.

Finally, if life safety is the only issue here, why is SEAOC making the
effort to create a performance based code?

Dennis Wish PE



-----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)