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RE: higher loads or better details.

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Of course, I agree that both connections and members should be "properly"
(whatever that is) sized, but short of that happening on everyone's every
project (but yours of course), I disagree with the apparent concept of some
Code authors wanting to bump up design loads to mitigate structural failure.

Say you had a shear wall which was subjected to 20% more than it's design
(Code) load. I would suspect that there would be no catastrophic failure.
Sure, there may be some nail popping and panel bucking, but a considerable
amount of energy would be absorbed. However, if the contractor left the nut
off the hold down at the end of the wall or a drag strut/strap connecting
the shear wall to the diaphragm, I doubt if it would perform anywhere close
to the designer's intent.

I suspect that structural failure is more probable due to a lack of
detailing on the designer's part and quality control on the jobsite than due
to Mc/I + P/A.

Regards,
Bill Allen

-----Original Message-----
From: Roger Turk [mailto:73527.1356(--nospam--at)compuserve.com]
Sent: Friday, September 04, 1998 4:13 PM
To: seaint(--nospam--at)seaint.org
Subject: RE: higher loads or better details.


Bill,

Neither, otherwise I agree with you.  (To put it in the proper perspective
for comparisons, I would want to have 20 percent of the members missing just
as I would not want to have 20 percent of the connections missing.)

I don't recall saying anything implying that connections are not important.
They are vitally important as is the design of *any* structural member.  I
stand by what I said:  "A 'good' detail for an inadequate load will have the
same result as a bad detail for a proper load."  If the connection is
underdesigned, it will fail no matter how well it is detailed ... as will a
badly detailed connection which was supposedly designed for the loads it
will
receive.

A. Roger Turk, P.E.(Structural)
Tucson, Arizona

Bill Allen wrote:

. > Roger, which would you rather have:
. > A. a structure where the members are 20% overstressed, or
. > B. a structure missing 20% of its connections?
. >
. > IMO, those who are inexperienced at providing a lateral load path from
. > roof to foundation (shear collection and transfer) are more dangerous
than
. > those who underestimate the design loads as well as codes that provide
. > too low of a design load.
. >
. > Regards,
. > Bill Allen
. >