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RE: More Interesting Questions from the Peer Reviewer

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Neil,

This is kinda of a new approach to me.  Could you elaborate/explain/answer
the following:

If you use only the nuts to transfer the download to the anchor bolts how
are you designing the base plate ?  Basic design philosphy (as illustrated
in AISC design guides) illustrates a bearing pressure distribution under the
plate.  If only the nuts be used to transfer loads you end up with a
"contact stress" problem where the top surface area of the nut and the
bottom of the plate transfer the high compressive stresses.  How do you
account for the high localized stresses ? Do you do this via finite element
modeling ?  Please elaborate.

Robert C. Rogers, PE
robert.rogers(--nospam--at)woolpert.com



-----Original Message-----
From: Neil Moore [mailto:nmoore(--nospam--at)innercite.com]
Sent: Thursday, April 27, 2000 12:23 AM
To: seaint(--nospam--at)seaint.org
Subject: Re: More Interesting Questions from the Peer Reviewer


Bill:

I design lots of poles and always consider the down loads being taken by
the nuts under the base plate.  If I'm using expansive grout and have
special inspection on the grouting, then I would use the grout to bear on.
One of my main clients only uses non-shrink grout, so I stay with the nuts
for transfering the loads to the anchor bolts and then into the concrete.
My argument is that the nuts under the plates have to fail first before the
grout will work.  Our base plates range around 44" in diameter and anywhere
from 1.5" to 2.5" thick.

I haven't done a big sign structure in years but I know I didn't supply any
fabrication details at that time.  I do lots of monopoles and taperpoles
that have only the design features and my client then prepares all of their
shop drawings separately.  

I hope your peer reviewer is someone who tried to obtain your project and
failed and is now your peer reviewer!  This happened to me a number of
years ago.  Sure slowed down a fast track project and required a third
structural to get in between.  I also won.

Neil Moore, S.E.