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RE: 2000 IBC

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The formulas as published in IBC 2000 are identical to those in PCA's
"Strength Design of Anchorage to Concrete" which was published last year. I
got a copy at a seminar on ACI 318-99 which I went to in Seattle a few
months ago, and this was supposed to be the last word on cast-in anchor
design. 

The material in the PCA publication came out of the ACI 318 committee and
was supposed to end up as an Appendix D to ACI 318 but didn't make it
through the adoption process for the 1999 edition, partly because they were
trying to reach agreement on post-installed anchor design and incorporate it
in the Appendix. 

If the constants in the formulas are in error as you suspect, then the
miracle of modern word processing has transmitted them as a virus into the
code publications.

-----Original Message-----
From: Rex Donahey [mailto:rdonahey(--nospam--at)thermomass.com]
Sent: Thursday, June 22, 2000 2:44 PM
To: seaint(--nospam--at)seaint.org
Subject: RE: 2000 IBC


Cliff Billington, Chief Engineer at Trent Concrete in the U.K., has pointed
out to me that IBC 2000 has errors in the factors accounting for edge
effects for anchors in concrete.  In his opinion, Equations 19-14 and 19-31
in the IBC should have the form 0.3 + 0.7(a/1.5b), rather than 0.7 +
0.3(a/1.5b).

Without going to Linda Hall Library, the first version of equation 19-14
that I can find was published in ACI 355.1R-91 (Eq. 3.14). The first version
of Eq. 19-31 that I can find is in the Eligehausen and Fuchs paper published
in Betonwerk + Fertigteil-Technik in 1988.  Both versions have the 0.3 value
as the constant, and are therefore more conservative than the more recently
published equations.

If this is an error, I assume that it originated during the drafting of the
proposed Appendix D to ACI 318.  I have found the change throughout a
document written by Richard Klingner for the 48th Annual Concrete Conference
at the University of Minnesota (Behavior and Design of Fastening to
Concrete) Dated December 3, 1998.   The change has also been published in
Appendix A of ASCE 7-98 (Eq. A.9.9.6-9b and Eq. A.9.9.6.20b) .
Interestingly, I can't find a citation for the source document in either the
IBC and ASCE 7 documents, although ASCE 7 does acknowledge that Section
A.9.9.6 provisions are copyrighted by ACI.

To get to my points:
1) Does anyone out there know if the change was intended or accidental?  If
the data show that the change is warranted, then I'm all for it.  If the
change is the result of a dyslexic moment, I'd like to correct it in my
standards.
2) Is it really necessary for either or both IBC and ASCE 7 to publish
anchorage standards?  If this really is an error, it might take years to
flush it from one document.  Who knows how long it will take to clean it
from multiple standards?

Rex Donahey
Composite Technologies Corporation



-----Original Message-----
From: Todd Hill [mailto:thill(--nospam--at)tkarch.com]
Sent: Thursday, June 22, 2000 11:29 AM
To: 'seaint(--nospam--at)seaint.org'
Subject: RE: 2000 IBC


Along the same lines, is there an errata for ASCE 7-98 also?

-----Original Message-----
From: Ritter, Mike [mailto:mritter(--nospam--at)lgt.lg.com]
Sent: Thursday, June 22, 2000 9:54 AM
To: SEAOC List Server (E-mail)
Subject: 2000 IBC


Friends,

I've been away for a while due to back surgery, but have re-joined the
list.

I am now working with a client who asked us to use the 2000 IBC, and I
have a question for those of you who are familiar with it.  Basically,
the section on estimation of building period (1617.4.2.1) appears to
have some equations misplaced or missing.  The first equation (Ta = .1N)
appears to belong lower on the page, where there is a missing equation.
I'm sure the first equation should be the typical period estimation (Ta
= Ct(hn)3/4).  Is there any errata for this code yet?

Thanks,  Mike

Michael D. Ritter, PE
Senior Structural Engineer
Lockwood Greene Technologies
1201 Oak Ridge Turnpike
Oak Ridge, TN  37831
(865) 220-4418
(865) 220-4310 (fax)