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 +
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
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.220.127.116.11b) .
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
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?
Composite Technologies Corporation
From: Todd Hill [mailto:thill(--nospam--at)tkarch.com]
Sent: Thursday, June 22, 2000 11:29 AM
Subject: RE: 2000 IBC
Along the same lines, is there an errata for ASCE 7-98 also?
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
I've been away for a while due to back surgery, but have re-joined the
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 (1618.104.22.168) 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?
Michael D. Ritter, PE
Senior Structural Engineer
Lockwood Greene Technologies
1201 Oak Ridge Turnpike
Oak Ridge, TN 37831
(865) 220-4310 (fax)