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Re[3]: Expansion Anchors in Masonry

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     Fred Turner said  <<Some expansion anchors have slipped right out of 
     their holes in past earthquakes. Paying attention to proper 
     installation procedures is one aspect of the problem, but there are 
     other aspects to some expansion anchor designs that warrant testing. 
     ATC and SEAOSC have recommended two somewhat different cyclic testing 
     protocols, but still very different protocols may be needed to
     address long, large pulses in near source shaking. Suffice to say that 
     there is not a uniform standard yet for cyclic test protocols. I am 
     glad to see ICBO adopt a go slow approach on approving building 
     systems such as these which appear to be quite sensitive to cyclic     
     loading. They have learned their lessons from the Northridge Earthquake.

I believe that ICBO has developed two Acceptance Criteria (AC) documents, 
and AC-58, to define dynamic testing for mechanical and adhesive 
anchors respectively.  The anchor manufacturers are currently testing their 
product line in accordance with these criteria (At least Hilti is).  The 
should be reflected in the next round of ICBO approvals.  This should result 
the removal of the disclaimers "Use of the anchors in resisting windd and 
seismic forces is beyond the scope of this report." that appeared in the 
reports after the Northridge Earthquake.

Rick Drake, SE
Fluor Daniel, Irvine

______________________________ Reply Separator 
Subject: Re:  Re: Expansion Anchors in Masonry
Author:  FredT5@aol.com_at_-FDInternet at FDINET
Date:    10/30/97 4:54 PM

Fred Turner
Staff Structural Engineer
Ca. Seismic Safety Commission
1900 K St. #100 Sacramento, CA 95814 
916-327-1606 916-322-9476 Fax