Return to index: [Subject] [Thread] [Date] [Author]

RE: Anchoring in seismic zones

[Subject Prev][Subject Next][Thread Prev][Thread Next]
You would typically have 3 options:

1) Use epoxy anchors.  Despite the concerns stated, they are widely used for
seismic applications in the U.S., and are widely accepted.

2) Use embedded anchors.  This requires placement before the concrete is
placed, which requires coordination and planning ahead, but it can create a
very nice connection.  

3) Use undercut anchors.  These mechanical anchors cut a bell shape at the
bottom of the hole, and thus rely on more than just friction to hold the
anchor in.  I believe that Hilti (and probably others) have one that has
been ICBO tested for seismic applications.  

Paul Crocker, P.E. (WA)


-----Original Message-----
From: Jan Hermanek [mailto:herzmi(--nospam--at)hotmail.com]
Sent: Tuesday, May 15, 2001 8:44 AM
To: seaint(--nospam--at)seaint.org
Subject: Anchoring in seismic zones




Dear Sirs,

I have a question about anchoring to the concrete.

Our structures are connected to the concrete by chemical or short mechanical

anchors. My question is about anchoring in seismic zones. Chemical anchors 
are not suitable for cracked concrete. In Europe they are not recommended 
because during seismic event concrete cracks. But in the USA I've seen 
evaluation documents for chemical anchors. There you can find that those 
anchors are not suitable for cracked concrete but they are allowed to resist

seismic forces and some document allows even increasing of allowable 
stresses (extra 33% up). I have also understood that mechanical anchors in 
seismic zones are not really welcomed in USA.
Thank you for any suggestion to this topic.

What should I do then to fulfill criteria accepted by US building officials?

Jan Hermanek


_________________________________________________________________
Get your FREE download of MSN Explorer at http://explorer.msn.com


* 
*   This email was sent to you via Structural Engineers 
*   Association of Southern California (SEAOSC) server. To 
*   subscribe (no fee) or UnSubscribe, please go to:
*
*   http://www.seaint.org/sealist1.asp
*
*   Questions to seaint-ad(--nospam--at)seaint.org. Remember, any email you 
*   send to the list is public domain and may be re-posted 
*   without your permission. Make sure you visit our web 
*   site at: http://www.seaint.org 

* 
*   This email was sent to you via Structural Engineers 
*   Association of Southern California (SEAOSC) server. To 
*   subscribe (no fee) or UnSubscribe, please go to:
*
*   http://www.seaint.org/sealist1.asp
*
*   Questions to seaint-ad(--nospam--at)seaint.org. Remember, any email you 
*   send to the list is public domain and may be re-posted 
*   without your permission. Make sure you visit our web 
*   site at: http://www.seaint.org