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

Re: Seismic Design of Expansion Anchors

[Subject Prev][Subject Next][Thread Prev][Thread Next]
Rich,

typically, manufacturers list the anchor capacities in a working stress format (hilti, ramset, etc..) so you should divide by 1.4.

For seismic anchorage, watch out for diameter/embedment ratios which can penalize you significantly. Be sure to do the combined shear and tension check, and ALWAYS Grout the bolts if you are anchoring equipment that needs leveleing. If this is a wall anchorage item, the 1.4 penalty on steel elements applies when you evaluate the strength of the actual material the anchor is composed of -which can govern if you have high loads and very deep embedment into concrete.

Watch out for special inspection requirements and ICBO approvals for applicability for EQ loading. Some Expansion anchors do not have approval for EQ and some municipalities require special inspection if they are to be used as tension anchors. If possible, Epoxy anchors are a better alternative for tension anchorage-Covert Epoxy has the highest values around for tension.

HTH,
-gerard
SF, CA

>>> rlewistx(--nospam--at)juno.com 06/22/01 10:11AM >>>
If I have calculated the load on an expansion anchor using 97 UBC it is a
strength design value.  What values do I use to design expansion anchors?
 The catalog gives allowable and ultimate level loads.  The factor of
safety is about 4 for shear and tension.  If I convert the strength load
to service level loads by UBC 1612.3.1 the conversion factor is 1.4.

What values are typically used for expansion anchors in seismic design?

Rich
________________________________________________________________
GET INTERNET ACCESS FROM JUNO!
Juno offers FREE or PREMIUM Internet access for less!
Join Juno today!  For your FREE software, visit:
http://dl.www.juno.com/get/tagj.

* 
*   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