Monday, November 9, 2009

RE: base plate design

Harold,

How does tank pressure cause anchor bolt stretching?

Rajendran


--- On Sun, 11/8/09, Harold Sprague <spraguehope@hotmail.com> wrote:

From: Harold Sprague <spraguehope@hotmail.com>
Subject: RE: base plate design
To: seaint@seaint.org
Date: Sunday, November 8, 2009, 7:35 PM

Yes.  I have known of several failures for tank anchor rods.  The anchor rods stretch a long way.  This most commonly occurs when tanks are overpressurized. 

Regards, Harold Sprague


 
> Date: Sun, 8 Nov 2009 11:07:01 -0500
> Subject: Re: base plate design
> From: ad026@hwcn.org
> To: seaint@seaint.org
>
> Highly neglected topic. No good single reference. The problem is the huge
> range of possibilities that can occur in: member section (shape and aspect
> ratios); load effects at the theoretical section end; local effects in the
> column, plate, rods, grout, concrete, welds; geometry of rod pattern; base
> shear (a topic in itself); elastic/plastic transition; flexible/rigid;
> assumptions...
>
> There was an interesting presentation at NASCC '09 in Phoenix, Better Base
> Plate Designs. I'll follow up if I can remember the researchers involved. I
> had a chat with them before I attended because I didn't want to waste my
> time. They reinforced the need for rigorous analysis. I believe that the
> work was supported by RISA Technologies for RISABase.
>
> I probably spend as much time with base plates as with the most complex
> connections in a structure. Lots of iteration and no single controlling
> case. I like to bracket my solutions to determine how much time to spend. If
> the best case and worst case are both within an order of magnitude, just go
> high. Quick method, to borrow a phrase from a colleague, "... round up and
> double ..."
>
> I'll repeat a question that I asked a while back:
> Has anybody ever known a structure failure due to base (steel/concrete) or
> anchor failure in the finished state (not during construction)?
> I have heard anecdotal stories but nothing confirmed as engineering failure
> vs overload, material or construction failures.
>
> Regards
> Paul
> --
> Paul Ransom, P.Eng.
> ph 905 639-9628
> fax 905 639-3866
> ad026@hwcn.org
>
>
> > From: "John J. Treff" <jjtreff@hotmail.com>
>
> > Does anyone have an example or a good reference for biaxial base plate desi=
> > gn? AISC Design Guide 1 deals only with uniaxial bending. Any references (=
> > books=2C manuals=2C papers=2C etc.)=2C suggestions or ideas on how to desig=
> > n biaxially (interaction of some sort or design separately for both axes an=
> > d then pick the worst case scenario) would be greatly appreciated.
>
>
> > From: "Adair, Joel" <jadair@shwgroup.com>
>
> > Not that this will provide you with any guidance or understanding, but
> > RISA makes RISABase, which will handle biaxial bending, and just about
> > any other load combination you can dream up. We had it when I worked
>
> > -- Joel Adair
>
>
> ******* ****** ******* ******** ******* ******* ******* ***
> * Read list FAQ at: http://www.seaint.org/list_FAQ.asp
> *
> * 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@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
> ******* ****** ****** ****** ******* ****** ****** ********


Windows 7: Unclutter your desktop. Learn more.