Need a book? Engineering books recommendations...

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

RE: Inverted Key vs Starter Wall

[Subject Prev][Subject Next][Thread Prev][Thread Next]
You can use shear-friction but the problem is that if you use a flush
joint at the wall to slab interface and use a 6" PVC waterstop, the 3"
projection of the waterstop into the slab will interfere with the top
slab reinforcement. 


William C. Sherman, PE 
(Bill Sherman) 
CDM, Denver, CO
Phone: 303-298-1311
Fax: 303-293-8236
email: shermanwc(--nospam--at)cdm.com
 

> -----Original Message-----
> From: Joe Grill [mailto:jgrill(--nospam--at)swiaz.com] 
> Sent: Friday, March 31, 2006 3:29 PM
> To: seaint(--nospam--at)seaint.org
> Subject: RE: Inverted Key vs Starter Wall
> 
> Maybe I do not understand this thread.  You are talking about 
> a 2x4, or 2x6 key as has traditionally (at least in the past) 
> been used at the bottom of a retaining wall stem to footing?  
> If so, why not use shear friction at the cold joint with the 
> waterstop?  As we speak, I'm working on a circular concrete 
> water tank.  I'm getting Vu=4.7 k/ft.  Using the formulas for 
> plain concrete from ACI 318-02 a 2x8 Key in a 12" thick wall 
> will not resist the load (I get phi Vn = .55x12x7.25x(4/3)x 
> sqrootf'c = 4.0 kips), but shear friction works just fine.  
> Am I not understanding something here?  Please set me 
> straight if I'm wrong.
> 
> Thanks,
> Joe
> 
> Joseph R. Grill, P.E. (Structural)
> Shephard - Wesnitzer, Inc.
> Civil Engineering and Surveying
> P.O. Box 3924
> Sedona, AZ  86340
> PHONE (928) 282-1061
> FAX (928) 282-2058
> jgrill(--nospam--at)swiaz.com
>  
> 
> 
> -----Original Message-----
> From: Harold Sprague [mailto:spraguehope(--nospam--at)hotmail.com]
> Sent: Friday, March 31, 2006 12:02 PM
> To: seaint(--nospam--at)seaint.org
> Subject: RE: Inverted Key vs Starter Wall
> 
> I have used an inverted key a lot.  But never on a tank for 
> the reasons that
> 
> you mentioned.  Of course the contractors would prefer an 
> inverted key, but they will not be in the crosshairs if the 
> tank leaks.  Some engineers will use inverted keys on a tank, 
> I won't.  It is a serviceability issue and ultimately it is your call.
> 
> Regards,
> Harold Sprague
> 
> 
> 
> 
> 
> >From: "Mark Urback, P.E." <murback(--nospam--at)ehrainc.com>
> >Reply-To: <seaint(--nospam--at)seaint.org>
> >To: <seaint(--nospam--at)seaint.org>
> >Subject: Inverted Key vs Starter Wall
> >Date: Fri, 31 Mar 2006 11:29:50 -0600
> >
> >Our standard detail for a wastewater tank wall is to provide 
> a starter 
> >wall on the slab with a key and PVC waterstop in the joint.  The 
> >contractor has proposed an inverted key using 1x4 form 
> attached to the 
> >inside of the vertical rebar with a PVC waterstop at the top 
> of the key.
> >My concern with this method is that the base of the key is at the 
> >slab/wall interface.  If the key were to crack at the slab 
> (where the 
> >bottom of the joint is located), there would be a potential 
> water path 
> >because the water stop would be above the crack.  Has anyone 
> used the 
> >inverted key and have there been any problems?
> >
> >
> >
> >Thank you,
> >
> >
> >
> >Mark L. Urback, PE
> >
> >Assistant Manager
> >
> >Public Infrastructure Services
> >
> >Edminster, Hinshaw, Russ and Associates
> >
> >10555 Westoffice Drive
> >
> >Houston, Texas  77042
> >
> >713-784-4500 ofc
> >
> >713-784-4577 fax
> >
> >713-202-1579 cell
> >
> >
> >
> 
> _________________________________________________________________
> Is your PC infected? Get a FREE online computer virus scan 
> from McAfeeR Security. 
> http://clinic.mcafee.com/clinic/ibuy/campaign.asp?cid=3963
> 
> 
> ******* ****** ******* ******** ******* ******* ******* ***
> *   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(--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 
> ******* ****** ****** ****** ******* ****** ****** ******** 
> 
> 
> 
> ******* ****** ******* ******** ******* ******* ******* ***
> *   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(--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 
> ******* ****** ****** ****** ******* ****** ****** ******** 
> 

******* ****** ******* ******** ******* ******* ******* ***
*   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(--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 
******* ****** ****** ****** ******* ****** ****** ********