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

Re: Cutoff Wall In Concrete Transition

[Subject Prev][Subject Next][Thread Prev][Thread Next]
Mr. Gerard
A cut off wall is a vertical wall at the end of the concrete slab-on-grade in the outlet & inlet of the cross drainage structure. This cut off wall is basically provided to prevent or delay water percolation beneath the slab. Mind you, this concrete slab together with the cut off wall ( at the inlet or outlet ) are termed as TRANSITION. Although its a hydraulic design issue but its a structural problem as well. Many an engineer, especially the contractor's engineers donot understand its importance hence resist its inclusion in the shop drawing simply its cumbersome to build. My question was therefore directed towards those experts who have the experience of design & detailing of cross drainage structures ( who would understand this issue better ) to advise me if this cut off wall was really necessary & without which we could expect damages to the whole transition itself. Thank you.
SYED FAIZ AHMAD
SENIOR STRUCTURAL ENGINEER
SAUDI OGER LTD.,
RIYADH, SAUDI ARABIA.


From: "Gerard Madden" <GMadden(--nospam--at)mplusl.com>
Reply-To: seaint(--nospam--at)seaint.org
To: <seaint(--nospam--at)seaint.org>
Subject: Re: Cutoff Wall In Concrete Transition
Date: Thu, 31 May 2001 17:11:35 -0700

Syed,

You probably didn't get a response because your question appears to be more of a hydraulic-fluids type question, not necessarily structural ... because you are asking about the need for this cut-off wall. I for one, am not sure what you are describing, sounds like a baffle or weir type of thing, but I forgot all that stuff the day after the PE exam and hope not to encounter it again. Just a guess, but is this something to do with the water hammer effect ???


Check to see is ASCE has a similar list service with a greater percentage of experts in this field. I'd venture to guess that the vast majority on this list are experienced in buildings, bridges, and other above surface structures, so there are only a few who could help. Plus the fact that there are maybe 50 people who actually answer questions on this list which I believe has subscribers numbering in the 1000's.

Good luck,
-gerard

>>> syedfaiz23(--nospam--at)hotmail.com 05/31/01 05:01PM >>>
Fellow Engineers
a week ago i had posted a question on the LIST about the afore mentioned
subject, unfortunately i am yet to see any response on the same. Iam posting
this question  again with a hope some expert will find time to respond
appropriately.
" iam designing & detailing a buried concrete box channel for storm water
drainage. It has a concrete transition both at inlet & outlet. From my
experience i know every concrete transition should have a cutoff wall at the
end. There is a resistance from some quarter for putting a cutoff wall in
the shop drawing. According to them its not necessary. i seek opinion of the
experts, on design of hydraulic structures, on this issue. Is cutoff wall
necessary or not in a concrete transition for a cross drainage structure?"
Thank you all in advance.
SYED FAIZ AHMAD
SENIOR STRUCTURAL ENGINEER
SAUDI OGER LTD.
RIYADH, SAUDI ARABIA.
******


*
*   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

_________________________________________________________________________
Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.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