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

Retaining Wall Surcharge Load

[Subject Prev][Subject Next][Thread Prev][Thread Next]
ASTM C857 Minimum Structural Design Loading for Underground Precast Concrete
Utility Structures recommends that you use a surcharge pressure of not less
than 0.5 percent of the wheel load, and says the surcharge can be neglected
when you are more than 8 feet below the surface. For an H20 wheel load of 16
kips, this works out to 80 psf. 
It's pretty common to use the equivalent lateral load from 2 feet of soil
surcharge for traffic loading (AASHTO guideline for abutment walls and H20
loads). So if you had a unit weight of say 120 pcf, and active or at-rest
coefficients of .33 or .50 respectively (phi = 30 degrees), the pressure for
the active case would be .33 * 2 ft*120 pcf = 79.20 psf and the at-rest case
would be 120 psf. I think the ASTM C857 value is based on active soil
conditions. 
Either way, I wouldn't carry the traffic load deeper than 8 feet.

--
This is a repost. Original said it bounced because I copied the original
message, which was too long. Probably due to image file in original post to
which I was responding.






This e-mail is intended to be delivered only to the named addressee(s) and
may contain information that is confidential and proprietary.  If this
information is received by anyone other than the named addressee(s), the
recipient(s) should immediately notify the sender by e-mail and promptly
delete the transmitted material from your computer and server.  In no event
shall this material be read, used, stored, or retained by anyone other than
the named addressee(s) without the express written consent of the sender or
the named addressee(s).



******* ****** ******* ******** ******* ******* ******* ***
*   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 
******* ****** ****** ****** ******* ****** ****** ********