×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Drainage pipe - Railroad Liveloads

Drainage pipe - Railroad Liveloads

Drainage pipe - Railroad Liveloads

(OP)
I have already determined that the liveloads over a drainage pipe (part of bridge drainage) that crosses a railroad is approx. 19psi.

The pipe I want to use is a 6in. or 8in. PVC SDR18. This might be very simple but how do I determine if this pipe can withstand the load?

Thanks

RE: Drainage pipe - Railroad Liveloads

Are you sure that the RR will let you get by without using a steel sleeve to run the PVC pipe through?

RE: Drainage pipe - Railroad Liveloads

there is a formula 'Spanglers' I think. Anyway it is in the ASTM F1216 for the deflection of a flexible pipe. Put your values in there and if deflection is over 5%, the pipe is in failure. Also like cub3bead stated, check with the railroad first. They usually have very strict ciriteria for pipes under tracks.

Richard A. Cornelius, P.E.
WWW.amlinereast.com

RE: Drainage pipe - Railroad Liveloads

(OP)
Thanks for your comments. The bridge where we are doing the improvements is actually a railroad bridge...  no problems there.

Now, I also found that ASTM through various product standards has recommended a Maximum Allowable Deflection Limit of 7.5%.
To find the deflection and the loads imposed on the pipe at different depths, I downloaded from UNI-BELL.ORG the software:

"external load design for uni-bell flexible conduits."  

Great tool to compare your hand made calculations.

I hope this helps

RC

RE: Drainage pipe - Railroad Liveloads

Suggest you download AS 2566 Australian Standard for Buried Flexible Pipelines from www.standards.com.au. It is moderate cost but is a world leader in such designs.

Books you may also consider are Buried Pipe Design by Moser or Structural Mechanics of Buried Pipelines. I am sure AWWA have similar design standards however AS 2566 is very comprehensive as a design standard and guide.

What you are looking at is a combined soil/pipe structure. Many railway organisations will insist on a sleeve. Beware if the railway is electrified stray currents could cause the failure of the steel inside 6 months. You may need to electrically isolated with a good coating.

The GAS Research Institute/Cornell University did a great deal of study. Their final report "Technical Summary and Database for Guidelines for Pipeline Crossings Railroads and Highways GRI-91/0285 is definitely worth the investment.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources