×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Contact US

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!

*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

pipe encasement

pipe encasement

pipe encasement

(OP)
We have an 18" diameter HDPE drainage pipe passing about 4 feet under a thickened slab supporting a train track (cooper e80 live load).  The allowable soil bearing pressure is good for 2500psf.  What's the best way to protect the pipe from crushing?  Could I design the thickened slab to span the 18" over the pipe?  Could I encase the pipe in reinforced concrete?  How do I design the encasement?  Do I assume the 2500psf bearing pressure from the thickened slab needs to be supported by the encasement and design the rebar in the encasement for an 18" span?  Does anybody know where I can find a good encasement detail?  I asked if the 18" HDPE pipe could be encased in a steel pipe, but it's already in place and the contractor wants to use concrete encasement.  Thanks.  

RE: pipe encasement

A steel pipe sleeve is the best solution. However, since you can't do that, a properly designed reinforced slab over the pipe is probably next best. Encasing an HDPE pipe in a block of concrete can create problems if the block settles under load - the differential settlement can shear the pipe where it enters/exits the encasement.

Suggest that you download the "Performance Pile Engineering Manual" at this link
http://www.cpchem.com/enu/performance_pipe_engineering_manual.asp
and check out page 100 in Chapter 7, "Buried Pipe Design"

Publications for the Plastics Pipe Institute, at this link may be helpful, too
http://plasticpipe.org/mi/water/publications.php

www.SlideRuleEra.net reading

RE: pipe encasement

We usually require a sleeve around the pipe (1" clear of the pipe all around) and then pour a concrete encasement. A split sleeve can be used around an existing pipe as long as it is bolted or welded back together before pouring the encasement.

RE: pipe encasement

(OP)
Thanks.  What do you use to maintain the 1" clear all around?  Do they make 22" diameter steel pipes?  Do you typically reinforce the concrete encasement?  Is the concrete encasement really needed if the pipe is steel encased?  

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! Already a Member? Login



News


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close