×
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

Trench Strengthening

Trench Strengthening

Trench Strengthening

(OP)
Existing sanitary sewer main with approx. 12 feet of cover.  Proposed project will increase cover to approximately 22 feet, which will exceed the pipes recommended maximum cover.

Any recommendations on ways to exceed typical maximum recommended cover on pipes?

RE: Trench Strengthening

Suggest you look into a product called ParaLink.  It is used to support embankments over voids.  Linear Composites may be able to help

RE: Trench Strengthening

Use a different pipe in the deeper areas.Which pipe are you using?

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

RE: Trench Strengthening

What is the pipe's recommended max cover? This may influence options available.

Replacing the existing pipe with a pipe of greater strength is an option, but I assume this is costly to do and is not your preference.

You could use cement-stabilised sand to provide extra support or otherwise modify the embankment to not increase the loading on the pipe. Piles are also a potential solution.  

RE: Trench Strengthening

Any possibility of using a lighter weight backfill (lightweight concrete or even big foam blocks)?  If you can reduce the unit weight by half, you could effectively double the cover depth.

RE: Trench Strengthening

I think that DMcGrath has hit the correct chord (a major as versus a minor or diminished!). The other possibility is to construct a cover slab across the trench at some depth down which will permit the above-lying soil from loading below. The geofoam blocks, though, appear to be appropriate (or the use of Elastizell - but this is expensive.

RE: Trench Strengthening

Pipe strength is a function of the surrounding backfill, use 100 psi flowable fill for pipe encasement and maximum depth can be increased.

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