×
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

CDFs affect on AC Water Pipe

CDFs affect on AC Water Pipe

CDFs affect on AC Water Pipe

(OP)
We have had several instances where a contractor has used CDF to backfill between a deep sewer and a crossing shallow AC water main. This is only done occasionally to avoid large water shutdowns that would normally take place to splice in a section of ductile iron pipe at the crossings. Not long after we have been seeing the AC water pipe develop a circumferential crack on the bottom in the middle of the section that crosses the trench line. I'm trying to convince our City engineers that we should ALWAYS splice in the DI pipe when we have crossings as opposed to using CDF. I couldn't find any good arguments to support my theory so I'm seeking the guidance of experts here.

RE: CDFs affect on AC Water Pipe

either
a) the CDF shrinks
b) the crack begins during temporary support before the CDF is placed and then gradually widens
c) both

I would require replacement with DIP or 11 month inspection to check for settlement / leakage before the contractor's warranty bond expires.

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