×
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

pipe through unstable soil

pipe through unstable soil

pipe through unstable soil

(OP)
I'm looking for information (design aids) related to the design of ductile iron pipe with restrained joints through areas of unstable (organic)soil.  Pipe is 8" to 12" water main, 5' of cover required and length of organic soil to cross is 300' to 600'.  Organic deposit is approx. 13' deep.  Organic content is presently unknow.  Desire is to install pipe by horizontal directional drilling due to several factors.  HD Polyethylene pipe has been eliminated from consideration by owner.   

RE: pipe through unstable soil

May I enquire the rationale at to the Owners objection to HDPE?  Is this area susceptible to frost?  What type of cathodic protection is being considered, if at all?

HDPE is inherently resistant to corrosion and highly tolerant to movement due to unstable ground.  DI is very rigid and brittle which therefore begs the thought as to the OWners considerations in the matter.

 

KRS Services
www.krs-services.com

RE: pipe through unstable soil

(OP)
Owner's Objection: unknown but firm.  Frost depth: 42".  Cath. Prot.: still considering alternatives, feel free to offer ideas.  Is HDPE resistant to hydrocarbons?  DIP allowed to deflect at joints.

RE: pipe through unstable soil

Hydrocarbons??  Your post refers to water.

What is the application?  The Owner should really reconsider.  I can take him/her on a few guided tours of DI and AC pipe placed in weaker soils...and show him all the repair locations over the years, both due to frost and swelling due to groundwater and other factors.  I'm currently involved in a  small job replacing DI pipe in medium soils due to movement and corrosion.  I strongly suggest an alternative, or get him/her to call me as one Owner to one experienced P.Works Manager.

KRS Services
www.krs-services.com

RE: pipe through unstable soil

The organic soils will give you an acidic soil condition. you will have to protect this DI pipe. HDPE can go in at 5 feet, 6 feet or any other depth. Even down in the stable soil. Is there a good reason to change pipe sizes in the weakened soil? HDPE moves well and can be designed for almost any condition. If you suspect VOC's in the water table maybe a double line? one inside the other. Owner should come out of the Dark Ages. Attend a few trade shows and see what's being done these days.

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