HDPE Storm Sewer Deep Burial Repair

[SusanWV]

Currently have 1750' of 30" HDPE double wall pipe carrying storm water across a new lock project. The pipe is buried at depths ranging from 20-30 feet. We are looking into ways of repairing a rupture and deflection issues of up to 17%. It must be remote access. I have looked into Link-Pipe. Has anyone had success with that type of repair in HDPE pipe? How about the glass fiber cure in place liner. That is what we are thinking about for the long term fix of the entire length. Anyone familiar with that?

 

[rconner]

Sounds like an unfortunate situation -- it is some interesting that you have reported a "rupture" in this piping, and with reported deflections of "up to 17%" (in light of some claims on the prior thread at

http://www.eng-tips.com/viewthread.cfm?qid=142221

that such pipe might take 20-30% deflection before failure!!) I'm not sure I'm aware of a dependable in-situ fix for such a rigorous service application, unless it might be by pipe-bursting or parallel HDD with stronger pipe?

 

[dicksewerrat]

I don't think you can force the pipe out to make it round again. CIPP will conform to the existing pipe shape. Unfortunately, 17% deflection is a little too high to rehab with standard CIPP. the design requirements will have to be the WRc method and this will make for a very thick liner. May not be able to construct this. Pipe burst with a heavier HDPE line. Call TT Technology in Illinois for names of contractors that may be able to do this.

Richard A. Cornelius, P.E.

http://WWW.amlinereast.com

 

[dicksewerrat]

Their phone number 800-533-2078. You should know the wall thickness of the existing pipe. this might be able to be done in one pull.

Richard A. Cornelius, P.E.

http://WWW.amlinereast.com

 

[SusanWV]

Thanks for the replys. Yes, we were surprised by the rupture, too, and believe it must have been damaged when installing, because the pipe on either side is only deflected about 7%. As far as the highly deflected areas, we also checked into a company in OH that does rerounding using a vibrator (the pipe is in a trench surrounded by concrete sand, so I can see where it might work). Is anyone familiar with that? What kind of entry do you need for the pipe bursting?

 

[rconner]

Given application of enough force and/or mechanical advantage (aye, maybe even aided by lubrication or vibration?), I believe just about anything can be moved or de/re-formed. Someone/somewhere very long ago may have even made a statement something to the effect, "Give me a lever and a place to stand and I will move the world" (I would thus not underestimate the ability of some contractors to apply brute force, even inside a pipe!) It would appear however that most engineering and regulatory new construction specifications, getting into any degree of specificity with regard to installed/discovered over-deflection conditions (I have seen over the years and/or as I viewed in a brief web search), for whatever reasons now specifically require over-deflected pipes to be re-excavated, inspected, and/or relaid. I have not happened to see any such construction specifications that specifically describe or define other suitable/acceptable means/equipment for repair of such conditions.
It is nevertheless interesting (based on a similar brief web search) that apparently multiple entrepeneurs around the country are now somehow making a living out of such unfortunate happenings with over-deflected pipes (and most of these folks are also now specifically mentioning plastics). These enterprising folks are offering (I suspect for a price that is some below what it costs to dig them up) their various equipment etc. for re-rounding (I would think at least temporarily) same in the ground. What a country!
Other than knowing of this interesting state of affairs/apparent rather widespread conundrum with contemporary pipes/installations, I otherwise have no experience with such services.

 

[dicksewerrat]

For pipe bursting you need an entry pit to bring in the bursting head and new pipe. the size is determined by the new pipe's ability to bend down to the old pipe and the exit pit only has to be large enough to extract the bursting head.
The rerounding with a vibrator may work if you can get the material around the pipe to move and force the pipe back to round. I would ask for a lot of references and tapes of the process and results of same before i contracted that.

Richard A. Cornelius, P.E.

http://WWW.amlinereast.com