|Posted by Ult Cable on April 29, 2002 at 15:36:33:|
|In response to Re: pipebursting sewer lateral|
: : : : In your experience, how often do you see overweight traffic (like cement trucks traveling on a crumbling street) breaking or crushing old clay sewer service lines?
: : : : My village engineer denies that any service line (over a few feet deep) can be affected by traffic -- regardless of road condtions. Instead, he has informed me that broken sewer services are often the cause of road damage!
: : : : Unfortunately, I am responsible for repairing the service all the way to the main sewer. I'll bet my lunch that you fellows have never seen a homeowner get a village to pick up part of the tab in a case like this (without a little help from Dowe Cheatum & How).
: : : None, As long as the sewer line is at least 18" in the ground traffic will not bother it. You mentioned pipe bursting. We replace sewer lines useing the pipe bursting trenchless method. You do not have to dig up your lawn or the whole road to replace this line. only one hole at the house and one at the city main.Dale's Plumbing Service Inc. LMP
: : The matter of clay pipe being crushed by traffic happens when there are inconsistencies in the backfill and compaction of the trench. In the event you bury vitreous china fired clay pipe (VCP) 24 inches deep and it lays flat on a solid very hard trench bottom like decomposed granite or a solid rock trench base, the pipe can break from heavy traffic compression when the bells and/or couplings aren't recessed into a lower area. The rubber band seal coulpings are an extension of 3/4 inch at each end of a ten foot rigid pipe span. Thats why the trench bottom needs to be scarified to provide a bed for the pipe length, and an ares for the couplings to sit deeper is afforded. When the clean backfill material is laid back into the trench on top of clay pipe, at less than eight inches, and then compacted with a mechanical stomper directly over the pipe instead of on each side of the pipe, it has a tendancy to crack the bells and has a tendancy to chip the ends inside band seal couplings if the pipe sags while being compacted. Clay pipe that has it's trench quickly backfilled by a backhoe or loader and isn't shaded by hand almost always drops rocks directly onto the brittle pipe and cracks it. But it isn't noticed, since it's backfill time, not inspection time. Then further layers above the pipe help protect the pipe from compression crushung. Bursting is an engineering term that is normally applied to the pipe expanding and breaking outwardly, while crushing or compression is usually applied to the pipe breaking inwardly. The monocline manufacturing process of clay pipe structurally withstands extremely high compression forces. It rarely is broken by traffic weight alone, unless that traffic vibrates an unclean fill material like rocks directly against the pipe. Having to replace newly laid clay pipe is usually a result of improper workmanship in the backfill and compaction stage. Did you watch your backfill guys closely?
: Can you recommend sewer contractors that do the pipebursting techniques on small jobs like mine (a single lateral replacement)? It would be great if there was a nationwide listing...
: I hope I can get someone to do this as it would help me avoid taking down a big tree and replacing sidewalk -- and a single lenth of HDPE means no more root infiltration - correct?
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