Directional Bore Pipe Sizes

[mes11]

Can a sanitary sewer be directionally bored under truck docks with the end result being a gravity sanitary sewer line? Pipe size would need to be 6" or 8". Length of the bore/pipe would end up being about 700 feet. I am trying to avoid tearing up trucks by installing an open cut sanitary sewer. This would also keep the docks in operation. Just wasn't sure how long you could do the boring and what pipe sizes could be done. Any insight is appreciated.

 

[dhengr]

Mes11:
6" or 8" dia. is no problem, and neither is 700', and good contractors can do a pretty darn good job of putting the pipe where you want it. They do have to be able dig and work at each end of the bored line, so as to do the drilling and to feed the pipe, etc. They usually drill the hole and then pull the pipe back as they pull the drilling string back out.

 

[rconner]

If you are talking about HDD, and while there are folks who claim to be able to do this, if you must hold a rather precise (for proper gravity service, no ponding etc) and slight grade from established point to point one side to another, even the best may find this a tall order. You might refer with advanced search feature to several past discussions e.g.

http://www.eng-tips.com/viewthread.cfm?qid=208273.

Also, I think some authorities like at least 8" pipe for gravity sewer (and maybe particularly for such long reach).
All have a good weekend.

 

[cvg]

I would not recommend HDD for gravity sewer mains. jack and bore with casing would be a better idea. However, I have seen installation of small diameter vcp sewer lateral house connections done with just an auger. so for a private sewerline, you might be able to do it.

 

[bimr]

Agree with the previous two responses. It is not possible to directionally bore a sewer because it is not possible to maintain the grade line with appropriate accuracy.

You can use jack and bore. Note that these technics require working areas in order to accomplish the task.

Note that sewer manholes for cleaning purposes are typically installed every 400 to 500 feet.

 

[mes11]

Thank you guys. The current proposal also had two lift stations that would be at each end of the 700' feet I was referencing. So there was also another motive to eliminate the furthest lift station as well. I know the force main could be done by HDD.

 

[HockeyPuck]

I'd highly doubt that you'd be able to find a contractor that would be willing to guarantee it would be constructed to design line & grade for that linear footage....I sure wouldn't.

I don't think the jack & bore is a cost effective installation either. By the time you add up all of the ancillary costs of building jacking & receiving pits, as well as the risk costs associate with installing something in-the-blind (think about the impact an obstruction in the bore might have....), you'll find that traditional open cut is the way to go.
Cheers!!

 

[amlinerrichard]

Check with some micro-tunneling contractors. they may be able to do this