Digging under fiber optic and electric

Currently working at UK Football Stadium. Digging about 7 foot deep and uncover a electric line encased in concrete, and fiber optic encased in concrete about 20' out from manhole. Electric run in 45 degree angle in ditch at about 1.5 under top of ground. Concrete encasing is about 2' thick. Fiber optic is running in 45 degree angle back the other direction making a V in the ditch. Electric
Guys dove there pipe under fiber line. Question, how much time should be allowed to
Tunnel under these lines? What is the best method if any?

Here's another picture of
Job site

what about using a vacuum excavator to clear the utilities?

The best I can tell from the pic is you have a 12-18" line running out of that manhole that has to cross the fiber and electric.

If there is nothing in between them, I would suggest a mini and some laborers with a slow timetable to dig between the lines to expose them with enough room to work. It's hard to tell but is the storm line going to pass over them? Or is there another line running beneath the core in the pic that will run under the lines?

Digging under electric and fiber

CM1995 said:

The best I can tell from the pic is you have a 12-18" line running out of that manhole that has to cross the fiber and electric.

If there is nothing in between them, I would suggest a mini and some laborers with a slow timetable to dig between the lines to expose them with enough room to work. It's hard to tell but is the storm line going to pass over them? Or is there another line running beneath the core in the pic that will run under the lines?

Click to expand...

Sorry about the picture CM1995. That pic is if a 6' manhole going on a 30" exiting RCP. The two other pipes in pic are 12"sanitary sch 45 PVC and 8" ductile iron water main. Done tunneled under these two. The ones in question are comeing out of the same manhole on the opposite side. Didn't get a pic of them. I do like your observation of the picture though. You must be an ol'pipe layer from way back.  Your the kind I people I like getting advice from. Been there done that!!! What's a reasonable time if possible on tunneling under very difficult area. The old Hoe Man I talked to last night told me there ain't no time table, just don't break nothing. I told the boss and others that keep coming up looking at the ditch that each bucket taken out is faster than shoveling it out. LOL

Yeah and they are goin to have to core another hole in manhole to get that 12" storm line to go under them two pipes in pic . Measured inside and coreing machine will fit inside to do the job. Going to charge time and material on that.

I agree with your old hoe man - "there ain't no timetable, just don't break anything." However much T&M it takes to uncover it will be far less than what it will cost to repair that fiber line.

When I give a guestimate to GC's or owners for work like this I like to err on the upper side of price. It's hard to give time advice without looking at it.

A year ago I was laying 24" RCP in the ROW between the curb and sidewalk, might have had 3' or so to work in. Had to cross a phone, cable and two copper water services in less than 8'. It was a bitch but we got it done.

Sound advice from above. My only other suggestion is to make sure the "upper superintendents" know this issue.Make sure you have other eyes on the line as your digging. Sometimes I expect the line to be here when from the operators seat the bucket is closer to contact. As above "don't hit it"is all fine and well but T & M can have pressure to get it done sooner rather than carefully. This can set you up for not getting paid completely for your time making sure you don't damage the line. The difficult dig and time it took can disappear after it's been back filled. Good luck

When ever I have to cross the fiber line I get very little sleep the night before. Three year ago it cost$40K per min for down time plus repairs. They have installed new gear and the cost has almost tripled. Almost every time I have done any digging the locate guy has been right there, he will even help hand dig at times. I always bid the jobs high or T&M, the one street has the water, gas, phone, and fiber all on one side. Take lots of time, and don't rush.