Damage PreventionData CollectionData InterpretationUtility Locating

What to do when your ground penetrating radar (GPR) can’t locate your target?

By October 7, 2016 5 Comments

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  • Ben Minutoli says:

    Nice work once again Dan and spot on, you might not be able to see the pipe, but at least if you can see the trench then you will still know where it is.

    There are of course times where no matter what you try you still won’t be able to see the pipe, trench or ground disturbance at all. But as you have mentioned in other videos you have done, this could be because of what the pipe is made out of or what the connectivity of the soil is like.

    A common one of me that I come across a fair bit that can’t be found are gas service lines to the house from the gas main. Sometimes we can see them or see where they have been trenched in. But there have been a lot of times we have not been able to find them with the GPR due to the pipe being small, made of plastic, not having a trace wire and the soil being too wet, with heavy clay and rocks in tree roots in the ground.

    But hey, I guess at least we go out and give it a go. It’s better than just saying to the client on the phone, sorry but it can’t be done 🙂

    • dpbigman says:

      Hey Ben,

      Thanks for another great comment! I hear you. Small gas lines can be rough. Sometimes those things are 3 inches in diameter, BRUTAL! It could help going way up in frequency (like 1000 MHz), but one problem we see in Georgia (where I live) there is a TON of clay. I once used a 900 MHz antenna on an archaeological project and literally the signal was attenuated on ground surface impact. Gas lines are real problematic near me, which is terrible because gas is probably the most dangerous of all utilities to damage.

      And agreed, take that thing off the truck and use it! Then see if it struggles.

  • Anthony says:

    Contaminated soils with poor fill causing clutter

    • dpbigman says:

      Yep! That can be a difficult one to interpret. Sometimes I try EM induction with a conductivity meter. Still can be rough!

      Thanks so much for the comment.