Anyone use GPR? 8

[dirtsqueezer]

Does anyone use ground penetrating radar in their business? I used one in college, and we've been throwing the idea around at the office, but they seem expensive. Anyone actually use them in the real world for practical application? Just curious about cost/effectiveness/usefulness. Thanks.

 

[heulenwolf]

I'm in R&D, so I wouldn't call what I do "real world," but we develop products that are actually used, if not in the commercial sector. We use gpr to look into concrete, roads, runways, train track foundations, various ground sites. Yeah, its used. Its just that it still requires an operator that knows GPR and some foreknowledge of the site. Its getting fairly simple to detect things in easy circumstances but imaging is not simple even in the easiest of circumstances.

GSSI (

http://www.geophysical.com),

Sensors and Software (

http://www.sensoft.ca/),

and Mala Geoscience (

http://www.malags.se/)

all make commercially available systems for various applications.

I think my company (ENSCO) found the costs (possibly internal) to be too high when they tried doing gpr investigations as a service.

 

[TJWATKINSPG]

Here in Florida they are used to define potential sinkhole areas. The present use is as a screening tool to define areas for SPT borings. As there are not always real surface indications on Subsidence sinkholes the GPR presents us with a clue as to where to expect a sink or other subsidence conditions.

When I was doing Environmental investigations I found GPR to be very beneficial in defining the limits of landfills, pinpointing large tanks,pipelines or other buried objects. Often the GPR was the only tool to focus our exploration.

Field truthing with a SPT or back hoe was still something that raised my level of confidence. With all due respect to the math folks , I have drilled too much behind Geophysical data to believe an interpretation completely.



The truth will set you free. Best of luck. Geodude

 

[Focht3]

I'm with TJWATKINSPG - really only a screening tool. And it depends on differences in density to work, so it has a hard time if the material overlying the "feature" you are looking for has about the same density.

There are some guys at Texas A & M that claim they can use GPR to find variations in soil moisture content as well as voids, etc. I'm still a big skeptic of their claims; after all, aren't this the same school that (about 20 years ago) considered "aging" a new building on their main campus by spraying a solution of water and bovine excrement all over it?

 

[cvg]

Was used recently here to locate an abandoned pipe within a dam embankment. Pipe was located approximately using prelim drawings / as-builts and then precisely located with GPR

 

[BigH]

I used it to local potential mine workings under a highway in Northern Ontario (posted in some other thread). I have name of someone in the business somewhere in this room of mine and will find in next day or so - then post it.

 

[dirtsqueezer]

Thanks. Funny about the bovine excrement. Did you hear about that university library whose design did not include the books? They are apparently experiencing slightly higher degrees of settlement than was on the plans. Not sure which institution.

Yeah I can relate about the operator knowledge required. A few guys in my graduation class had as their final project writing the how-to manual for the new GPR. From what I hear, it took them all quarter.

Thanks for the good input.

 

[Ron]

dirtsqueezer...We use GPR for the same as TJWATKINSPG...for preliminary soils info in subsidence cases, for locating stuff underground, for concrete screening, and for roadway characterization. It is almost never our only tool in the toolbox for these investigations, but can help you out in some instances.

Watch out for those who claim it can find anything and everything, along with curing the common cold.

 

[BigH]

Good cautions. My contact in the business, as indicated earlier - Geophysics GPR International Inc.; Milan Situm, 282 Belfield Rd, Rexdale, ON M9W 1H5; gptor@ican.net (+1-416-675-6880 fax).

 

[Rjeffery]

Hey dirtsqueezer, I have been on a team that used GPR to locate PT cables on a parking deck so that additional electrical conduit and plumbing could be passed vert. through the deck(s). NEVER hit a cable. also found numerous voids in the PT beams and in columns. I worked with a firm that used GPR to locate USTs and Karst formations with great success. As Ron has indicated, two asprin, plenty of bed rest and lots of water is much better for colds and the flu that GPR!

 

[abarker]

dirtsqueezer,
Our firm has used it to locate old graves in a pauper cemetary for a roadway realignment project. Worked well, but we weren't about to calibrate the data with a backhoe! The few times we've used it, we've rented it from the manufacturer. It's been my belief that the best use is where you're trying to find something containing a void.

 

[Ron]

Rjeffery...you forgot the Jack Daniels

 

[Rjeffery]

I don't think Jack will help dirtsqueezer using GPR any more than Jim Beam would. Perhaps Jemmison?

OH! you meant for the cold or the flu! Yea, I left out the hot toddy and the chicken soup in case MADD or PETA were visiting the forums...

 

[Eduardo5000]

Hi. At the moment we are using GPR to look buried objects (metallic). We got very good results when we were over a buried pipe, we obtained depth and a nice image. The detail is that we knew the pipe was there, it was just a test. Nothing in particular has been found, even we know that lots of blocks of concrete were buried there.
Images are very hard to interpret, we never saw what comes in the manual. Advice: Only use it when you are looking for metalic objects or pipes.

E5000

 

[Ron]

Rjeffery...Jack and Jim will put a whole new perspective in the data interpretation.

 

[Rjeffery]

Ron,

 

[BigH]

So might a "Wild Turkey"!! If you crack one open, draw a shot for me!!