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624 views
06:26 Jan-21-2008

Frank Lehmann

R & D
GE,
India,
Joined Jan 2008
1
GPR applied to a bored pile wall

Hello,

I'm planning to use GPR to check the thickness of a bored pile concrete wall. Every other pile is unreinforced and should have a diameter of 1.2m (47 1/4in). The height of the groundwater table behind the wall is not known, neither is the soil type. After some trials on different test specimens I've decided to go for either the 500MHz or the 900MHz antenna, depending on the conditions I'll find on site. Does anyone have experience with this kind of job, i.e. does it make sense to use the equipment as specified? Earlier measurements with US were not successful because of sand embeddings and the poor surface condition. Thank you very much,

Frank Lehmann


 
07:14 Jan-21-2008

Ernst Niederleithinger

R & D, -
BAM (Fed. inst. for material research and testing,
Germany,
Joined Jun 2001
7
Re: GPR applied to a bored pile wall Dear Frank,

it will be dangerous to guarantee success to a client. We have made lots of measurements i. e. on foundations slabs and did not see a reflection (neither with 900 MHz nor with 500 MHz antennas) from the base of a foundation slab (0.75-1.2 m thickness, accessible for trials at our site). Penetration depth depends much on moisture content, wich will be probably unfavourable high in your case. Nevertheless an interesting idea and it should be tried. I would be interested to see/discuss results. Or to assisst in the measurements/interpretation.

What kind uf US equipment did you use?

Ernst Niederleithinger


----------- Start Original Message -----------
: Hello,
: I'm planning to use GPR to check the thickness of a bored pile concrete wall. Every other pile is unreinforced and should have a diameter of 1.2m (47 1/4in). The height of the groundwater table behind the wall is not known, neither is the soil type. After some trials on different test specimens I've decided to go for eitherthe 500MHz or the 900MHz antenna, depending on the conditions I'll find on site. Does anyone have experience with this kind of job, i.e. does it make sense to use the equipment as specified? Earlier measurements with US were not successful because of sand embeddings and the poor surface condition. Thank you very much,
: Frank Lehmann
------------ End Original Message ------------




 


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