Scanning area for Caves , What is the best approach ?
Scanning area for Caves , What is the best approach ?
(OP)
Hello ,
We have a project in an area where the soil consists mainly from limestone rock with present of caves.
We are planning to scan the area using Ground Penetrating Radar.
My Question is whether GPR is suitable for this job and what is the proper depth we need to scan the soil for. The project is 140 residential buildings with a height of around 35 meters.
Another question is what is the suitable way of grouting any subsurface caves.
Please find attached pictures of one cave we found during excavation works.
We have a project in an area where the soil consists mainly from limestone rock with present of caves.
We are planning to scan the area using Ground Penetrating Radar.
My Question is whether GPR is suitable for this job and what is the proper depth we need to scan the soil for. The project is 140 residential buildings with a height of around 35 meters.
Another question is what is the suitable way of grouting any subsurface caves.
Please find attached pictures of one cave we found during excavation works.





RE: Scanning area for Caves , What is the best approach ?
I could not open your photo, don't know what the problem might be, so I don't know what the cave you found looks like. But if you have shallow caves in bedrock; then the area is not suitable for houses.
As for grouting caves, that is almost always a bad idea. The caves likely carry groundwater, if you grout them that water will go somewhere else at least temporarily. You can cause flooding and changes to the surface and groundwater flow in a wide area. The other problem is, depending on the conditions, the water may erode the material beside the grout and reopen the cave in a few years.
At a minimum, you need to get a very experienced geotechnical engineer involved with the project.
Mike Lambert
RE: Scanning area for Caves , What is the best approach ?
RE: Scanning area for Caves , What is the best approach ?
http://www.geophysical.com/gssifaqs.htm
http://gp-radar.com/Limitations-of-GPR.html
http://www.global-gpr.com/gpr-technology/how-gpr-w...
http://www.gp-radar.com/faq.htm
https://en.wikipedia.org/wiki/Ground-penetrating_r...
http://www.uvm.edu/~lewebb/CCLI/various%20papers/S...
All imply that ≤ 400 MHz and dry limestone might be a good combination to get well past a few feet.
TTFN
I can do absolutely anything. I'm an expert!
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers
RE: Scanning area for Caves , What is the best approach ?
http://www.spectrum-geophysics.com/voiddelineation...
http://files.dnr.state.mn.us/waters/groundwater_se...
RE: Scanning area for Caves , What is the best approach ?
RE: Scanning area for Caves , What is the best approach ?
RE: Scanning area for Caves , What is the best approach ?
I saw this link and think it is good solution: http://www.smiddleton.com/environment/sinkhole.htm
Also, I found Sowers book "Building on Sinkholes" as a goo reference....
RE: Scanning area for Caves , What is the best approach ?
http://www.enr.com/articles/38948-iraq-hires-trevi...
RE: Scanning area for Caves , What is the best approach ?
Seismic refraction doesn't work. Not sure about reflection.
Drill holes are essential, just to bring regional geology to the site and confirm what you have. In core holes, we've used the televiewer to actually photograph down-hole findings and capture structure.
Nothing is easy. . .
f-d
ípapß gordo ainÆt no madre flaca!
RE: Scanning area for Caves , What is the best approach ?
At ANY frequency? So are all the guys with < 400 MHz GPRs lying about the performance?
TTFN
I can do absolutely anything. I'm an expert!
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers
RE: Scanning area for Caves , What is the best approach ?
If you have other perspectives, I'm love to learn more about advances in GPR and case studies that show these innovations in practice.
f-d
ípapß gordo ainÆt no madre flaca!
RE: Scanning area for Caves , What is the best approach ?
RE: Scanning area for Caves , What is the best approach ?
RE: Scanning area for Caves , What is the best approach ?
I'm still interested in advances in GPR that can see down to 30 ft or so.
f-d
ípapß gordo ainÆt no madre flaca!
RE: Scanning area for Caves , What is the best approach ?