Extrapolation of Geotech Study Results
Extrapolation of Geotech Study Results
(OP)
I have a project to install a truck scale and foundation in Southern Alberta. We have a geotech study at the site that was completed for a different project, but the area that the study was done is approximately 150m away from where the new truck scale will be situated. Is it reasonable to use the results from this geotech study, or is this too far away to extrapolate the results?





RE: Extrapolation of Geotech Study Results
Reminds me of a question I frequently would get through the years. "How many borings needed?" My routine answer was "At least one". But here "maybe more".
RE: Extrapolation of Geotech Study Results
RE: Extrapolation of Geotech Study Results
In my practice, I'll stop a consultant if they rely on extrapolation. Then again, I work for a public agency and don't want to adopt the problems of my consultant.
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ípapß gordo ainÆt no madre flaca!
RE: Extrapolation of Geotech Study Results
Consult the original geotechnical engineer!
RE: Extrapolation of Geotech Study Results
master ICC inspector, AWS CWI
RE: Extrapolation of Geotech Study Results
I've compared soil reports (mine and one the company did 20 years earlier) in an area where we also had several other reports in the same geological setting. Given the same geological setting (such as the Peel Till Plain in Ontario) one can be pretty safe in having consistent designs - 150 ft apart is not all that far in such a setting - one would need to be cognizant, though, of old stream beds that might have been infilled - you might check out old agricultural maps as they can get pretty detailed. Another problem, even if you have investigated the site, is whether there are old utility lines or former house basements that have been infilled - the former should be covered in your report (if you are writing one). I used former reports of our company on a major paper mill site in Northern Ontario - no probs.
The big thing is, an none of us can help you out here as we aren't "local", how consistent is the geological setting in your area of the project. Only you can have a gut or reasoned feeling as to the uniformity in the area. (I did a location in southern Ontario that for a small development, had three different founding conditions - where only one was expected).
As an aside, years ago, I read some papers in an Alberta geo conference or workshop where a residential development ran into problems in that they encountered a dinosaur latrine!!! So, in Alberta, you might have to consider this!!!
RE: Extrapolation of Geotech Study Results
Call the Geotechnical Engineer that did the existing report and ask. If you offer to pay him to write a sealed letter, he might be agreeable to that. If he/she says no, get more borings. This is very cheap insurance against a very big problem.
We work on water and wastewater treatment plants. These are large area facilities and are constantly being expanded and revised. Every area in the plant has been analyzed at one time or another. I use existing reports a lot, but I always feel a little dirty about doing it. I sometimes ask the PM if we can get a letter from the original Geotechnical Engineer verifying using the report for another project. It's usually about $500 or so. Of course borings plus a full report costs more.
RE: Extrapolation of Geotech Study Results
RE: Extrapolation of Geotech Study Results