"Generalized Soil Profile"? 2

[boffintech]

The lab manager wants a "Generalized Soil Profile" for a particular job. Soil Profile? I'm looking in my Soil Mechanics text (McCarthy) and I don't see it in the index. What do you think he is talking about?

 

[Dirtguy4587]

I would suggest that he is requesting a bit of soil stratigraphy - i.e. the probable soil layering at the site. This would include approximate depths at which the interfaces between different soil types are found. Included within the profile should be a general soil description (at the very least), possible a USCS description. This could be obtained from test borings or test pits that may have been performed on the site.

 

[Grouser]

boffintech

I believe that standard practice no longer recommends reporting a "generalized subsuface profile" because of the hard-to-deny logic that if you are only sampling <.1% of the site, how can you generalize. It used to be that geotechs considered part of their service to provide it and the reports weighed more but nowadays the lawyers are too hungry.

If you are seeking quantity information for a borrow pit or similar mining activity then interpolating between bore holes is connecting the stratigraphic surface points.

It is good practice to do it with borings from the preliminary geotech investigation phase, in order to help identify areas that need further investigation. Also to see if the site conditions match the expected geology. Mark it as "preliminary" in your records and don't report it. ASFE (American Society of Foundation Engineers) can provide guidelines for model report formats.

 

[DRC1]

Let's say you hae a site yo need to develop a design for a pile bent. None of thhe five orings ae a the bent location, but all are in close proximity. You will find the blow counts for all the borings at the same level will vary. The depths of the layers of soil will vary. Some borings may show lenses or inclusions that others don't. In order to design the bent a resonable single soil profile must be interpolated. No real cookbook on how to do it, but gets easier with practice. I believe this is what your boss is looking for.