How do I recognize a fat clay vs a lean clay in the field (while logging the boreholes) without doing any LL tests on it? Also, any tips to distinguish clay from silt?
fat clay will stick to your shoes, silty clay will have a little grit when rub between your finger. I know it sounds like I,m joking but think about it.
The US Army corps of Engineers has a site for geotechnical investigations aimed at "low tech analysis". This site ahs a number of documents freely available, including a terrific chart on the classification of soils by hand.
Unfortunately I do not have the site address any more due to a PC upgrade. If I can find it again I will post it here.