Plasticity chart

[BC93]

I have plotted the PI versus the liquid limit on the plasticity chart designed by Casagrande and all the points (from different boreholes and different depths) are aligned (quite well actually) on a straight line that is fairly parallel to the A-line (and above). What can I conclude from the chart other that this is highly plastic soft clay? For instance that the whole area "belongs" to the same geological formation?
Thx.

 

[reyv]

If I recall the chart you are referring to, it is used to get a rough estimate of the the type of clay mineral that makes up a soil deposit. As far as if they are from the same type of formation, a Geologist (many companies have them in-house) or some research regarding geological formation from aerial maps with respect to the project site (see my blog post) can give you an indication if they are from the same group. These two pieces of information can help you come to that conclusion.

Rey Villa, MS, PE

http://geotech-apps.com