Correlation of Atterberg limits to shear strength
Correlation of Atterberg limits to shear strength
(OP)
I am about to embark on some research into the relationship between PI and shear strength.
As I understand at present, there is a vast amount of work already undertaken in this field, however this is largely based on overconsolidated clays (London, Gault etc). Can anyone tell me if the work extends into all soil types or if it was soley undertaken on the overconsolidated clays?
Many thanks
As I understand at present, there is a vast amount of work already undertaken in this field, however this is largely based on overconsolidated clays (London, Gault etc). Can anyone tell me if the work extends into all soil types or if it was soley undertaken on the overconsolidated clays?
Many thanks





RE: Correlation of Atterberg limits to shear strength
RE: Correlation of Atterberg limits to shear strength
Stark, 2005, 1997 and 1994 - all published in ASCE Geoetch Journal
Mesri, 2003 - published in ASCE Geotech Journal.
These publications provide specific discussions on the use of Atterberg limits and CLay Fractions as itr relates to residual strengths ...
RE: Correlation of Atterberg limits to shear strength
Any more suggestions always welcome.
RE: Correlation of Atterberg limits to shear strength
As you are uk based, you may want to look up an old CIRIA publication which gives a correlation between liquidity index and undrained shear strength. The publication is CIRIA Special Publication 25, dated 1983, 'Site Investigation Manual'.
Hope this is of assistance.
RE: Correlation of Atterberg limits to shear strength
RE: Correlation of Atterberg limits to shear strength
Specifically, do you know of any work in this field which relates to more complex glacial till (boulder clays) deposits as oppose to relatively homogenous cohesive deposits? I would like to possibly develop/prove empirical relationships by incorporating a local geological model to these deposits. My aim is to provide a more accurate way of predicting undrained shear strength by looking at the geological history of the site.
An Ambitious Post Grad!
RE: Correlation of Atterberg limits to shear strength
To get a better relationship you are probably going to have to look at a way of taking into account the proportion of coarse/fine material. This could perhaps be done by determining the liquidity index on the basis of the 'modified' natural moisture content, ie, the moisture being held only in the proportion finer than 425microns and not the coarser fractions.
Good luck with your research
RE: Correlation of Atterberg limits to shear strength
RE: Correlation of Atterberg limits to shear strength
I think it is better to have an actual number to work with rather than an assessment based on a description. If you are determining the PI according to BS1377, the test is undertaken on material finer than 425microns, so any lab doing the test will determine the amount of such material as part of the test. You are then in a position to modify the PI or moisture content.
Over to you, jicker23
RE: Correlation of Atterberg limits to shear strength
Sorry, being a bit slow - my initial thinking was that the gravel and cobble content would effect the undrained shear strength during the lab test and therefore effect the correlation. However this of course is not a function of the shear strength and the test result would not be valid anyway.
Thanks for your advice to date - its appreciated. This is the first time i've used this site properly and I am impressed by the prompt number of replies.