Discussion: Determining the plasticity properties of high plastic clays: a new empirical approach [Arab J Geosci (2020) 13(11), 394]

This article presents a discussion of the Arabian Journal of Geosciences, 394, Vol. 13, No. 11, which (among other things) proposed a new empirical correlation for the prediction of the plasticity index magnitude (and hence by association the plastic limit value) of fine-grained soils sampled from different depths in the Bakirkoy District of Istanbul City. As inputs, the proposed correlation employs the activity index, along with defining parameters of the semi-logarithmic flow curve obtained from the Casagrande (percussion-cup) liquid limit test. This article presents the following: (i) a discussion of the relevant literature that was not covered in the original paper; (ii) clarifications on, and observations regarding, the general approach adopted in the original investigation; (iii) concerns over whether the proposed new empirical correlation can be meaningfully recalibrated for particular clay soil types specific to other regions around the world; and (iv) suggestions for improvement of the new empirical correlation by adopting a different set of input parameters.