Liquid limit of selected postglacial soils from west-central Poland

Abstract

The aim of this paper is to establish a correlation between the liquid limit value obtained in the Casagrande apparatus (w_L/cup) and in the cone penetrometer (w_L/cone) for typical glacial sediments from west-central Poland and compare them with the correlation equations published in the literature.

The following correlation was formulated: w_L/cone = 0.91w_L/cup + 1.98. The analysis presented in this paper proves that deriving a generalised and universal relationship w_L/cup/w_L/cone for all cohesive soils, regardless of their origin, is not possible.

It is verified that in the range of low values of liquid limit cone penetrometer gives higher values of w_L than those obtained from the Casagrande apparatus. However, for the Polish postglacial soils analysed in this paper, the cone penetrometer underestimates the results in relation to Casagrande apparatus above w_L = 22%. For the purpose of this study, w_L = 22% was defined as ‘the point of equivalent results’ (w_L/cone=w_L/cup).

The aim of this paper is to establish a correlation between the liquid limit value obtained in the Casagrande apparatus (w_L/cup) and in the cone penetrometer (w_L/cone) for typical glacial sediments from west-central Poland and compare them with the correlation equations published in the literature. The following correlation was formulated: w_L/cone = 0.91w_L/cup + 1.98. The analysis presented in this paper proves that deriving a generalized and universal relationship w_L/cup/w_L/cone for all cohesive soils, regardless of their origin, is very challenging and may not be reliable for use in the engineering practice. It is verified that, in the range of low values of liquid limit, the cone penetrometer gives higher values of w_L than those obtained from the Casagrande apparatus. However, for the Polish postglacial soils analysed in this paper, the cone penetrometer underestimates the results in relation to the Casagrande apparatus above w_L = 22%. For the purpose of this study, w_L = 22% was defined as “the point of equivalent results” (w_L/cone = w_L/cup).