Correlation between effective cohesion and plasticity index of clay

Correlations of engineering properties are a useful tool in geotechnical engineering practice. This paper aims to provide a correlation between the effective cohesion and plasticity index for natural, undisturbed clay soils from the Kozloduy area (NW Bulgaria), based on the results from laboratory tests. It has been demonstrated that there is a strong correlation between the plasticity index and the effective cohesion. The derived regression equation can be used to estimate the effective cohesion as first approximation in preliminary design of engineering projects of Pliocene and Quaternary clays encountered in northwest Bulgaria.