Correlations Between Geotechnical Design Parameters and Index Properties for Low-Plasticity Clays

This research aims to develop simple models to estimate the unconfined compressive strength, modulus of elasticity, and plastic strain of low-plasticity clays using liquid limit, plasticity index, optimum moisture content, and maximum dry density, which are simple properties that could be easily found using simple laboratory tests. To address this aim, samples were collected from six locations of proposed small dams in the Kurdistan Region of Iraq. These samples were then tested in the laboratory to determine the soil classification and the unconfined compressive strength, modulus of elasticity, and plastic strain. These results were then utilized in regression analysis to develop new models to estimate the unconfined compressive strength, modulus of elasticity, and plastic strain of low-plasticity clay. As a result, three regression models have been developed. The models scored coefficients of determination of 0.9949, 0.9906, and 0.9986, respectively, which demonstrate excellent accuracy. The findings of this research have practical implications for geotechnical engineering and construction and could be used by designers to find the mentioned parameters using simple properties.