Unified Evaluation of Consolidation Parameters for Low to High Plastic Range of Cohesive Soils

Abstract

Knowing the engineering properties of geomaterials is imperative to make the right decision while designing and executing any geotechnical project. For the economical and safe geotechnical design, quick characterization of the compressibility properties of the cohesive soil is often desirable; these properties are indeed tedious to determine through actual tests. Therefore, correlating the consolidation parameters of the soils with its index properties has a great significance in the geotechnical engineering field. Several attempts have been made in the past to develop correlations between the consolidation parameters and index properties of the cohesive soils, within certain limitations. However, there is still a need to develop such correlations based on the extensive database, composing of unified plasticity range of soils, i.e., low to high plasticity. In the current study, 148 undisturbed soil specimens were obtained from different areas of Pakistan. Out of which 120 samples were utilized to develop correlations, and 28 samples were used to check the validity of the developed correlations. In order to enhance the index properties database, 30 more bentonite mixed soil samples were prepared and tested accordingly. Correlations to envisage different consolidation parameters such as compression index, compression ratio and coefficient of volume compressibility were developed using 150 cohesive soil samples of low to high plasticity. In addition, the performance of these developed correlations was verified on a set of 40 soil samples and compared with the performance of different correlations available in the literature. The percentage deviation in the prediction of compressibility characteristics through developed correlations in the present study was found to be very less, which endorsed the excellent reliability of the developed correlations.