ABSTRACT
This paper elucidates a technique for prediction of cone-penetrometer index of unsaturated soil. The solution is based on identifying the state parameter establishing the linkage between the cone surface stress and pore volume within the critical state space of soil. The state parameter associated with soil type and moisture content is a two-parametric linear function that provides the basis for correlation analysis. The cone penetrometer performance under the laboratory and field situations require the establishment of the basic Mohr-Coulomb failure criteria and the critical state parameters of the soil over a range of moisture contents. The experimental evidences show a systematic change in state parameter of c-ϕ soils over a range of moisture contents. The state parameter coefficients estimated as a function of moisture content could be used a ready tool for converting the penetrometer readings to bulk density or pore-space estimates. The predictive performance of the cone-index model was found most encouraging.
