Review of Correlations between Unconfined Compressive Strength (UCS) Values and Dynamic Cone Penetrometer (DCP–DN) Values of Stabilized Soils

Abstract

This paper discussed test methods, test and sample types, types of stabilisers and soils, applications, and limitations of various developed relationships between UCS and DCP DN values. The review of correlations between unconfined Compression Strength (UCS) values and Dynamic Cone Penetration (DCP-DN) values of stabilised soils will provide guidance on the selection of suitable regression models from what is available in the literature to enable the estimation of UCS from DCP values. The DCP test was found to be economical, rapid, portable, easy to operate and understand, and the most versatile test that provides comprehensive results. Many studies and various nations have adopted the ASTM D6951 DCP equipment for use. Previous studies show that DCP DN values are affected by the soil type, stabiliser and curing period, particle size, plasticity, moisture contents, liquid limit, dry density, UCS, confinement in mould, and investigation depth. The various existing regression models are useful for quick estimation of in-situ UCS of stabilised layers since the termination of in-situ UCS is expensive, tedious, difficult, and time-consuming. However, these regression models must be used with caution as they are dependent on material properties and other factors that influence the DCP DN values. Furthermore, the available correlations cannot be treated as an absolute substitute for laboratory values, and their application requires experience and engineering judgment. This allows further research to develop multiple regression models to correlate UCS and DCP with the same compactive effort and mould size, which will consider material properties and the effect of confinement on the laboratory DCP DN test in the standard mould.