Use of Cone Penetration Test for Classification of Some Sudanese Soils; the State of the Art

Abstract

The cone penetration test (CPT) method has successfully been applied in Sudan for research, foundation design and the solution of geotechnical problems for various engineering structures since 1977. Based on analyses of database accumulated during four decades correlation relationships have been developed to classify local soils from CPT data. This paper presents the state of the art and the main findings of previous studies carried out on the application of CPT for soil classification. A simple and reliable CPT method based on the statistical “discriminant analysis” technique was proposed in 1980 to classify a given soil of known CPT parameters into one of four main USCS soil groups. Another correlation was proposed in a different study between CPT data andrelative consistency of highly plastic clay soils. The original soil classification method was further modified in 2003 to include more database and incorporate additional features relating to the consistency of clay soils and relative density of sandy soils. The accuracy of the CPT based soil classification method was examined amongst worldwide known methods by comparison of the soil types predicted from CPT and the actual soil profiles. The comparison study showed that the method performed quite well in classifying alluvial soils which are similar to those used in their development.