Classification of Soils

Abstract

Different soils with similar properties may be classified into groups and subgroups according to their engineering behavior. Classification systems are a common language to concisely express the general characteristics of soils, which are infinitely varied. Most of the soil classification systems of transported soils that have been developed for engineering purposes are based on simple index properties such as particle-size distribution and plasticity, such as the USCS and AASHTO systems. Although several classification systems are now in use, none is totally definitive of any soil for all possible applications because of the wide diversity of soil properties. In addition, in the case of residual soils, their specific features are not adequately covered by conventional methods of soil classification. In this case, classification systems such as Wesley (2009) proposed are based in their mineralogical composition and soil micro-and macrostruc-ture. These different classification systems are intended to provide an orderly division of residual soils into groups which belong together because of common factors in their formation and/or compositions, which can be expected to give them similar engineering properties.