Towards the digital indexation of USCS classification: Case study in Israel

Abstract USCS soil classification is extensively used in different engineering applications. However, being “symbolic and descriptive classification”, it does not allow of an application of numerical methods for map drawing and hence hand drawn soil maps are still subjective to some degree. Application of mathematical extrapolation to soil mapping based on digitization of soil indexes significantly decreases the time taken to complete map drawing and excludes voluntarism from its production. Among other things, both these factors are of paramount importance for preliminary soil reserve estimation. This paper presents the first attempt to find a digital analogy to 17 out of 23 USCS groups (mainly poor graded soils). Examination of digitally and hand drawn vertical sections shows good correspondence between them especially where sharp transition between lithologically distant classification groups is missing from a geological section.