A methodology for comparing soils for use in knowledge-based systems

Abstract Knowledge-based systems (KBSs) can be particularly useful in assisting with the interpretation of ground conditions from site investigation information, a major part of geotechnical design. This requires interpolating or extrapolating from observations at discrete points, such as boreholes, and involves considerable engineering (and geological) judgement. Such a system must be able to compare soils observed at two or more locations, in order to identify whether the soils observed belong to the same horizon. A scheme is put forward for calculating the similarity of two soils based on engineering soil descriptions. The descriptive terms are converted to quantitative representations. Similarity numbers can then be calculated from the quantitative parameters for a number of different factors such as soil type, structure, consistency and colour. These similarity numbers can then be combined using appropriate weighting factors to give an overall similarity number which represents a comparison based on all these factors. The approach used is procedural, but can be used as part of a KBS for interpreting ground conditions.