Statistical to Fuzzy Approach Toward CPT Soil Classification

Abstract

A soil engineering classification derived from the cone penetration test (CPT) involves the uncertainty of correlation between soil composition and soil mechanical behavior. This uncertainty results in overlaps of different soil types in currently used CPT soil classification systems. Accordingly, two statistical soil classification criteria, region estimation and point estimation, are suggested to address this problem. Further, a new fuzzy subset approach is introduced to develop a truly independent CPT soil engineering classification, and to establish a transition between the new fuzzy approach and conventional soil classifications by utilizing local site- and project-specific calibrations. CPT results conducted at the National Geotechnical Experimentation Site at Texas A&M University are used to demonstrate this new CPT soil engineering classification methodology.