Soil Behavior Type Classification System Based On Cone Penetration Test

A soil classification system is used to group soils according to shared qualities or characteristics based on simple cost effective tests. The most common soil classification systems used in geotechnical engineering are based on physical (textural) characteristics such as grain size and plasticity. Ideally, geotechnical engineers would also like to classify soils based on behavior characteristics that have a strong link to fundamental insitu behavior. Existing textural-based classification systems have a weak link to in-situ behavior since they are measured on disturbed and remolded samples. The cone penetration test (CPT) has been gaining in popularity for site investigations due to the cost effective, rapid, continuous and reliable measurements. The most common CPT-based classification systems are based on behavior characteristics and are often referred to as a Soil Behavior Type (SBT) classification. This paper presents an update of popular CPT-based SBT classification systems to use behavior-based descriptions. The update includes a method to identify the existence of microstructure in soils and examples are used to illustrate the advantages and limitations of such a system.