Representation of the concept of a linear geological and geotechnical model, usually an interpretation but sometimes created direct from ground penetrating measurement. The assembly may contain one of more strata and other elements such as capping and lining. The contained subtypes of IfcGeotechnicalStratum will have shape representations made from straight or bent tubes reflecting the bore diameter, or discs if a 'Yabuki' top surface model is being used.

This IfcElement subtype is an anomaly in the sense that it does not have a PredefinedType attribute. This is to be provided in subsequent versions of the standard.