Development and Application of an Industry Foundation Classes-Based Metro Protection Information Model

Table 1

Comparison between the expanded IFC and the original.

Element/Model	Expanded expression	Original expression
LayerElement	IfcGeoLayerElement	IfcBuildingElementProxy
MetroElement	IfcMetroElement	IfcBuildingElementProxy
GroundElement	IfcGroundElement	IfcBuildingElementProxy
ExternalElement	IfcExternalElement	IfcBuildingElementProxy
ExternalBuilding	IfcExternalBuilding	IfcBuilding
GeologicalLayer	IfcGeoLayer	IfcBuilding
MetroBuilding	IfcMetroBuilding	IfcBuilding
Ground	IfcGround	IfcBuilding