EngineeringexcavationGIS(E2GIS)isareal-3DGISservingforgeosciencesrelatedtogeo-engineering,civilengineeringandminingengineeringbasedongeneralizedtri-prism(GTP)model.AstwoinstancesofGTPmodel,G-GTPisusedforthereal-3Dmodelingofsubsurfacegeologicalbodies,andE-GTPisusedforthereal-3Dmodelingofsubsurfaceengineeringexcavations.InthelightofthediscussionsonthefeaturesandfunctionsofE2GIS,themodelingprinciplesofG-GTPandE-GTPareintroduced.Thetwomodelscoupletogetherseamlesslytoformanintegralmodelforsubsurfacespatialobjectsincludingbothgeologicalbodiesandexcavations.Anobject-orientedintegralreal-3Ddatamodelandintegralspatialtopologicalrelationsarediscussed.
