[IFC4.3] Which Ifc class to use for structure gauge?

M by Martin156131 on 24 Sep 2022, edited 11 Oct 2022 #

So i used this tool here https://blenderbim.org/search-ifc-class.html

And it did not show me a suitable ifc class.

A structure gauge is simply put a virtual volume reserved for vehicle -> it's relevant for road, rail, bridge and even buildings <- if you built for example a car park

https://en.wikipedia.org/wiki/Structure_gauge

Does someone know?

M by Moult on 25 Sep 2022 #

IfcVirtualElement with predefined type of CLEARANCE.

http://ifc43-docs.standards.buildingsmart.org/IFC/RELEASE/IFC4x3/HTML/lexical/IfcVirtualElement.htm

http://ifc43-docs.standards.buildingsmart.org/IFC/RELEASE/IFC4x3/HTML/lexical/IfcVirtualElementTypeEnum.htm

In IFC4 you'd use IfcBuildingElementProxy with PROVISIONFORSPACE (which was migrated and renamed to CLEARANCE for clarity to prevent confusion).

M by Martin156131 on 27 Sep 2022, edited 27 Sep 2022 #

Thanks for the info!

What about IfcSpatialZone with predefined type of SECURITY?

http://ifc43-docs.standards.buildingsmart.org/IFC/RELEASE/IFC4x3/HTML/lexical/IfcSpatialZone.htm

http://ifc43-docs.standards.buildingsmart.org/IFC/RELEASE/IFC4x3/HTML/lexical/IfcSpatialZoneTypeEnum.htm

What is the difference?

M by Moult on 27 Sep 2022 # +2 votes

Security zones are like this https://www.protectivesecurity.govt.nz/physical-security/lifecycle/design/apply-good-practices/security/

M by Martin156131 on 10 Oct 2022 #

So when i create an ifc with just an structure gauge, how should the ifc be structured?

The use case for this example is the Domain Road (highway) -> each discipline create their own little ifc model and in the end there should be a federation <- to dedect a collision for example between a bridge and the structure gauge.

Variant 1:

IfcProject -> IfcSite -> IfcRoad -> IfcRoadPart -> IfcVirtualElement (Predefined Type: CLEARANCE)

Variant 2:

IfcProject -> IfcSite -> IfcRoad -> IfcSpatialZone ?? (Predefined Type: SECURITY) ?? -> IfcVirtualElement (Predefined Type: CLEARANCE)

Or any other variant, i am open for suggestions :)

Another question: Why is there no Pset_Clearance? Was there no need?

M by Martin156131 on 11 Oct 2022 #

When i read the http://ifc43-docs.standards.buildingsmart.org/IFC/RELEASE/IFC4x3/HTML/lexical/IfcShapeRepresentation.htm website -> there is in the Table 8.18.3.17.O (indicates the defined list of values for RepresentationIdentifier) Clearance as a value, see in the image below:

So now we have defined two times Clearance? One time in IfcShapeRepresentation and one time in IfcVirtualElement ?