6.1.3.40 IfcSlabStandardCase

Decke / Dachfläche / Bodenplatte - Standard
Dalle standard

The standard slab, IfcSlabStandardCase, defines a slab with certain constraints for the provision of material usage, parameters and with certain constraints for the geometric representation. The IfcSlabStandardCase handles all cases of slabs, that:

The definitions of slab openings and niches are the same as given at the supertype IfcSlab. The same agreements to the special types of slabs, as defined in the PredefinedType attribute apply as well.

NOTE  If the IfcSlabStandardCase is of type Landing and is used within an IfcStair or IfcRamp, the special agreements to handle stair and ramp geometry will also affect the geometric representation of the IfcSlabStandardCase.
HISTORY  New entity in IFC4.

Common Use Definitions

The following concepts are inherited at supertypes:

 Instance diagram

Material Layer Set Usage

The Material Layer Set Usage concept applies to this entity.

Multi-layer slabs can be represented by refering to several IfcMaterialLayer's within the IfcMaterialLayerSet that is referenced from the IfcMaterialLayerSetUsage

Material information can also be given at the IfcSlabType, defining the common attribute data for all occurrences of the same type. It is then accessible by the inverse IsDefinedBy relationship pointing to IfcSlabType.HasAssociations and via IfcRelAssociatesMaterial.RelatingMaterial. The IfcSlabStandardCase defines in addition that the IfcSlabType should have a unique IfcMaterialLayerSet, that is referenced by the IfcMaterialLayerSetUsage assigned to all occurrences of this IfcSlabType.

 

Material layer set and usage
EXAMPLE  Figure 211 illustrates assignment of IfcMaterialLayerSetUsage and IfcMaterialLayerSet to the IfcSlabStandardCase as the slab occurrence and to the IfcSlabType. The same IfcMaterialLayerSet shall be shared by many occurrences of IfcMaterialLayerSetUsage. This relationship shall be consistent to the relationship between the IfcSlabType and the IfcSlabStandardCase.

Figure 211 — Slab type definition

 

Figure 212 illustrates slab material usage, where the following conventions shall be met:

slab material layer set
roof slab material layer set

Figure 212 — Slab material layers



Product Placement

The Product Placement concept applies to this entity as shown in Table 172.
TypeRelativeDescription
IfcLocalPlacementIfcLocalPlacementRelative placement according to position and rotation relative to container.
IfcLocalPlacement Absolute placement according to position and rotation of world coordinate system.
IfcGridPlacement Placement according to grid intersection.

Table 172 — IfcSlabStandardCase Product Placement

The following restriction is imposed:



Body SweptSolid Geometry

The Body SweptSolid Geometry concept applies to this entity.

The following additional constraints apply to the swept solid representation:

 

standard slab
EXAMPLE  Figure 213 illustrates a 'SweptSolid' geometric representation. The following interpretation of dimension parameter applies for polygonal slabs (in ground floor view): IfcArbitraryClosedProfileDef.OuterCurve: closed bounded curve interpreted as area (or foot print) of the slab.

Figure 213 — Slab body extrusion

 


Body Clipping Geometry

The Body Clipping Geometry concept applies to this entity.

The following constraints apply to the 'Clipping' representation:

 

advanced slab
EXAMPLE  Figure 214 illustrates a 'Clipping' geometric representation with definition of a roof slab using advanced geometric representation. The profile is extruded non-perpendicular and the slab body is clipped at the eave.

Figure 214 — Slab body clipping

 



XSD Specification:

 <xs:element name="IfcSlabStandardCase" type="ifc:IfcSlabStandardCase" substitutionGroup="ifc:IfcSlab" nillable="true"/>
 <xs:complexType name="IfcSlabStandardCase">
  <xs:complexContent>
   <xs:extension base="ifc:IfcSlab"/>
  </xs:complexContent>
 </xs:complexType>

EXPRESS Specification:

ENTITY IfcSlabStandardCase
SUBTYPE OF IfcSlab;
WHERE
HasMaterialLayerSetusage : SIZEOF (QUERY(temp <* USEDIN(SELF, 'IFCKERNEL.IFCRELASSOCIATES.RELATEDOBJECTS') | ('IFCPRODUCTEXTENSION.IFCRELASSOCIATESMATERIAL' IN TYPEOF(temp)) AND ('IFCMATERIALRESOURCE.IFCMATERIALLAYERSETUSAGE' IN TYPEOF(temp.RelatingMaterial)) )) = 1;
END_ENTITY;

Link to EXPRESS-G diagram EXPRESS-G diagram

Formal Propositions:

HasMaterialLayerSetusage : A valid instance of IfcSlabStandardCase relies on the provision of an IfcMaterialLayerSetUsage.

Inheritance Graph:

ENTITY IfcSlabStandardCase
ENTITY IfcRoot
GlobalId : IfcGloballyUniqueId;
OwnerHistory : OPTIONAL IfcOwnerHistory;
Name : OPTIONAL IfcLabel;
Description : OPTIONAL IfcText;
ENTITY IfcObjectDefinition
INVERSE
HasAssignments : SET OF IfcRelAssigns FOR RelatedObjects;
Nests : SET [0:1] OF IfcRelNests FOR RelatedObjects;
IsNestedBy : SET OF IfcRelNests FOR RelatingObject;
HasContext : SET [0:1] OF IfcRelDeclares FOR RelatedDefinitions;
IsDecomposedBy : SET OF IfcRelAggregates FOR RelatingObject;
Decomposes : SET [0:1] OF IfcRelAggregates FOR RelatedObjects;
HasAssociations : SET OF IfcRelAssociates FOR RelatedObjects;
ENTITY IfcObject
ObjectType : OPTIONAL IfcLabel;
INVERSE
IsDeclaredBy : SET [0:1] OF IfcRelDefinesByObject FOR RelatedObjects;
Declares : SET OF IfcRelDefinesByObject FOR RelatingObject;
IsTypedBy : SET [0:1] OF IfcRelDefinesByType FOR RelatedObjects;
IsDefinedBy : SET OF IfcRelDefinesByProperties FOR RelatedObjects;
ENTITY IfcProduct
ObjectPlacement : OPTIONAL IfcObjectPlacement;
Representation : OPTIONAL IfcProductRepresentation;
INVERSE
ReferencedBy : SET OF IfcRelAssignsToProduct FOR RelatingProduct;
ENTITY IfcElement
Tag : OPTIONAL IfcIdentifier;
INVERSE
FillsVoids : SET [0:1] OF IfcRelFillsElement FOR RelatedBuildingElement;
ConnectedTo : SET OF IfcRelConnectsElements FOR RelatingElement;
IsInterferedByElements : SET OF IfcRelInterferesElements FOR RelatedElement;
InterferesElements : SET OF IfcRelInterferesElements FOR RelatingElement;
HasProjections : SET OF IfcRelProjectsElement FOR RelatingElement;
ReferencedInStructures : SET OF IfcRelReferencedInSpatialStructure FOR RelatedElements;
HasOpenings : SET OF IfcRelVoidsElement FOR RelatingBuildingElement;
IsConnectionRealization : SET OF IfcRelConnectsWithRealizingElements FOR RealizingElements;
ProvidesBoundaries : SET OF IfcRelSpaceBoundary FOR RelatedBuildingElement;
ConnectedFrom : SET OF IfcRelConnectsElements FOR RelatedElement;
ContainedInStructure : SET [0:1] OF IfcRelContainedInSpatialStructure FOR RelatedElements;
ENTITY IfcBuildingElement
INVERSE
HasCoverings : SET OF IfcRelCoversBldgElements FOR RelatingBuildingElement;
ENTITY IfcSlab
PredefinedType : OPTIONAL IfcSlabTypeEnum;
ENTITY IfcSlabStandardCase
END_ENTITY;

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