IfcFooting

Semantic definitions at the entity

Entity definition

A part of the foundation of a structure that spreads and transmits the load directly to the soil.

HISTORY New entity in IFC Release 2x2

Property Set Use Definition:

The property sets relating to the IfcFooting are defined by the IfcPropertySet and attached by the IfcRelDefinesByProperties relationship. It is accessible by the inverse IsDefinedBy relationship. The following property set definitions specific to the IfcFooting are part of this IFC release:

Pset_ReinforcementBarCountOfIndependentFooting: property set for independent IfcFooting occurrences.
Pset_ReinforcementBarPitchOfContinuousFooting: property set for continuous IfcFooting occurrences.

Geometry Use Definitions:

The geometric representation of IfcFooting is given by the IfcProductDefinitionShape, allowing multiple geometric representations. Included are:

Local Placement
The local placement for IfcFooting is defined in its supertype IfcProduct. It is defined by the IfcLocalPlacement, which defines the local coordinate system that is referenced by all geometric representations.

The PlacementRelTo relationship of IfcLocalPlacement shall point (if given) to the local placement of the same IfcSpatialStructureElement, which is used in the ContainedInStructure inverse attribute, or to a spatial structure element at a higher level, referenced by that.
If the relative placement is not used, the absolute placement is defined within the world coordinate system.

Standard Geometric Representation
Provided that it is possible the standard geometric representation of IfcFooting is defined using the swept solid representation. The RepresentationType attribute of IfcShapeRepresentation should have the value 'SweptSolid'. The following constraints apply to the standard representation:

Solid: IfcExtrudedAreaSolid shall be supported
Profile: All applicable profile types shall be supported
Extrusion: All extrusion directions shall be supported.

If it is impossible to define the geometry using the swept solid representation the representations defined in its supertype IfcBuildingElement may be used.

Attribute definitions

#	Attribute	Type	Cardinality	Description
9	PredefinedType	IfcFootingTypeEnum	[1:1]	The generic type of the footing.

Formal Propositions

Rule	Description
WR1	The attribute ObjectType shall be given, if the predefined type is set to USERDEFINED.

Inherited definitions from supertypes

Entity inheritance

Attribute inheritance

#	Attribute	Type	Cardinality	Description
IfcRoot
1	GlobalId	IfcGloballyUniqueId	[1:1]	Assignment of a globally unique identifier within the entire software world.
2	OwnerHistory	IfcOwnerHistory	[1:1]	Assignment of the information about the current ownership of that object, including owning actor, application, local identification and information captured about the recent changes of the object, NOTE: only the last modification in stored.
3	Name	IfcLabel	[0:1]	Optional name for use by the participating software systems or users. For some subtypes of IfcRoot the insertion of the Name attribute may be required. This would be enforced by a where rule.
4	Description	-		This attribute is out of scope for this model view definition and shall not be set.
IfcObjectDefinition
	IsDecomposedBy	IfcRelDecomposes @RelatingObject	S[0:?]	Reference to the decomposition relationship, that allows this object to be the composition of other objects. An object can be decomposed by several other objects.
	Decomposes	IfcRelDecomposes @RelatedObjects	S[0:1]	References to the decomposition relationship, that allows this object to be a part of the decomposition. An object can only be part of a single decomposition (to allow hierarchical strutures only).
	HasAssociations	IfcRelAssociates @RelatedObjects	S[0:?]	Reference to the relationship objects, that associates external references or other resource definitions to the object.. Examples are the association to library, documentation or classification.
IfcObject
5	ObjectType	IfcLabel	[0:1]	The type denotes a particular type that indicates the object further. The use has to be established at the level of instantiable subtypes. In particular it holds the user defined type, if the enumeration of the attribute PredefinedType is set to USERDEFINED.
	IsDefinedBy	IfcRelDefines @RelatedObjects	S[0:?]	Set of relationships to type or property (statically or dynamically defined) information that further define the object. In case of type information, the associated IfcTypeObject contains the specific information (or type, or style), that is common to all instances of IfcObject referring to the same type.
IfcProduct
6	ObjectPlacement	IfcObjectPlacement	[0:1]	Placement of the product in space, the placement can either be absolute (relative to the world coordinate system), relative (relative to the object placement of another product), or constraint (e.g. relative to grid axes). It is determined by the various subtypes of IfcObjectPlacement, which includes the axis placement information to determine the transformation for the object coordinate system.
7	Representation	IfcProductRepresentation	[0:1]	Reference to the representations of the product, being either a representation (IfcProductRepresentation) or as a special case a shape representations (IfcProductDefinitionShape). The product definition shape provides for multiple geometric representations of the shape property of the object within the same object coordinate system, defined by the object placement.
IfcElement
8	Tag	-		This attribute is out of scope for this model view definition and shall not be set.
	ConnectedTo	IfcRelConnectsElements @RelatingElement	S[0:?]	Reference to the element connection relationship. The relationship then refers to the other element to which this element is connected to.
	HasOpenings	IfcRelVoidsElement @RelatingBuildingElement	S[0:?]	Reference to the Voids Relationship that creates an opening in an element. An element can incorporate zero-to-many openings.
	IsConnectionRealization	IfcRelConnectsWithRealizingElements @RealizingElements	S[0:?]	Reference to the connection relationship with realizing element. The relationship then refers to the realizing element which provides the physical manifestation of the connection relationship.
	ConnectedFrom	IfcRelConnectsElements @RelatedElement	S[0:?]	Reference to the element connection relationship. The relationship then refers to the other element that is connected to this element.
	ContainedInStructure	IfcRelContainedInSpatialStructure @RelatedElements	S[0:1]	Containment relationship to the spatial structure element, to which the element is primarily associated.
IfcBuildingElement
IfcFooting
9	PredefinedType	IfcFootingTypeEnum	[1:1]	The generic type of the footing.

Formal representations

XSD Specification

 <xs:element name="IfcFooting" type="ifc:IfcFooting" substitutionGroup="ifc:IfcBuildingElement" nillable="true"/>

 <xs:complexType name="IfcFooting">

  <xs:complexContent>

   <xs:extension base="ifc:IfcBuildingElement">

    <xs:attribute name="PredefinedType" type="ifc:IfcFootingTypeEnum" use="optional"/>

   </xs:extension>

  </xs:complexContent>

 </xs:complexType>

EXPRESS Specification


*)

ENTITY IfcFooting

 SUBTYPE OF (IfcBuildingElement);

  PredefinedType : IfcFootingTypeEnum;

 WHERE

  WR1 : (PredefinedType <> IfcFootingTypeEnum.USERDEFINED) OR ((PredefinedType = IfcFootingTypeEnum.USERDEFINED) AND EXISTS(SELF\IfcObject.ObjectType)) ;
END_ENTITY;

(*

 EXPRESS-G diagram

Inheritance Graph:

ENTITY IfcFooting
ENTITY IfcRoot
  GlobalId : IfcGloballyUniqueId;
  OwnerHistory : IfcOwnerHistory;
  Name : OPTIONAL IfcLabel;
  Description : OPTIONAL IfcStrippedOptional;
ENTITY IfcObjectDefinition
INVERSE
  IsDecomposedBy : SET [0:?] OF IfcRelDecomposes FOR RelatingObject;
  Decomposes : SET [0:1] OF IfcRelDecomposes FOR RelatedObjects;
  HasAssociations : SET [0:?] OF IfcRelAssociates FOR RelatedObjects;
ENTITY IfcObject
  ObjectType : OPTIONAL IfcLabel;
INVERSE
  IsDefinedBy : SET [0:?] OF IfcRelDefines FOR RelatedObjects;
ENTITY IfcProduct
  ObjectPlacement : OPTIONAL IfcObjectPlacement;
  Representation : OPTIONAL IfcProductRepresentation;
INVERSE
ENTITY IfcElement
  Tag : OPTIONAL IfcStrippedOptional;
INVERSE
  ConnectedTo : SET [0:?] OF IfcRelConnectsElements FOR RelatingElement;
  HasOpenings : SET [0:?] OF IfcRelVoidsElement FOR RelatingBuildingElement;
  IsConnectionRealization : SET [0:?] OF IfcRelConnectsWithRealizingElements FOR RealizingElements;
  ConnectedFrom : SET [0:?] OF IfcRelConnectsElements FOR RelatedElement;
  ContainedInStructure : SET [0:1] OF IfcRelContainedInSpatialStructure FOR RelatedElements;
ENTITY IfcBuildingElement
ENTITY IfcFooting
  PredefinedType : IfcFootingTypeEnum;
END_ENTITY;