Definitions applying to Bridge View

 Instance diagram

For bridges, this entity is used to represent supporting ground structures that perform multiple functions, including abutments and piers. Elements are decomposed according to connectivity, including construction joints. Reinforcing may be indicated within inner elements such as footings, columns, members, and walls (see documentation at corresponding elements for usage), but not directly within IfcCivilElement; such reinforcing should reflect how it is to be placed at time of construction such that rebar connecting between elements is projected out of the element where it is initially placed.

Abutments and piers are placed relative to the horizontal alignment curve (NOT the vertical alignment curve), with components placed according to Cartesian placement within. This reflects the positioning indicated on the plans, where all dimension lines are based on Cartesian positioning relative to the position and orientation of the station along the horizontal alignment curve.

Figure 1 — Bridge abutment plans

For the abutment shown in Figure 1, the wing walls and cheek walls are modeled using IfcWall (an arbitrarily shaped wall), with geometry represented by IfcExtrudedAreaSolidTapered, and interconnected with construction joints using IfcRelConnectsElements.

The foundation of the abutment shown consists of a single IfcFooting with shape defined by IfcExtrudedAreaSolid of an IfcArbitraryClosedProfileDef extruded upwards. Each pile is modeled using a separate IfcPile with shape defined using IfcExtrudedAreaSolid of an IfcIShapeProfileDef extruded upwards, and is connected to the footing using IfcRelConnectsElements where RelatingElement refers to the pile. The footing connects to each wall using IfcRelConnectsElements where RelatingElement refers to the footing.

Drainage piping is modeled using IfcPipeSegment assigned to IfcDistributionSystem of type DRAINAGE with geometry using IfcSweptAreaSolid of IfcCircleHollowProfileDef. Conduit for wire is modeled using IfcCableCarrierSegment with geometry using IfcSweptAreaSolid of IfcCircleHollowProfileDef.

Figure 2 — Bridge abutment model

Figure 2 illustrates a 3D rendering of an abutment.

While it is possible to represent such abutment in other ways (e.g. a single unified object with BREP or tessellated geometry), the particular composition used was chosen to indicate detail required for construction.

Figure 3 — Bridge pier plans

As shown in Figure 3, Piers are modelled as a combination of interconnected components, typically comprising IfcPile, IfcFooting, IfcColumn, and IfcMember. Each of these components are connected to the next using IfcRelConnectsElements or a subtype, where RelatingElement refers to the anchoring component and RelatedElement refers to component attached, which also implies the order of construction. The IfcRelConnectsElements relationship implies construction joints (no specific fasteners or adhesion other than rebar); otherwise specific connectivity is indicated using the IfcRelConnectsWithRealizingElements subtype instead

Figure 4 — Bridge pier model

For this particular example, the each pile is modeled using IfcPile. The concrete geometry is represented by IfcExtrudedAreaSolid extruded upwards (in the +Z direction) with the cross-section defined by IfcCircleProfileDef. The footing is modeled using IfcFooting. The concrete geometry is represented by IfcExtrudedAreaSolid extruded towards the alignment curve with the cross-section defined by IfcArbitraryClosedProfileDef to accommodate the notch used for the construction joint.

The column (the section above the footing between construction joints) is modeled using IfcColumn (as an axial compression member). The concrete geometry is represented by IfcExtrudedAreaSolid extruded towards the alignment curve with the cross-section defined by IfcArbitraryClosedProfileDef to accommodate the notches for construction joint, consisting of IfcIndexedPolyCurve.

The top section is modeled using IfcMember (as an arbitrary load-carrying member) and with its base at a vertical offset (+Z) and zero horizontal offset. The concrete geometry is represented by IfcExtrudedAreaSolid extruded towards the alignment curve with the cross-section defined by IfcArbitraryClosedProfileDef to accommodate the irregular shape, consisting of IfcIndexedPolyCurve.

The architectural treatment is modeled using IfcCovering, with IfcExtrudedAreaSolid of IfcRectangleProfileDef indicating the shape and the rock texture indicated using IfcStyledItem, IfcSurfaceStyle, IfcSurfaceStyleWithTextures, and IfcImageTexture.

The drainage pipes are modeled using IfcPipeSegment, with IfcExtrudedAreaSolid of IfcCircleHollowProfileDef indicating the shape. The drain above is modeled using IfcWasteTerminal. All piping components belong to an IfcDistributionSystem of predefined type STORMWATER, and have ports at each end indicating connectivity using IfcDistributionPort. Ports are connected according to flow using IfcRelConnectsPorts.

This separate modeling associated with the construction joints facilitates connectivity of the supported elements in fashion similar to that used for structural analysis and construction sequencing.

Concept usage

Object Typing

The Object Typing concept applies to this entity as shown in Table 8.

Type IfcCivilElementType

Table 8 — IfcCivilElement Object Typing

Exchange
Import		O
Export		O

Element Decomposition

The Element Decomposition concept applies to this entity as shown in Table 9.

RelatedObjects Description IfcWall Cheek walls and wing walls of abutments IfcMember Top segments of piers supporting bridge girder(s) IfcColumn Vertical segments of piers separated by construction joints IfcFooting Footings of piers and abutments IfcPile Piles of piers and abutments IfcPipeSegment Pipe segments to support drainage or de-icing IfcPipeFitting Pipe fittings to support drainage or de-icing IfcCableCarrierSegment Conduit segments to support lighting or signage IfcCableCarrierFitting Conduit fittings to support lighting or signage IfcCovering Architectural panels

Table 9 — IfcCivilElement Element Decomposition

Abutments are typically decomposed into piles, footings, walls (outer cheek wall and wing walls), and mechanical fasteners (bearings).

Piers are typically decomposed into piles, footings, columns (separate instances according to construction joints), a member (for top portion that spans out to support the bridge deck), and mechanical fasteners (bearings).

In addition to structural elements, such elements may contain pipe segments and fittings for piping used for drainage or de-icing chemicals, and cable carrier segments and fittings for electrical conduit.

Figure 157 — Bridge abutment components

Exchange
Import		R
Export		R

Element Positioning

The Element Positioning concept applies to this entity as shown in Table 10.

Placement Transform Description HORIZONTAL PLACE Piers and abutments are always placed relative to the horizontal alignment curve and are not transformed.

Table 10 — IfcCivilElement Element Positioning

Exchange
Import		O
Export		O

Path Connectivity

The Path Connectivity concept applies to this entity as shown in Table 11.

RelatedElement Description IfcMechanicalFastener Connection from pier or abutment to bearing(s)

Table 11 — IfcCivilElement Path Connectivity

Exchange
Import		O
Export		O

Product Assignment

The Product Assignment concept applies to this entity as shown in Table 12.

Type Description IfcStructuralCurveMember Idealized representation(s) of element for structural analysis of piers with constant cross-section. IfcStructuralSurfaceMemberVarying Idealized representation(s) of element for structural analysis of piers with varying cross-section. IfcTask Tasks assigned to bridge components indicating applicable construction phases

Table 12 — IfcCivilElement Product Assignment

Exchange
Import		O	R
Export		O	R

Formal representations