# Sleeper Slab \[SIG]

For the modeled approach slabs, sleeper slabs can be modeled as a separate object using this object of the workflow.

## General

**Approach Slab:** This parameter can be used to specify the approach slab for which the sleeper slab will be modeled.

**Longitudinal Offset:** This parameter can be used to define the offset in the longitudinal direction for the sleeper slab. A value of 0 will place the sleeper slab with its center at the downstation-start section of the approach slab. A positive value will offset the sleeper slab in the upstation direction.

**Material:** This parameter can be used to assign a material to the sleeper slab. Materials can be selected from previously defined options under **Properties-Materials** or imported as needed.

**Length:** This parameter can be used to specify the length of the sleeper slab in the longitudinal direction. For a visual representation, refer to the figure provided below.

**Width:** This parameter can be used to specify the width of the sleeper slab in the transverse direction. For a visual representation, refer to the figure provided below.

**Thickness:** This parameter can be used to specify the thickness of the sleeper slab in the vertical direction. For a visual representation, refer to the figure provided below.

**Secondary Slab Width Extension:** Additional transverse width added to the sleeper slab beyond the primary slab width, used when the sleeper slab extends past the approach slab edge.

**Left Secondary Slab Start Skew Angle:** Skew angle at the start (downstation) end of the left secondary slab portion. Use with Secondary Slab Width Extension to shape an offset left region.

**Left Secondary Slab End Skew Angle:** Skew angle at the end (upstation) end of the left secondary slab portion.

**Right Secondary Slab Start Skew Angle:** Skew angle at the start (downstation) end of the right secondary slab portion.

**Right Secondary Slab End Skew Angle:** Skew angle at the end (upstation) end of the right secondary slab portion.

**Sleeper Slab Head Wall:** Pick the Sleeper Slab Head Wall workflow item that sits at the downstation end of this sleeper slab. Leave unset when no head wall is used.

![image-20250115-133430.png](https://openbrim.atlassian.net/wiki/download/attachments/2847703042/image-20250115-133430.png?api=v2)

## IFC

**Type:** The IFC entity type for BIM export. Default is IfcSlab.

**Predefined Type:** The IFC Predefined Type is specified using this parameter. Available options include:

* APPROACH\_SLAB (default)
* BASESLAB
* FLOOR
* LANDING
* PAVING
* ROOF
* SIDEWALK
* TRACKSLAB
* WEARING
* USERDEFINED
* NOTDEFINED

**Parent \[Bridge/Superstructure/Deck/Substructure/Foundation/Approach\_Structure/Retaining\_Structure]:** The IFC Parent is specified using this parameter to define the hierarchy relationship in the IFC model.

## Quantities

**Volume:** Based on the definitions provided by the user, the volume of the object is calculated and presented in this column. (Read-only)

**Weight:** The total weight of the sleeper slab based on volume and material density. (Read-only)


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