> For the complete documentation index, see [llms.txt](https://docs.openbrim.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.openbrim.org/templates/steel-tub-girder-bridge-workflow/superstructure-attachments-stg/roadway-stg.md). # Roadway \[STG] ## Roadway The roadway definition is used for influence surface-based live load analysis. Based on the roadway definition, an influence surface path is generated and influence coefficients are computed. OpenBrIM Influence surface-based live load analysis automatically places lanes at the transverse locations, so the only important parameter to define is the extent of the roadway. ### General #### Bridge Understanding the bridge data is crucial to identify the deck components where the roadway will be placed. #### Roadway Dimensions To define the start and end station of the roadway, users need to define at least two rows. If there is a variation in the roadway width, additional rows can be defined to accurately represent the variation. * **Station:** Station along the PGL. * **Transverse Offset:** The transverse offset is measured from the PGL. A value of 0 indicates that the center of the roadway is located at the PGL. Positive values indicate offsetting the center of the roadway to the right, and negative values offset the center of the roadway to the left when looking upstation along the PGL. {% hint style="info" %} The positive direction of the Y-axis will be to the left when looking upstream along the PGL. However, based on the requests of engineers who have been using OpenBrIM for their bridge projects, positive transverse offset values will indicate the right-hand side when looking upstream along the PGL. This distinction should be taken into account when defining the location of bridge elements using transverse offset values (where positive transverse offset indicates the right side), as well as when making definitions related to FEM and loading (where positive Fy indicates the left side along the PGL). {% endhint %} * **Right Width \[Right Barrier Inner Edge/ Deck Right Edge]:** The distance that extends toward the right side when looking up the station along the alignment line. This parameter can either be defined using the options provided or set to a specific value. If the roadway will be generated by taking barriers into account, this parameter can be set to **Right Barrier Inner Edge** if the barrier should be generated with respect to the deck's edge at that station. The **Deck Right Edge** option can be used. * **Left Width \[Left Barrier Inner Edge/ Deck Left Edge]:** The distance that extends toward the left side when looking up the station along the alignment line. This parameter can either be defined using the options provided or set to a specific value. If the roadway will be generated by taking barriers into account, this parameter can be set to **Left Barrier Inner Edge** if the barrier should be generated with respect to the deck's edge at that station. The **Deck Left Edge** option can be used. * **Skew:** A skew angle of 0 degrees indicates that the line is perpendicular to the PGL. A positive skew angle rotates the perpendicular line in a clockwise direction, while a negative skew angle rotates it in a counterclockwise direction. ![](https://openbrim.atlassian.net/wiki/download/attachments/2124283997/image-20230314-113906.png?api=v2) ![](https://openbrim.atlassian.net/wiki/download/attachments/2124283997/image-20230314-113949.png?api=v2) ![](https://openbrim.atlassian.net/wiki/download/attachments/2124283997/image-20230316-152245.png?api=v2) #### Support Lines Used For Span Length Comp **Support Lines Used For Span Length Comp. \[All/Selection]:** Roadway definitions are essential for Influence Surface-Based analysis, making it critical to ensure the accuracy of the roadway setup. Since support lines may be used for various purposes, not just as span dividers, it’s necessary to eliminate unnecessary ones to define the correct Live Load (LL) path. If support lines are used exclusively for span dividers in a project, the parameter can be defined using the option ‘ALL.’ However, if support lines serve other roles, it is recommended to use the 'Selection' option for more precise control. #### Selected Support Lines If the Support Lines Used for Span Length Comp. parameter is defined with the option ‘Selection,’ then support lines can be chosen using this parameter; otherwise, this parameter will not be applicable (N/A). #### Live Load Path Edge Tolerance The influence surface path is built from the roadway rows, and between two rows its edge is a straight line. When a width is set to a barrier inner edge or a deck edge that curves between two rows, that straight line can run outside the roadway, and live load is then applied where there is no roadway. On an edge that bulges outward it cuts inside the roadway instead, and part of the roadway is not loaded. To prevent this, rows are added along the curved edge wherever the straight line would be farther from the edge than this tolerance. The default is 3 in. A roadway saved before this input existed is set to 0 (**Roadway Input Rows Only**) when the project's workflow is updated, so its results do not change until a tolerance is entered. A roadway added to such a project copies the existing roadway's value. * The distance is measured in plan, perpendicular to the PGL, on the right and left edges separately. * Rows are added only between two rows that use the same edge option on a side, for example **Right Barrier Inner Edge** at both. A width given as a value is a straight line between its rows, so nothing is added there. * A row is added only if its corners on both edges lie between the corners of the rows around it, so the path never turns back at a skewed end. * No row is added where a side set to a barrier inner edge would take its edge from a barrier placed on the other side, for example in a gap between two barriers on one side; the path crosses that stretch in a straight line. * No rows are added when the roadway rows are listed in descending station order, or when the rows themselves already give a path that turns back (for example a sudden width change at one station). * No rows are added when the roadway has a stretch with no barrier on either side and a side set to a barrier inner edge continues after that stretch, for example where the barriers on both sides stop for a gap; the path then uses only the rows in the Roadway Dimensions table. * The added rows are used only for the live load path. The Roadway Dimensions table, the 3D roadway and the other objects that use the roadway are not changed. * A smaller tolerance adds more rows, which means more unit loads and a longer live load analysis. **Roadway Input Rows Only** uses only the rows in the Roadway Dimensions table, with no rows added. ![The live load path edge tolerance: rows are added at the edge points farthest from the straight line between two rows until the edge points are within the tolerance, except where noted above](https://2645910244-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FGR3Y2oTOZjlXFJKoQ7ar%2Fuploads%2Fgit-blob-e6c393d9cc4cd13587568984008daa152d8b95d8%2Flive-load-path-edge-tolerance.png?alt=media) ### Roadway 3D The following parameters are used solely for 3D visualization purposes and are not used for finite element analysis. #### Uniform Lane Width **\[YES/NO]** If the lanes in the project have the same widths, then this parameter should be set to ‘YES’; otherwise, it should be set to ‘NO.’ #### Lane Widths **Lane Widths (from the right edge of the roadway):** If the Uniform Lane Width parameter is set to ‘NO,’ this parameter can be used to define the lane widths sequentially, starting from the right. Otherwise, if uniform lane widths are applied, this parameter will not be applicable. #### Lane Width This parameter is used to define the lane widths when Uniform Lane Width parameter is set to ‘YES’. #### Right Shoulder Width The right shoulder width of the roadway can be specified using this parameter. The definition made for this parameter will not affect the 3D model but will affect the CADD output. #### Left Shoulder Width The left shoulder width of the roadway can be specified using this parameter. Similar to the right shoulder width, the definition made for this parameter will not affect the 3D model but will influence the CADD output. #### Lane Divider Spacing The spacing of lane dividers in the longitudinal direction can be specified using this parameter. #### Lane Divider Width The widths of lane dividers in the transverse direction can be specified using this parameter. #### Graphical Thickness The thickness of the graphical representation of the roadway can be defined here. #### Number of Segments **Number of Segments (Graphical):** Used for the graphics only. This parameter can be specified with a higher value if a more detailed graphics display is needed for the roadway. A higher value is recommended for achieving a smoother edge on roadways with small radius circular bridges. #### Show or Hide **Show/Hide \[YES/NO]:** To display the roadway in the 3D model, this parameter should be set to ‘YES.’ If the option ‘NO’ is chosen, the roadway will not be displayed. ![image-20241010-104324.png](https://openbrim.atlassian.net/wiki/download/attachments/2124283997/image-20241010-104324.png?api=v2) ### IFC #### Type The IFC entity type for BIM export. Default is IfcRoad. #### Predefined Type The IFC Predefined Type is specified using this parameter. Available options include: * 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. --- # Agent Instructions This documentation is published with GitBook. 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