To design prestressed girders using Line Girder Analysis (preview)

Line Girder Analysis allows you to review, adjust, and validate the design of all pre-stressed girders for any concrete bridge you select. View initial results in canvas or purchase detailed girder design documentation (in PDF format) using cloud credits.

Select a bridge and add information about your project using the Line Girder Analysis asset card. Once you have input project information, press Start Analysis in the Line Girder Analysis asset card. Project information you enter appears in the title block of the detailed girder design documentation.

Note: View the Bridge Design Video Playlist for more information.

To add project information

  1. Select the desired design bridge.
  2. Click .
    Note: The bridge deck is automatically hidden for you so that you can focus on girders. To toggle deck visibility, click
  3. Click Project information in the Line Girder Analysis asset card.

    Input values for Project Name, Company Name, and Address in the Project Information panel that displays. Project information you specify will display in the title block of the detailed girder design documentation that you can purchase. You can also upload a logo file. When you are finished, close the Project Information panel.

To design pre-stressed girders using line girder analysis

Once you have input project information, start your analysis.

  1. Enter a Job name and Job number in the Line Girder Analysis card.
  2. Select Reverse bending plot or leave that option unselected. This does not have an affect on in-canvas results.

    Reverse bending plot affects the graphic representations you receive in the detailed girder design documentation, if you choose to purchase the full report. Reverse bending plot changes the direction of bending moments, but does not change the direction of torsion moments.

  3. Click Start Analysis.
    The service will begin running analysis on every girder of your bridge.
    Your line girder analysis results may take a few minutes to load.
  4. When the analysis is complete you can hover over individual girders to view in-canvas results.
    Note: InfraWorks 360 identifies in-canvas whether or not all the girders in your bridge satisfy design requirements.
    • If a girder exceeds design parameters, that girder will be highlighted pink on your bridge.
    • If a girder is close to exceeding design parameters analysis, it will be highlighted orange on your bridge.
    • If a girder satisfies design parameters, it will not be highlighted.
    In the example below, all girders satisfied design parameters. Hovering over the girder displayed a prestress transfer performance ratio of 0.77 , which represents the design over the permissible value at the critical position along the girder.
  5. Select an individual girder to view analysis results for that girder using the in-canvas asset card.

To review Line Girder Analysis results

  1. Key results can be viewed in the in-canvas asset card. This does not require cloud credits. You can make changes to your bridge design in-canvas and re-run the in-canvas analysis as many times as you want before you purchase a full report.

    Design Standard: Line Girder Analysis performs analysis on all pre-stressed girders using the bridge's design standard. You can change the Design Standard for a bridge anytime.

      Performance Ratios: The following analysis results are performance ratios that represent the design over the permissible value at the critical position along the selected girder:

    • Prestress Transfer: Design at transfer of prestress to the girder stage.
    • Erection Stage: Design on placing the precast girder into position.
    • Construction Stage: Design on casting the deck slab (and diaphragms where applicable).
    • LL Bending: Strength + ve: Strength/Ultimate state design for maximum positive/hogging bending.
    • LL Bending: Strength -ve: Strength/Ultimate state design for maximum negative/sagging bending.
    • LL Bending: Service I/III: +ve: Service/Ability state design for maximum positive/hogging bending
    • LL Bending: Service I/III: -ve: Service/Ability state design for maximum negative/sagging bending
    • Shear: Shear design capacity along the girder length.
  2. When you are ready, you can use your cloud credits to purchase detailed girder design documentation for a selected bridge. Before you purchase the full report, you can view or download a full-length sample in PDF format. See: Line Girder Analysis Sample Report. When you select Get Full Report, InfraWorks 360 creates a new proposal in your model so that you can compare designs.
    The full report contains:
    • Girder Design Summary
    • Girder Design Calculations
    • Transverse Live Load Distribution Factor Calculations
    • Analysis Load Envelopes
    • Analytical Model Data
    3. Note: When you purchase the full report, Line Girder Analysis also generates a full model of your bridge that you can open and work with in the standalone version of Autodesk Structural Bridge Design as well.
    • Once you have completed Line Girder Analysis, click the icon next to the Get Report button.
    • If you have Autodesk Structural Bridge Design 2016 installed, the line beam model containing the selected girder will be opened directly in the application so that you can continue with detailed design. If you do not have it installed, you will be directed to a website where you can learn more about Autodesk Structural Bridge Design.
  3. Displays the message log.

Additional information

See Autodesk A360 Cloud Credits FAQ for more information about cloud credits.

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