Generative Objects

Open the Steel I-Girder Workflow

1. Log in to your account and locate Project in the top-right corner.

   
2. Click Project, then click NEW in the top-left corner.

   
3. Under Steel Bridge Workflows, find Steel I-Girder Bridge Workflow and click New Project.

   

   
4. Provide a name for your project and open the example.

   

   

The initial download of the library components takes approximately 2 minutes 30 seconds. Subsequent openings of the same project are noticeably faster because OpenBrIM library objects are cached in your browser; loading then takes less than 2–3 seconds.

Create the Superstructure with a Generative Library Object

1. Click an empty area in the graphics window, then click the magic icon.

   
2. Choose Generative: Modeling, then Steel I Girder Bridge Layout. A warning appears because superstructure generation requires at least one alignment. Switch back to the spreadsheet to create one.

   
3. Click DATA in the bottom-middle of the screen to open the spreadsheet.

   
4. Set Start Station to 0.

   
5. Click the three-dot menu in the Start Station cell, then click Editor to define alignment properties.

   
6. Click the + icon next to Horizontal and add a circular segment.

   
7. Set Length = 530 ft, Radius = 700 ft, Direction = Towards Right, then click Accept.

   
8. Click Accept, then click Zoom Extent to view the alignment in the graphics window.

   

   

   
9. Click an empty area in the graphics window, click the magic icon, choose Generative: Modeling, then Steel I Girder Bridge Layout again.

   

   
10. Set Bridge Start Station = 0 ft and Bridge Length = 530 ft, then click Generate.

    
11. Open the Support Lines spreadsheet and set the support stations to 0, 160, 370, 530. After generation, you can keep customizing — for example, open the Plate Girder spreadsheet to enter plate dimensions.

    

    

    

Create the Substructure with Generative Library Objects

1. Click an empty area in the graphics window, click the magic icon, choose Generative: Modeling, then Hammerhead Pier.

   

   

   
2. Open the Pier Cap section in the workflow tree and adjust the rebar data. See the screenshots for step-by-step guidance.

   

   

   
3. Click an empty area in the graphics window, click the magic icon, choose Generative: Modeling > Straddle Bent, then set Support Line to SL2.

   

   

   

   
4. Return to Boundary Conditions and set the bearing fixities and Transfer Forces to Substructure parameter. Because both Support Line 1 and Support Line 2 now have substructures, Transfer Forces to Substructure should be Yes for both locations.

   

Create Stages with Generative Library Objects

1. Click an empty area in the graphics window, click the magic icon, choose Generative: FEA, then Steel I Girder Staged Construction and Loading. Adjust the loads as needed and click Generate.

   

   
2. Review the FEA stages and loads that have been generated.

   

Add Code-Check Objects for the Superstructure and Substructure

1. Click an empty area in the graphics window, click the magic icon, choose Generative: Design > Steel I Girder Code Check. Select the girder and click Generate — 10 code-check stations are created per span along the girder.

   

   

   
2. Click an empty area in the graphics window, click the magic icon, choose Generative: Design > Steel I Girder Substructure Code Check. This creates a code-check object for the pier at the top and bottom of the pier column.

   

   

   

Analysis for this project typically takes around 2.5 minutes, and the design run takes around 10 minutes.

1. Run Analysis and Design.

   

   

Generation is complete. You can now view the design reports.

AI-Powered Generative Modeling (Roadmap)

OpenBrIM is being trained with machine-learning algorithms to optimize input parameters for generative bridge components automatically, taking project-specific site constraints into account. This capability is in active development.