Concrete U Girder

This section defines the Concrete U Girder properties including section variations, haunch thickness, and FEA settings.

Navigation: Superstructure > Girders > Concrete U Girder

For detailed parameter explanations, see the Concrete U Girder Reference.

Steps

Step 1: Navigate to Concrete U Girder

Navigate to Girders > Concrete U Girder in the tree view.

Navigation

Step 2: Assign Girder Layout

Click the three-dots icon on the Girder Layout cell and select GL1 from the dropdown.

Step 3: Edit Girder Sections

Click the three-dots icon on Girder Sections and select Edit.

Edit Sections

The CUG1 beam will have section variations according to station. The sections U78G5 and U54G5 (defined in the Sections page) are applied at different stations.

Section Variations

Step 4: Define Section Stations

Select the Reference Support Line option.

Use the Station Difference Along PGL parameter to designate the specific station where each section is positioned.

Station Definition

Step 5: Set Variation Transitions

Define the desired appearance of variation transitions between sections.

Variation Transitions

Step 6: Apply Configuration to All Spans

Apply the station-dependent configuration for SL1 (Reference Support Line) throughout the entire bridge span.

All Spans

Step 7: Set Haunch Thickness

Enter Haunch Thickness as 4 inches.

Haunch Thickness
Quick Tip: Haunch Thickness

The haunch is the concrete buildup between the top of the girder and the bottom of the deck slab.

Haunch Diagram

Step 8: Configure FEA Settings

Navigate to the FEA Settings tab.

FEA Settings

When you define a RigidSection in the Section spreadsheet, OpenBrIM automatically assigns the Rigid Section parameter. The girder FE model uses FeLine elements for flanges and FeSurface elements for the web.

Step 9: Define Second Girder

For the second girder, use GL2 in the Girder Layout.

Second Girder

Replicate all actions performed for CUG1 for CUG2.

Verification

Completed Girders 1
Completed Girders 2

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