> 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/examples/concrete-bridge-examples/example-concrete-u-girder-bridge/superstructure-ex1-cug/u-girders-ex1-cug/concrete-u-girder-ex1-cug.md).
# Concrete U Girder
This section defines the Concrete U Girder properties including section variations, haunch thickness, and FEA settings.
{% hint style="info" %}
**Navigation:** Superstructure > Girders > Concrete U Girder
For detailed parameter explanations, see the [Concrete U Girder Reference](https://docs.openbrim.org/templates/concrete-u-girder-bridge-workflow/superstructure-cug/u-girder-cug/concrete-u-girder-cug).
{% endhint %}
## Steps
### Step 1: Navigate to Concrete U Girder
Navigate to **Girders > Concrete U Girder** in the tree view.
### 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**.
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.
### 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.
### Step 5: Set Variation Transitions
Define the desired appearance of variation transitions between sections.
### Step 6: Apply Configuration to All Spans
Apply the station-dependent configuration for **SL1** (Reference Support Line) throughout the entire bridge span.
### Step 7: Set Haunch Thickness
Enter **Haunch Thickness** as **4** inches.
Quick Tip: Haunch Thickness
The haunch is the concrete buildup between the top of the girder and the bottom of the deck slab.
### Step 8: Configure FEA Settings
Navigate to the **FEA Settings** tab.
{% hint style="info" %}
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.
{% endhint %}
### Step 9: Define Second Girder
For the second girder, use **GL2** in the Girder Layout.
Replicate all actions performed for **CUG1** for **CUG2**.
## Verification
{% hint style="success" %}
After completing these steps, the girders should appear as shown below.
{% endhint %}
---
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