> 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/steel-bridge-examples/example-steel-tub-girder-bridge-ex1-stg/superstructure-ex1-stg/boundary-conditions-ex1-stg/bearing-fixity-ex1-stg.md).

# Bearing Fixity

This section defines bearing restraints at each support location.

{% hint style="info" %}
**Navigation:** Superstructure > Boundary Conditions > Bearing Fixity
{% endhint %}

## Steps

### Step 1: Navigate to Bearing Fixity

Navigate to **Superstructure > Boundary Conditions > Bearing Fixity** in the tree view.

![Bearing Fixity navigation](https://openbrim.atlassian.net/wiki/download/attachments/2169110536/image-20230217-164537.png?api=v2)

### Step 2: Select Insertion Points

Click the first cell in the **Insertion Point** column and click **Pick** to select support locations.

![Pick insertion points](https://openbrim.atlassian.net/wiki/download/attachments/2169110536/image-20230217-164723.png?api=v2)

### Step 3: Define Fixities

Set **Tx/Ty/Tz/Rx/Ry/Rz** values for each bearing based on bearing type.

![Fixity values](https://openbrim.atlassian.net/wiki/download/attachments/2169110536/image-20230217-165440.png?api=v2)

### Step 4: Configure Load Transfer

* Set **Transfer Force to Substructure** = **Yes** for interior pier locations
* Set **Transfer Force to Substructure** = **No** for abutment locations

<details>

<summary><strong>Quick Tip:</strong> Coordinate System</summary>

DOFs are assigned based on the local coordinate system at each insertion point, which changes along the support line and alignment. The **Bearing Rotation** parameter rotates the support clockwise in the XY plane.

</details>

## Verification

{% hint style="success" %}
The completed bearing fixity configuration is shown below.
{% endhint %}

![Completed bearing fixity](https://openbrim.atlassian.net/wiki/download/attachments/2169110536/image-20230217-165802.png?api=v2)


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