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# Bearing Fixity
This section defines bearing fixity conditions at each support location, specifying translational and rotational constraints.
{% 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.
### Step 2: Select Insertion Points
Click the first cell in the **Insertion Point** column and use the **Pick** button to select insertion points that define the bearing locations.
### Step 3: Define Fixity Values
Set the translational (Tx, Ty, Tz) and rotational (Rx, Ry, Rz) fixity values for each bearing:
| Parameter | Description |
| --------- | ----------------------------------------------------------------------------------------------------- |
| Tx | Axial direction - Only IP1 and IP2 have assigned values (axial forces accommodated at these supports) |
| Ty, Tz | Transverse and vertical directions - Remain constant for all bearings |
| Rx | Torsional stability - Set to **10** for all supports to maintain stability during construction |
| Ry, Rz | Rotational constraints - Set as needed |
Quick Tip: Rx Parameter for Torsional Stability
Setting a non-zero Rx value is necessary to address torsional stability when constructing a beam without transverse components like diaphragms or decks. In this example, all supports are assigned Rx = 10.
### Step 4: Configure Force Transfer
Set **Transfer Force to Substructure** to **Yes** for all bearing locations.
Quick Tip: Transfer Force to Substructure
| Setting | Behavior |
| ------- | ------------------------------------------------------------------------------------------------------------- |
| **Yes** | Creates a two-node spring between pier cap and girder (use when substructure is modeled) |
| **No** | Creates a one-node spring at the bottom of the girder (use for abutment locations without substructure model) |
## Verification
{% hint style="success" %}
The completed bearing fixity configuration is shown below.
{% endhint %}
---
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