# Steel Girders

This section defines the steel tub girder geometry and plate configurations.

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**Navigation:** Superstructure > Steel Girders
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## Overview

Steel tub girders are the primary load-carrying elements with:

* Variable plate thicknesses along the span
* Composite action with the concrete deck
* FE model generation using line and surface elements

## Sections

| Section                                                                                                                                                                        | Description                                |
| ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | ------------------------------------------ |
| [Tub Girder](https://docs.openbrim.org/examples/steel-bridge-examples/example-steel-tub-girder-bridge-ex1-stg/superstructure-ex1-stg/steel-girders-ex1-stg/tub-girder-ex1-stg) | Define tub girder dimensions and materials |

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Complete girder definitions before defining bracing and connections.
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