# Superstructure

This section defines all superstructure components for the Steel Tub Girder Bridge including girders, deck, bracing, and connections.

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**Navigation:** Superstructure
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## Overview

The superstructure consists of:

* **Steel Girders:** Tub (box) girders with variable plate thicknesses
* **Deck:** Composite concrete deck with cross-sections
* **Bracing:** Internal and external cross-frames, lateral bracing, diaphragms
* **Connections:** Bolted field splices, shear studs, bolt properties
* **Boundary Conditions:** Bearing fixity at support locations

## Sections

| Section                                                                                                                                                                    | Description                                        |
| -------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------- |
| [Steel Girders](https://docs.openbrim.org/examples/steel-bridge-examples/example-steel-tub-girder-bridge-ex1-stg/superstructure-ex1-stg/steel-girders-ex1-stg)             | Define tub girder geometry and materials           |
| [Deck](https://docs.openbrim.org/examples/steel-bridge-examples/example-steel-tub-girder-bridge-ex1-stg/superstructure-ex1-stg/deck-ex1-stg)                               | Configure deck cross-sections and concrete deck    |
| [Bracing](https://docs.openbrim.org/examples/steel-bridge-examples/example-steel-tub-girder-bridge-ex1-stg/superstructure-ex1-stg/bracing-ex1-stg)                         | Internal/external cross-frames and lateral bracing |
| [Connections](https://docs.openbrim.org/examples/steel-bridge-examples/example-steel-tub-girder-bridge-ex1-stg/superstructure-ex1-stg/connections-ex1-stg)                 | Field splices, shear studs, and bolt properties    |
| [Boundary Conditions](https://docs.openbrim.org/examples/steel-bridge-examples/example-steel-tub-girder-bridge-ex1-stg/superstructure-ex1-stg/boundary-conditions-ex1-stg) | Bearing fixity at supports                         |

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Complete Superstructure definition before configuring Construction staging.
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