# Substructure

This section defines all substructure components for the Steel Tub Girder Bridge including piers, foundations, and piles.

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**Navigation:** Substructure
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## Overview

The substructure consists of:

* **Piers:** Hammerhead pier caps and circular columns
* **Foundations:** Rectangular and custom-shaped footings
* **Piles:** Driven piles supporting the foundations

## Sections

| Section                                                                                                                                                | Description                               |
| ------------------------------------------------------------------------------------------------------------------------------------------------------ | ----------------------------------------- |
| [Pier](https://docs.openbrim.org/examples/steel-bridge-examples/example-steel-tub-girder-bridge-ex1-stg/substructure-ex1-stg/pier-ex1-stg)             | Define pier caps and columns              |
| [Foundation](https://docs.openbrim.org/examples/steel-bridge-examples/example-steel-tub-girder-bridge-ex1-stg/substructure-ex1-stg/foundation-ex1-stg) | Configure rectangular and custom footings |
| [Pile](https://docs.openbrim.org/examples/steel-bridge-examples/example-steel-tub-girder-bridge-ex1-stg/substructure-ex1-stg/pile-ex1-stg)             | Define pile layout and properties         |

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Complete Substructure definition before configuring Construction staging.
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