# 7. Construction

This section defines the staged construction sequence for the bridge, enabling time-dependent analysis with proper load application at each phase.

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Construction staging is essential for accurate analysis of steel bridges, as it captures non-composite behavior during erection and composite behavior after deck curing.
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## Construction Stages

| Stage                                                                                                                                                                                  | Description                                                 |
| -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ----------------------------------------------------------- |
| [Construction Stage](https://docs.openbrim.org/examples/steel-bridge-examples/example-steel-i-girder-bridge-ex1-sig/construction-ex1-sig/construction-stage-ex1-sig)                   | Define the overall construction timeline and stage sequence |
| [Superstructure Construction](https://docs.openbrim.org/examples/steel-bridge-examples/example-steel-i-girder-bridge-ex1-sig/construction-ex1-sig/superstructure-construction-ex1-sig) | Girder erection, deck pouring, and barrier placement        |
| [Substructure Construction](https://docs.openbrim.org/examples/steel-bridge-examples/example-steel-i-girder-bridge-ex1-sig/construction-ex1-sig/substructure-construction-ex1-sig)     | Bearing, pier, foundation, and pile construction            |

## Staged Construction Workflow

1. **Substructure Construction**: Foundations, piles, columns, and caps
2. **Bearing Installation**: Place bearings at support locations
3. **Girder Erection**: Steel girder and cross-frame placement
4. **Deck Construction**: Concrete deck pouring sequence
5. **Superstructure Attachments**: Barriers and roadway elements

## Key Concepts

* **Non-composite Stage**: Steel girders carry construction loads before deck hardens
* **Composite Stage**: Combined steel-concrete section after deck curing
* **Time-dependent Effects**: Creep and shrinkage per CEB-FIP 1990