# Example Concrete U Girder Bridge

This example demonstrates how to model, analyze, and design a Concrete U Girder (Spliced Girder) Bridge using OpenBrIM.App.

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**Ready to start?** Access the completed example in **New Project > Example Projects**, or follow this step-by-step guide to build from scratch.
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## Capabilities

### 3D Modeling

* Generate parametric 3D model with substructure and superstructure
* Spliced U-girder segments with closure pours
* Export to DGN/DXF/IFC formats

### Finite Element Analysis

* Parametric FEA model generation
* Time-dependent staged construction analysis
* Influence surface-based live load analysis
* Creep and shrinkage per CEB-FIP 1990
* Post-tensioning tendon analysis

### Loading

* Wind load on structure (AASHTO) with automatic nodal load calculation
* Wind load on live load
* HL-93, Legal Trucks, Permit Trucks (custom trucks supported)
* Temperature loads
* Surface/Line/Point loads
* Post-tensioning tendon stressing

### Staged Construction

* Girder segment erection sequence
* Closure pour placement
* Deck pouring sequence (transverse and longitudinal)
* Temporary support management
* Non-composite and composite state modeling
* Short-term and long-term modulus of elasticity

### Analysis Results

* Stage-by-stage results (incremental and cumulative)
* Deflection visualization and spreadsheet export
* Combination results for all limit states
* Composite section results
* Stress distributions
* Critical vehicle location visualization

### Design

Components supported per AASHTO 9th Edition:

* Spliced U Girder
* Cross Frames
* Pier Caps, Columns, Footings
* Piles, Drilled Shafts

### Export & Reports

* Export to LARSA 4D, CSI Bridge, Midas
* Quantity Report
* Seat/Slab Elevation Tables
* Project Inputs
* Vertical Clearance Report
* 2D Drawings (DGN/DXF export)

## Workflow Steps

Follow these sections to complete the bridge design:

| Step | Section                                                                                                                                                       | Description                                 |
| ---- | ------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------- |
| 1    | [Modeling on OpenBrIM.App](https://docs.openbrim.org/examples/concrete-bridge-examples/example-concrete-u-girder-bridge/modeling-on-openbrim.app-ex1-cug)     | Create new project                          |
| 2    | [Bridge Geometry](https://docs.openbrim.org/examples/concrete-bridge-examples/example-concrete-u-girder-bridge/bridge-geometry-ex1-cug)                       | Define alignment, supports, girder layout   |
| 3    | [Properties](https://docs.openbrim.org/examples/concrete-bridge-examples/example-concrete-u-girder-bridge/properties-ex1-cug)                                 | Define materials, rebars, sections, strands |
| 4    | [Superstructure](https://docs.openbrim.org/examples/concrete-bridge-examples/example-concrete-u-girder-bridge/superstructure-ex1-cug)                         | Model U-girders, deck, diaphragms, bearings |
| 5    | [Superstructure Attachments](https://docs.openbrim.org/examples/concrete-bridge-examples/example-concrete-u-girder-bridge/superstructure-attachments-ex1-cug) | Add barriers, roadway                       |
| 6    | [Substructure](https://docs.openbrim.org/examples/concrete-bridge-examples/example-concrete-u-girder-bridge/substructure-ex1-cug)                             | Model piers, foundations, piles             |
| 7    | [Tendon](https://docs.openbrim.org/examples/concrete-bridge-examples/example-concrete-u-girder-bridge/tendon-ex1-cug)                                         | Define post-tensioning tendons              |
| 8    | [Construction](https://docs.openbrim.org/examples/concrete-bridge-examples/example-concrete-u-girder-bridge/construction-ex1-cug)                             | Define construction stages                  |
| 9    | [Loading](https://docs.openbrim.org/examples/concrete-bridge-examples/example-concrete-u-girder-bridge/loading-ex1-cug)                                       | Apply all load types                        |
| 10   | [Combinations](https://docs.openbrim.org/examples/concrete-bridge-examples/example-concrete-u-girder-bridge/combinations-ex1-cug)                             | Set up load combinations                    |
| 11   | [Templates](https://docs.openbrim.org/examples/concrete-bridge-examples/example-concrete-u-girder-bridge/templates-for-code-check-ex1-cug)                    | Configure code check templates              |
| 12   | [Superstructure Code Checks](https://docs.openbrim.org/examples/concrete-bridge-examples/example-concrete-u-girder-bridge/superstructure-code-checks-ex1-cug) | Run girder design checks                    |
| 13   | [Substructure Code Checks](https://docs.openbrim.org/examples/concrete-bridge-examples/example-concrete-u-girder-bridge/substructure-code-checks-ex1-cug)     | Run substructure design checks              |
| 14   | [Load Rating](https://docs.openbrim.org/examples/concrete-bridge-examples/example-concrete-u-girder-bridge/load-rating-ex1-cug)                               | Perform load rating analysis                |
| 15   | [Report](https://docs.openbrim.org/examples/concrete-bridge-examples/example-concrete-u-girder-bridge/report-ex1-cug)                                         | Generate quantity takeoffs                  |

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Whenever you modify a bridge component parameter or alignment, all associated results and reports will automatically update. This demonstrates the power of parametric bridge engineering in OpenBrIM.
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