Example Concrete U Girder Bridge

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

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

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	Create new project
2	Bridge Geometry	Define alignment, supports, girder layout
3	Properties	Define materials, rebars, sections, strands
4	Superstructure	Model U-girders, deck, diaphragms, bearings
5	Superstructure Attachments	Add barriers, roadway
6	Substructure	Model piers, foundations, piles
7	Tendon	Define post-tensioning tendons
8	Construction	Define construction stages
9	Loading	Apply all load types
10	Combinations	Set up load combinations
11	Templates	Configure code check templates
12	Superstructure Code Checks	Run girder design checks
13	Substructure Code Checks	Run substructure design checks
14	Load Rating	Perform load rating analysis
15	Report	Generate quantity takeoffs

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.