Webinar Notes on Design Optimization of Reinforced Concrete Culvert Bridge

Introduction

• Presenter: Dr. Dan, Central Africa Manager, currently working in South Korea.
• Session Overview: Features company presentation, design optimization of reinforced concrete culvert bridge, and various loading conditions.
• Company Overview: Vias – offers engineering tools and training globally, including regions like Africa, India, Europe, and USA.
• Training Importance: Continuous practice with the company's software to gain expertise.

Webinar Agenda

• Company Introduction
• Explanation on the design optimization of reinforced concrete culvert bridges
• Modeling and applying various loading conditions
• Analysis, design optimization, results interpretation, and report generation

Culvert Bridge Design Process

1. Establish design conditions
   • Ground investigation
   • Select and specify material properties
   • Analyze soil pressure, groundwater pressure, live load, and seismic load
   • (Seismic load will be covered in a separate session)
2. Pre-dimension and define boundary conditions
3. Analyze the structure
4. Design the structure and generate construction drawings

Material Properties

• Reinforced concrete: 24.5 KN/m³
• Mortar: 21 KN/m³
• Concrete strength: 24 MPa
• Young's modulus of concrete: 27 MPa
• Yield strength of steel: 400 MPa
• Modulus of elasticity of steel: 200,000 MPa

Design Conditions

• **Soil properties: **
  • Soil unit weight: 19 KN/m³
  • Submerged soil unit weight: 10 KN/m³
  • Internal friction of soil: 30°
  • Coefficient of earth pressure: 0.5
  • Groundwater level and unit weight
• Loads:
  • Soil pressure
  • Groundwater pressure
  • Live load: Standard vehicle DB24
  • Seismic load

Load Analysis & Calculation

• Vertical Earth Pressure: Calculated with considered height and soil unit weight.
• Horizontal Earth Pressure: Uses coefficient of earth pressure and height.
• Self Weight Calculation: For slab, walls, hunches, and underground water.
• Buoyancy Check: Ensuring resisting force is higher than buoyant force.
• Live Load Calculation: Distributes load based on height and width of structure.
• Pressure Application: Using formulas for vertical and horizontal pressures.

Modeling Technique in MIDAS Civil

• Nodes and Elements: Created using node to line extrusion method.
• Local Axis: Proper orientation for accurate load application.
• Load Cases: Defined loads including dead, live (vertical and horizontal), earth pressure (with and without underground water), and water pressure.
• Spring Support: Compression-only spring element, stiffness of spring calculations based on subgrade reaction.
• Boundary Conditions: Defined to stabilize the structure.

Structural Analysis

• Running the Model: Verifying that loads and boundary conditions are correctly applied.
• Bending and Shear Diagrams: Viewing results to ensure structural integrity.
• Load Combination: Using ultimate strength design factors and serviceability parameters.
• Envelope Creation: For combined loading conditions.

Concrete Design (Eurocode)

1. Material and Sections: Define material properties, concrete cover, and section data.
2. Beam Design (Upper & Lower Slabs): Check for bending moment and shear resistance.
3. Column Design (Walls): PM interaction diagrams and shear resistance.
4. Serviceability Parameters: Exposure class, stress parameters, crack control, and deflection.
5. Generating Reports: Detailed and graphic reports for design validation.

Q&A Highlights

• Recording: Available post-editing for all attendees.
• Moving Load: Detailed in a future webinar.
• Discount: 30% discount on MIDAS products for attendees.

Closing Remarks

• Next Steps: Future sessions on moving loads.
• Contact: Send messages via email or LinkedIn for further queries.