Bridge Definition and Purpose Quiz

Bridge Definition and Purpose

• A bridge spans physical obstacles like water, valleys, and roads.
• AASHTO defines a bridge as any structure with an opening of at least 6100mm that is part of or located over/under a highway.
• Bridges provide essential passage over obstacles and are critical components of transportation systems.

Importance in Transportation Systems

• Bridges control traffic capacity by managing volume and weight.
• Insufficient carriage width leads to traffic flow restrictions.
• Strength deficiencies can prevent bridges from carrying heavy loads, which necessitates rerouting.
• The cost of bridge construction is substantial compared to approach roadways, requiring careful planning.

Failure Implications

• Bridge failures can paralyze transportation systems, making alternative routes ineffective.
• Detours may increase travel time and fuel expenses.
• Normalcy in transportation is restored only after fixing or replacing the bridge.

Key Considerations in Bridge Design

• Balancing future traffic handling capabilities, load demands, and the cost of heavier and wider structures is vital.
• Strength is the primary concern, and measures should be in place to mitigate deterioration.

Structural Characteristics and Concerns

• Bridges are exposed to various conditions, including temperature fluctuations and durability challenges.
• They endure large, repetitive loads, leading to fatigue, which can cause structural cracking.

Bridge Engineering Overview

• Bridge engineering encompasses surveying, planning, design, analysis, construction, management, and maintenance.
• Engineers are responsible for ensuring designs meet safety and serviceability standards.

Civil Engineering Disciplines Involved

• Surveying and mapping aid in layout and grading.
• Highway design focuses on alignment for efficient traffic flow.
• Structural design covers the superstructure and substructure components.
• Geotechnical engineering ensures sturdy foundations for supports.
• Hydraulic engineering concerns itself with span length and site drainage.

Classifications of Bridges

• Based on Span Length:
  • Short Span
  • Medium Span
  • Long Span
  • Culvert Bridge
• Based on Structural Form:
  • Arch
  • Truss
  • Beam/Girder
  • Slab
  • Suspension
  • Cable-Stayed

Additional Classifications

• Based on Purpose/Use:
  • Highway
  • Railroad
  • Pedestrian
  • Pipeline
  • Aqueducts
• Based on Deck Location:
  • Deck Bridge
  • Through Bridge
  • Half Through Bridge
• Based on Geometry:
  • Straight
  • Skewed
  • Curved
• Based on Movable Features:
  • Bascule
  • Swing
  • Lift