1. Design & Engineering CAMS South
Bridges
Design & Engineering
CAMS South

2. Some Uses of Bridges Walkways Highways/Roads Railways Pipelines
Connecting lands
Crossing rivers and canyons

3. Types of Bridges
Arch
Truss
Cantilever
Cable-Stayed
Beam
Suspension

4. What makes a bridge stay up?
Forces
Compression – a pushing or squeezing force
Tension – a pulling or stretching force
Load – the weight a structure must support
Dead Load – weight of the structure
Live Load – additional weight such as cars, people, snow, wind, etc.

5. BEAM BRIDGE
BEAM BRIDGE - A bridge built of beams whose ends rest on piers or abutments.
BEAM - A horizontal structure member supporting vertical loads by resisting bending.
PIER - A vertical structure that supports the ends of a beam.
SPAN - The horizontal space between two supports of a structure.

6. I 81 and Rt 30 Chambersburg, PA

7. Lake Pontchartrain Causeway
23.83 Miles Long

8. Truss Bridges
Truss – a rigid frame composed of short, straight pieces joined to form a series of triangles or other stable shapes
Many variations of truss bridge designs

9. Truss Bridge Definitions
Road Bed – Roadway portion of bridge, sometimes called “Deck”
Superstructure – Consists of all bridge components including and above the road bed or deck
Substructure – Consists of all bridge components below the road bed or deck

10. Martin’s Mill Bridge Greencastle, PA
Truss Bridge
Town Lattice Truss Design

11. Walnut St Bridge Harrisburg, PA

12. Arch Bridges
Arch Bridge - A bridge whose main support structure is an arch
Arch – Curved structural member spanning an opening and serving as a support
Bridge Abutments – The structures that support the ends of the bridge

13. Arch Bridges
Works by
Compression

14. Arch Bridges
Durable bridge form - Many old stone arch bridges are still standing today.
Can be constructed with many materials stone, wood, steel, concrete
Have you seen these bridges?

15. Burnside Bridge, Antietam Battlefield, Sharpsburg, MD

16. I 70 South Mountain

17. New River Gorge Bridge, West Virginia

18. Suspension Bridges
A bridge which carries its deck with many tension members attached to cables draped over tower piers.

19. Suspension Bridges Can clear span great distances.
Beautiful design and many are iconic.
Extremely efficient in terms of materials
Most expensive type of bridge to construct.
World Record span between towers: Akashi Kaikyō Bridge 6532 feet main span
Have you seen these bridges?

20. Suspension Bridges
Works by Tension and Compression

21. Golden Gate Bridge, San Francisco, CA

22. Brooklyn Bridge, Brooklyn, NY

23. Chesapeake Bay Bridge, Annapolis, Maryland

24. Verrazano-Narrows Bridge, New York, NY
Longest main span in United States 4260 feet

25. Akashi Kaikyō Bridge, Japan 6532 feet main span

26. Tacoma Narrows Bridge Failure
Video

27. Cable-Stayed Bridges
A variation of suspension bridge in which the tension members extend from one or more towers at varying angles to carry the deck.
Less expensive and faster to construct compared to a suspension bridge.
Relatively new form of bridge.

28. Cable-Stayed Bridges Piers – the vertical supporting structures
Cables – thick steel ropes from which the decking is suspended
Decking – the supported roadway on a bridge

29. Cable-Stayed Bridges
Works by Tension AND Compression

30. Zakim Bridge, Boston, MA

31. Sunshine Skyway Bridge, Tampa, FL

32. Sundial Bridge, Redding, CA

33. Cantilever Bridges
A structural member that projects beyond a supporting column or wall and is counterbalanced and/or supported at only one end.
Cantilever
Firth of Forth-Forth Rail Bridge, Edinburgh, Scotland