1. Click mouse to advance each slide.

3. There are threeThere are three
major types ofmajor types of
bridges...bridges...
3

4. 3 Main3 Main BridgeBridge TypesTypes::
•Beam BridgeBeam Bridge
•Arch BridgeArch Bridge
•Suspension BridgeSuspension Bridge

5. The biggest difference between
the three bridge types is the
distances they can each cross in
a single span.
A span is the distance
between two bridge supports.

6. Beam bridges usually coverBeam bridges usually cover
relatively short distances.relatively short distances.

7. As beam bridges are lengthened, theyAs beam bridges are lengthened, they
need more supporting piers.need more supporting piers.
But adding piers makes themBut adding piers makes them
unsuitable if a lot of space is neededunsuitable if a lot of space is needed
underneath them.underneath them.

8. Many elevated roadways areMany elevated roadways are
beam bridges.beam bridges.

10. A beam bridge spans
short distances...

11. …or beam bridges can be
connected to cover
long distances.

12. Beam bridgesBeam bridges
must resistmust resist
bending forcesbending forces

13. A truss may be added to
a beam to help resist
bending forces

14. A truss is a framework
formed of triangles that
provide strength.
A truss is lightweight and
allows wind to pass
through.

15. Often the truss is
added to the top of
the beam

16. The angled piers of this beam bridge
transfer its loads to the ground.

17. AA Cantilever BeamCantilever Beam bridgebridge
has triangular structureshas triangular structures
that weigh down each endthat weigh down each end
of the beams.of the beams.

18. Cantilever bridges are expensive,
because they require a large
amount of materials.

19. The Firth of Forth Cantilever Bridge
Scotland

20. Stone arch
bridges
have been
built for
thousands
of years.

21. Stone arch bridges cross
short spans, and
compression helps them
keep their shape.

22. Arch bridges are also
built with steel.

23. The steel arch
structure provides
the strength for the
span, and allows

26. Smaller arches can be used as abutments.

27. An arch can also be
anchored into a canyon,
and then the deck is placed
on top.

28. Anchors placed in solid
soil keep the base of the
arch from spreading.

29. Suspension Bridges are the most
spectacular of all.

31. The Tacoma Narrows Suspension Bridge.
A Famous Engineering Failure.

32. The New Tacoma Narrows Bridges.

33. The Golden Gate Suspension Bridge
Notice the trusses under the deck
that allow the wind to pass through.

34. The Golden Gate Suspension Bridge
Under Construction

39. Another kind of
suspension bridge is a
Cable-Stayed Bridge.

42. The New Cable-Stayed Bridge in Boston.
The Zakim Bunker Hill Bridge

47. A Cable-Stayed Bridge Under Construction.

55. Identify the parts of a suspension bridge:
• Twin Towers • Main Cable
• Cable Anchorages • Deck/Roadway
• Suspenders • Tower Anchors

56. Identify these
bridge types...

57. a. Suspension Bridge
b. Arch Bridge
c. Beam Bridge
d. Cable-stayed

58. a. Suspension Bridge
b. Arch Bridge
c. Beam Bridge
d. Cable-stayed Bridge

59. a. Suspension Bridge
b. Arch Bridge
c. Beam Bridge
d. Cable-stayed Bridge

60. a. Suspension Bridge
b. Arch Bridge
c. Beam Bridge
d. Cable-stayed Bridge

61. a. Suspension Bridge
b. Arch Bridge
c. Beam Bridge
d. Cable-stayed Bridge

62. a. Suspension Bridge
b. Arch Bridge
c. Beam Bridge
d. Cable-stayed Bridge

63. a. Suspension Bridge
b. Arch Bridge
c. Beam Bridge

64. The End