Bridges

1
Bridges

• By Alaa, Dustin, Kamran, and Maggie

2
Importance

• Necessary to daily life
• Makes for easy transportation over water or
  valleys
• Makes land travel faster and more efficient

3
History

• Bridges have been around since before the first
  century A.D.
• A main use was to move water to where it was
  needed though aqueducts

4
History

• In the late 1700s cast iron was innovated into
  bridges.
• With the innovation of steel mills came stronger
  and longer bridges, such as the suspension bridge

5
Types of Bridges

• Arch Bridges
• Beam Bridges
• Suspension Bridges
• Truss Bridges

6
Arch Bridges

• One of the oldest types of bridges
• The weight of the bridge is carried out along the
  curve of the arch
• This support takes the load and keeps the ends
  from flatting out
• Mostly constructed from stone or brick

7
Beam Bridges

• Consists of a horizontal beam
• Made from almost anything wood, stone, steel,
  ect.
• Supported at each end by piers
• Weight of the beam pushes down on the piers,
  without them the bridge would sink into the ground

8
Suspension Bridges

• Suspended roadway by cables, sometimes spanning
  the length of the bridge
• Cables rest on top of towers, this enables the
  main cable to be draped over long distances
• Must be constantly maintenance to perform
  properly

9
Truss Bridges

• A beam bridge with two sides that extend to the
  top and or bottom are the trusses
• Hold the weight of the bridge in the truss
• Most common design of truss or the interior of a
  truss is triangles

10
Active Forces

• Tension- The state of being stretched
• Torsion- To twist in opposing directions
• Compression- To push together
• Shear- Two objects to slide past one another in
  opposing directions

11
Triangles

• One of the most stabilizing force in architecture
• If weight is applied onto a triangle the pressure
  due to compression is distributed evenly
• Only if a side of the triangle is compromised
  will the triangle fail and break
• They are used in bridges, buildings and towers

12
Rigidity

• When a triangle is added to a structure it
  becomes more rigid
• When a structure is more rigid it can be made
  longer and bigger

13
Engineering

• To engineer a bridge theorems and postulates are
  used
• If a triangle did not add up to 180 in a truss
  then the truss would have no support

14
No Geometry?

• Without geometry life would be very basic
• There would be no large bridges, planes, trains,
  cars or other forms of transportation
• Buildings would not be more than a story tall