Bridge Basics
What is the basic definition of a bridge?
A structure that connects two places
The first bridges on record were ___________.
Natural bridges.
What material was most available to early civilizations as they built bridges?
Wood (and dirt)
What is a bridge’s greatest enemy?
Nature
What type of engineer builds bridges?
Civil engineers
Bridges aren’t just built over water. They are constructed over....(Name 2 more)
Valleys, rough and rocky land, other roads
Why are natural bridges not "enough?"
They limit you. You can only cross where they are formed. They are not very strong.
What was the fundamental problem with early wood and dirt bridges?
During heavy rains, they usually collapsed when dirt was washed away.
What is compression?
The force an object feels when it is being squeezed.
For many centuries in Europe, stone bridges were used everywhere. In fact, some stone bridges actually became a type of house called:
Inhabited bridges.
What is a natural bridge? Give an example.
A bridge created by the natural formation of rock or land, such as a fallen tree branch.
The first man-made bridges were designed to make it easier to ____________ far from home.
Trade
What solution did the ancient Romans discover to create stronger, longer lasting bridges?
They invented mortar.
What is tension?
Tension is the force that pulls or stretches a material outward.
How do engineers test bridge designs against high winds?
They build a complete bridge at a smaller scale and test in a wind tunnel.
The first bridges date back more than ________ years ago:
4,000
Increase in trade made early civilizations realize that they needed bridges to be ____________________.
Stronger
In 1779, a new and stronger material became available for building bridges. This material was very strong and capable of withstanding extreme weather. What was this material?
Iron
What is the dead load and load of a bridge?
The weight of the bridge itself is the dead load. The weight that the bridge carries (such as traffic) is the load.
What is the most frequent natural cause of bridge collapses?
Floods and rising water.
What do you call a bridge that is made just for people?
A pedestrian or foot bridge
Which ancient civilization’s engineers are credited with creating some of the first durable bridges?
Ancient Rome
By the 1800’s, iron gave way to an even stronger and more durable material. What was this material?
Steel
What is torsion?
A twisting force that turns or twirls a material.
For a bridge to remain standing, the forces acting on it need to be ____________.
Balanced.