1. Understanding Structural Engineering
Building Bridges
Understanding Structural Engineering

2. Bridges are very important structures in our transportation system
Bridges are very important structures in our transportation system. They allow us to carry loads across such obstacles as rivers, canyons, and roads. Bridges must be designed to withstand large amounts of weight while maintaining safety and stability.
Why do we need bridges?

3. Beam Bridges Consists of a horizontal beam supported by end piers
Can’t span a great distance because the further apart the piers, the weaker the bridge
Beam Bridges

4. Truss Bridges Consists of an assembly of triangles
Made from straight, steel bars
Bars rarely bend
Can span a further distance than beam bridges
Truss Bridges

5. Arch Bridges Most are made of steel or concrete
Very strong bridge design
Can span up to 800 feet
Arch Bridges

6. Suspension Bridges Can span a great distance (2,000-7,000 feet)
Most have truss system underneath to keep from bending of twisting
Massive steel cables in an “A” shape help support the bridge
Suspension Bridges

7. Thinking like an Engineer!
Not only do structural engineers have to design bridges that with withstand extremely large amounts of weight, they also must keep in mind:
Earthquakes
Strong Winds
Freezing and Thawing
Type of land
Purpose of the bridge
Cost of the bridge
Thinking like an Engineer!

8. Now that you have become an expert on bridges, it is time for you to build and test your own bridge!