Types of Forces
This force pulls or stretches objects
Tension
Strongest shape used in truss bridges
Triangle
A flat bridge with piers underneath
Beam bridge
Strong wind can do this to bridges
Shake or lift them
These support the ends of arch bridges
Abutments
This force squeezes or pushes materials.
Compression
This shape handles compression really well
Arch
This bridge uses triangles for strength
Truss bridge
Flooding can do this to supports
Erode them
Flexible joints protect bridges from this
Earthquakes
This force twists objects like a screwdriver.
Torsion
This shape needs bracing to stay strong
Rectangle
A curved bridge with end supports
Arch bridge
Earthquakes cause this type of motion
Torsion
These help bridges resist strong wind
Aerodynamic shapes
This force causes parts to slide apart
Shear
What diagonal bracing does to rectangles
Turns them into triangles
A curved bridge with end supports
Suspension bridge
This keeps bridges from being slippery
De-icing
Raised foundations protect from this
Flooding
The total weight a structure supports
Load
What arch bridges transfer weight to
The abutments
Arch bridge with a tension tie
Tied-arch bridge
Helps air move smoothly around structures
Aerodynamic shape
Heated decks prevent this winter hazard
Ice buildup