Transcript Bridge Background Information

Bridge Background
Information
Build-a-Bridge Project
Project
• You and a partner will be asked to design,
construct and test a bridge
• This is a summative project
• Take notes on the following information to
help you design a good bridge!
Basic Terms you need to Know
• Span – distance bridge has to cross
• Tension – a force that acts to lengthen or
expand an object
• Compression – a force that acts to shorten
an object
Tension and Compression
• A bridge needs to balance these forces
Parts of a Bridge
Load Point
• This is the point of the bridge where the
weight is going to be loaded
• Your bridge design needs to center around
this point
Load Point
Types of Bridges
• Beam Bridge
– Beams with Trusses
• Arch Bridge
• Suspension Bridge
Beam Bridges
• Simplest kind of bridge
• Used to span short distances
• Needs to be stiff
Beam Bridges
• Span can be increased by adding trusses
Truss Design
• A truss is a triangular shape
• The truss design can affect the load a
bridge can bear
• Different designs = different results
Warren Truss
Pratt Truss
Howe Truss
K Truss
Arch Bridge
• Always under compression
• Tension is small
• The force of the compression pushes
outward along the curve of the arch to the
abutments