Building Bridges. Physics of Bridge Building Three basic types –Span: simplest form – beam...
Transcript of Building Bridges. Physics of Bridge Building Three basic types –Span: simplest form – beam...
Building BridgesBuilding Bridges
Physics of Bridge Building
• Three basic types– Span: simplest form – beam supported on vertical
supports. Also truss bridge, cantilever bridge– Arch: compression forces push outwards
horizontally against the supports– Suspension: main cables anchored to towers,
suspender cables support roadway. Cables are in tension.
A bridge in New South Wales, Australiaexample of truss system (rigid triangular
framework)
Forth Rail Bridge example of cantilever bridge
Clachan Bridge, Isle of Seil“The Bridge over the Atlantic”
example of stone arch bridge
Pont Du Gard Roman Aqueducttriple arch bridge
Corrieshalloch GorgeSuspension Bridge
Golden Gate Bridge San Fransiscoexample of suspension bridge
Akashi Kaikyo Bridge Japan(Longest single span in the world)
3-span 2-hinged truss-stiffened suspension bridge
Oresund Bridge, linking Sweden and Denmark
Lake Pontchartrain CausewayNew Orleans, LA
Some Physics Considerations• Choice of material
– Strength:
in tension, compression, bending, torsion
• Shape of framework – (why triangular?)
• Testing the design – use of models– Physical scale models– Computer models
Tacoma Narrows Bridge
Tacoma Narrows Bridge
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Tacoma Narrows Bridge
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Tacoma Narrows Bridge
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Millenium Bridge, River Thames, London
Millenium Bridge, River Thames, London
The Bridge Competition
• You are a team of bridge designers working for the internationally known bridge building company ………………………………………….(choose a name for your company)
• Your task is to design and build a single span bridge to the specifications given on the sheet, using the materials provided.
• The bridges will be judged on three categories
– Technical Merit– Artistic Impression
– Weight
Technical specifications
>90cm
>10cm
<30°
Coke can (full)
Makes bridge bend by less than 2cm at the centre
Single-track car deck (made from card)