Bridge
History
Concept
BALANCING FORCES
Science (ACSU117)
Maths (ACMMG223)
APPLICATIONS OF
SCIENCE TO
MODERN INDUSTRY
Science (ACSHE136)
Bridges have been constructed from a range of materials and
support systems over the centuries from simple rope bridges to
wood, stone and steel. There are a range of different techniques
that can be employed to transfer the forces acting on the surface of
the bridge down to the earth and thus make a strong bridge. The
Romans perfected stone arches which transfer the weight forces
very effectively to the ground. Other bridges use an inverted arch
(such as the Sydney Harbour Bridge) or a suspension arch (such
as the Golden Gate) and a lot of metal bridges are made of
interlinking triangles to support the forces applied to the bridge deck.
Additional Reading: http://www.historyofbridges.com/
Scientific Principles Involved
The basic principle behind the bridge involves beams, arches,
trusses and suspension. Each of these construction methods are
used to support load on the bridge surface in different ways but
with the underlying principal of spreading the load at any point.
Details on applications of each of these can be found here:
http://science.howstuffworks.com/engineering/civil/bridge.htm
Modern Applications
The concept of spreading the load is not unique to bridges. It is
used in all forms of construction from houses to large commercial
buildings. Beams and trusses are used in almost every construction
and while arches are less common these days they were common
through the middle ages as a building technique. Suspension is
used in some modern hanging garden type constructions and is
gaining in application as a general building technique.
At the microscopic level nano tubes are also a form of truss
construction, applications of these techniques are endless.
http://science.howstuffworks.com/nanotechnology2.htm
Resources
Suspension Bridge
Simple experiment with straws to show the impact of simple
suspension design to strengthen a bridge.
http://www.sciencebuddies.org/science-fair-projects/project_ideas
/CE_p007.shtml
General Resources
A wide list of resources on bridge design and applications and
projects.
http://www.bridgesite.com/funand.htm
Bridge designs with paper and cardboard
A series of short projects that can be done with simple paper and
cardboard to explore the forces acting on different styles of bridges
and how these effectively strengthen constructions.
http://www.hometrainingtools.com/a/bridge-science-projectsfor-elementary