Arch bridges
• Arch bridges cannot bend,
that is why they are made
from many different types
of materials such as
masonry materials eg.
Stone, brick etc.
• Arch bridges have been
around for many years and
were first developed in the
roman era.
Keystone in arch bridges.
• The picture on
the right shows
what an arch
bridge consists
of. The stones
join up in a semi
circle and meet in
the centre where
the keystone sits.
This keystone
gives the main
structure and
support for the
bridge.
• The parapet is the second part of
the bridges structure which gives
extra support for the vehicles
crossing.
Beam bridges
• Beam bridges are very
similar to arch bridges
but consist of one long
span of material Eg.
reinforced concrete
beam. When arch
bridges were being
developed, materials of
this kind were not
available.
• Most of the beam bridges have pillars to support the
weight and can be seen on motorway cross over to basic
small stream bridges.
Cantilever bridges
• The cantilever bridge is also similar to the beam bridge but is
usually made from strengthened steel to support heavy
vehicles such as trains.
• They are able to reach longer distances and are in the shape
of triangles which gives the extra support to the complex
structure.
Suspension bridges
The suspension bridge is
mainly used for crossing
long distances in one
span.
The towers support the
main cables that are
attached to hanger cables
which are fixed to the
beam of the bridge. This
gives the ultimate support.
How it works.
• The towers are attached into earth and the main
cable is tied from the top of the towers to the end of
the bridge.
• The hanger cables are fixed to the main part of the
bridge to give the extra support.