Investigating Structures and Materials Structures Activity

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Investigating Structures and MaterialsStructures
Activity
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Tarr Steps A Prehistoric Beam Bridge, Devon, UK

• Mode of transport foot material - stone
• 1. Take one span of the bridge and use the
  drawing tools to indicate which part is in
  tension and which is in compression? Also draw
  forces on the beam.
• 2. Is stone good in compression or tension?
• 3. Why do you think this bridge is still standing?

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Trestle Bridge Noojee, Victoria

• Rail bridge constructed from wood. About 100
  years old
• On various members, draw where they may be in
  tension and compression.
• Is this structure good in compression or tension?
  What is the difference in strength between wood
  in tension and compression? How does wood act
  under load? (Is it brittle or tough?)

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Arch bridge Avenel, Victoria

• Originally used by horse and cart 100 years
  old stone structure
• Arch construction a technique perfected by the
  ancient Romans
• Draw an arch and indicate where the load is
  distributed on the arch.
• Why is the arch such an effective structure?
• Is the structure designed for tension or
  compression?

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Railway bridge - Malmsbury

• Another example of an arch bridge
• What does the keystone do?

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Inverted brick arch Old Post Office, Bendigo

• Located adjacent to foundations
• Draw the forces acting on the structure.
• What effect does inverting the arch have on the
  load?

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Some information on the arch
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Arch Bridge Wycoller, England

• Draw the forces acting on the right-hand arch. Is
  it in compression or tension?
• List some possible reasons for the left-hand arch
  being on a lean.

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Suspension Bridge Ambyne, Victoria

• Originally used by horse and cart, now motor
  vehicles constructed from wood and steel
• Draw on the photograph which segments are in
  tension, which are in compression.
• Why are wood and steel used in their particular
  locations? What effect would replacing the wood
  sections with steel and the steel sections with
  wood have?
• How could we strengthen this bridge?

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Cable staid bridge - Tasmania

• Use - Motor vehicles constructed from steel and
  concrete
• Identify the main parts of the bridge.
• Identify areas of compression and tension.
• Why are steel and concrete used in a structure
  such as this?
• Why would a truss be used in this structure?

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Truss Bridge Walhalla, Victoria

• Used for motor vehicles constructed from steel
  and concrete
• Draw one section of the truss shown above. On
  this indicate which member would be in
  compression and which would be in tension.
• Why is the truss made from steel only? Could
  parts of it could be constructed of other
  materials?
• If the load was decreased significantly, which
  materials could the bridge be constructed from?

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Railway overpass under construction Princes
Highway between Morwell and Traralgon

• Constructed from steel and concrete
• Note the rail tunnel in the background this is
  a reinforced earth structure, comprising a steel
  core with compacted earth surrounding it
• Why are the piers made from reinforced concrete?
• How would the load be distributed around the
  reinforced earth structure?

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Swing Bridge - near Sale, Victoria

• Steel bridge swings so that two cantilever spans
  are present
• Draw the areas of tension and compression on the
  bridge in both the closed position (as shown) and
  when allowing river traffic to pass.
• What properties of the bridge prevent it from
  failing when in use?

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North Arm Bridge Lakes Entrance

• Use - motor vehicles constructed from reinforced
  and prestressed concrete
• How does prestressing work? Why would you used
  prestressing?

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Cantilever Verandah

• Draw a diagram of each of the two verandahs and
  show where the forces may be in the structures.
• Why would one have supports holding it up and the
  other one not have supports?
• If this was constructed from reinforced concrete,
  where would the reinforcing best be placed?

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Foundations

• Why would these foundations be spread?