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5. Construction Technologies Construction technology involves building structures in order to contain, shelter, manufacture, transport, communicate, and provide recreation.5.2 Identify and describe three major types of bridges (e.g., arch, beam, and suspension) and their appropriate uses (e.g., site, span, resources, and load). 5.3Explain how the forces of tension, compression, torsion, bending, and shear affect the performance of bridges.5.4 Describe and explain the effects of loads and structural shapes on bridges. Learning Standards
At the conclusion of the lesson students will be able to: Learning Objectives • Define Bridge • 2) Identify & describe 5 major parts of a bridge • 3) Identify & describe 5 forces that affect bridges • 4) Identify & describe 7 types of bridges
Bridge A structure built to span a physical obstacle Ex: Road, Valley, Railroad Track, River, etc.
Parts of a Bridge Thick wire that supports the deck of the bridge Cables Heavy column above the bridge that supports cables Surface on which traffic moves Tower Deck Heavy column that holds up a bridge Abutments Pier Span Distance between 2 supports or towers Heavy supports at the end of a bridge
Parts of a Bridge Truss Triangular framework used to support the bridge
Early Bridges The first bridges were: Stepping Stones Log Over a Stream
Early Bridges Later people used large flat rocks connect the stepping stones allowing them to cross over the bridge with small carts
Forces Upon Bridges Forces must be considered when building bridges A force that pushes Compression A force that pulls Tension A force that twists Torsion What happens when something heavy crosses a structure Bending A force acting across any structure Shear Click here to learn more about the forces that affect bridges
Beam Bridge Most common & oldest type of bridge Example: Highway overpasses
Beam Bridge Unsupported beams can span distances only up to 250 feet Longer Beam Bridges need piers for support along the span
Beam Bridge Top of Beam Bridges are under COMPRESSION Bottom of Beam Bridges are under TENSION
Drawbridge Also known as a Bascule Bridge A Beam Bridge that has surfaces that can be raised or lowered to allow the passage of boats
Arch Bridge First designed & created by the Romans First Arch Bridges were made of wedge shaped stones locked in a curve (Keystone)
Arch Bridge Arch bridges distribute weight sideways & down around the curve Arch bridges rely on the force of compression to work effectively Arch bridges typically span distances of 200 – 800 feet (can span longer distances)
Suspension Bridge Bridge is suspended (hangs) from large vertical cables Used to cross very wide spans (2000 - 7000 ft)
Suspension Bridge Cables & abutments (anchorages) are under the force of tension Towers are under the force of compression
Cable Stayed Bridge Cheaper & easier to construct than traditional Suspension Bridge Cables connected to towers stretch down diagonally to support beam Typically span distances of 500 – 2800 feet (can be longer)
Cable Stayed Bridge Cables are under the force of tension Towers are under the force of compression
Cable Stayed Bridge Different styles of Cable Stayed Bridges Fan Style Harp Style
Truss Bridge Made of steel beams constructed into rigid triangle shapes called trusses The trusses can be above or below the bridge Why triangles??? Triangles are considered one of the strongest shapes
Truss Bridge Forces affecting Truss Bridges Blue Arrows represent TENSION COMPRESSION Red Arrows represent
Cantilever Bridge (using trusses) Cantilever: Self supporting beam that is fastened to the ground at one end 2 cantilevers meet in the middle & are connected by trusses The strong design of these bridges resist high winds
Types of Bridges Beam Bridge CantileverBridge Types of Bridges Drawbridge Arch Bridge Cable StayedBridge Truss Bridge SuspensionBridge
Braga Bridge 5780 ft long Opened in 1965 Cantilever Bridge (using trusses)
Tappan Zee Bridge Crosses the Hudson River 25 miles north of NYC Cantilever Bridge (using trusses)
Washington BridgeProvidence, RI Opened 9/25/1930 Bridge consisting of a series of arches
Glen Canyon Bridge & Dam Lake Powell, Az Crosses Colorado River Opened in 1966 1560 ft long Steel Arch Bridge
Eads Bridge 1st major all steel bridge was built in 1874 Crosses the Mississippi River - Connects St. Louis, Missouri & East St. Louis, Illinois
Brooklyn Bridge Crosses East River in New York City Connects Manhattan & Brooklyn Opened May 24, 1883 – it took 13 years to build Longest Suspension Bridge in the world when it was built 5989 Feet
Golden Gate Bridge Crosses SF Bay Connects SF & Marin County Opened May 27, 1937 Longest Suspension Bridge in the world when it was built 8981 Feet
Manhattan Bridge Suspension Bridge Crosses the East River – Connects Manhattan & Brooklyn
Akashi Kaikyo Bridge OpenedApril 5, 1998 Connects Kobe & Awaji Island Also known as the Pearl Bridge Built to withstand 178 MPH winds, earthquakes measuring 8.5 on the Richter Scale & harsh sea currents Currently the world’s longest Suspension Bridge 12,831 Feet Center Span 6,532 Feet
Mt. Hope Bridge Opened October 24, 1929 Crosses Mt. Hope Bay Connects Bristol & Portsmouth Rhode Island 6,130 Feet Center Span 1,200 Feet Suspension Bridge
Crosses the Narragansett Bay – Connects Newport & Jamestown Claiborne Pell Newport Bridge Suspension Bridge
Leonard P. Zakim Bunker Hill Memorial Bridge Crosses the Charles River Opened in 2003 Widest Cable Stayed Bridge in the world: 183 feet wide 1432 feet long
Sunshine Skyway - St. Petersburg, Fla Crosses Tampa Bay Opened 4/20/87 5 1/2 miles long Cable Stayed Bridge
Millau Viaduct Spans the valley of the River Tarn near Millau, France Tallest bridge in the world – one of the masts has a summit of 1,125 ft Taller than the Eiffel Tower & just shorter (125 ft) than the Empire State Building Opened December 14, 2004 (ahead of schedule) – work began in October 2001 Total length: 8,071 ft
Brightman Street Bridge Opened 10/10/1908 Closed October 2011 922 ft long
Brightman Street Bridge Somerset, Mass.
Veterans Memorial Bridge Somerset, Mass.
London Tower Bridge Drawbridge with Suspension
Providence RiverRailroad Bridge Drawbridge
Bourne Bridge Arch Bridge (w/ suspended deck)Crosses Cape Cod Canal in Bourne, MaOpened in 1935 Sagamore Bridge Crosses Cape Cod Canal in Sagamore, MaOpened in 1935
IWay Bridge IWay Video Part 1 IWay Video Part 2