unit test review updated 4/24/2012.. famous bridges bridge namelocationimportance brooklyn bridge...
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FAMOUS BRIDGESFAMOUS BRIDGESFAMOUS BRIDGESFAMOUS BRIDGESBridge Name Location Importance
Brooklyn BridgeBrooklyn BridgeBrooklyn – Manhattan, NYCBrooklyn – Manhattan, NYC
crosses East Rivercrosses East River
Designer: John Roebling; completed in 1883Designer: John Roebling; completed in 1883
Used caissons to build piers (caisson disease)Used caissons to build piers (caisson disease)
Uses cable-stayed AND main cable designsUses cable-stayed AND main cable designs
George WashingtonGeorge Washington Manhattan, NYC – Fort Lee, NJ Manhattan, NYC – Fort Lee, NJ crosses Hudson Rivercrosses Hudson River
First modern suspension bridge built after collapse of Quebec First modern suspension bridge built after collapse of Quebec Bridge during construction, proved strength and safety of Bridge during construction, proved strength and safety of suspension bridges for very long crossingssuspension bridges for very long crossings
Golden Gate BridgeGolden Gate Bridge San Francisco – Marin County, San Francisco – Marin County, CA; crosses Golden GateCA; crosses Golden Gate
National iconNational icon
Oakland BayOakland BayOakland – San FranciscoOakland – San Francisco
crosses Oakland Baycrosses Oakland Bay
Collapsed in earthquake in 1989Collapsed in earthquake in 1989
Two bridges combined: suspension & beamTwo bridges combined: suspension & beam
On-ramp section melted in truck fire in 2007On-ramp section melted in truck fire in 2007
Sunshine SkywaySunshine SkywayBradenton – St. Petersburg, FLBradenton – St. Petersburg, FL
crosses Tampa Baycrosses Tampa Bay
Freighter hit it in 1980Freighter hit it in 1980
Rebuilt with cable-stayed designRebuilt with cable-stayed design
Uses damage-sensing monitors (smart bridge), dolphinsUses damage-sensing monitors (smart bridge), dolphins
Tacoma NarrowsTacoma Narrows
(“Galloping Gertie”)(“Galloping Gertie”)
Tacoma – Gig Harbor, WA Tacoma – Gig Harbor, WA
crosses Tacoma Narrowscrosses Tacoma Narrows
Collapsed in 1940, ignored effect of constant 40 mph windCollapsed in 1940, ignored effect of constant 40 mph wind
Rebuilt in 1950 using flexible, open designRebuilt in 1950 using flexible, open design
Parallel bridge completed in 2007Parallel bridge completed in 2007
Verrazano NarrowsVerrazano NarrowsBrooklyn – Staten Island, NYCBrooklyn – Staten Island, NYC
crosses Verrazano Narrowscrosses Verrazano NarrowsLongest suspension span in the United StatesLongest suspension span in the United States
Akashi KaikyoAkashi KaikyoKobe – Awaji Island, JapanKobe – Awaji Island, Japan
crosses Akashi Straightcrosses Akashi StraightLongest suspension span in the world, built across a fault lineLongest suspension span in the world, built across a fault line
PURPOSE of BRIDGESPURPOSE of BRIDGESPURPOSE of BRIDGESPURPOSE of BRIDGES
Bridges cross barriers (water, chasms, low areas, Bridges cross barriers (water, chasms, low areas, roads, other bridges)roads, other bridges)
Primary purpose: get people and their goods to the Primary purpose: get people and their goods to the other side of barriersother side of barriers
Roman bridgesRoman bridges1.1. Move armies/troops to conquer landMove armies/troops to conquer land
2.2. Move goods (trade) throughout empireMove goods (trade) throughout empire Form & functionForm & function: balance the beauty (shape) of a : balance the beauty (shape) of a
bridge with its purpose (usefulness, strength)bridge with its purpose (usefulness, strength) CommerceCommerce: carry trade and services between cities: carry trade and services between cities
Main typeMain type Roadbed supportRoadbed support Sub-typeSub-type ExampleExample
Beam straight pieces
triangles
Truss Usher Park bridge
Trestle
Girder RR bridge over Spring Brook
Draw Chicago River draw bridges
King Post Morton Arboretum ped bridges
Arch curves
Roman curved deck Irving Park ped. bridge
Through
Half-through
Deck
Suspension suspended from cables
Main (anchored) cable
Golden Gate
Akashi Kaikyo
Verrazano Narrows
Cable-stayedSunshine Skyway
Brooklyn Bridge
TYPES of BRIDGESTYPES of BRIDGESTYPES of BRIDGESTYPES of BRIDGES
Beam Bridge TypesBeam Bridge TypesBeam Bridge TypesBeam Bridge Types
Triangle
Truss
Trestle
Draw Bridge
King Post
King Post
Beam BridgesBeam BridgesBeam BridgesBeam Bridges
Firth of Forth Rail Bridge
New Zealand trestle bridge
box beam
Chicago draw bridges
girder bridge, Itasca
Arch Bridge TypesArch Bridge TypesArch Bridge TypesArch Bridge Types
THROUGH ARCHHALF-THROUGH ARCHDECK ARCHROADBEDROMAN ARCH
Arch BridgesArch BridgesArch BridgesArch Bridges
on the California Hwy.
aqueduct, Segovia, Spain
Rialto Bridge, Venice
Eads Bridge, St. Louis
Suspension Bridge TypesSuspension Bridge TypesSuspension Bridge TypesSuspension Bridge Types
ROADBEDMAIN (ANCHORED) CABLE
PIERS (TOWERS)CABLE-STAYED
Suspension BridgesSuspension BridgesSuspension BridgesSuspension Bridges
Millau Viaduct, France
Mackinac Bridge,
Michigan
Zakim Bridge, Boston
Clifton Bridge, Bristol, England
Capilano Bridge, Vancouver
OTHER BRIDGESOTHER BRIDGESOTHER BRIDGESOTHER BRIDGES
aqueductaqueduct: bridge that carries water: bridge that carries water cantilevercantilever: bridge with middle section supported by : bridge with middle section supported by
counterweightscounterweights pontoonpontoon: bridge that floats: bridge that floats
PARTS of a BRIDGEPARTS of a BRIDGEPARTS of a BRIDGEPARTS of a BRIDGE
LengthSpan
RoadbedRoadbed: carries the traffic: carries the traffic SuperstructureSuperstructure: part of bridge above the roadbed: part of bridge above the roadbed SubstructureSubstructure: part of bridge below the roadbed: part of bridge below the roadbed PierPier: primary vertical support: primary vertical support LengthLength: distance from one end of bridge to the other, : distance from one end of bridge to the other,
including access roadwaysincluding access roadways SpanSpan
Arch/beam: distance from edge to edge of area crossedArch/beam: distance from edge to edge of area crossed Suspension: distance from one pier/tower to the otherSuspension: distance from one pier/tower to the other
PARTS of a BRIDGEPARTS of a BRIDGEPARTS of a BRIDGEPARTS of a BRIDGE
CaissonCaisson: pier construction method where sections : pier construction method where sections are sunk as the river bottom is dug out insideare sunk as the river bottom is dug out inside
DolphinDolphin: “bumper” that protects bridge piers from : “bumper” that protects bridge piers from boat trafficboat traffic
JOINTSJOINTSJOINTSJOINTS ButtButt: end of one piece attached : end of one piece attached
to side of another at right anglesto side of another at right angles MiterMiter: end of one piece attached : end of one piece attached
to side at an angle, often 45 to side at an angle, often 45 degreesdegrees
NotchNotch: both pieces cut halfway : both pieces cut halfway through and joined, like Lincoln through and joined, like Lincoln logslogs
LapLap: end of one piece is “hung” : end of one piece is “hung” over the side of anotherover the side of another
LaminationLamination: full length of two : full length of two sides are attached to each othersides are attached to each other
NATURAL MATERIALSNATURAL MATERIALSNATURAL MATERIALSNATURAL MATERIALS
No tools yetNo tools yet hanging vineshanging vines piles of stones, rocks moved by waterpiles of stones, rocks moved by water fallen treesfallen trees
FIRST BRIDGESFIRST BRIDGESFIRST BRIDGESFIRST BRIDGES Tools were neededTools were needed
woven vines, ropeswoven vines, ropes stepping stones placed stepping stones placed
by humansby humans woodwood
MODERN MATERIALSMODERN MATERIALSMODERN MATERIALSMODERN MATERIALS Modern (since Roman times)Modern (since Roman times)
stone (Roman arch)stone (Roman arch) wood (covered bridges)wood (covered bridges) iron (early railroad, cracked easily)iron (early railroad, cracked easily) steel (requires painting to prevent rust)steel (requires painting to prevent rust) steel-reinforced concretesteel-reinforced concrete
STRESSES and FORCESSTRESSES and FORCESSTRESSES and FORCESSTRESSES and FORCES compressioncompression: squeezing or pressing together: squeezing or pressing together tensiontension: stretching or pulling apart: stretching or pulling apart neutral axisneutral axis: point in a beam where compression and tension : point in a beam where compression and tension
are equalare equal torsiontorsion: torque or twisting motion: torque or twisting motion oscillationoscillation: bending or swinging back and forth in an even : bending or swinging back and forth in an even
rhythmrhythm shearshear: two parallel and opposing compression forces (think : two parallel and opposing compression forces (think
scissors)scissors)
Compression
Tension
APPLYING STRESSAPPLYING STRESSAPPLYING STRESSAPPLYING STRESS shapesshapes
triangletriangle: strongest shape for resisting bridge forces: strongest shape for resisting bridge forces rackingracking: collapse of a rectangle to a parallelogram; : collapse of a rectangle to a parallelogram;
corrected by bracingcorrected by bracing loadsloads
deaddead: the weight of the bridge load itself: the weight of the bridge load itself livelive: the weight of loads that change, e.g., traffic, wind, ice, : the weight of loads that change, e.g., traffic, wind, ice,
snowsnow
BRIDGE SAFETYBRIDGE SAFETYBRIDGE SAFETYBRIDGE SAFETY
civil engineercivil engineer: a design engineer who builds : a design engineer who builds municipal infrastructure, i.e., bridges, roads, power municipal infrastructure, i.e., bridges, roads, power plants, etc.plants, etc.
bridge failuresbridge failures: about 150 to 200 bridges, partially or : about 150 to 200 bridges, partially or totally each year in the U.S.totally each year in the U.S.
inspectionsinspections: U.S. bridges over 20 feet require : U.S. bridges over 20 feet require inspections every 2 yearsinspections every 2 years
““smart” bridgessmart” bridges: use computer sensors to warn of : use computer sensors to warn of damage before it gets seriousdamage before it gets serious