Download - Bridge Building Intro
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BRIDGE BUILDING
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Bridge Facts!
Can you name the longest bridge in the world?
The Akashi-Kaikyo Bridge
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Bridge Facts!
Comparing the various bridges..
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Bridge Facts (cont.)
! Can you name the longest bridge in America?
The Lake Pontchartrain Causeway Bridge (23.9 miles)
(Louisiana)
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Bridge Facts (cont.)
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What is the oldest standing stone bridge in the world?
The Zhaozhou Bridge( China)
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Bridge Facts (cont.)
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What is the highest suspension bridge in the world?
The Royal Gorge Bridge above the Arkansas River
Click here to cross the bridge!
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Bridge Facts (cont.)
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New York City Bridges!!
Famous Bridges of New York!!
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Bridge Facts (cont.)
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Different types of Bridges!!
Tower Bridge -
London!!
Cable and Wooden
Planck Bridge
New Zealand!!
Tsurimi Tsubasa Bridge- Japan!!
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Definition
! What is a bridge?
"A structure built in order to allow people or vehicles tocross a river or a valley etc. Bridges are structures which
carry people and vehicles across natural or man-made
obstacles.
! When was the first bridge built?
"Prehistoric time
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Materials Used
! What materials are used in bridge construction?
"Stone"Wood
"
Grass
"Steel"Concrete
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Types of Bridges
"Do you know any type of bridges??
"Where did you see it??
"What engineering aspects did you notice??
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Types of Bridges
" Beam
"Truss
" Arch
" Suspension
"Modern Suspension
"Cable-Stayed
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Beam Bridge
! Beam bridgesare the simplest and least expensive type of bridges
to build!!
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A horizontal beam supported at its ends comprises the structure of a
beam bridge (span a distance of approximately 200 feet).! Highway overpasses, flyovers or walkways
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Beam Bridge - (Truss Bridge)
! A truss bridge is built by connecting straight elements with the
help of pin joints (span a distance of approximately 1200 feet)
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Deck truss railroad bridge that extends over the Erie Canal is
one of the many famous truss bridges.
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Suspension Bridge
Modern Suspension Bridges
! Modern Suspension bridgeshave an M-Shaped pattern and
are the most impressive type of bridge with their long main
span and beauty!!
! A bridge falling under this category is suspended from cables.
The suspension cables are anchored at each end of the bridge(span a distance of approximately 2000 to 7000 feet).
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! Cable-Stayed Bridges have an A-shaped pattern and use less
cable and are the BRIDGES OF CHOICE!!
! The forces Compressive and Tensile are same for both
suspension bridges (span a distance of approximately 500 to
3000 feet).
Suspension Bridge
Cable-Stayed Bridges
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The Tower Bridge in London is
three types of bridges in one.
The shore-to-tower spansare suspension bridges
The pedestrian walkwaysare truss (beam) bridges
The center span is movableto allow tall ships to pass.
Guess the types of bridges
embedded in this one bridge!!!
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Forces acting on
Beam Bridges and Truss BridgesTwo important forces dealt by all bridges:
Compression is a force that acts to compress or shorten
the thing it is acting on.
Tension is a force that acts to expand or lengthen the
thing it is acting on.When something pushes down on the beam, the beam bends. Its top edge
is pushed together, and its bottom edge is pulled apart.
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Forces acting on
Arch Bridges
The arch is squeezed together, and this squeezing force is carried
outward along the curve to the supports at each end. The supports,
called abutments, push back on the arch and prevent the ends of the arch
from spreading apart.
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Forces acting on Suspension Bridges
Modern Suspension BridgesIn all suspension bridges, the roadway hangs from massive steel cables,
which are draped over two towers and secured into solid concrete blocks,
called anchorages, on both ends of the bridge. The cars push down on the
roadway, but because the roadway is suspended, the cables transfer the
load into compression in the two towers. The two towers support most ofthe bridge's weight.
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Forces acting on Suspension Bridges
Cable- Stayed Bridges
Cables are anchored directly to the towers and eliminate the
need for an anchorage system. The same tensile and
compressive forces are seen in a cable-stayed bridge as they
are in a modern suspension bridge.
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#Designing the various load combinations and determining the
required size of the bridge.
#Creating models of beam, arch and suspension bridges and
apply forces to understand how they disperse the loads.
#Building a model Truss Bridge using straws and popsicle
sticks.
#Exploring the Bridge building software and designing new
bridges.#Bridge Building Competition.
Exploring Activities
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Bridge Challenge #1
A growing community needs a bridge, to connect the city and a major
highway crossing a river. They're very picky about what they want! Help
them by testing your engineering skills and match the right bridge to the
location shown in the figure below!!
Multi-lane bridge for commuters and tourists
Special Notes:"I want a one-of-a-kind bridge that will span
our beautiful river and welcome visitors from
all over the world to our thriving city. Make
sure the new bridge leaves enough room for
sailboats on the river. Please don't build a
bridge that looks like the Golden Gate Bridge
in San Francisco or the Brooklyn Bridge in
New York."
-- Mayor of Craggy Rock
Span: 2,000 feet
Crossing: River
Connects: City and major
highway
Source: http://www.pbs.org/wgbh/buildingbig/bridge/challenge/
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Bridge Challenge #1
# Beam Bridge
#
Suspension Bridge
# Arch Bridge
# Draw Bridge
Multi-lane bridge for commuters and tourists
Span: 2,000 feet
Crossing: River
Connects: City and majorhighway
Source: http://www.pbs.org/wgbh/buildingbig/bridge/challenge/
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Bridge Challenge #1
# Draw Bridge
Multi-lane bridge for commuters and tourists
Span: 2,000 feet
Crossing: River
Connects: City and major
highway
But, there is a problem - the residents of Craggy Rock spoke out
against the new drawbridge. "It's ugly," one angry resident said,
"and there's always traffic on the bridge. They open it for boats, but
what about us? We have to get to work, too!"
Source: http://www.pbs.org/wgbh/buildingbig/bridge/challenge/
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Bridge Challenge #1Multi-lane bridge for commuters and tourists
Span: 2,000 feetCrossing: River
Connects: City and major
highway
The mayor is begging you to build a new bridge. The local steelworkers
are on strike, so she advises you to build a bridge with as little steel as
possible.# Cable-stayed Bridge
# Cantilever Bridge
# Combination Arch
& Beam Bridge
Source: http://www.pbs.org/wgbh/buildingbig/bridge/challenge/
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Bridge Challenge #1Multi-lane bridge for commuters and tourists
Span: 2,000 feet
Crossing: River
Connects: City and major
highway
# Cable-stayed Bridge
These have become one of the most popular bridge types in recent years.The roadway hangs from cables like a suspension bridge, forming a
unique "A" shape. The mayor is happy because the bridge is made
mostly of concrete, a relatively cheap material. The residents are thrilled
because ships can pass beneath the bridge without causing traffic jams!
Source: http://www.pbs.org/wgbh/buildingbig/bridge/challenge/
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Bridge Challenge #2
A growing community needs a bridge, to connect the bike paths in East and
West Craggy Rock. They're very picky about what they want! Help them by
testing your engineering skills and match the right bridge to the location
shown in the figure below!!
A bridge for rollerbladers and bikers
Special Notes:"We're tired of getting bumped off the road by
angry drivers! We want a simple bridge -- one
that will connect the bike paths in East and
West Craggy Rock over the city stream. We
don't have much money, so we're not asking for
much. We just want to get to work every daywithout risking our lives!"
-- Craggy Rock Bike-n-Blade CoalitionSpan: 100 feet
Crossing: Stream
Connects: Two bike paths
Source: http://www.pbs.org/wgbh/buildingbig/bridge/challenge/
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# Beam Bridge
#
Suspension Bridge
# Arch Bridge
# Draw Bridge
Span: 100 feet
Crossing: Stream
Connects: Two bike paths
Bridge Challenge #2A bridge for rollerbladers and bikers
Source: http://www.pbs.org/wgbh/buildingbig/bridge/challenge/
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# Beam Bridge
This is an excellent spot for a beam bridge!! Beam bridges typicallyspan up to 250 feet, and they're also the cheapest and easiest bridges to
build.
Congrats -- you've just made a lot of
rollerbladers and bikers very happy!
Bridge Challenge #2A bridge for rollerbladers and bikers
Span: 100 feet
Crossing: Stream
Connects: Two bike paths
Source: http://www.pbs.org/wgbh/buildingbig/bridge/challenge/
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When it rains, the city stream rises. A really strong storm could causeflash floods, turning the stream into a raging river. Piles of rocks and
a wall of gooey mud could push on the piers of the concrete beam
bridge and cause it to topple. Luckily, you can fix it before that
happens!
Bridge Challenge #2A bridge for rollerbladers and bikers
Span: 100 feet
Crossing: Stream
Connects: Two bike paths
# Beam BridgeHowever, there isa problem.
Source: http://www.pbs.org/wgbh/buildingbig/bridge/challenge/
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How will you build a new, flood-proof bridge?
# Build deeper piers
# Build higher deck
# Use stronger
material
Bridge Challenge #2A bridge for rollerbladers and bikers
Span: 100 feet
Crossing: Stream
Connects: Two bike paths
Source: http://www.pbs.org/wgbh/buildingbig/bridge/challenge/
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# Deeper piers
Great Idea!!
One of the best ways to strengthen a bridge in a flood zone is to
set the piers deeper into the ground. The deeper the piers are
lodged into the ground, the harder it is to knock them over. The
next time floodwaters pound on the piers of your new bridge, it
probably won't budge!
Bridge Challenge #2A bridge for rollerbladers and bikers
Span: 100 feet
Crossing: Stream
Connects: Two bike paths
Source: http://www.pbs.org/wgbh/buildingbig/bridge/challenge/
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Bridge Challenge #3
A growing community needs a bridge, to connect the two halves of the city
across the harbor entrance. They're very picky about what they want! Help
them by testing your engineering skills and match the right bridge to the
location shown in the figure below!!
A highway bridge across a busy shipping port
Special Notes:"Our records indicate that more than 500 ships
pass through Craggy Rock Harbor each day.
Please build a bridge that does not block the
flow of water traffic. We do not want angry
sailors or congestion of any kind in our harbor.
Thank you."
-- The United States Coast GuardSpan: 5000feet
Crossing: Ocean bay
Connects: Island and mainland
Source: http://www.pbs.org/wgbh/buildingbig/bridge/challenge/
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# Beam Bridge
#
Suspension Bridge
# Arch Bridge
# Draw Bridge
Bridge Challenge #3
Span: 5000feet
Crossing: Ocean bay
Connects: Island and mainland
A highway bridge across a busy shipping port
Source: http://www.pbs.org/wgbh/buildingbig/bridge/challenge/
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# Suspension Bridge
This is an ideal location for a suspension bridge. Suspension bridges,like the Akashi Kaikyo Bridge in Japan, can span great distances and
still leave room for passing ships and boats. The U.S. Coast Guard is
thrilled with your selection!
Bridge Challenge #3
Span: 5000feet
Crossing: Ocean bay
Connects: Island and mainland
A highway bridge across a busy shipping port
Source: http://www.pbs.org/wgbh/buildingbig/bridge/challenge/
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Your new bridge is moving up and down a lot in the wind! This isn't abig problem under normal conditions, but what if a hurricane were to
blow through town? It could cause the bridge to move too much, or
even twist so violently that it would snap in half!
However, there is a problem.# Suspension Bridge
Bridge Challenge #3
Span: 5000feet
Crossing: Ocean bay
Connects: Island and mainland
A highway bridge across a busy shipping port
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How can you strengthen the bridge to resist strong winds?
# Stiffen the deck
with an open
TRUSS?
# Stiffen the deck
with a solid steel
GIRDER?
# Make the bridge
NARROWER?
Bridge Challenge #3
Span: 5000feet
Crossing: Ocean bay
Connects: Island and mainland
A highway bridge across a busy shipping port
Source: http://www.pbs.org/wgbh/buildingbig/bridge/challenge/
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# Open Truss
Great Idea!!
This is a great solution! By adding an open truss beneath the deck of
the bridge, you've designed a structure that is less likely to move up
and down a lot on a gusty day, because the wind will blow right
through it! Since the Tacoma Narrows Bridge disaster in 1940, many
major suspension bridges have been built with a stiffening truss.
A highway bridge across a busy shipping port
Bridge Challenge #3
Span: 5000feet
Crossing: Ocean bay
Connects: Island and mainland
Source: http://www.pbs.org/wgbh/buildingbig/bridge/challenge/
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Conclusion
! Based on the above activities different types of bridges can be
built.
!
Different types of structures and materials can be experimentedwith in order to increase the strength of the bridge.
! Efficiency of the bridge can also be calculated.