Bridges & Design
Bridges are everywhere and are there to connect places to places that will help people move
around easier. There are various and many types of bridges that are built in different and unique ways
for several reasons. One of the main and most common types of bridges also the earliest form of bridges
the beam bridge.
The beam bridge consists of a horizontal beam that is supported by piers at each end. The
weight carried by the beam pushes down onto the piers. Which mean that the further away the piers
the weeker the bridge will end up being
so it can only be up to about 250 feet
for it to remain strong. When
something is put on the beam the top
compresses and the bottom gets pulled
apart.
A truss bridge consists of triangles which are assembled together. Rigid arms go and extend
from both sides of the two piers. Diagonal tubes
going from top to bottom of both the piers keep
these arms in its place. Each bar in the bridge either
experiences a pushing of pulling force. Depending
on where they are located. These bars rarely bend
because of the way the weight is spread out that is
why truss bridges can go for longer distances than
beam bridges.
The arch is squeezed together and the force of the
squeezing is passed along the curve which supports each end. The
support pushes back which makes the arch not spread apart. Arch
bridges can be the most consistent.
Suspension bridges can spread further than
any other type. The suspension bridge a support
the road with huge steel cables that goes to a pillar
forming an A shape. The car on the road pushes
down but the load of the car because the road is
suspended gets sent to the towers.
There are many good qualities of a bridge, as bridges are there to serve its objective whether it
is to carry heavy loads or are there to let people walk across. Bridges connect point A to point B which
helps people move people and goods easier.
There can be a few problems in the making of a bridge; if the proportions aren’t right the force
won’t balance itself out which can make the bridge clasps. If the bars or pieces aren’t placed in the
rhythmic place then the flow of the force won’t work and shall become rigid.
When I made my tower out of straws I tried the truss system, the idea was right the only thing
was that I needed more tape. It held the 10 g weight but if it was to be taller it would try another
system, because the truss makes it strong not tall. The triangular shapes help make the structure firm
and rigid because it even out the force and sends the force around the triangle making it rigid. Hollow
tubes are more rigid because it takes more force to bend a hollow mettle bar than a solid mettle bar
because of the gap inside.
Works Cited
"Bridge Basics - A Spotter's Guide to Bridge Design." Bridges and Tunnels of Allegheny County and
Pittsburgh, PA - Pghbridges.com. Web. 05 Dec. 2011. <http://pghbridges.com/basics.htm>.
"BUILDING BIG: Bridge Basics." PBS: Public Broadcasting Service. Web. 05 Dec. 2011.
<http://www.pbs.org/wgbh/buildingbig/bridge/basics.html>.
"HowStuffWorks "BATS: The Basics of Bridge Design"" HowStuffWorks "Science" Web. 05 Dec.
2011. <http://science.howstuffworks.com/engineering/civil/bridge1.htm>.
Model Bridge Design. Web. 05 Dec. 2011. <http://www.garrettsbridges.com/>.
Nabihah 7A
Word Count: 498