For my first bridge I took a piece of paper and folded the edges to the middle. Next I took the sides and folded those straight up. Finally I took the middle and folded it straight up. On the ends I put the paper clips.
Suspension bridges usedto be made of twistedgrass but usual thoughtwisted grass does notlast long. Today onlyone bridge made fromtwisted grass is stillthere. It is in Andes.Measuring 90 ft or27 meters Golden gate bridge. The golden gate bridge is built in San Fran Cisco. It was built there because people wanted a way across the water with out having to take a ferry. The bridge was final built and open for use on may 27 1937Suspension Bridges suspend cables by towers thatsupport a majority of weight. Weight pushes down onthe suspension bridges deck then the compressionstravels up the cables or chains. It then goes into the 4tower and is dissipated directly into the earth.
Arch bridgesThe semicircular shape distributes weight onto twocomponets of the bridge that directly take on all thepressure. The curve of the arch thought allow it todispute the force outward greatly reduces the effectsof tension on the underside of the arch.Mongomery MeigsThe bridge was completed in 1863 and was thelongest masonary arch in the world. It held for arecord 40 years. The main arch has a span of 220feet. And is 57 ft above a creek. This bridge wasdesigned as a part of the Washington Aqudect. Fun fact These bridges are a popular choice because they offer all the advantages of a suspension bridge just that they cost less,are faster to build, require less steel cables and incorporate more precast concrete 5
Beam bridgeThe beam bridge is very simple. To build a beam bridge you needhorizontal structure and two supports. One at each end. Although the on the beam bridge thebridge endures both tension and compression. This is caused by adding weight it causes the bridge to bend so you need steel to handle the load.Is the longest bridge in the world. It on the Lake Pontchartain Causeway in Louisiana. It is aproximently 24miles long and is supported by more then 9,00 pilings. This lake was built so thattravlers would not have to go all the way around the lake. 6
Cable stay bridgesThe tower of cable-stay bridges are responsible for dealingwith compressional forces. The cables attached to the rodewayin various ways. In a radial patter cables extend from severalpoints onto the road to a single point at a tower. Like a bunchof fishing lines attached to one pole. In a parrel patter thecables attach to both the radway and the towr at severalpoints.The longest cable stay bridge is the Cooper River Bridge inCharslton south Carolina. It open in the summer of 2005 and is2.5 miles long and 186 ft above a river. It was built becausethe town of River Creek needed to cross the Cooper River. 7
I chosse an arch bridge. I chose this because it holds up well and has a very pretty look to it. I used white clay to make the platform and tooth picks as the railings. Cups for the support forms and popsiclesticks on the side to help keep its form. i could put all the pennies and staples on the bridge and it did not budge. 8