|
Abstract Suspension bridges, with their tall towers, long spans, and gracefully curving cables, are beautiful examples of the work of civil engineers. How do the cables and towers carry the load of the bridge? Can a suspension bridge carry a greater load than a simple beam bridge? This simple project shows you how to find out.Objective The goal of this project is to compare the strength of two simple bridge designs: a beam bridge vs. a suspension bridge. Introduction The Akashi-Kaikyo Bridge (pictured at right) is the longest suspension bridge in the world, at the time of this writing (June, 2006). The bridge is 3911 m long overall, with a central span of 1991 m. It connects Maiko in Kobe and Iwaya on Awaji Island as part of the Honshu-Shikoku Highway (Wikipedia contributors, 2006). In addition to the sheer length of the bridge, the engineers who designed it also had to consider the environment: high winds, strong sea currents, salt air, and the potential for earthquakes in the area. In a suspension bridge, the bridge deck is hung (suspended) from massive cables that stretch between the bridge towers, and are securely anchored at each end. The cables are thus under tension, while the bridge towers are under compression. For long spans, the suspension bridge is usually the most economical choice, because the amount of material required per unit length is less than for other bridge types. However, since suspension bridges are relatively flexible structures, stress forces introduced by high winds can be a serious problem. The dramatic collapse of the Tacoma Narrows Bridge, captured on film, is a pointed example (see Ketchum, 2000). In this project, you will use simple construction materials to build and test two types of bridges: a beam bridge and a simple suspension bridge. Which bridge supports more weight? Terms, Concepts, and Questions to Start Background Research To do this project, you should do research that enables you to understand the following terms and concepts:
Questions
Bibliography
Materials and Equipment To do this experiment you will need the following materials and equipment:
Experimental Procedure
Variations
Credits Edited by Andrew Olson, Ph.D., Science Buddies Sources This project idea, including the experimental procedure and construction images, is from:
|
If you like this project, you might enjoy exploring related careers.
![]() |
Civil Engineers If you turned on a faucet, used a bathroom, or visited a public space (like a road, a building, or a bridge) today, then you’ve used or visited a project that civil engineers helped to design and build. Civil engineers work to improve travel and commerce, provide people with safe drinking water and sanitation, and protect communities from earthquakes and floods. This important and ancient work is combined with a desire to make structures that are as beautiful and environmentally sound, as they are functional and cost-effective. |
![]() |
Mechanical Engineer Mechanical engineers are part of your everyday life, designing the spoon you used to eat your breakfast, your breakfast's packaging, the flip-top cap on your toothpaste tube, the zipper on your jacket, the car, bike, or bus you took to school, the chair you sat in, the door handle you grasped and the hinges it opened on, and the ballpoint pen you used to take your test. Virtually every object that you see around you has passed through the hands of a mechanical engineer. Consequently, their skills are in demand to design millions of different products in almost every type of industry. | |
![]() |
Transportation Engineer Have you ever visited family members for the holidays? You might have started your trip by taking the subway or a train to the airport. Then you jumped on a plane and flew to your destination. Finally, a family member picked you up in his or her car and drove you home. You traveled hundreds of miles in just one day. How did this happen? Who planned the subway route to the airport? Who decided the position of the airport runway? Who designed the highways and roadways? The answer to all of these questions is the transportation engineer. The goal of the transportation engineer is to move people and goods safely and efficiently. | |||
|
Join Science Buddies
Become a Science Buddies member! It's free! As a member you will be the first to receive our new and innovative project ideas, news about upcoming science competitions, science fair tips, and information on other science related initiatives. |