Bridges are made up of various structural elements that keep the bridges functional and safe for long-term use. While not every bridge is built the same, these general components make up a basic bridge structure. Deck:The deck is the roadway surface of the bridge, where vehicles, pedestrians...
Bridges. New York: Macmillan, 1993. Cassady, Stephen. Spanning the Gate. Mill Valley, CA: Squarebooks, 1979. Kingston, Jeremy. How Bridges are Made. New York: Facts on File, 1985. Troitsky, M.S. Planning and Design of Bridges. New York: John Wiley & Sons, 1994. Perio...
which is what the world's greatest bridges represent. Whether we need to crossriversor valleys, connect islands to the mainland, carry cars, people, or manmade waterways, bridges are a brilliant solution whenever nature gets in our
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The first bridgeswere built in the form of trees falling across small rivers. The wood was strong enough to holdthe weight of a person or two at a time.Later people made bridges by putting rope(绳子) lines across an open are a In Chin a andother places, rope bridges are stll used....
37 Rope bridges are still used in China and other countries. They're strong enough for more people to walk on. 38 Some of them were built over 1,500 years ago, and they're still in use. Even today, people build arch (拱形的) bridges, but they are usually made of wood or stone....
Most highway beam bridges are built of concrete and steel. The Romans used concrete made of lime and pozzalana (a red, volcanic powder) in their bridges. This material set quickly, even under water, and it was strong and waterproof. During the Middle Ages in Europe, lime mortar was used...
new capacity, bridges, roads and power systems are unable to cope with expanding populations. With the exception of South Africa, the only light rail metro system in sub-Saharan Africa is in Addis Ababa, Ethiopia. Traffic jam leads to expense and unpredi...
1 Are we the restless adventurers of our imagination, like the explorers and inventors of the past, forever searching for new places to discover or for bridges to build, relentless in our desire to travel? Or are we – deep down – rather more home-loving people, who are prone to homesic...
Goal: Construct different paper bridges to test their strength Age: Middle school and up Safety concerns: None Time: 1 hour Bridges are an amazing feat of engineering. Although some of the most basic bridges are made of only a couple of logs and span only a few feet across a creek, the...