Bridges


 * [[image:Navajo_Bridges_1.gif width="409" height="341" align="right"]]Bridges **

====As we have learned in this unit, a bridge is usually defined as a link or connection between two objects - usually places either side of an obstacle, such as a river, chasm, or estuary. But the true meaning I see is that bridges are made to break down separation and foster connectedness, it cutts dowmn to crossing an obstacle, but architecturaly speaking is crossing an obstacle through a piece of art. Also crossing a bridge cuts down the effort and time needed to cross the space. Bridges bring a lot of benefits, such as, getting things through difficult terrain in a shorter amount of time, it lowers the cost of travel and makes bigger opportunities of sharing. There are of course different types of bridges that have also been modified through the years. The Beam Bridge is the earliest and simplest of all. At this type of bridge the weight is carried only by the ground supports called piers and that is also its disadvantage. It's most likely your cheapest option for a bridge. But then again the beam isn't so strong so it tends to sag and the piers hog their upper parts. So it is not always the best option. On the other hand there's the Arch Bridge, this one is made by a curved beam that has support on its sides so it doesen't spread or straightens. Its key feature is that it can dissipate partially the vertical forces in an horizontal way and a cool history architectural tip about this type of bridge is that it was the most important type of bridge for the romas. Although the effects of scale puts a limit on how long an arch can be...Then we have the Suspension Bridge, one, where the road deck is suspended by cables, like the ones made of ropes only, across a river. Nowdays, in suspension bridges the roadway hangs from steel cables that are drapped over two towers and secured with concrete blocks at both ends. The only problem sits on the flexibillity of the cables against the wind. A variant version of the suspension bridge is the Cable-Stayed Bridge where the deck is hung from diagonal cables that exert a force towards the towers as well as vertically. On top of that, the cables stabillise the towers from both sides. They offer an enormous variety of designs. On a personal point of view I think we've reached a time in the human existence where we can no longer use the worlds resources without consecuences, for we need to start reusing and repairing what the nature and G-d have been giving to us for the past 5770 years. That's why I believe green architecture and green construction couldn't have come in a better time. Bridge Builders USA Inc., have been using green construction methods and that makes them the USA's leading builder of ecologically sensitive vehicular timber bridges and public access boardwalk complexes. For more than 25 years they've been doing our part to make the world a better place through green construction. And they say: From the beginning, we were sensitive to the fact that we were building structures to carry vehicles and people through wetlands and very special habitats. It was clear to us that wood was the ecologically sensitive material to use for green bridge construction; So their evolving the use of wood to make it part of our life in a technological new and green way, I think they give us hope and serve as a Role Model.====

This is a version of the "green" london bridge.