The arch bridge works by distributing compression through its semicircular form into a horizontal thrust restrained by its abutments, or legs. Longer bridges often consist of a series of arches, as the greater the curvature, the more tension on the bridge's underside. If the arch is too big, tension overcomes the natural strength of the semicircular design.
Though there are architectural variations to arch bridges, the basic structure remains the same. In the past, arch bridges were often made of stones, with a keystone in the middle that bore the bulk of the weight. The more weight the bridge bore, the stronger its structure became. Due to their inherent weight, these bridges required extremely sturdy foundations. Most modern arch bridges are made of reinforced concrete.
Arch bridges are durable. The oldest standing arch bridge in the world, the Arkadiko Bridge on the Peloponnese in Greece, was built around 1300 B.C. but is still used today. Many Roman bridges and aqueducts, built in segmented arches, still stand. Medieval builders improved the span and height of arch bridges by modifying the thickness of the arch barrels. Modern arch bridges include the Lupu Bridge in Shanghai, which is more than 1,800 feet long, and the New River Gorge Bridge in West Virginia, which is 1,700 feet long.Learn More
Leader in Energy and Environmental Design or LEED, is a green building certification that measures the sustainability of a building or community. LEED certification can be applied to various types of projects and has five rating systems, which are Building Design and Construction, or BD+C; Interior Design and Construction, or ID+C; Homes; Building Operations and Maintenance, or BO+M; and Neighborhood Development, or ND.Full Answer >
The plot of land that the Pentagon was originally planned to be built on was bound on five sides due to roads and other divisions, so the Pentagon was designed to conform to these restrictions. When the build site was moved, the Pentagon kept its original shape.Full Answer >
A "chute" is a channel or long rut that is used to move things from a higher plane to a lower plane. A chute can also be a water slide.Full Answer >
Architects use the Pythagorean theorem, which is expressed by the equation: a2 + b2 = c2, in designing and computing the measurements of building structures and bridges. One example involves roof design. A gable roof is made of two right triangles, where the base of one right triangle is called the run, the height is called the rise and the slope is called the rafter.Full Answer >