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.Continue Reading
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 about Architecture
Beam bridges disperse the weight of traffic and the weight of the beam itself by utilizing strong pillars for supports on each end. Adding additional supports along the length of the beam increases the strength of the bridge. The material used for the beam and for the supports can also be modified, with steel-and-concrete-beam bridges able to handle heavier loads than wooden-beam bridges.Full Answer >
Bridges are built with cables, girders, arches and reinforced steel and concrete to channel the weight of the bridge onto abutments at either end of the structure and piers along the span of the bridge that rest on concrete pilings driven into the land or water beneath them. Types of bridges include, suspension, arch and cablestayed.Full Answer >
A truss consists of a set of members that act in compression or tension as a unit, and truss bridges stay up because of the forces that pull outward on the ends of the tension member, forming a triangular structure that keeps the bridge in place. A triangle is the ideal shape to hold this tension because a triangle does not experience distortion from the pushing and pulling of stress.Full Answer >
A proscenium arch stage is a type of theater setup that allows the audience to view the stage from a perspective of a picture frame created by the proscenium, or the space surrounding the stage opening, and the arch that is on top of the proscenium. A proscenium arch stage or theater is also referred to as a picture frame stage.Full Answer >