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A bridge is a structure built to span physical obstacles such as a body of water, valley, or road, for the purpose of providing passage over the obstacle. Designs of bridges vary depending on the function of the bridge, the nature of the terrain where the bridge is constructed, the material used to make it and the funds available to build it.
TOPIC: BRIDGE TYPES 1. Introduce A bridge is a structure built to span physical obstacles such as a body of water, valley, or road, for the purpose of providing passage over the obstacle. Designs of bridges vary depending on the function of the bridge, the nature of the terrain where the bridge is constructed, the material used to make it and the funds available to build it. There are six main types of bridges: beam bridges, truss bridges, arch bridges, cantilever bridges, suspension bridges and cablestayed bridges Illustration for bridges type I. Beam bridges Beam bridges are the most simple of structural forms being supported by an abutment at each end of the deck. No moments are transferred through the support hence their structural type is known as simply supported The simplest beam bridge could be a slab of stone, or a plank of wood laid across a stream. Bridges designed for modern infrastructure will usually be constructed of steel or reinforced concrete, or a combination of both. The concrete used can either be reinforced, prestressed or posttensioned Types of construction could include having many beams side by side with a deck across the top of them, to a main beam either side supporting a deck between them. The main beams could be Ibeams, trusses, or box girders. They could be halfthrough, or braced across the top to create a through bridge Beam bridges are often only used for really short distances because, unlike truss bridges, they have no built in supports. The only supports are provided by piers Feiyun River Bridge, Zhejiang Province The beam bridges famous Rio-niteroi Bridge Seven Mile Bridge II. Truss bridges A truss bridge is a bridge composed of connected elements(typically straight) which may be stressed from tension, compression, or sometimes both in response to dynamic loads. Truss bridges are one of the oldest types of modern bridges. The basic types of truss bridges shown in this article have simple designs which could be easily analyzed by nineteenth and early twentieth century engineers. A truss bridge is economical to construct owing to its efficient use of materials The truss bridges famous TrangTien bridge ErieCanalRRBridge III. Arch bridges An arch bridge is a bridge with abutments at each end shaped as a curved arch. Arch bridges work by transferring the weight of the bridge and its loads partially into a horizontal thrust restrained by the abutments at either side. A viaduct (a long bridge) may be made from a series of arches, although other more economical structures are typically used today Arch bridge: construction that allows automobiles to travel between two points separated by an obstacle Portal frame: construction that carries the weight of a suspended load to the ground Arch: arched vault that is supported by the abutments Deck: platform of the bridge Lower chord: lower supporting piece Upper chord: upper supporting piece Pile: masonry pylon that serves as support The arch bridges famous Fredrikstad_BridgeacrossGlomma01 Fredrikstad Na Uy Si-o-se Pol bridge, Iran HarlemRiverBridges (New York , Mỹ ) Cantilever bridge • A cantilever bridge is a bridge built using cantilevers, structures that project horizontally into space, supported on only one end For small footbridges, the cantilevers may be simple beams; however, large cantilever bridges designed to handle road or rail traffic use trusses built from structural steel, or box girders built from prestressed concrete The steel truss cantilever bridge was a major engineering breakthrough when first put into practice, as it can span distances of over 1,500 feet (460 m), and can be more easily constructed at difficult crossings by virtue of using little or no falsework Ironton-Russell Bridge (America) Suspension bridge: construction that allows automobiles to travel between two points separated by an obstacle Side span: segment between two pylons at the ends of a bridge Centre span: segment between two pylons at the centre of a bridge Side pylon: towerlike vertical construction situated at the side, usually supporting the cables of a suspension bridge or a cablestayed bridge Foundation of a pylon: very durable lower part of a tower Suspender: support cable. Suspension cable: set of braided wire that supports a bridge Pylon: towerlike vertical support that usually supports the cables of a suspension bridge or a cablestayed bridge Stiffening girder: tightener beam A suspension bridge is a type of bridge which is built by suspending the roadway from cables attached to a master cable which runs above the length of the bridge. In addition to being strong and lightweight, suspension bridges are also beautiful, and some of the most famous bridges in the world are also suspension bridges, including San Francisco's iconic Golden Gate Bridge and New York's Brooklyn Bridge. A suspension bridge is a type of bridge in which the deck (the loadbearing portion) is hung below suspension cables on vertical suspenders This type of bridge has cables suspended between towers, plus vertical suspender cables that carry the weight of the deck below, upon which traffic crosses. Golden gate bridge Brooklyn Bridge VI. Cablestayed bridges A cablestayed bridge is a bridge that consists of one or more columns (normally referred to as towers or pylons), with cables supporting the bridge deck There are two major classes of cablestayed bridges: In a harp design, the cables are made nearly parallel by attaching them to various points on the tower(s) so that the height of attachment of each cable on the tower is similar to the distance from the tower along the roadway to its lower attachment. In a fan design, the cables all connect to or pass over the top of the tower(s) Compared to other bridge types, the cablestayed is optimal for spans longer than typically seen in cantilever bridges, and shorter than those typically requiring a suspension bridge. This is the range in which cantilever spans would rapidly grow heavier if they were lengthened, and in which suspension cabling does not get more economical, were the span to be shortened 21 tháng năm 2000 Sutong yangtze with the longest main span in the would as of 2011 1088m, side span 300m 306m high tower, total bridge length 8206m Cám ơn mọi người đã lắng nghe!!! ... engineers. A truss bridge is economical to construct owing to its efficient use of materials The truss bridges famous TrangTien bridge ErieCanalRRBridge III. Arch bridges An arch bridge is a bridge with abutments ... supports are provided by piers Feiyun River Bridge, Zhejiang Province The beam bridges famous Rio-niteroi Bridge Seven Mile Bridge II. Truss bridges A truss bridge is a bridge composed of connected elements(typically straight) ... tension, compression, or sometimes both in response to dynamic loads. Truss bridges are one of the oldest types of modern bridges. The basic types of truss bridges shown in this article have simple designs which could be easily