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 cable-stayed 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 post-tensioned. 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 I-beams, trusses, or box girders. They could be half-through, 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 . | 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 cable-stayed 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