History of Bridges
Model Bridge Building
Types of Bridges
Bridges by Structure
– These bridges uses arch as a main structural component (arch is always located below the bridge, never above it). They are made with one or more hinges, depending of what kind of load and stress forces they must endure. Examples of arch bridge are “Old Bridge” in Mostar, Bosnia and Herzegovina and The Hell Gate Bridge in New York.
– Very basic type of bridges that are supported by several beams of various shapes and sizes. They can be inclined or V shaped. Example of beam bridge is Lake Pontchartrain Causeway in southern Louisiana.
designs that uses diagonal mesh of posts above the bridge. The two most common designs are the king posts (two diagonal posts supported by single vertical post in the center) and queen posts (two diagonal posts, two vertical pots and horizontal post that connect two vertical posts at the top).
– Similar in appearance to arch bridges, but they support their load not trough vertical bracing but trough diagonal bracing. They often use truss formation both below and above the bridge. Example of cantilever bridge is Queensboro Bridge in New York City.
Tied arch bridges
– Similar to arch bridges, but they transfer weight of the bridge and traffic load to the top chord that is connected to the bottom cords in bridge foundation. They are often called bowstring arches or bowstring bridges.
– Bridges that use ropes or cables from the vertical suspender to hold the weight of bridge deck and traffic. Example of suspension bridge is Golden Gate Bridge in San Francisco.
– Bridge that uses deck cables that are directly connected to one or more vertical columns. Cables are usually connected to columns in two ways – harp design (each cable is attached to the different point of the column, creating harp like design of “strings” and fan design (all cables connect to one point at the top of the column).
Fixed or moveable types
– Majority of bridges are fixed, with no moveable parts to provide higher clearance for river/sea transport that is flowing below them. They are designed to stay where they are made to the point they are deemed unusable or demolished.
– Bridges made from modular basic components that can be moved by medium or light machinery. They are usually used in military engineering or in circumstances when fixed bridges are repaired.
– They have moveable decks, most often powered by electricity.
Types by use
– The most common type of bridge, with two or more lanes designed to carry car and truck traffic of various intensities.
– Usually made in urban environments, or in terrain where car transport is inaccessible (rough mountainous terrain, forests, etc.).
– Built to provide best possible flow of traffic across bodies of water or rough terrain. Most offen they have large amount of car lanes, and sometimes have dedicated area for train tracks.
– Bridges made specifically to carry one or multiple lane of train tracks.
– Bridges made to carry pipelines across water or inaccessible terrains. Pipelines can carry water, air, gas and communication cables.
– Ancient structures created to carry water from water rich areas to dry cities.
– Modern bridges that host commercial buildings such as restaurants and shops.
Types by materials
Concrete and Steel