A bridge is a structure built to span a physical obstacle without blocking the way underneath. It is constructed for the purpose of providing passage over the obstacle, which is usually something that is otherwise difficult or impossible to cross. There are many different designs of bridges, each serving a particular purpose and applicable to different situations. Designs of bridges vary depending on factors such as the function of the bridge, the nature of the terrain where the bridge is constructed and anchored, and the material used to make it, and the funds available to build it.
A suspension bridge is a type of bridge in which the deck is hung below suspension cables on vertical suspenders. The first modern examples of this type of bridge were built in the early 1800s. Simple suspension bridges, which lack vertical suspenders, have a long history in many mountainous parts of the world.
A cable-stayed bridge has one or more towers, from which cables support the bridge deck. A distinctive feature are the cables or stays, which run directly from the tower to the deck, normally forming a fan-like pattern or a series of parallel lines. This is in contrast to the modern suspension bridge, where the cables supporting the deck are suspended vertically from the main cable, anchored at both ends of the bridge and running between the towers. The cable-stayed bridge is optimal for spans longer than cantilever bridges and shorter than suspension bridges. This is the range within which cantilever bridges would rapidly grow heavier, and suspension bridge cabling would be more costly.
The Lions Gate Bridge, opened in 1938 and officially known as the First Narrows Bridge, is a suspension bridge that crosses the first narrows of Burrard Inlet and connects the City of Vancouver, British Columbia, to the North Shore municipalities of the District of North Vancouver, the City of North Vancouver, and West Vancouver. The term "Lions Gate" refers to the Lions, a pair of mountain peaks north of Vancouver. Northbound traffic on the bridge heads in their general direction. A pair of cast concrete lions, designed by sculptor Charles Marega, were placed on either side of the south approach to the bridge in January 1939.
The Alamillo Bridge is a structure in Seville, Andalucia (Spain), which spans the Canal de Alfonso XIII, allowing access to La Cartuja, a peninsula located between the canal and the Guadalquivir River. The bridge was constructed as part of infrastructure improvements for Expo 92, which was held on large banana farms on the island. Construction of the bridge began in 1989 and was completed in 1992 from a design by Santiago Calatrava.
A plate girder bridge is a bridge supported by two or more plate girders.
The Tampico Bridge is a vehicular cable-stayed bridge connecting the Mexican states of Tamaulipas and Veracruz in eastern Mexico.
A suspension bridge supports its structural load with cables, ropes, or chains anchored at each end. Cables on the earliest suspension bridges were anchored in the ground; some modern suspension bridges anchor the cables to the ends of the bridge itself. Earliest suspension bridges had no towers or piers but the majority of larger modern suspension bridges have them. All of the 14 longest bridges in the world are suspension bridges.
The Nordhordland Bridge is a combined cable-stayed and pontoon bridge which crosses Salhusfjorden between Klauvaneset and the island of Flatøy in Vestland county, Norway. It is 1,614 meters (5,295 ft) long, of which the pontoon section is 1,246 meters (4,088 ft) long. The cable-stayed section consists of a single 99-meter (325 ft) tall H-pylon which has a length of 368 meters (1,207 ft) and a main span of 172 meters (564 ft). This allows for a clearance of 32 meters (105 ft).
A girder is a beam used in construction. It is the main horizontal support of a structure which supports smaller beams. Girders often have an I-beam cross section composed of two load-bearing flanges separated by a stabilizing web, but may also have a box shape, Z shape, or other forms. Girders are commonly used to build bridges.
The Hale Boggs Memorial Bridge is a cable-stayed bridge over the Mississippi River in St. Charles Parish, Louisiana. It is named for the late United States Congressman Hale Boggs.
A girder bridge is a bridge that uses girders as the means of supporting its deck. The two most common types of modern steel girder bridges are plate and box.
The Papineau-Leblanc Bridge was one of the first cable-stayed spans in North America. It is part of Quebec Autoroute 19 and is one of the connections between Laval and Montreal, Quebec, Canada, spanning Rivière des Prairies. It was fabricated from weathering steel and has an orthotropic deck. The freeway ends abruptly at the southern end of the bridge at the intersection of Henri Bourassa Boulevard, where Autoroute 19 follows Avenue Papineau down to Quebec Autoroute 40.
The Salford Quays lift bridge, also known as the Salford Quays Millennium footbridge or the Lowry bridge, is a 91.2-metre (299 ft) long vertical lift bridge spanning the Manchester Ship Canal between Salford and Trafford in Greater Manchester, England. The pedestrian bridge, which was completed in 2000, is near the terminus of the ship canal at the old Manchester Docks. It is sited beside The Lowry theatre and gallery and links Salford Quays and MediaCityUK to Trafford Wharf and the Imperial War Museum North. It has a lift of 18 metres (59 ft), allowing large watercraft to pass beneath.
A deck is the surface of a bridge. A structural element of its superstructure, it may be constructed of concrete, steel, open grating, or wood. Sometimes the deck is covered by a railroad bed and track, asphalt concrete, or other form of pavement for ease of vehicle crossing. A concrete deck may be an integral part of the bridge structure or it may be supported with I-beams or steel girders.
The San Mateo–Hayward Bridge is a bridge crossing the American state of California's San Francisco Bay, linking the San Francisco Peninsula with the East Bay. The bridge's western end is in Foster City, a suburb on the eastern edge of San Mateo. The eastern end of the bridge is in Hayward. It is the longest fixed-link bridge in California and the 25th longest in the world by length. The bridge is owned by the state of California, and is maintained by California Department of Transportation (Caltrans), the state highway agency. Further oversight is provided by the Bay Area Toll Authority (BATA).
The Adomi Bridge is a latticed steel arch suspension bridge crossing the Volta River at Atimpoku in Ghana in West Africa. It is the first permanent bridge to span the Volta River, which drains south into the Gulf of Guinea, and is Ghana's longest suspension bridge. It provides the main road passage, just south of the Akosombo Dam, between the Eastern Region and the Volta Region of Ghana. It was opened in 1957 by Kwame Nkrumah, Ghana's first president. The iconic crescent-shaped arch bridge is featured in Ghanaian stamps and currency.
Incremental launch is a method in civil engineering of building a complete bridge deck from one abutment of the bridge only, manufacturing the superstructure of the bridge by sections to the other side. In current applications, the method is highly mechanised and uses pre-stressed concrete.
The Surtees Rail Bridge is a rail bridge on the Tees Valley Line over the River Tees in the Borough of Stockton-on-Tees. The bridge is south of Stockton-on-Tees town centre and just north of the adjacent Surtees Bridge which carries the A66 road. The bridge is built on the site of a series of Tees Bridges alternating between two adjacent crossing sites.
Buckland & Taylor Ltd was a Canadian structural engineering firm specializing in bridge design and also research and building code development. It was founded in 1972 by Peter G. Buckland and Peter R. Taylor. Both had had experience with the design of major bridges. The firm continued until it was merged into COWI North America, a subsidiary of COWI A/S of Denmark, in 2015.
