HOME

TheInfoList




A bridge is a
structure A structure is an arrangement and organization of interrelated elements in a material object or system A system is a group of Interaction, interacting or interrelated elements that act according to a set of rules to form a unified whole. A ...
built to span a physical obstacle, such as a
body of water (Lysefjord) in Norway Norway, officially the Kingdom of Norway,Names in the official and recognised languages: Bokmål Bokmål (, ; literally "book tongue") is an official written standard for the Norwegian language, alongside Nynorsk. ...

body of water
,
valley A valley is an elongated low area often running between hills or mountains, which will typically contain a river or stream running from one end to the other. Most valleys are formed by erosion of the land surface by rivers or streams over a ...

valley
, or
road A road is a wide way leading from one place to another, typically one with a specially prepared surface which vehicles and bikes can use. Roads consist of one or two roadways (British English: carriageways), each with one or more lanes and any ...

road
, without closing the way underneath. It is constructed for the purpose of providing passage over the obstacle, usually something that is otherwise difficult or impossible to cross. There are many different designs that each serve a particular purpose and apply to different situations. Designs of bridges vary depending on the function of the bridge, the nature of the
terrain Relief map of Sierra Nevada, Spain Terrain or relief (also topographical Topography is the study of the forms and features of land surfaces. The topography of an area could refer to the surface forms and features themselves, or a desc ...

terrain
where the bridge is constructed and anchored, the material used to make it and the funds available to build it. Most likely, the earliest bridges were fallen trees and
stepping stones Stepping stones or stepstones are sets of stones arranged to form a simple bridge A bridge is a Nonbuilding structure, structure built to Span (engineering), span a physical obstacle, such as a body of water, valley, or road, without closing th ...

stepping stones
, while
Neolithic The Neolithic period is the final division of the Stone Age The Stone Age was a broad prehistoric Prehistory, also known as pre-literary history, is the period of human history Human history, also known as world history, is t ...
people built
boardwalk A boardwalk (alternatively board walk, boarded path, or promenade An esplanade or promenade is a long, open, level area, usually next to a river or large body of water ( Lysefjord) in Norway Norway ( nb, ; nn, ; se, Norga; smj, ...

boardwalk
bridges across marshland. The
Arkadiko Bridge The Arkadiko Bridge or Kazarma Bridge is a Mycenaean bridge A bridge is a structure A structure is an arrangement and organization of interrelated elements in a material object or system A system is a group of Interaction, interacting or ...
dating from the 13th century BC, in the
Peloponnese The Peloponnese (), Peloponnesia, or Peloponnesus (; el, Πελοπόννησος, Pelopónnēsos, ) is a peninsula and geographic regions of Greece, geographic region in southern Greece. It is connected to the central part of the country by the ...
, in southern Greece is one of the oldest
arch bridge 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 structural load, loads partially into a horizontal thrust restrained by the abutments at either sid ...

arch bridge
s still in existence and use.


Etymology

The ''
Oxford English Dictionary The ''Oxford English Dictionary'' (''OED'') is the principal historical dictionary A historical dictionary or dictionary on historical principles is a dictionary which deals not only with the latterday meanings of words but also the historica ...
'' traces the origin of the word ''bridge'' to an
Old English Old English (, ), or Anglo-Saxon, is the earliest recorded form of the English language English is a West Germanic language of the Indo-European language family The Indo-European languages are a language family A language ...
word ''brycg'', of the same meaning. The word can be traced directly back to Proto-Indo-European ''*bʰrēw-.'' The word for the card game of the same name has a different origin.


History

The simplest and earliest types of bridges were
stepping stones Stepping stones or stepstones are sets of stones arranged to form a simple bridge A bridge is a Nonbuilding structure, structure built to Span (engineering), span a physical obstacle, such as a body of water, valley, or road, without closing th ...

stepping stones
.
Neolithic The Neolithic period is the final division of the Stone Age The Stone Age was a broad prehistoric Prehistory, also known as pre-literary history, is the period of human history Human history, also known as world history, is t ...
people also built a form of
boardwalk A boardwalk (alternatively board walk, boarded path, or promenade An esplanade or promenade is a long, open, level area, usually next to a river or large body of water ( Lysefjord) in Norway Norway ( nb, ; nn, ; se, Norga; smj, ...

boardwalk
across marshes; examples of such bridges include the
Sweet Track The Sweet Track is an ancient trackway Historic roads (historic trails in USA and Canada) are paths or routes that have historical importance due to their use over a period of time. Examples exist from prehistoric times until the early 20t ...
and the
Post Track The Post Track is an ancient causeway A causeway is a track, road or railway on the upper point of an embankment Embankment may refer to: Geology and geography * A levee, an artificial bank raised above the immediately surrounding land t ...
in England, approximately 6000 years old. Undoubtedly, ancient people would also have used
log bridge A log bridge is a timber bridge A timber bridge or wooden bridge is a bridge A bridge is a Nonbuilding structure, structure built to Span (engineering), span a physical obstacle, such as a body of water, valley, or road, without closing th ...

log bridge
s; that is a
timber bridge A timber bridge or wooden bridge is a bridge A bridge is a Nonbuilding structure, structure built to Span (engineering), span a physical obstacle, such as a body of water, valley, or road, without closing the way underneath. It is constructe ...
that fall naturally or are intentionally felled or placed across streams. Some of the first man-made bridges with significant span were probably intentionally felled trees. Among the oldest
timber bridge A timber bridge or wooden bridge is a bridge A bridge is a Nonbuilding structure, structure built to Span (engineering), span a physical obstacle, such as a body of water, valley, or road, without closing the way underneath. It is constructe ...
s is the
Holzbrücke Rapperswil-Hurden Holzbrücke Rapperswil-Hurden is a wooden pedestrian bridge between the city of Rapperswil and the village of Hurden crossing the Obersee (Zürichsee), upper Lake Zürich (''Obersee'') in Switzerland. The prehistoric timber piles discovered to the ...
crossing upper
Lake Zürich Lake Zurich (Swiss German/Alemannic German, Alemannic: ''Zürisee''; German language, German: ''Zürichsee''; rm, Lai da Turitg) is a lake in Switzerland, extending southeast of the city of Zürich. Depending on the context, Lake Zurich or ''Z ...
in Switzerland; the prehistoric timber piles discovered to the west of the
Seedamm Seedamm is the partially artificial causeway A causeway is a track, road or railway on the upper point of an embankment Embankment may refer to: Geology and geography * A levee, an artificial bank raised above the immediately surrounding la ...
date back to 1523 BC. The first wooden footbridge led across Lake Zürich, followed by several reconstructions at least until the late 2nd century AD, when the
Roman Empire The Roman Empire ( la, Imperium Rōmānum ; grc-gre, Βασιλεία τῶν Ῥωμαίων, Basileía tôn Rhōmaíōn) was the post-Republican Republican can refer to: Political ideology * An advocate of a republic, a type of governme ...

Roman Empire
built a wooden bridge. Between 1358 and 1360,
Rudolf IV, Duke of Austria Rudolf IV (1 November 1339 – 27 July 1365), also called Rudolf the Founder (german: der Stifter), was a scion of the House of Habsburg The House of Habsburg (; ; alternatively spelled Hapsburg in English; german: Haus Habsburg, es, Casa de ...
, built a 'new' wooden bridge across the lake that has been used to 1878 – measuring approximately in length and wide. On April 6, 2001, the reconstructed wooden footbridge was opened, being the longest wooden bridge in Switzerland. The
Arkadiko Bridge The Arkadiko Bridge or Kazarma Bridge is a Mycenaean bridge A bridge is a structure A structure is an arrangement and organization of interrelated elements in a material object or system A system is a group of Interaction, interacting or ...
is one of four Mycenaean
corbel arch A corbel arch (or corbeled / corbelled arch) is an arch An arch is a vertical curved structure that Span (architecture), spans an elevated space and may or may not support the weight above it, or in case of a horizontal arch like an arch da ...
bridges part of a former network of roads, designed to accommodate
chariot A chariot is a type of carriage A carriage is a private four-wheeled vehicle for people and is most commonly horse-drawn A horse-drawn vehicle is a mechanized piece of equipment pulled by one horse or by a team of horses. These vehicles ...

chariot
s, between the fort of Tiryns and town of Epidauros in the
Peloponnese The Peloponnese (), Peloponnesia, or Peloponnesus (; el, Πελοπόννησος, Pelopónnēsos, ) is a peninsula and geographic regions of Greece, geographic region in southern Greece. It is connected to the central part of the country by the ...
, in southern Greece. Dating to the Greek
Bronze Age The Bronze Age is a prehistoric Periodization, period that was characterized by the use of bronze, in some areas proto-writing, and other early features of urban civilization. The Bronze Age is the second principal period of the Three-age sys ...
(13th century BC), it is one of the oldest
arch bridge 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 structural load, loads partially into a horizontal thrust restrained by the abutments at either sid ...

arch bridge
s still in existence and use. Several intact arched stone bridges from the
Hellenistic era The Hellenistic period spans the period of History of the Mediterranean region, Mediterranean history between the death of Alexander the Great in 323 BC and the emergence of the Roman Empire, as signified by the Battle of Actium in 31  ...
can be found in the Peloponnese. The greatest bridge builders of antiquity were the
ancient Romans In historiography Historiography is the study of the methods of historian ( 484– 425 BC) was a Greek historian who lived in the 5th century BC and one of the earliest historians whose work survives. A historian is a person who studi ...
. The Romans built arch bridges and
aqueducts Aqueduct may refer to: Bridges *Aqueduct (bridge) Aqueduct of Vanvitelli, Italy, built by Luigi Vanvitelli. It is a World Heritage Site and one of the finest examples of an aqueduct in Europe. Aqueducts or water bridges are bridges constructe ...
that could stand in conditions that would damage or destroy earlier designs. Some stand today. An example is the
Alcántara Bridge The Alcántara Bridge (also known as Trajan's Bridge at Alcantara) is a Roman bridge at Alcántara, in Extremadura, Spain. Alcántara is from the Arabic word ''al-Qantarah'' (القنطرة) meaning "the arch". The stone arch bridge was built ...
, built over the river
Tagus The Tagus ( ; es, Tajo ; pt, Tejo ; see below) is the longest river in the Iberian Peninsula The Iberian Peninsula , ** * Aragonese and Occitan: ''Peninsula Iberica'' ** ** * french: Péninsule Ibérique * mwl, Península Eib ...

Tagus
, in
Spain , image_flag = Bandera de España.svg , image_coat = Escudo de España (mazonado).svg , national_motto = , national_anthem = , image_map = , map_caption = , image_map2 ...

Spain
. The Romans also used
cement A cement is a binder (material), binder, a substance used for construction that solidification, sets, hardens, and adheres to other materials to bind them together. Cement is seldom used on its own, but rather to bind sand and gravel (constru ...
, which reduced the variation of strength found in natural stone. One type of cement, called
pozzolana Pozzolana or pozzuolana ( , ), also known as pozzolanic ash ( la, pulvis puteolanus), is a natural silica, siliceous or siliceous-Aluminium oxide, aluminous material which reacts with calcium hydroxide in the presence of water at room temperature ( ...
, consisted of water,
lime Lime refers to: * Lime (fruit), a green citrus fruit * Lime (material), inorganic materials containing calcium, usually calcium oxide or calcium hydroxide * Lime (color), a color between yellow and green Lime may also refer to: Botany * Austra ...
, sand, and
volcanic rock Volcanic rock (often shortened to volcanics in scientific contexts) is a formed from erupted from a . In other words, it differs from other by being of origin. Like all rock types, the concept of volcanic rock is artificial, and in nature vo ...

volcanic rock
.
Brick A brick is a type of block used to build walls, pavements and other elements in masonry construction. Properly, the term ''brick'' denotes a block composed of dried clay, but is now also used informally to denote other chemically cured cons ...

Brick
and
mortar Mortar may refer to: * Mortar (weapon), an indirect-fire infantry weapon * Mortar (masonry), a material used to fill the gaps between blocks and bind them together * Mortar and pestle, a tool pair used to crush or grind * Mortar, Bihar, a village in ...
bridges were built after the Roman era, as the technology for cement was lost (then later rediscovered). In India, the ''
Arthashastra The ''Arthaśāstra'' ( sa, अर्थशास्त्र, ) is an ancient India According to consensus in modern genetics, anatomically modern humans first arrived on the Indian subcontinent from Africa between 73,000 and 55,000 ye ...

Arthashastra
'' treatise by
Kautilya Chanakya (IAST The International Alphabet of Sanskrit Transliteration (IAST) is a transliteration scheme that allows the lossless romanisation Romanization or romanisation, in linguistics Linguistics is the science, scientific ...

Kautilya
mentions the construction of dams and bridges. A
Mauryan The Maurya Empire was a geographically extensive Iron Age list of ancient great powers, historical power in South Asia based in Magadha, founded by Chandragupta Maurya in 322 BCE, and existing in loose-knit fashion until 185 BCE. Quote: "Ma ...
bridge near
Girnar Girnar is an ancient hill in Junagadh Junagadh () is the headquarters of Junagadh district in the States and territories of India, Indian state of Gujarat. Located at the foot of the Girnar, Girnar hills, southwest of Ahmedabad and Gand ...

Girnar
was surveyed by
James Princep
James Princep
. The bridge was swept away during a flood, and later repaired by Puspagupta, the chief architect of emperor
Chandragupta I Chandragupta I (Gupta script: File:Gupta allahabad pt.jpg, 12px ''Cha-ndra-gu-pta'', r. c. 319-335 or 319-350 CE) was a king of the Gupta dynasty, who ruled in northern India. His title ''Maharajadhiraja'' ("great king of kings") suggests that ...
.Dutt, Romesh Chunder (2000). ''A History of Civilisation in Ancient India: Vol II'', Routledge, p. 46, . The use of stronger bridges using plaited bamboo and iron chain was visible in India by about the 4th century. A number of bridges, both for military and commercial purposes, were constructed by the
Mughal Mughal or Moghul may refer to: * The Mughal Empire of South Asia ** Mughal dynasty ** Mughal emperors ** Mughal people, a social group of South Asia ** Mughal Army, the Army of Mughal Empire * Cultural influences of the Mughal Empire ** Mughal arc ...
administration in India. Although large Chinese bridges of wooden construction existed at the time of the
Warring States period The Warring States period () was an era in ancient Chinese history characterized by warfare, as well as bureaucratic and military reforms and consolidation. It followed the Spring and Autumn period#REDIRECT Spring and Autumn period The Spri ...
, the oldest surviving stone bridge in China is the
Zhaozhou Bridge The Anji Bridge () is the world's oldest open-spandrel segmental arch bridge 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 in ...

Zhaozhou Bridge
, built from 595 to 605 AD during the
Sui dynasty The Sui dynasty (, ) was a short-lived Dynasties in Chinese history, imperial dynasty of China of pivotal significance. The Sui unified the Northern and Southern dynasties and reinstalled the rule of ethnic Han Chinese, Han in the entirety of ...

Sui dynasty
. This bridge is also historically significant as it is the world's oldest
open-spandrel , Arc de Triomphe du Carrousel The Arc de Triomphe du Carrousel () is a triumphal arch 300px, The Arc de Triomphe, Paris A triumphal arch is a free-standing monumental structure in the shape of an archway with one or more arched passageways, ...

open-spandrel
stone segmental arch bridge. European segmental arch bridges date back to at least the Alconétar Bridge (approximately 2nd century AD), while the enormous Roman era
Trajan's Bridge Trajan's Bridge ( ro, Podul lui Traian; sr, Трајанов мост / ''Trajanov most''), also called Bridge of Apollodorus over the Danube, was a Roman segmental arch bridge, the first bridge to be built over the lower Danube The Danube ...
(105 AD) featured open-spandrel segmental arches in wooden construction. Rope bridges, a simple type of
suspension bridge A suspension bridge is a type of bridge in which the deck (the load-bearing portion) 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 br ...

suspension bridge
, were used by the
Inca The Inca Empire, also Quechuan and Aymaran spelling shift, known as Incan Empire and the Inka Empire, and at the time known as the Realm of the Four Parts,,  "four parts together" was the largest empire in pre-Columbian America. The admin ...

Inca
civilization in the
Andes The Andes, Andes Mountains or Andean Mountains ( es, Cordillera de los Andes) are the List of mountain ranges#Mountain ranges by length, longest continental mountain range in the world, forming a continuous highland along the western edge of Sou ...

Andes
mountains of South America, just prior to European colonization in the 16th century. The Ashanti built bridges over streams and rivers. They were constructed by pounding four large forked tree trucks into the stream bed, placing beams along these forked pillars, then positioning cross-beams that were finally covered with four to six inches of dirt. During the 18th century there were many innovations in the design of timber bridges by , Johannes Grubenmann, and others. The first book on bridge engineering was written by Hubert Gautier in 1716. A major breakthrough in bridge technology came with the erection of
the Iron Bridge The Iron Bridge is a cast iron that crosses the in . Opened in 1781, it was the first major bridge in the world to be made of . Its success inspired the widespread use of cast iron as a structural material, and today the bridge is celebrate ...
in Shropshire, England in 1779. It used
cast iron Cast iron is a group of iron-carbon alloys with a carbon content more than 2%. Its usefulness derives from its relatively low melting temperature. The alloy constituents affect its colour when fractured: white cast iron has carbide impuritie ...
for the first time as arches to cross the river Severn. With the
Industrial Revolution The Industrial Revolution was the transition to new manufacturing processes in Great Britain, continental Europe Continental Europe or mainland Europe is the contiguous continent A continent is any of several large landmasse ...
in the 19th century,
truss A truss is an assembly of ''members'' such as beams, connected by ''nodes'', that creates a rigid structure. In engineering, a truss is a structure A structure is an arrangement and organization of interrelated elements in a material object ...

truss
systems of
wrought iron Wrought iron is an iron Iron () is a with Fe (from la, ) and 26. It is a that belongs to the and of the . It is, on , right in front of (32.1% and 30.1%, respectively), forming much of Earth's and . It is the fourth most common . ...
were developed for larger bridges, but iron does not have the
tensile strength Ultimate tensile strength (UTS), often shortened to tensile strength (TS), ultimate strength, or F_\text within equations, is the maximum stress that a material can withstand while being stretched or pulled before breaking. In brittle tensi ...
to support large loads. With the advent of steel, which has a high tensile strength, much larger bridges were built, many using the ideas of
Gustave Eiffel Alexandre Gustave Eiffel (born Bonickhausen dit Eiffel; ; ; 15 December 1832 – 27 December 1923) was a French civil engineer. A graduate of École Centrale des Arts et Manufactures, he made his name with various bridges for the French railway n ...

Gustave Eiffel
. In Canada and the United States, numerous timber
covered bridges A covered bridge is a timber-truss bridge A truss bridge is a bridge A bridge is a Nonbuilding structure, structure built to Span (engineering), span a physical obstacle, such as a body of water, valley, or road, without closing the way unde ...
were built in the late 1700s to the late 1800s, reminiscent of earlier designs in
Germany ) , image_map = , map_caption = , map_width = 250px , capital = Berlin Berlin (; ) is the Capital city, capital and List of cities in Germany by population, largest city of Germany by both area and population. Its 3,769,495 inh ...

Germany
and
Switzerland , french: Suisse(sse), it, svizzero/svizzera or , rm, Svizzer/Svizra , government_type = Federalism, Federal semi-direct democracy under an assembly-independent Directorial system, directorial republic , leader_title1 = Fe ...

Switzerland
. Some covered bridges were also built in Asia. In later years, some were partly made of stone or metal but the trusses were usually still made of wood; in the United States, there were three styles of trusses, the Queen Post, the Burr Arch and the Town Lattice. Hundreds of these structures still stand in North America. They were brought to the attention of the general public in the 1990s by the novel, movie, and play ''
The Bridges of Madison County ''The Bridges of Madison County'' (also published as ''Love in Black and White'') is a 1992 best-selling romance Romance (from Vulgar Latin , "in the Roman language", i.e., "Latin") may refer to: Common meanings * Romance (love) Romance ...
''. In 1927
welding Welding is a process that joins materials, usually s or s, by using high to melt the parts together and allowing them to cool, causing . Welding is distinct from lower temperature metal-joining techniques such as and , which do not the base ...

welding
pioneer Stefan Bryła designed the first welded
road bridge A bridge is a structure A structure is an arrangement and organization of interrelated elements in a material object or system A system is a group of Interaction, interacting or interrelated elements that act according to a set of rules to ...

road bridge
in the world, the Maurzyce Bridge which was later built across the river Słudwia at Maurzyce near Łowicz, Poland in 1929. In 1995, the
American Welding Society The American Welding Society (AWS) was founded in 1919 as a non-profit organization A nonprofit organization (NPO), also known as a non-business entity, not-for-profit organization, or nonprofit institution, is a legal entity organized and oper ...
presented the Historic Welded Structure Award for the bridge to Poland.


Types of bridges

Bridges can be categorized in several different ways. Common categories include the type of structural elements used, by what they carry, whether they are fixed or movable, and by the materials used.


Structure types

Bridges may be classified by how the actions of
tension Tension may refer to: Science * Psychological stress * Tension (physics), a force related to the stretching of an object (the opposite of compression) * Tension (geology), a stress which stretches rocks in two opposite directions * Voltage or elect ...
,
compression Compression may refer to: Physical science *Compression (physics), size reduction due to forces *Compression member, a structural element such as a column *Compressibility, susceptibility to compression *Gas compression *Compression ratio, of a co ...
,
bending In applied mechanics Applied mechanics is a branch of the physical science Physical science is a branch of natural science that studies abiotic component, non-living systems, in contrast to life science. It in turn has many branches, each re ...

bending
, torsion and
shear Shear may refer to: Textile production * Animal shearing, the collection of wool from various species **Sheep shearing Sheep shearing is the process by which the woollen fleece of a sheep Sheep (''Ovis aries'') are quadruped The zebr ...

shear
are distributed through their structure. Most bridges will employ all of these to some degree, but only a few will predominate. The separation of forces and moments may be quite clear. In a suspension or cable-stayed bridge, the elements in tension are distinct in shape and placement. In other cases the forces may be distributed among a large number of members, as in a truss. Some Engineers sub-divide 'beam' bridges into slab, beam-and-slab and box girder on the basis of their cross-section. A slab can be solid or voided (though this is no longer favored for inspectability reasons) while beam-and-slab consists of concrete or steel girders connected by a concrete slab. A cross-section consists of a single-cell or multi-cellular box. In recent years, construction has also become popular.


Fixed or movable bridges

Most bridges are fixed bridges, meaning they have no moving parts and stay in one place until they fail or are demolished. Temporary bridges, such as
Bailey bridge A Bailey bridge is a type of portable, pre-fabricated, truss A truss is an assembly of ''members'' such as beams, connected by ''nodes'', that creates a rigid structure. In engineering, a truss is a structure A structure is an arrangemen ...
s, are designed to be assembled, taken apart, transported to a different site, and re-used. They are important in military engineering and are also used to carry traffic while an old bridge is being rebuilt.
Movable bridge A moveable bridge, or movable bridge, is a bridge A bridge is a Nonbuilding structure, structure built to Span (engineering), span a physical obstacle, such as a body of water, valley, or road, without closing the way underneath. It is const ...
s are designed to move out of the way of boats or other kinds of traffic, which would otherwise be too tall to fit. These are generally electrically powered.


Double-decked bridges

Double-decked (or double-decker) bridges have two levels, such as the
George Washington Bridge The George Washington Bridge is a double-decked suspension bridge spanning the Hudson River, connecting the New York City borough of Manhattan with the Borough (New Jersey), New Jersey borough of Fort Lee, New Jersey, Fort Lee. The bridge is ...

George Washington Bridge
, connecting
New York City New York, often called New York City to distinguish it from New York State New York is a state State may refer to: Arts, entertainment, and media Literature * ''State Magazine'', a monthly magazine published by the U.S. Department of ...

New York City
to
Bergen County Bergen County is the most populous county A county is a geographical region of a country used for administrative or other purposesChambers Dictionary The ''Chambers Dictionary'' (''TCD'') was first published by William Chambers (publi ...
,
New Jersey New Jersey is a U.S. state, state in the Mid-Atlantic States, Mid-Atlantic and Northeastern United States, Northeastern regions of the United States. It is bordered on the north and east by the state of New York (state), New York; on the ea ...
, US, as the world's busiest bridge, carrying 102 million vehicles annually;
truss A truss is an assembly of ''members'' such as beams, connected by ''nodes'', that creates a rigid structure. In engineering, a truss is a structure A structure is an arrangement and organization of interrelated elements in a material object ...

truss
work between the roadway levels provided stiffness to the roadways and reduced movement of the upper level when the lower level was installed three decades after the upper level. The
Tsing Ma Bridge Tsing Ma Bridge is a bridge in Hong Kong Hong Kong (, ), officially the Hong Kong Special Administrative Region of the People's Republic of China (HKSAR) (), is a metropolitan area and Special administrative regions of China, special ad ...

Tsing Ma Bridge
and
Kap Shui Mun Bridge The Kap Shui Mun Bridge (KSMB) in Hong Kong Hong Kong (, ), officially the Hong Kong Special Administrative Region of the People's Republic of China (HKSAR) (), is a metropolitan area and Special administrative regions of China, special adm ...
in
Hong Kong Hong Kong (; , ), officially the Hong Kong Special Administrative Region of the People's Republic of China (HKSAR), is a city A city is a large human settlement.Goodall, B. (1987) ''The Penguin Dictionary of Human Geography''. London: Pe ...

Hong Kong
have six lanes on their upper decks, and on their lower decks there are two lanes and a pair of tracks for
MTR The Mass Transit Railway (MTR) is a major public transport network serving :Hong Kong. Operated by the MTR Corporation Limited (MTRCL), it consists of heavy rail, light rail, and feeder bus service centred on a 10-line rapid transit network s ...

MTR
metro trains. Some double-decked bridges only use one level for street traffic; the Washington Avenue Bridge in
Minneapolis Minneapolis () is a city in the U.S. state of Minnesota. With a population of 429,954 as of 2020 United States census, 2020, it is the most populous city in the state and the 46th most populous in the nation. The county seat of Hennepin County, ...

Minneapolis
reserves its lower level for automobile and light rail traffic and its upper level for pedestrian and bicycle traffic (predominantly students at the
University of Minnesota The University of Minnesota, Twin Cities (the U of M or Minnesota) is a public In public relations Public relations (PR) is the practice of managing and disseminating information from an individual or an organization An organ ...

University of Minnesota
). Likewise, in
Toronto Toronto (, ) is the capital city of the Provinces and territories of Canada, Canadian province of Ontario. With a recorded population of 2,731,571 in 2016 in 2016, it is the List of the largest municipalities in Canada by population, most p ...

Toronto
, the
Prince Edward Viaduct The Prince Edward Viaduct System, commonly referred to as the Bloor Viaduct, is the name of a truss arch bridge system in Toronto, Ontario, Canada, connecting Bloor Street East, on the west side of the system, with Danforth Avenue on the east. The ...

Prince Edward Viaduct
has five lanes of motor traffic, bicycle lanes, and sidewalks on its upper deck; and a pair of tracks for the Bloor–Danforth
subway line Rapid transit or mass rapid transit (MRT), also known as heavy rail, metro, subway, tube, U-Bahn, metropolitana or underground, is a type of high-capacity public transport generally found in urban areas. Unlike buses or trams, rapid transit s ...
on its lower deck. The western span of the
San Francisco–Oakland Bay Bridge The San Francisco–Oakland Bay Bridge, known locally as the Bay Bridge, is a complex of bridges spanning San Francisco Bay in California. As part of Interstate 80 in California, Interstate 80 and the direct road between San Francisco and Oakland ...
also has two levels.
Robert Stephenson Robert Stephenson Fellow of the Royal Society, FRS HFRSE FRSA Doctor of Civil Law, DCL (16 October 1803 – 12 October 1859) was an English civil engineer and designer of locomotives. The only son of George Stephenson, the "Father of Railways ...

Robert Stephenson
's
High Level Bridge The High Level Bridge is a road and railway bridge spanning the River Tyne The River Tyne is a river in North East England and its length (excluding tributaries) is . It is formed by the confluence of two rivers: the North Tyne and the ...
across the
River Tyne The River Tyne is a river in North East England. Its length (excluding tributaries) is . It is formed by the North Tyne and the South Tyne, which converge at Warden, Northumberland, Warden Rock near Hexham in Northumberland at a place dubbed ' ...
in
Newcastle upon Tyne Newcastle upon Tyne ( , ), often simply Newcastle, is the largest city A city is a large .Goodall, B. (1987) ''The Penguin Dictionary of Human Geography''. London: Penguin.Kuper, A. and Kuper, J., eds (1996) ''The Social Science Encyclopedi ...

Newcastle upon Tyne
, completed in 1849, is an early example of a double-decked bridge. The upper level carries a railway, and the lower level is used for road traffic. Other examples include
Britannia Bridge Britannia Bridge ( cy, Pont Britannia) is a bridge across the Menai Strait between the island of Anglesey Anglesey (; cy, Ynys Môn ), an island off the north-west coast of Wales, forms the Local government in Wales, principal area (as I ...
over the
Menai Strait The Menai Strait ( cy, Afon Menai, the "river Menai") is a narrow stretch of shallow tidal water about long, which separates the island of Anglesey Anglesey (; cy, Ynys Môn ), an island off the north-west coast of Wales, forms the Local go ...

Menai Strait
and
Craigavon Bridge The Craigavon Bridge is one of three bridge A bridge is a Nonbuilding structure, structure built to Span (engineering), span a physical obstacle, such as a body of water, valley, or road, without closing the way underneath. It is constructed ...

Craigavon Bridge
in
Derry Derry, officially Londonderry (), is the second-largest City status in the United Kingdom, city in Northern Ireland and the fifth-largest city on the island of Ireland. The name Derry is an anglicisation of the Old Irish name ''Daire'' (mod ...

Derry
,
Northern Ireland Northern Ireland ( ga, Tuaisceart Éireann ; sco, label=Ulster-ScotsUlster Scots, also known as Scotch-Irish, may refer to: * Ulster Scots people The Ulster Scots (Ulster-Scots The Ulster Scots (Ulster Scots dialects, Ulster- ...

Northern Ireland
. The between
Copenhagen Copenhagen ( da, København ) is the capital and most populous city of Denmark. As of 1 January 2021, the city had a population of 799,033 (638,117 in Copenhagen Municipality, 103,677 in Frederiksberg Municipality, 42,670 in Tårnby Municipal ...

Copenhagen
and
Malmö Malmö (, ; da, Malmø ) is the largest city in the Counties of Sweden, Swedish county (län) of Skåne County, Scania (Skåne). It is the List of urban areas in Sweden by population, third-largest city in Sweden, after Stockholm and Gothenbur ...

Malmö
consists of a four-lane highway on the upper level and a pair of railway tracks at the lower level.
Tower Bridge Tower Bridge is a combined bascule and suspension bridge in London London is the capital city, capital and List of urban areas in the United Kingdom, largest city of England and the United Kingdom. The city stands on the River Thames in ...

Tower Bridge
in London is different example of a double-decked bridge, with the central section consisting of a low-level bascule span and a high-level
footbridge A footbridge (also a pedestrian bridge, pedestrian overpass, or pedestrian overcrossing) is a bridge A bridge is a structure A structure is an arrangement and organization of interrelated elements in a material object or system A system ...

footbridge
.


Viaducts

A viaduct is made up of multiple bridges connected into one longer structure. The longest and some of the highest bridges are viaducts, such as the
Lake Pontchartrain Causeway The Lake Pontchartrain Causeway (french: Chaussée du lac Pontchartrain), also known as The Causeway, is a fixed link composed of two parallel bridges crossing Lake Pontchartrain in southeastern Louisiana, United States. The longer of the two br ...

Lake Pontchartrain Causeway
and
Millau Viaduct The Millau Viaduct (french: Viaduc de Millau, ) is a multi-span cable-stayed bridge A cable-stayed bridge has one or more ''towers'' (or ''pylons''), from which cables support the bridge deck. A distinctive feature are the cables or sta ...
.


Multi-way bridge

A multi-way bridge has three or more separate spans which meet near the center of the bridge. Multi-way bridges with only three spans appear as a "T" or "Y" when viewed from above. Multi-way bridges are extremely rare. The Tridge,
Margaret Bridge Margaret Bridge or Margit híd (sometimes ''Margit Bridge'') is a three-way bridge in Budapest Budapest (, ) is the capital and the List of cities and towns of Hungary, most populous city of Hungary, and the Largest cities of the European ...
, and Zanesville Y-Bridge are examples.


Bridge types by use

A bridge can be categorized by what it is designed to carry, such as trains, pedestrian or road traffic (road bridge), a pipeline or waterway for water transport or barge traffic. An
aqueduct Aqueduct may refer to: Bridges *Aqueduct (bridge), a bridge to convey water over an obstacle, such as a ravine or valley *Navigable aqueduct, or water bridge, a structure to carry navigable waterway canals over other rivers, valleys, railways or r ...
is a bridge that carries water, resembling a viaduct, which is a bridge that connects points of equal height. A road-rail bridge carries both road and rail traffic. Overway is a term for a bridge that separates incompatible intersecting traffic, especially road and rail. A bridge can carry overhead power lines as does the
Storstrøm Bridge The Storstrøm Bridge ( da, Storstrømsbroen, ) is a road and railway arch bridge 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 partial ...
. Some bridges accommodate other purposes, such as the tower of Nový Most Bridge in
Bratislava Bratislava (, also ; ; formerly ; hu, Pozsony) is the Capital city, capital and largest city of Slovakia. Officially, the population of the city is about 430,000; however, it is estimated to be more than 660,000 - approximately 150% of the off ...

Bratislava
, which features a restaurant, or a
bridge-restaurantA bridge restaurant or restaurant bridge is a restaurant, usually indoors, built like a bridge over a road, mostly over freeways or motorways. It usually provides access from both sides of the road without the need of crossing the road by tunnel or f ...
which is a bridge built to serve as a restaurant. Other suspension bridge towers carry transmission antennas. Conservationists use to reduce
habitat fragmentation Habitat fragmentation describes the emergence of discontinuities (fragmentation) in an organism's preferred environment Environment most often refers to: __NOTOC__ * Natural environment, all living and non-living things occurring naturally * Biop ...
and animal-vehicle collisions. The first sprung up in France in the 1950s, and these types of bridges are now used worldwide to protect both large and small wildlife. Bridges are subject to unplanned uses as well. The areas underneath some bridges have become makeshift shelters and homes to homeless people, and the undertimbers of bridges all around the world are spots of prevalent graffiti. Some bridges attract people attempting
suicide Suicide is the act of intentionally causing one's own death Death is the permanent, irreversible cessation of all biological functions that sustain a living Living or The Living may refer to: Common meanings *Life, a condition t ...

suicide
, and become known as
suicide bridge A suicide bridge is a bridge A bridge is a Nonbuilding structure, structure built to Span (engineering), span a physical obstacle, such as a body of water, valley, or road, without closing the way underneath. It is constructed for the purpose ...
s.


Bridge types by material

The materials used to build the structure are also used to categorize bridges. Until the end of the 18th century, bridges were made out of timber, stone and masonry. Modern bridges are currently built in concrete, steel, fiber reinforced polymers (FRP), stainless steel or combinations of those materials. Living bridges have been constructed of live plants such as ''
Ficus elastica ''Ficus elastica'', the rubber fig, rubber bush, rubber tree, rubber plant, or Indian rubber bush, Indian rubber tree, is a species of plant in the ficus, fig genus, native to eastern parts of South Asia and southeast Asia. It has become naturali ...

Ficus elastica
'' tree roots in India and
wisteria ''Wisteria'' is a genus Genus (plural genera) is a taxonomic rank Taxonomy (general) is the practice and science of classification of things or concepts, including the principles that underlie such classification. The term may also refer to ...

wisteria
vines in Japan.


Military bridge

The Tank bridge transporter (TBT) has the same cross-country performance as a tank even when fully loaded. It can deploy, drop off and load bridges independently, but it cannot recover them.


Analysis and design

Unlike buildings whose design is led by architects, bridges are usually designed by engineers. This follows from the importance of the engineering requirements; namely spanning the obstacle and having the durability to survive, with minimal maintenance, in an aggressive outdoor environment. Bridges are first analysed; the bending moment and shear force distributions are calculated due to the applied loads. For this, the
finite element method The finite element method (FEM) is a widely used method for numerically solving differential equations In mathematics, a differential equation is an equation In mathematics, an equation is a statement that asserts the equality (mathematics) ...
is the most popular. The analysis can be one-, two-, or three-dimensional. For the majority of bridges, a two-dimensional plate model (often with stiffening beams) is sufficient or an upstand finite element model. On completion of the analysis, the bridge is designed to resist the applied bending moments and shear forces, section sizes are selected with sufficient capacity to resist the stresses. Many bridges are made of
prestressed concrete Prestressed concrete is a form of concrete Concrete is a composed of fine and coarse bonded together with a fluid (cement paste) that hardens (cures) over time. Concrete is the second-most-used substance in the world after water, and i ...

prestressed concrete
which has good durability properties, either by pre-tensioning of beams prior to installation or post-tensioning on site. In most countries, bridges, like other structures, are designed according to Load and Resistance Factor Design (LRFD) principles. In simple terms, this means that the load is factored up by a factor greater than unity, while the resistance or capacity of the structure is factored down, by a factor less than unity. The effect of the factored load (stress, bending moment) should be less than the factored resistance to that effect. Both of these factors allow for uncertainty and are greater when the uncertainty is greater.


Aesthetics

Most bridges are utilitarian in appearance, but in some cases, the appearance of the bridge can have great importance. Often, this is the case with a large bridge that serves as an entrance to a city, or crosses over a main harbor entrance. These are sometimes known as signature bridges. Designers of bridges in parks and along parkways often place more importance on aesthetics, as well. Examples include the stone-faced bridges along the
Taconic State Parkway The Taconic State Parkway (often called the Taconic or the TSP and known administratively as New York State Route 987G or NY 987G) is a parkway between Kensico Dam and Chatham, the longest in the U.S. state of New York. It follows a ...

Taconic State Parkway
in New York. To create a beautiful image, some bridges are built much taller than necessary. This type, often found in east-Asian style gardens, is called a
Moon bridge A moon bridge (円月橋) (''engetsu-kyou'') is a highly-rounded arched pedestrian of Alinga Street and Northbourne Avenue, Canberra Canberra ( ) is the capital city of Australia. Founded following the Federation of Australia, federat ...
, evoking a rising full moon. Other garden bridges may cross only a dry bed of stream-washed pebbles, intended only to convey an impression of a stream. Often in palaces, a bridge will be built over an artificial waterway as symbolic of a passage to an important place or state of mind. A set of five bridges cross a sinuous waterway in an important courtyard of the
Forbidden City The Forbidden City () is a palace A palace is a grand residence, especially a royal residence, or the home of a or some other high-ranking dignitary, such as a or . The word is derived from the name palātium, for in Rome which housed ...

Forbidden City
in
Beijing Beijing ( ), as Peking ( ), is the of the . It is the world's , with over 21 million residents within an of 16,410.5 km2 (6336 sq. mi.). It is located in , and is governed as a under the direct administration of the with .Figures ...

Beijing
,
China China (), officially the People's Republic of China (PRC; ), is a country in East Asia East Asia is the eastern region of Asia Asia () is Earth's largest and most populous continent, located primarily in the Eastern Hemisphere ...

China
. The central bridge was reserved exclusively for the use of the Emperor and Empress, with their attendants.


Bridge maintenance

The estimated life of bridges varies between 25 and 80 years depending on location and material. However, bridges may age hundred years with proper maintenance and rehabilitation. Bridge maintenance consisting of a combination of structural health monitoring and testing. This is regulated in country-specific engineer standards and includes an ongoing monitoring every three to six months, a simple test or inspection every two to three years and a major inspection every six to ten years. In Europe, the cost of maintenance is considerable and is higher in some countries than spending on new bridges. The lifetime of welded steel bridges can be significantly extended by aftertreatment of the weld transitions. This results in a potential high benefit, using existing bridges far beyond the planned lifetime.


Bridge traffic loading

While the response of a bridge to the applied loading is well understood, the applied traffic loading itself is still the subject of research. This is a statistical problem as loading is highly variable, particularly for road bridges. Load Effects in bridges (stresses, bending moments) are designed for using the principles of Load and Resistance Factor Design. Before factoring to allow for uncertainty, the load effect is generally considered to be the maximum characteristic value in a specified
return periodA return period, also known as a recurrence interval or repeat interval, is an average time or an estimated average time between events such as earthquake An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface o ...
. Notably, in Europe, it is the maximum value expected in 1000 years. Bridge standards generally include a load model, deemed to represent the characteristic maximum load to be expected in the return period. In the past, these load models were agreed by standard drafting committees of experts but today, this situation is changing. It is now possible to measure the components of bridge traffic load, to weigh trucks, using weigh-in-motion (WIM) technologies. With extensive WIM databases, it is possible to calculate the maximum expected load effect in the specified return period. This is an active area of research, addressing issues of opposing direction lanes, side-by-side (same direction) lanes, traffic growth, permit/non-permit vehicles and long-span bridges (see below). Rather than repeat this complex process every time a bridge is to be designed, standards authorities specify simplified notional load models, notably HL-93, intended to give the same load effects as the characteristic maximum values. The
Eurocode The Eurocodes are the ten European standards (EN; harmonised technical rules) specifying how structural design Structural engineering is a sub-discipline of civil engineering in which structural engineers are trained to design the 'bones and m ...
is an example of a standard for bridge traffic loading that was developed in this way.


Traffic loading on long span bridges

Most bridge standards are only applicable for short and medium spans - for example, the Eurocode is only applicable for loaded lengths up to 200 m. Longer spans are dealt with on a case-by-case basis. It is generally accepted that the intensity of load reduces as span increases because the probability of many trucks being closely spaced and extremely heavy reduces as the number of trucks involved increases. It is also generally assumed that short spans are governed by a small number of trucks traveling at high speed, with an allowance for dynamics. Longer spans on the other hand, are governed by congested traffic and no allowance for dynamics is needed. Calculating the loading due to congested traffic remains a challenge as there is a paucity of data on inter-vehicle gaps, both within-lane and inter-lane, in congested conditions. Weigh-in-Motion (WIM) systems provide data on inter-vehicle gaps but only operate well in free flowing traffic conditions. Some authors have used cameras to measure gaps and vehicle lengths in jammed situations and have inferred weights from lengths using WIM data. Others have used
microsimulation Microsimulation (from microanalytic simulation or microscopic simulation) is a category of computerized analytical tools that perform highly detailed analysis of activities such as highway traffic flowing through an intersection, financial transacti ...
to generate typical clusters of vehicles on the bridge.


Bridge vibration

Bridges vibrate under load and this contributes, to a greater or lesser extent, to the stresses. Vibration and dynamics are generally more significant for slender structures such as pedestrian bridges and long-span road or rail bridges. One of the most famous examples is the
Tacoma Narrows Bridge The Tacoma Narrows Bridge is a pair of twin Twins are two offspring produced by the same pregnancy.MedicineNet > Definition of TwinLast Editorial Review: 19 June 2000 Twins can be either ''monozygotic'' ('identical'), meaning that they develop ...

Tacoma Narrows Bridge
that collapsed shortly after being constructed due to excessive vibration. More recently, the in London vibrated excessively under pedestrian loading and was closed and retrofitted with a system of dampers. For smaller bridges, dynamics is not catastrophic but can contribute an added amplification to the stresses due to static effects. For example, the Eurocode for bridge loading specifies amplifications of between 10% and 70%, depending on the span, the number of traffic lanes and the type of stress (bending moment or shear force).


Vehicle-bridge dynamic interaction

There have been many studies of the dynamic interaction between vehicles and bridges during vehicle crossing events. Fryba did pioneering work on the interaction of a moving load and an Euler-Bernoulli beam. With increased computing power, vehicle-bridge interaction (VBI) models have become ever more sophisticated. The concern is that one of the many natural frequencies associated with the vehicle will resonate with the bridge first natural frequency. The vehicle-related frequencies include body bounce and axle hop but there are also pseudo-frequencies associated with the vehicle's speed of crossing and there are many frequencies associated with the surface profile. Given the wide variety of heavy vehicles on road bridges, a statistical approach has been suggested, with VBI analyses carried out for many statically extreme loading events.


Bridge failures

The failure of bridges is of special concern for
structural engineers Structural engineers analyze, design, plan, and research structural components and structural system The term structural system or structural frame in structural engineering refers to the load-resisting sub-system of a building or object. The s ...
in trying to learn lessons vital to bridge design, construction and maintenance. The failure of bridges first assumed national interest during the
Victorian era In the history of the United Kingdom The history of the United Kingdom began in the early eighteenth century with the Treaty of Union A treaty is a formal, legally binding written agreement between actors in international l ...
when many new designs were being built, often using new materials. In the United States, the
National Bridge Inventory The National Bridge Inventory (NBI) is a database, compiled by the Federal Highway Administration The Federal Highway Administration (FHWA) is a division of the United States Department of Transportation that specializes in highway transportatio ...
tracks the structural evaluations of all bridges, including designations such as "structurally deficient" and "functionally obsolete".


Bridge health monitoring

There are several methods used to monitor the condition of large structures like bridges. Many long-span bridges are now routinely monitored with a range of sensors. Many types of sensors are used, including strain transducers,
accelerometer An accelerometer is a tool that measures proper acceleration In relativity theory, proper acceleration is the physical acceleration (i.e., measurable acceleration as by an accelerometer) experienced by an object. It is thus acceleration relative ...

accelerometer
s, tiltmeters, and GPS. Accelerometers have the advantage that they are inertial, i.e., they do not require a reference point to measure from. This is often a problem for distance or deflection measurement, especially if the bridge is over water. An option for structural-integrity monitoring is "non-contact monitoring", which uses the
Doppler effect The Doppler effect or Doppler shift (or simply Doppler, when in context) is the change in frequency Frequency is the number of occurrences of a repeating event per unit of time A unit of time is any particular time Time is the ...

Doppler effect
(Doppler shift). A
laser A laser is a device that emits light Light or visible light is electromagnetic radiation within the portion of the electromagnetic spectrum that is visual perception, perceived by the human eye. Visible light is usually defined as h ...

laser
beam from a
Laser Doppler Vibrometer A laser Doppler vibrometer (LDV) is a scientific instrument that is used to make non-contact vibration measurements of a surface. The laser beam from the LDV is directed at the surface of interest, and the vibration amplitude and frequency are extra ...
is directed at the point of interest, and the vibration amplitude and frequency are extracted from the Doppler shift of the laser beam frequency due to the motion of the surface. The advantage of this method is that the setup time for the equipment is faster and, unlike an accelerometer, this makes measurements possible on multiple structures in as short a time as possible. Additionally, this method can measure specific points on a bridge that might be difficult to access. However, vibrometers are relatively expensive and have the disadvantage that a reference point is needed to measure from. Snapshots in time of the external condition of a bridge can be recorded using
Lidar Lidar (, also LIDAR, or LiDAR; sometimes LADAR) is a method for determining ranges (variable distance) by targeting an object with a laser A laser is a device that emits light Light or visible light is electromagnetic radiati ...
to aid bridge inspection. This can provide measurement of the bridge geometry (to facilitate the building of a computer model) but the accuracy is generally insufficient to measure bridge deflections under load. While larger modern bridges are routinely monitored electronically, smaller bridges are generally inspected visually by trained inspectors. There is considerable research interest in the challenge of smaller bridges as they are often remote and do not have electrical power on site. Possible solutions are the installation of sensors on a specialist inspection vehicle and the use of its measurements as it drives over the bridge to infer information about the bridge condition. These vehicles can be equipped with accelerometers, gyrometers, Laser Doppler Vibrometers and some even have the capability to apply a resonant force to the road surface in order to dynamically excite the bridge at its resonant frequency.


Visual index


See also

*
Air draft Air draft (or air draught) is the distance from the surface of the water to the highest point on a vessel. This is similar to the " deep draft" of a vessel which is measured from the surface of the water to the deepest part of the hull below th ...
*
Architectural engineering Architectural engineering, also known as building engineering or architecture engineering, is an engineering discipline Discipline is action ACTION is a bus operator in Canberra Canberra ( ) is the capital city of Australia. Found ...
*
Bridge chapel A bridge chapel is a small place of Christian Christians () are people who follow or adhere to Christianity Christianity is an Abrahamic religions, Abrahamic Monotheism, monotheistic religion based on the Life of Jesus in the New Testament, ...
*
Bridge tower A bridge tower (german: Brückenturm) was a type of fortified tower A fortified tower (also defensive tower or castle tower or, in context, just tower) is one of the defensive structures used in fortification A fortification is a military ...
*
Bridge to nowhere A bridge to nowhere is a bridge where one or both ends are broken, incomplete, or unconnected to any roads. If it is an overpass or an Interchange (road), interchange, the term overpass to nowhere or interchange to nowhere may be used, respecti ...

Bridge to nowhere
*
Bridges Act Bridges Act is a stock short title used in the United Kingdom for legislation relating to bridges. List Acts of the Parliament of England *The Bridges Act 1530 (22 Hen 8 c 5) *The Bridges Act 1670 (22 Car 2 c 12) *The Bridges Act 1702 (1 Anne c 12) ...
* BS 5400 *
Causeway A causeway is a track, road or railway on the upper point of an embankment (earthworks), embankment across "a low, or wet place, or piece of water". It can be constructed of earth, masonry, wood, or concrete. One of the earliest known wooden c ...

Causeway
* Coal trestle *
Covered bridges A covered bridge is a timber-truss bridge A truss bridge is a bridge A bridge is a Nonbuilding structure, structure built to Span (engineering), span a physical obstacle, such as a body of water, valley, or road, without closing the way unde ...
*
Cross-sea traffic ways Cross-sea traffic ways are vehicle or railroad traffic Traffic on roads consists of ''road users'' including pedestrians, ridden or herded animals, vehicle A vehicle (from la, vehiculum) is a machine that transport Transport (c ...
*
Culvert A culvert is a structure that channels water past an obstacle or to channel a subterranean waterway. Typically embedded so as to be surrounded by soil, a culvert may be made from a pipe (fluid conveyance), pipe, reinforced concrete or other m ...

Culvert
* Deck *
Devil's Bridge Devil's Bridge is a term applied to dozens of ancient bridge A bridge is a Nonbuilding structure, structure built to Span (engineering), span a physical obstacle, such as a body of water, valley, or road, without closing the way underneath. ...
*
Footbridge A footbridge (also a pedestrian bridge, pedestrian overpass, or pedestrian overcrossing) is a bridge A bridge is a structure A structure is an arrangement and organization of interrelated elements in a material object or system A system ...

Footbridge
*
Jet bridge A jet bridge (also termed jetway, jetwalk, airgate, gangway, aerobridge/airbridge, skybridge, finger, airtube, expedited suspended passenger entry system (E-SPES), or its official industry name passenger boarding bridge (PBB)) is an enclosed, m ...
*
Landscape architecture Landscape architecture is the design of outdoor areas, landmarks, and structures to achieve environmental, social-behavioural, or aesthetic outcomes. It involves the systematic design and general engineering of various structures for constructio ...
*
Megaproject A megaproject is an extremely large-scale investment Investment is the dedication of an asset to attain an increase in value over a period of time. Investment requires a sacrifice of some present asset, such as time, money, or effort. In fin ...
* Military bridges * Orphan bridge * Outline of bridges * Overpass * Pontoon bridge * Rigid-frame bridge * Structure gauge * Transporter bridge * Tensegrity * Trestle bridge * Tunnel


References


Further reading

* Brown, David J. ''Bridges: Three Thousand Years of Defying Nature''. Richmond Hill, Ont: Firefly Books, 2005. . * Sandak, Cass R. ''Bridges''. An Easy-read modern wonders book. New York: F. Watts, 1983. . * Whitney, Charles S. ''Bridges of the World: Their Design and Construction''. Mineola, NY: Dover Publications, 2003. (Unabridged republication of ''Bridges : a study in their art, science, and evolution''. 1929.)


External links


Digital Bridge: Bridges of the Nineteenth Century
a collection of digitized books at Lehigh University
Structurae
– International Database and Gallery of Engineerings Structures with over 10000 Bridges.
U.S. Federal Highway Administration Bridge Technology

The Museum of Japanese Timber Bridges
Fukuoka University
"bridge-info.org": site for bridges
{{Authority control Bridges, Structural engineering Articles containing video clips Infrastructure