An
arch bridge is a bridge with
abutmentAn abutment is, generally, the point where two structures or objects meet. This word comes from the verb abut, which means adjoin or having common boundary. An abutment is an engineering term that describes a structure located at the ends of a bridge, where the bridge slab adjoins the approaching...
s at each end shaped as a curved
archAn arch is a structure that spans a space and supports a load. Arches appeared as early as the 2nd millennium BC in Mesopotamian brick architecture and their systematic use started with the Ancient Romans who were the first to apply the technique to a wide range of structures.-Technical aspects:The...
. Arch bridges work by transferring the weight of the bridge and its
loadsStructural loads or actions are forces, deformations or accelerations applied to a structure or its components.Loads cause stresses, deformations and displacements in structures. Assessment of their effects is carried out by the methods of structural analysis...
partially into a horizontal thrust restrained by the abutments at either side. A
viaductA viaduct is a bridge composed of several small spans. The term viaduct is derived from the Latin via for road and ducere to lead something. However, the Ancient Romans did not use that term per se; it is a modern derivation from an analogy with aqueduct. Like the Roman aqueducts, many early...
(a long bridge) may be made from a series of arches, although other more economical structures are typically used today.
History
Possibly the oldest existing arch bridge is the
MycenaeanMycenaean Greece was a cultural period of Bronze Age Greece taking its name from the archaeological site of Mycenae in northeastern Argolis, in the Peloponnese of southern Greece. Athens, Pylos, Thebes, and Tiryns are also important Mycenaean sites...
Arkadiko bridgeThe Arkadiko Bridge or Kazarma Bridge is a Mycenaean bridge near the modern road from Tiryns to Epidauros on the Peloponnese, Greece. Dating to the Greek Bronze Age, it is one of the oldest arch bridges still in existence and use....
in Greece from about 1300 BC. The stone
corbel archA corbel arch is an arch-like construction method that uses the architectural technique of corbeling to span a space or void in a structure, such as an entranceway in a wall or as the span of a bridge...
bridge is still used by the local populace. The well-preserved Hellenistic
Eleutherna BridgeThe Eleutherna Bridge is an ancient Greek corbel arch bridge near the Cretan town of Eleutherna, Greece.The well-preserved structure has a single span of 3.95 m, which is quite large for a false arch. The opening is cut from the unmortared limestone blocks in the shape of an isosceles...
has a triangular corbel arch. The 4th century BC
Rhodes FootbridgeThe Rhodes Footbridge is an ancient Greek arch bridge in the city of Rhodes, Greece. Dating to the 4th century BC or early Hellenistic period, the modest structure represents the oldest known Greek bridge with a voussoir arch.- Construction and location :...
rests on an early
voussoirA voussoir is a wedge-shaped element, typically a stone, used in building an arch or vault.Although each unit in an arch or vault is a voussoir, two units are of distinct functional importance: the keystone and the springer. The keystone is the center stone or masonry unit at the apex of an arch. A...
arch.
Although true arches were already known by the Etruscans and
ancient GreeksAncient Greece is a civilization belonging to a period of Greek history that lasted from the Archaic period of the 8th to 6th centuries BC to the end of antiquity. Immediately following this period was the beginning of the Early Middle Ages and the Byzantine era. Included in Ancient Greece is the...
, the
RomansAncient Rome was a thriving civilization that grew on the Italian Peninsula as early as the 8th century BC. Located along the Mediterranean Sea and centered on the city of Rome, it expanded to one of the largest empires in the ancient world....
were - as with the
vaultA Vault is an architectural term for an arched form used to provide a space with a ceiling or roof. The parts of a vault exert lateral thrust that require a counter resistance. When vaults are built underground, the ground gives all the resistance required...
and the
domeA dome is a structural element of architecture that resembles the hollow upper half of a sphere. Dome structures made of various materials have a long architectural lineage extending into prehistory....
- the first to fully realize the potential of arches for bridge construction. A list of
Roman bridgeRoman bridges, built by ancient Romans, were the first large and lasting bridges built. Roman bridges were built with stone and had the arch as its basic structure....
s compiled by the engineer Colin O'Connor features 330 Roman stone bridges for traffic, 34 Roman timber bridges and 54 Roman aqueduct bridges, a substantial part still standing and even used to carry vehicles. A more complete survey by the Italian scholar Vittorio Galliazzo found 931 Roman bridges, mostly of stone, in as many as 26 different countries (including former
YugoslaviaYugoslavia refers to three political entities that existed successively on the western part of the Balkans during most of the 20th century....
).
Roman arch bridges were usually
semicircularIn mathematics , a semicircle is a two-dimensional geometric shape that forms half of a circle. Being half of a circle's 360°, the arc of a semicircle always measures 180° or a half turn...
, although a number were segmental arch bridges (such as
Alconétar BridgeThe Alconétar Bridge , also known as Puente de Mantible, was a Roman segmental arch bridge in the Extremadura region, Spain. The ancient structure, which featured flattened arches with a span-to-rise ratio of 4–5:1, is one of the earliest of its kind...
), a bridge which has a curved arch that is less than a semicircle. The advantages of the
segmentalIn geometry, a circular segment is an area of a circle informally defined as an area which is "cut off" from the rest of the circle by a secant or a chord. The circle segment constitutes the part between the secant and an arc, excluding the circle's center...
arch bridge were that it allowed great amounts of flood water to pass under it, which would prevent the bridge from being swept away during floods and the bridge itself could be more lightweight. Generally, Roman bridges featured wedge-shaped primary arch stones (
voussoirA voussoir is a wedge-shaped element, typically a stone, used in building an arch or vault.Although each unit in an arch or vault is a voussoir, two units are of distinct functional importance: the keystone and the springer. The keystone is the center stone or masonry unit at the apex of an arch. A...
s) of the same in size and shape. The Romans built both single spans and lengthy multiple arch aqueducts, such as the
Pont du GardThe Pont du Gard is a notable ancient Roman aqueduct bridge that crosses the Gard River in southern France. It is part of a long aqueduct that runs between Uzès and Nîmes in the South of France. It is located in Vers-Pont-du-Gard near Remoulins, in the Gard département...
and
Segovia AqueductThe Aqueduct of Segovia is a Roman aqueduct and one of the most significant and best-preserved ancient monuments left on the Iberian Peninsula...
. Their bridges featured from an early time onwards flood openings in the piers, e.g. in the
Pons FabriciusThe Pons Fabricius or Ponte dei Quattro Capi, is the oldest Roman bridge in Rome, Italy, still existing in its original state. Built in 62 BC, it spans half of the Tiber River, from the Campus Martius on the east side to Tiber Island in the middle...
in Rome (62 BC), one of the world's oldest major bridges still standing.
Roman engineers were the first and until the
industrial revolutionThe Industrial Revolution was a period from the 18th to the 19th century where major changes in agriculture, manufacturing, mining, transportation, and technology had a profound effect on the social, economic and cultural conditions of the times...
the only ones to construct bridges with
concreteRoman concrete was a material used in construction during the late Roman Republic through the whole history of the Roman Empire. Roman concrete was based on a hydraulic-setting cement with many material qualities similar to modern Portland cement...
, which they called Opus caementicium. The outside was usually covered with brick or ashlar, as in the Alcántara bridge.
The Romans also introduced segmental arch bridges into bridge construction. The 330 m long
Limyra BridgeThe Limyra Bridge is a late Roman bridge in Lycia, in modern south-west Turkey, and one of the oldest segmented arch bridges in the world. The long bridge is located near the ancient city of Limyra, and spans the Alakır Çayı river over 26 segmental arches...
in southwestern
TurkeyTurkey , known officially as the Republic of Turkey , is a Eurasian country located in Western Asia and in East Thrace in Southeastern Europe...
features 26 segmental arches with an average span-to-rise ratio of 5.3:1, giving the bridge an unusually flat profile unsurpassed for more than a millennium.
Trajan's bridgeTrajan's Bridge or Bridge of Apollodorus over the Danube was a Roman segmental arch bridge, the first to be built over the lower Danube. For more than a thousand years, it was the longest arch bridge in the world, in terms of both total and span length...
over the
DanubeThe Danube is a river in the Central Europe and the Europe's second longest river after the Volga. It is classified as an international waterway....
featured open-spandrel segmental arches made of wood (standing on 40 m high concrete piers). This was to be the longest arch bridge for a thousand years both in terms of overall and individual span length, while the longest extant Roman bridge is the 790 m long
Puente RomanoThe Puente Romano is a Roman bridge over the Guadiana River at Mérida, Spain. It is the longest surviving bridge from ancient times, having once featured an estimated overall length of 755 m with 62 spans. Today, there are 60 spans on a length of 721 m between the abutments...
at
MéridaMérida is the capital of the autonomous community of Extremadura, western central Spain. It has a population of 57,127 . The Archaeological Ensemble of Mérida is a UNESCO World Heritage site since 1993.- Climate :...
. The late Roman
Karamagara BridgeThe Karamagara Bridge is a late Roman bridge in the ancient region of Cappadocia in eastern Turkey, and possibly the earliest known pointed arch bridge.- Location and situation:...
in
CappadociaCappadocia is a historical region in Central Anatolia, largely in Nevşehir Province.In the time of Herodotus, the Cappadocians were reported as occupying the whole region from Mount Taurus to the vicinity of the Euxine...
may represent the earliest surviving bridge featuring a pointed arch.
In medieval Europe, bridge builders improved on the Roman structures by using narrower
piersIn architecture, a pier is an upright support for a superstructure, such as an arch or bridge. Sections of wall between openings function as piers. The simplest cross section of the pier is square, or rectangular, although other shapes are also common, such as the richly articulated piers of Donato...
, thinner arch barrels and lower span-rise ratios on bridges.
GothicGothic architecture is a style of architecture that flourished during the high and late medieval period. It evolved from Romanesque architecture and was succeeded by Renaissance architecture....
pointed arches were also introduced, reducing lateral thrust, and spans increased as with the eccentric
Puente del DiabloThe Pont del Diable is a medieval bridge crossing the river Llobregat in Martorell-Castellbisbal, Catalonia, Spain. The present bridge, featuring a large pointed arch, was constructed in 1283 on Roman foundations. The main clear span is an impressive 37.3 m with a stone chapel on top. A...
(1282).
The 14th century in particular saw bridge building reaching new heights. Span lengthes of 40 m, previously unheard of in the history of masonry arch construction, were now reached in places as diverse as Spain (
Puente de San MartínThe Puente de San Martín is a medieval bridge across the river Tagus in Toledo, Spain. The bridge was constructed in the late 14th century by archbishop Pedro Tenorio to provide access to the old town from the west, complementing the older Puente de Alcántara linking to the east...
), Italy (
Castelvecchio BridgeThe Castelvecchio Bridge or Scaliger Bridge is a fortified bridge in Verona, northern Italy, over the Adige River...
) and France (
Devil's bridgeThe Pont du Diable or Pont Vieux is a medieval stone arch bridge at Céret, France, built between 1321 and 1341. Spanning the river Tech with an imposing single arch of 45.45 m span length, the Pont du Diable featured at the time of its construction the world's largest bridge arch.The apex of the...
and
Pont GrandThe Pont Grand is a stone bridge connecting Tournon-sur-Rhône to Saint-Jean-de-Muzols, in Ardèche, France, built between 1379 and 1583. The bridge features a single, semi-circular arch over the river Doux with a span of 49.20 m...
) and with arch types as different as semi-circular, pointed and segmental arches. The
bridge at Trezzo sull'AddaThe Trezzo sull'Adda Bridge or Trezzo Bridge was a medieval bridge at Trezzo sull'Adda in Lombardy, Italy, spanning the Adda river. Completed in 1377, the single arch bridge held the record for the largest span for over four hundred years, until the beginnings of the Industrial Age, while it was...
, destroyed in the 15th century, even featured a span length of 72 m, not matched until 1796.
Constructions such as the acclaimed
FlorentineFlorence is the capital city of the Italian region of Tuscany and of the province of Florence. It is the most populous city in Tuscany, with approximately 370,000 inhabitants, expanding to over 1.5 million in the metropolitan area....
segmental arch bridge
Ponte VecchioThe Ponte Vecchio is a Medieval stone closed-spandrel segmental arch bridge over the Arno River, in Florence, Italy, noted for still having shops built along it, as was once common. Butchers initially occupied the shops; the present tenants are jewellers, art dealers and souvenir sellers...
(1345) combined sound engineering (span-to-rise ratio of over 5.3 to 1) with aesthetical appeal. The three elegant arches of the
RenaissanceThe Renaissance was a cultural movement that spanned roughly the 14th to the 17th century, beginning in Italy in the Late Middle Ages and later spreading to the rest of Europe. The term is also used more loosely to refer to the historical era, but since the changes of the Renaissance were not...
Ponte Santa TrinitaThe Ponte Santa Trìnita is a Renaissance bridge in Florence, Italy, spanning the Arno. The Ponte Santa Trìnita is the oldest elliptic arch bridge in the world, the three flattened ellipses giving the structure its celebrated elegant appearance...
(1569) constitute the oldest elliptic arch bridge worldwide. Such low rising structures required massive
abutmentAn abutment is, generally, the point where two structures or objects meet. This word comes from the verb abut, which means adjoin or having common boundary. An abutment is an engineering term that describes a structure located at the ends of a bridge, where the bridge slab adjoins the approaching...
s, which at the
VenetianVenice is a city in northern Italy which is renowned for the beauty of its setting, its architecture and its artworks. It is the capital of the Veneto region...
Rialto bridgeThe Rialto Bridge is one of the four bridges spanning the Grand Canal in Venice, Italy. It is the oldest bridge across the canal, and was the dividing line for the districts of San Marco and San Polo.- History :...
and the
FleischbrückeThe Fleisch Bridge or Pegnitz Bridge is a late Renaissance bridge in Nuremberg, Germany. The bridge crosses the river Pegnitz in the center of the old town, linking the districts St. Sebald and St. Lorenz along the axis of the main market...
in
NurembergNuremberg[p] is a city in the German state of Bavaria, in the administrative region of Middle Franconia. Situated on the Pegnitz river and the Rhine–Main–Danube Canal, it is located about north of Munich and is Franconia's largest city. The population is 505,664...
(span-to-rise ratio 6.4:1) were founded on thousands of wooden piles, partly rammed obliquely into the grounds to counteract more effectively the lateral thrust.
In China, the oldest existing arch bridge is the
Zhaozhou BridgeThe Anji Bridge is the world's oldest open-spandrel stone segmental arch bridge. Credited to the design of a craftsman named Li Chun, the bridge was constructed in the years 595-605 during the Sui Dynasty...
of
605Year 605 was a common year starting on Friday of the Julian calendar. The denomination 605 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.- Asia :* As a result of a quarrel between Numan III,...
AD, which combined a very low span-to-rise ratio of 5.2:1, with the use of spandrel arches (buttressed with iron brackets). The Zhaozhou Bridge, with a length of 167 feet (50.9 m) and span of 123 feet (37.5 m), is the world's first wholly stone open-spandrel segmental arch bridge, allowing a greater passage for flood waters.
In more modern times, stone and brick arches continued to be built by many civil engineers, including
Thomas TelfordThomas Telford FRS, FRSE was a Scottish civil engineer, architect and stonemason, and a noted road, bridge and canal builder.-Early career:...
,
Isambard Kingdom BrunelIsambard Kingdom Brunel, FRS , was a British civil engineer who built bridges and dockyards including the construction of the first major British railway, the Great Western Railway; a series of steamships, including the first propeller-driven transatlantic steamship; and numerous important bridges...
and
John RennieJohn Rennie was a Scottish civil engineer who designed many bridges, canals, and docks.-Early years:Rennie, a farmer's younger son, was born at Phantassie, near East Linton, East Lothian, Scotland, and showed a taste for mechanics at a very early age, and was allowed to spend much time in the...
. A key pioneer was
Jean-Rodolphe PerronetJean-Rodolphe Perronet 27 October 1708, Suresnes – 27 February 1794, Paris) was a French architect and structural engineer, known for his many stone arch bridges. His best known work is the Pont de la Concorde .-Life and career:...
, who used much narrower piers, revised calculation methods and exceptionally low span-to-rise ratios. Different materials, such as
cast ironCast iron is derived from pig iron, and while it usually refers to gray iron, it also identifies a large group of ferrous alloys which solidify with a eutectic. The color of a fractured surface can be used to identify an alloy. White cast iron is named after its white surface when fractured, due...
,
steelSteel is an alloy that consists mostly of iron and has a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most common alloying material for iron, but various other alloying elements are used, such as manganese, chromium, vanadium, and tungsten...
and
concreteConcrete is a composite construction material, composed of cement and other cementitious materials such as fly ash and slag cement, aggregate , water and chemical admixtures.The word concrete comes from the Latin word...
have been increasingly used in the construction of arch bridges.
Simple compression arch bridges
Advantages of simple materials
Stone, brick and other such materials are strong in compression and somewhat so in
shearShearing in continuum mechanics refers to the occurrence of a shear strain, which is a deformation of a material substance in which parallel internal surfaces slide past one another. It is induced by a shear stress in the material...
, but cannot resist much force in
tensionIn physics, tension is the magnitude of the pulling force exerted by a string, cable, chain, or similar object on another object. It is the opposite of compression. As tension is the magnitude of a force, it is measured in newtons and is always measured parallel to the string on which it applies...
. As a result, masonry arch bridges are designed to be constantly under compression, so far as is possible. Each arch is constructed over a temporary
falseworkFalsework consists of temporary structures used in construction to support spanning or arched structures in order to hold the component in place until its construction is sufficiently advanced to support itself...
frame, known as a
centringCentring , or centering , is the structure upon which the stones of arches or vault are laid during construction. Once the arch is complete, it supports itself, but until the keystone is inserted, it has no strength and needs the centring to keep the voussoirs in their correct relative...
. In the first compression arch bridges, a
keystoneA keystone is the wedge-shaped stone piece at the apex of a masonry vault or arch, which is the final piece placed during construction and locks all the stones into position, allowing the arch to bear weight. This makes a keystone very important structurally...
in the middle of the bridge bore the weight of the rest of the bridge. The more weight that was put onto the bridge, the stronger its structure became. Masonry arch bridges use a quantity of fill material (typically compacted rubble) above the arch in order to increase this dead-weight on the bridge and prevent tension from occurring in the arch ring as loads move across the bridge. Other materials that were used to build this type of bridge were brick and unreinforced concrete. When masonry (cut stone) is used the angles of the faces are cut to minimize shear forces. Where random masonry (uncut and unprepared stones) is used they are mortared together and the mortar is allowed to set before the falsework is removed.
Traditional masonry arches are generally durable, and somewhat resistant to settlement or undermining. However, relative to modern alternatives, such bridges are very heavy, requiring extensive
foundationsA foundation is the lowest and supporting layer of a structure. Foundations are generally divided into two categories: shallow foundations and deep foundations.-Shallow foundations:...
. They are also expensive to build wherever labor costs are high.
Construction sequence
- Where the arches are founded in a stream bed the water is diverted and the gravels excavated to a good footing. From this the foundation piers
In architecture, a pier is an upright support for a superstructure, such as an arch or bridge. Sections of wall between openings function as piers. The simplest cross section of the pier is square, or rectangular, although other shapes are also common, such as the richly articulated piers of Donato...
are raised to the base of the arches, a point known as the springing.
- Falsework centering is fabricated, typically from timbers and boards. Since each arch of a multi-arch bridge will impose a thrust upon its neighbors, it is necessary either that all arches of the bridge be raised at the same time, or that very wide piers are used. The thrust from the end arches is taken into the earth by footings at the canyon walls, or by large inclined planes forming ramps to the bridge, which may also be formed of arches.
- The several arches are constructed over the centering. Once the basic arch barrel is constructed, the arches are stabilized with infill masonry between the arches, which may be laid in horizontal running bond courses. These may form two walls, known as the spandrels, which are then infilled with loose material and rubble.
- The road is paved and parapet
A parapet is a wall-like barrier at the edge of a roof, terrace, balcony or other structure. Where extending above a roof, it may simply be the portion of an exterior wall that continues above the line of the roof surface, or may be a continuation of a vertical feature beneath the roof such as a...
walls protectively confine traffic to the bridge.
Corbel arch bridge
The corbel arch bridge is a masonry, or stone, bridge where each successively higher course (layer) cantilevers slightly more than the previous course. The steps of the masonry may be trimmed to make the arch have a rounded shape. The
corbel archA corbel arch is an arch-like construction method that uses the architectural technique of corbeling to span a space or void in a structure, such as an entranceway in a wall or as the span of a bridge...
does not produce thrust, or outward pressure at the bottom of the arch, and is not considered a true arch. It is more stable than a true arch because it does not have this thrust. The disadvantage is that this type of arch is not suitable for large spans.
Aqueducts and canal viaducts
- In some locations it is necessary to span a wide gap at a relatively high elevation, such as when a canal or water supply must span a valley. Rather than building extremely large arches, or very tall supporting columns (difficult using stone), a series of arched structures are built one atop another, with wider structures at the base. Roman civil engineers
Civil engineering is a professional engineering discipline that deals with the design, construction, and maintenance of the physical and naturally built environment, including works like roads, bridges, canals, dams, and buildings...
developed the design and constructed highly refined structures using only simple materials, equipment, and mathematics. This type is still used in canal viaducts and roadways as it has a pleasing shape, particularly when spanning water, as the reflections of the arches form a visual impression of circles or ellipses.
Deck arch bridge
This type of bridge comprises an arch where the deck is completely above the arch. The area between the arch and the deck is known as the
spandrelA spandrel, less often spandril or splaundrel, is the space between two arches or between an arch and a rectangular enclosure....
. If the spandrel is solid, usually the case in a masonry or stone arch bridge, it is call a closed-spandrel arch bridge. If the deck is supported by a number of vertical columns rising from the arch, it is known as an open-spandrel arch bridge. The
Alexander Hamilton BridgeThe Alexander Hamilton Bridge carries eight lanes of traffic over the Harlem River in New York City between the boroughs of Manhattan and the Bronx, connecting the Trans-Manhattan Expressway in the Washington Heights section of Manhattan and the Cross-Bronx Expressway, as part of Interstate 95...
is an example of an open-spandrel arch bridge.
Through arch bridge
This type of bridge comprises an
archAn arch is a structure that spans a space and supports a load. Arches appeared as early as the 2nd millennium BC in Mesopotamian brick architecture and their systematic use started with the Ancient Romans who were the first to apply the technique to a wide range of structures.-Technical aspects:The...
which supports the deck by means of suspension cables or tie bars. The
Sydney Harbour BridgeThe Sydney Harbour Bridge is a steel through arch bridge across Sydney Harbour that carries rail, vehicular, bicycle and pedestrian traffic between the Sydney central business district and the North Shore. The dramatic view of the bridge, the harbour, and the nearby Sydney Opera House is an iconic...
is a through arch bridge which uses a truss type arch.
These through arch bridges are in contrast to suspension bridges which use the
catenaryIn physics and geometry, the catenary is the curve that an idealised hanging chain or cable assumes when supported at its ends and acted on only by its own weight. The curve is the graph of the hyperbolic cosine function, and has a U-like shape, superficially similar in appearance to a parabola...
in tension to which the aforementioned cables or tie bars are attached and suspended.
Tied arch bridge
Also known as a bowstring arch, this type of arch bridge incorporates a tie between two opposite ends of the arch. The tie is capable of withstanding the horizontal thrust forces which would normally be exerted on the abutments of an arch bridge.
Use of modern materials
Most modern arch bridges are made from
reinforced concreteReinforced concrete is concrete in which reinforcement bars , reinforcement grids, plates or fibers have been incorporated to strengthen the concrete in tension. It was invented by French gardener Joseph Monier in 1849 and patented in 1867. The term Ferro Concrete refers only to concrete that is...
. This type of bridge is suitable where a temporary centring may be erected to support the forms, reinforcing steel, and uncured concrete. When the concrete is sufficiently set the forms and falseworks are then removed. It is also possible to construct a reinforced concrete arch from
precast concreteBy producing precast concrete in a controlled environment , the precast concrete is afforded the opportunity to properly cure and be closely monitored by plant employees. Utilizing a Precast Concrete system offers many potential advantages over site casting of concrete...
, where the arch is built in two halves which are then leaned against each other.
Many modern bridges, made of steel or reinforced concrete, often bear some of their load by tension within their structure. This reduces or eliminates the horizontal thrust against the abutments and allows their construction on weaker ground. Structurally and analytically they are not true arches but rather a
beamA beam is a horizontal structural element that is capable of withstanding load primarily by resisting bending. The bending force induced into the material of the beam as a result of the external loads, own weight, span and external reactions to these loads is called a bending moment.- Overview...
with the shape of an arch. See
truss arch bridgeA truss arch bridge combines the elements of the truss bridge and the arch bridge. The actual resolution of forces will depend upon the design. If no horizontal thrusting forces are generated this becomes an arch-shaped truss, essentially a bent beam — see moon bridge for an example...
for more on this type.
A modern evolution of the arch bridge is the long-span through arch bridge. This has been made possible by the use of light materials that are strong in tension such as steel and prestressed concrete.
See also
- Deck (bridge)
A bridge deck or road bed is the roadway, or the pedestrian walkway, surface of a bridge. It is not to be confused with any deck of a ship.The deck may be of concrete,wood which in turn may be covered with asphalt concrete or other pavement...
- List of arch bridges by length
- List of longest masonry arch bridge spans
- Roman bridge
Roman bridges, built by ancient Romans, were the first large and lasting bridges built. Roman bridges were built with stone and had the arch as its basic structure....
- Skew arch
A skew arch is a method of construction that enables an arch bridge to span an obstacle at some angle other than a right angle. This results in the faces of the arch not being perpendicular to its abutments and its plan view being a parallelogram, rather than the rectangle that is the plan view of...
- Through arch bridge
- Tied arch bridge
A tied-arch bridge is an arch bridge in which the outward-directed horizontal forces of the arch, or top chord, are borne as tension by the bottom chord , rather than by the ground or the bridge foundations...
- Truss arch bridge
A truss arch bridge combines the elements of the truss bridge and the arch bridge. The actual resolution of forces will depend upon the design. If no horizontal thrusting forces are generated this becomes an arch-shaped truss, essentially a bent beam — see moon bridge for an example...
External links