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57-541: The Welsh Bridge is a masonry arch viaduct in the town of Shrewsbury , England , which crosses the River Severn . It connects Frankwell with the town centre. It is a Grade II* listed building. The bridge was designed and built from 1793 to 1795 by John Tilley and John Carline (whose namesake father was a mason on the English Bridge ), who had built Montford Bridge for Thomas Telford . It replaced

114-401: A composite manner of brick , stonemasonry , and rubble . The bricks of the segmental arches are made of yellow-red clay, mixed with fine brick fragments. The bricks are rectangular plates, measuring ca. 40 cm × 50 cm (15.7 in × 19.7 in) and 5 cm (2.0 in) thick. They are placed with the shorter side upright facing outwards, so that the total thickness of

171-512: A deck arch bridge. Any part supported from arch below may have spandrels that are closed or open. The Sydney Harbour Bridge and the Bayonne Bridge are a through arch bridge which uses a truss type arch. Also known as a bowstring arch, this type of arch bridge incorporates a tie between two opposite ends of the arch. The tie is usually the deck and is capable of withstanding the horizontal thrust forces which would normally be exerted on

228-609: A length of 167 feet (51 m) and span of 123 feet (37 m), is the world's first wholly stone open-spandrel segmental arch bridge, allowing a greater passage for flood waters. Bridges with perforated spandrels can be found worldwide, such as in China ( Zhaozhou Bridge , 7th century). Greece ( Bridge of Arta , 17th century) and Wales ( Cenarth Bridge , 18th century). In more modern times, stone and brick arches continued to be built by many civil engineers, including Thomas Telford , Isambard Kingdom Brunel and John Rennie . A key pioneer

285-448: 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)

342-415: A result, masonry arch bridges are designed to be constantly under compression, so far as is possible. Each arch is constructed over a temporary falsework frame, known as a centring . In the first compression arch bridges, a keystone 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

399-454: 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 countries (including former Yugoslavia ). Roman arch bridges were usually semicircular , although a number were segmental arch bridges (such as Alconétar Bridge ), a bridge which has a curved arch that

456-430: A three-hinged bridge has hinged in all three locations. Most modern arch bridges are made from reinforced concrete . 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 concrete , where

513-613: A triangular corbel arch. The 4th century BC Rhodes Footbridge rests on an early voussoir arch. Although true arches were already known by the Etruscans and ancient Greeks , the Romans were – as with the vault and the dome – the first to fully realize the potential of arches for bridge construction. A list of Roman bridges compiled by the engineer Colin O'Connor features 330 Roman stone bridges for traffic, 34 Roman timber bridges and 54 Roman aqueduct bridges ,

570-428: 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 arch 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

627-573: Is further corroborated by the fact that no wagon ruts are evident on the paving of the Limyra bridge, nor any traces of a parapet or breastwork. With a length of 360 m (1,181.1 ft), the Limyra Bridge qualifies as the largest surviving engineering achievement of antiquity in Lycia. The bridge stands on 26 uniform segmental arches consisting of a double, radially laid course of bricks. At

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684-452: Is less than a semicircle. The advantages of the segmental 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 ( voussoirs ) of the same in size and shape. The Romans built both single spans and lengthy multiple arch aqueducts , such as

741-451: Is located only 30–40 cm (11.8–15.7 in) over the arches' apex, is 3.55–3.70 m (11.6–12.1 ft) wide, increasing towards either end at 4.30 m (14.1 ft) and projects ca. 10 cm (3.9 in) over the superstructure on either side. It is paved with large and irregular limestone cobblestones , although smaller pebbles have been used in the repairs at the two semicircular arches. The exact chronological placement of

798-403: Is no indication of a later sinking of the structure, this nearly uniform height indicates careful levelling and the existence of solid pier foundations. In contrast, the lengthwise axis of the bridge displays often significant deviations from arch to arch. Remarkably, the support line of the structure's dead load is almost identical with the curve of the vault arch. The statical analysis of

855-432: Is that this type of arch is not suitable for large spans. 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 developed

912-402: 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 foundations . They are also expensive to build wherever labor costs are high. The corbel arch bridge

969-610: The Alcántara Bridge . The Romans also introduced segmental arch bridges into bridge construction. The 330 m-long (1,080 ft) Limyra Bridge in southwestern Turkey 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 bridge over the Danube featured open- spandrel segmental arches made of wood (standing on 40 m-high (130 ft) concrete piers). This

1026-683: The Pont du Gard and Segovia Aqueduct . Their bridges featured from an early time onwards flood openings in the piers, e.g. in the Pons Fabricius in Rome (62 BC), one of the world's oldest major bridges still standing. Roman engineers were the first and until the Industrial Revolution the only ones to construct bridges with concrete , which they called Opus caementicium . The outside was usually covered with brick or ashlar , as in

1083-703: The Venetian Rialto bridge and the Fleischbrücke in Nuremberg (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 Bridge of 605 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

1140-565: The 15th century, even featured a span length of 72 m (236 ft), not matched until 1796. Constructions such as the acclaimed Florentine segmental arch bridge Ponte Vecchio (1345) combined sound engineering (span-to-rise ratio of over 5.3 to 1) with aesthetical appeal. The three elegant arches of the Renaissance Ponte Santa Trinita (1569) constitute the oldest elliptic arch bridge worldwide. Such low rising structures required massive abutments , which at

1197-741: The 1970s did researchers from the Istanbul branch of the German Archaeological Institute carry out field examinations on the site. No information on the bridge survives from ancient sources. The first descriptions appear in European travellers' accounts from the 19th century. The British archaeologist Charles Fellows was the first to explore the region of Lycia, and visited the bridge in May ;1840. Fellows, as well as T.A.B. Spratt and Edward Forbes, who visited

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1254-524: The 3rd-century AD aqueduct of Aspendos , and the Romans certainly knew how to build segmented-arched bridges, as attested by surviving examples, three of which are listed by Wurster and Ganzert themselves. An earlier construction date in the 2nd or 3rd centuries AD cannot therefore be excluded. The case for an earlier construction date has been strengthened in recent years with the discovery of further seven Roman segmented arch bridges. The remnants of

1311-542: The Alakır Çayı and into the neighbouring region of Pamphylia and Attaleia, must have been of special importance, since the two regions were united in a single province, Lycia et Pamphylia , until the 4th century. In comparison to the main arterial roads of the Roman Empire however, the roads of Lycia were, with 3–4 m (9.8–13.1 ft) width, rather modest and confined to pedestrian and pack animal traffic. This

1368-438: The Alakır Çayı river over a length of 360 m (1,181.1 ft) on 26 segmental arches. These arches, with a span-to-rise ratio of 5.3:1, give the bridge an unusually flat profile, and were unsurpassed as an architectural achievement until the late Middle Ages . Today, the structure is largely buried by river sediments and surrounded by greenhouses . Despite its unique features, the bridge remains relatively unknown, and only in

1425-534: The Limyra bridge is difficult due to its unique place within Roman engineering tradition and the lack of comparable structures. Wurster and Ganzert used following characteristics as a starting point: In contrast to these, most Roman stone bridges were faced with ashlar and rested on voussoir arches, a method which is dominant in other vaulted structures in Lycia too. Compared to the massive and tall semicircular-arched bridges that are typical of Roman architecture ,

1482-408: The Limyra bridge, with its flat segmented arches, offers a markedly lower and more elongated appearance, so that Wurster and Ganzert offer a "provisional" late dating, approximately during the reign of emperor Justinian I in the 6th century, during which the use of mixed brick and stone is attested in other structures of the region. On the other hand, this mixed technique is already present in

1539-436: The abutments of an arch bridge. The deck is suspended from the arch. The arch is in compression, in contrast to a suspension bridge where the catenary is in tension. A tied-arch bridge can also be a through arch bridge. An arch bridge with hinges incorporated to allow movement between structural elements. A single-hinged bridge has a hinge at the crown of the arch , a two-hinged bridge has hinges at both springing points and

1596-416: The arch and the deck is known as the spandrel . If the spandrel is solid, usually the case in a masonry or stone arch bridge, the bridge is called a closed-spandrel deck arch bridge . If the deck is supported by a number of vertical columns rising from the arch, the bridge is known as an open-spandrel deck arch bridge . The Alexander Hamilton Bridge is an example of an open-spandrel arch bridge. Finally, if

1653-400: 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 beam with

1710-422: The arch supports the deck only at the top of the arch, the bridge is called a cathedral arch bridge . This type of bridge has an arch whose base is at or below the deck, but whose top rises above it, so the deck passes through the arch. The central part of the deck is supported by the arch via suspension cables or tie bars, as with a tied-arch bridge . The ends of the bridge may be supported from below, as with

1767-409: The arches measures ca. 80 cm . The bricks are bound with grout of lime mortar mixed with brick shards and fine gravel, forming 4 cm (1.6 in)-thick joints . The two later semi-circular arches were built with smaller bricks, although surviving bricks from the original arch were re-used at places. The abutment stones are dressed limestone ashlar blocks, and form a sloping surface to support

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1824-399: The arches' abutments and the pavement surface could be determined at only 3.25 m (10.7 ft). The surface level is almost horizontal: the roadway lies at a height of 20.05–20.55 m (65.8–67.4 ft) above sea level between arches 1 to 20, and falls slightly in its eastern section, between arches 21 and 26 to a level of 19.94 to 19.66 m (65.4 to 64.5 ft). Since there

1881-426: The arches. The double-layer technique facilitated a more effective use of the falsework, since they could be removed and used elsewhere as soon as the lower course was finished: The construction of the two layers of the double brick-arches in two separate phases had two advantages. In the first phase, the falsework only had to carry the weight of the lower course, so that it could itself be of lighter construction. In

1938-430: The breadth of a pier: 2.10 m (6.9 ft). Subtracting this value from the common arch span of 12.75 m (41.8 ft), a clear span of 10.65 m (34.9 ft) remains. Since all arches have a rise of ca. 2 m (6.6 ft), the Limyra Bridge has an unusually large span-to-rise ratio of 5.3 to 1 . Such flattened arches were very rare at the time for stone bridges, and were not matched and surpassed until

1995-408: The bridge proves the structure's great load capacity: In modern classification, the bridge would be able to support loads of a Class 30 bridge (per DIN 1072 ); this would mean, that it could support a 30- tonne vehicle on one arch and additionally on the remaining surface of the arch a load of 500  kp/m² . The bridge was thus very safe for ancient traffic. The Limyra bridge was built in

2052-414: 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. This type of bridge comprises an arch where the deck is completely above the arch. The area between

2109-406: The eastern end, the original 27th arch has been replaced by two smaller, semicircular arches of later construction. The latter are built with a single course of bricks. Traces of the original, flat beginning of the collapsed arch are still visible on the piers. At the time of Wurster's and Ganzert's visit to the site, the entire bridge was buried by river sediments up to the springing line of

2166-503: The eccentric Puente del Diablo (1282). The 14th century in particular saw bridge building reaching new heights. Span lengths of 40 m (130 ft), previously unheard of in the history of masonry arch construction, were now reached in places as diverse as Spain ( Puente de San Martín ), Italy ( Castelvecchio Bridge ) and France ( Devil's bridge and Pont Grand ) and with arch types as different as semi-circular, pointed and segmental arches. The bridge at Trezzo sull'Adda , destroyed in

2223-495: The facing consists of ashlar blocks. The two repaired arches 27a and 27b are differentiated from the earlier work through the use of smaller unworked stones and the incorporation of irregularly placed brick tiles. In arch 26, the lower side of the arch still features a projecting bearing used for the placement of the falsework. The interior of the superstructure consists of a combination of unworked masonry blocks and large river boulders, bound with lime mortar. The bridge surface

2280-440: The medieval St George's Bridge . Four of the arches span 43 feet 4 inches, while the fifth and central arch is 46 feet 2 inches. The bridge is 30 feet wide, and built from Grinshill sandstone. In total it is 266 feet long. It was completed in 1795 at a cost of £8,000. On the south end of the bridge, on the junction with Victoria Avenue, one of the parapets of the bridge has the words "Commit No Nuisance" chiselled into

2337-407: The nearby Kemer Bridge over the river Xanthos , which dates to the 3rd century and has some architectural similarities with the Limyra bridge, could further reinforce that case. Wurster and Ganzert describe the remarkable bridge near Limyra… The outstanding feature of the bridge is that the arches are segmental… It is believed that the bridge is Roman . If this is the case, then it is one of

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2394-452: The point where the narrow river valley opens into the wide estuary plain, and where the crossing of the river during the rain period would be obstructed by high water. While the eastern end of the bridge levels off at the gravel plain, the western end abuts directly to the rising rock wall of the mountain, presumably for protection against floods. The resulting sharp bend in the course of the road could also be exploited in case of need to block

2451-419: The reappearance of segmental arch bridges in 14th century Italy . For the largest arch in the Limyra Bridge, the ratio is even greater, spanning a width 6.4 times its height. The two later arches, in contrast, are, with a ratio of 2.7:1, quite ordinary semi-circular arches. The total height of the bridge could not be determined because most of the structure is silted up. However, the distance between

2508-419: The road. A modern dam, Alakır Barajı, was constructed upstream for irrigation purposes and flood protection. Lycia did not, in contrast to other Roman provinces , possess a very developed road system. While the north–south traffic was conducted primarily through the few river valleys, the east–west routes led, unlike today, mostly on and along the mountain ridges. This particular road, leading from Limyra over

2565-505: The ruins of Limyra (distance measured from the city's theatre) and 3.8 km (2.4 mi) north of the modern coastline, close to the modern road from Turunçova to Kumluca . The local topography is dominated by the foothills of the Toçak Dağı mountains, which blend here with the alluvial bottomlands of the Bay of Finike . In this transitional area, the bridge was built immediately above

2622-430: The second phase, the weight of the upper layer could be already borne by the lower vault; the falsework was thus already available for use in a different arch. As far as can be determined, between arches 2 to 21, the outer facing of the superstructure consists of four layers of brick, followed by layers of rough stonemasonry bound with mortar. In contrast, between arches 22 and 26, as well as in both ramps on either end,

2679-455: The shape of an arch. See truss arch bridge 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. "The Romans were the first builders in Europe, perhaps the first in the world, fully to appreciate the advantages of the arch,

2736-401: The site two years later, describe it as having 25 arches. In 1882, an Austrian expedition, including Otto Benndorf , interpreted the structure as part of an ancient road that connected Limyra with the city of Attaleia (modern Antalya ) to the east. However, this mission failed to produce any plans or sketches of the site. The first, and as of 2008 only scientific examination of the bridge

2793-481: The size of the spans, one can distinguish four groups, with the following median values: The reason for this grouping is unclear; they certainly cannot be attributed to an attempt to match the lay of the river bed. The differences however could point to the repeated use of differently-sized falsework structures in the construction of the barrel vaults (see animation below). Only in a single case, between arches 26 and 27, were Wurster and Ganzert able to determine

2850-405: The spotlight: Recently, citrus fruit plantations were created in this fertile bottomland; greenhouses for early vegetables are now being built east of the bridge. The bridge is greatly endangered through the beginning of intensive cultivation in the vicinity. The locals strip the still intact bridge surface for stones; bulldozers employed to build irrigation canals rip the structure apart and crush

2907-413: The stone pavement with their caterpillar tracks . In 1993, the civil engineer Colin O'Connor summarized their report in his English-language monograph on Roman bridges, and also emphasized the exceptional character of this bridge. No further scientific examinations of the Limyra Bridge are known. The bridge crosses the Alakır Çayı stream, whose ancient name is unknown, 3.2 km (2.0 mi) east of

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2964-566: The stone. This is an archaic injunction not to urinate in public. 52°42′36″N 2°45′28″W  /  52.71000°N 2.75778°W  / 52.71000; -2.75778 Arch bridge Possibly the oldest existing arch bridge is the Mycenaean Arkadiko Bridge in Greece from about 1300 BC. The stone corbel arch bridge is still used by the local populace. The well-preserved Hellenistic Eleutherna Bridge has

3021-566: The vault and the dome." Limyra Bridge The Bridge near Limyra (in Turkish : Kırkgöz Kemeri , "Bridge of the Forty Arches") is a late Roman bridge in Lycia , in modern south-west Turkey , and one of the oldest segmented arch bridges in the world. Located near the ancient city of Limyra , it is the largest civil engineering structure of antiquity in the region, spanning

3078-459: The vaults. No efforts to dig them up were undertaken by Wurster and Ganzert. Only two of the 28 arches were exposed enough so that direct measurements of the clear span and the pier width could be undertaken. It was, however, possible to calculate the dimensions of the remaining bays from their exposed sections. The spans of the arches ranged from 11.60 m (38.1 ft) to 14.97 m (49.1 ft) (arches 2 and 26 respectively). Based on

3135-402: Was Jean-Rodolphe Perronet , who used much narrower piers, revised calculation methods and exceptionally low span-to-rise ratios. Different materials, such as cast iron , steel and concrete have been increasingly used in the construction of arch bridges. Stone, brick and other such materials are strong in compression and somewhat so in shear , but cannot resist much force in tension . As

3192-713: 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 (2,590 ft) long Puente Romano at Mérida . The late Roman Karamagara Bridge in Cappadocia may represent the earliest surviving bridge featuring a pointed arch. In medieval Europe, bridge builders improved on the Roman structures by using narrower piers , thinner arch barrels and higher span-to-rise ratios on bridges. Gothic pointed arches were also introduced, reducing lateral thrust, and spans increased as with

3249-602: Was undertaken by the German archaeologists Wolfgang W. Wurster and Joachim Ganzert in two successive days in September ;1973, and completed through further visits in subsequent years. Their findings were published in 1978 in the Archäologischer Anzeiger journal of the German Archaeological Institute , with the express intent of bringing the imperiled state of the hitherto almost intact bridge into

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