An arch is a curved vertical structure spanning an open space underneath it. Arches may support the load above them, or they may perform a purely decorative role. As a decorative element, the arch dates back to the 4th millennium BC, but structural load-bearing arches became popular only after their adoption by the Ancient Romans in the 4th century BC.
The ancient Romans were the first civilization to build large, permanent bridges. Early Roman bridges used techniques introduced by Etruscan immigrants, but the Romans improved those skills, developing and enhancing methods such as arches and keystones. There were three major types of Roman bridge: wooden, pontoon, and stone. Early Roman bridges were wooden, but by the 2nd century stone was being used. Stone bridges used the arch as their basic structure, and most used concrete, the first use of this material in bridge-building.
Beam bridges are the simplest structural forms for bridge spans supported by an abutment or pier at each end. No moments are transferred throughout the support, hence their structural type is known as simply supported.
The Anji Bridge is the world's oldest open-spandrel segmental arch bridge of stone construction. Credited to the design of a craftsman named Li Chun, the bridge was constructed in the years 595–605 during the Sui dynasty (581–618). Located in the southern part of Hebei Province, it is the oldest standing bridge in China. It is considered one of the Four Treasures of Hebei.
The Francis Scott Key Bridge, more commonly known as the Key Bridge, is a six-lane reinforced concrete arch bridge carrying U.S. Route 29 (US 29) across the Potomac River between the Rosslyn neighborhood of Arlington County, Virginia, and the Georgetown neighborhood of Washington, D.C. Completed in 1923, it is Washington's oldest surviving road bridge across the Potomac River.
The fourth Berkley–Dighton Bridge is a four-span concrete arch bridge with closed spandrel walls of cast-in-place concrete, using pile-supported abutments and piers. The bridge was made such that it appears to be constructed of stone masonry rather than concrete. The two end spans are 74 feet (23 m) and the two center spans are 92 feet (28 m) for a total bridge length of approximately 350 feet (110 m).
A tied-arch bridge is an arch bridge in which the outward-directed horizontal forces of the arch(es) are borne as tension by a chord tying the arch ends rather than by the ground or the bridge foundations. This strengthened chord may be the deck structure itself or consist of separate, independent tie-rods.
The Store Street Aqueduct in central Manchester, England, was built in 1798 by Benjamin Outram on the Ashton Canal. A Grade II* listed building, it is built on a skew of 40° across Store Street, and is believed to be the first major aqueduct of its kind in Great Britain and the oldest still in use today.
The 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. Due to its design, it is assumed that the bridge was erected in the early 2nd century AD by the emperors Trajan or Hadrian, possibly under the guidance of Apollodorus of Damascus, the most famous architect of the time.
The Alcántara Bridge 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 over the Tagus River between 104 and 106 AD by an order of the Roman emperor Trajan in 98.
The Ponte San Lorenzo is a Roman bridge over the river Bacchiglione in Padua, Italy. Constructed between 47 and 30 BC, it is one of the very earliest segmental arched bridges in the world. It is also notable for the slenderness of its piers, unsurpassed in antiquity.
The Eurymedon Bridge was a late Roman bridge over the river Eurymedon, near Aspendos, in Pamphylia in southern Anatolia. The foundations and other stone blocks (spolia) of the Roman structure were used by the Seljuqs to build a replacement bridge in the 13th century, the Köprüpazar Köprüsü, which stands to this day. This bridge is characterized by a significant displacement along its mid-line, noticeable by looking at its ancient piers.
The Bridge near Limyra 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 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 the 1970s did researchers from the Istanbul branch of the German Archaeological Institute carry out field examinations on the site.
The Macestus Bridge or Bridge of Sultançayır was a Roman bridge across the Macestus River at Balıkesir, in the northwestern part of modern-day Turkey. Its flattened arches, slender piers and the hollow chamber system documented the progress made in late antique bridge building. A first cursory investigation of the 234 m long structure was conducted in the early 20th century, but since then its existence has been largely neglected by scholars. Current photos from 2009 show that the bridge has collapsed in the meantime.
The Karamagara Bridge is a Byzantine or late Roman bridge in the ancient region of Cappadocia in eastern Turkey, and possibly the earliest known pointed arch bridge.
The Ponte Corvo, rarely Ponte Corbo, is a Roman segmental arch bridge across the Bacchiglione in Padua, Italy. Dating to the 1st or 2nd century AD, its three remaining arches cross a branch of the river and are today partly buried respectively walled up. The span-to-rise ratio of the bridge varies between 2.8 and 3.4 to 1, the ratio of clear span to pier thickness from 4.9 to 6.9 to 1.
The Eleutherna Bridge is an ancient Greek corbel arch bridge near the Cretan town of Eleutherna, Greece. A similar second bridge standing a short distance south of it collapsed toward the end of the 19th century, with only very few traces remaining.
Canal Lake Concrete Arch Bridge is an arch bridge in Ontario, Canada, spanning a portion of Canal Lake on the Trent–Severn Waterway between Balsam Lake and Lake Simcoe. It is north-northeast from the town of Bolsover.
A segmental arch is a type of arch with a circular arc of less than 180 degrees. It is sometimes also called a scheme arch.
