An arch is a curved vertical structure spanning an open space underneath it. Arch can either support the load above it or perform a purely decorative role. The arch dates back to fourth millennium BC, but became popular only after its adoption by the Romans in the 4th century BC.
Ancient Roman architecture adopted the external language of classical ancient Greek architecture for the purposes of the ancient Romans, but was different from Greek buildings, becoming a new architectural style. The two styles are often considered one body of classical architecture. Roman architecture flourished in the Roman Republic and to an even greater extent under the Empire, when the great majority of surviving buildings were constructed. It used new materials, particularly Roman concrete, and newer technologies such as the arch and the dome to make buildings that were typically strong and well engineered. Large numbers remain in some form across the former empire, sometimes complete and still in use today.
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.
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 into a horizontal thrust restrained by the abutments at either side. A viaduct may be made from a series of arches, although other more economical structures are typically used today.
A 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. A corbel vault uses this technique to support the superstructure of a building's roof.
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 Nysa Bridge is a late imperial Roman bridge over the Cakircak stream in Nysa in the ancient region of Caria, modern-day Turkey. The 100 m (328 ft) long substructure was the second largest of its kind in antiquity, after the Pergamon Bridge.
The Bridge near Seydikemer was a Roman segmental arch bridge near the ancient city of Xanthos in Lycia, in modern-day southwestern Turkey. Its remains are located on the upper reaches of the Xanthos river, 4 km upstream from the town of Seydikemer, at a site where the gravel river bed reaches a width of 500 m. Only a 29 m long and 4.5 m wide section on the right river bank, outside the inundation zone, is left today, having once served as approach to the bridge proper. Despite its near-complete destruction, the bridge represents a noteworthy example of the early use of segmental arches and hollow chambers in bridge building.
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 Aesepus Bridge was a late antique Roman bridge over the Aesepus River in the ancient region of Mysia in modern-day Turkey. It is notable for its advanced hollow chamber system which has also been employed in other Roman bridges in the region, such as the Makestos Bridge. In a field examination carried out in the early 20th century, the four main vaults of the bridge were found in ruins, while nearly all piers and the seven minor arches had still remained intact. Today, the two remaining pier stubs in the riverbed are still extant, while the condition of the rest of the structure is difficult to determine.
The Ponte Nomentano is a Roman bridge in Rome, Italy, which carried the Via Nomentana over the Aniene. Having lain outside the city limits for most of its history, the picturesque bridge is noted for its medieval bridge tower, which served to protect this important northern approach to Rome.
The Ponte Salario, also called Ponte Salaro during the Middle Ages, is a road bridge in Rome, Italy, whose origins date back to the Roman period. In antiquity, it lay outside the city limits, 3 km north of the Porta Collina, at the point where the Via Salaria crossed the Aniene, a tributary of the Tiber. The visible side arches are assumed to originate from the first stone structure built during the 1st century BC.
The Lake Homs Dam, also known as Qattinah Dam, is a Roman-built dam near the city of Homs, Syria, which is in use to this day.
The Band-e Kaisar, Pol-e Kaisar, Bridge of Valerian or Shadirwan was an ancient arch bridge in the city of Shushtar, Khuzestan province, Iran, and the first in the country to combine it with a dam. Built by the Sassanids, using Roman prisoners of war as workforce, in the 3rd century AD on Sassanid order, it was also the most eastern example of Roman bridge design and Roman dam, lying deep in Persian territory. Its dual-purpose design exerted a profound influence on Iranian civil engineering and was instrumental in developing Sassanid water management techniques.
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.
The Susegana Bridge is one of a series of Roman bridges on the Via Claudia Augusta in Susegana, northern Italy. The small structure is notable for its flattened arch, which classify it as a Roman segmental arch bridge.
