The Romans constructed numerousaqueductsto serve any large city in theirempire, as well as many small towns and industrial sites. The city ofRomehad the largest concentration of aqueducts, with water being supplied by eleven aqueducts constructed over a p eriod of about 500 years. They servedpotable waterand supplied the numerous baths and fountains in the city, as well as finally being emptied into the sewers, where the once-usedgray waterperformed their last function in removing waste matter.
The first Roman aqueduct was theAqua Appia, built in 312 BC during theRoman Republic. The methods of construction are described byVitruviusin his workDe Architecturawritten in the first century BC. His book would have been of great assistance toFrontinus, a general who was appointed in the late first century CE to administer the many aqueducts ofRome. He discovered a discrepancy between the intake and supply of water caused by illegal pipes inserted into the channels to divert the water, and reported on his efforts to improve and regulate the system to the emperor Trajan at the end of the first century AD. The report of his investigation is known asDe aquaeductu. In addition to masonry aqueducts, the Romans built many moreleats channels excavated in the ground, usually with a clay lining. They could serve industrial sites such asgold mines,leadandtinmines,forges,water-millsand baths orthermae.Leatswere very much more expensive than the masonry design, but all aqueducts required good surveying to ensure a regular and smooth flow of water.
Roman bridges, built byancient Romans, were the first large and lasting bridges built.Roman bridges were built with stone and had thearchas its basic structure. Most utilizedconcreteas well; which the Romans were the first to use for bridges.
Roman bridges could be built of wood if they needed to go up quickly, but those didn't last. Roman bridges made of stone, with repairs made as needed, are still in use today. When they were built, they would have helped move armies, serving as part of the road system.
As with thevaultand thedome- the Romans were 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 330Roman stone bridgesfor traffic, 34Roman timber bridgesand 54Roman 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 formerYugoslavia; see right table).
Roman arch bridges were usuallysemicircular, although a few weresegmental(such asAlconétar Bridge). Asegmental archis an arch that is less than a semicircle.http://en.wikipedia.org/wiki/Roman_bridge - cite_note-5The advantages of thesegmentalarch 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 archaqueducts, such as thePont du GardandSegovia Aqueduct. Their bridges featured from an early time onwards flood openings in the piers, e.g. in thePons Fabriciusin Rome (62 BC), one of the world's oldest major bridges still standing.
Roman engineers were the first and until theindustrial revolutionthe only ones to construct bridges withconcrete, which they calledOpus 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 longLimyra Bridgein southwesternTurkeyfeatures 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 bridgeover theDanubefeatured 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 longPuente RomanoatMérida.
The late RomanKaramagara BridgeinCappadociamay represent the earliest surviving bridge featuring a pointed arch.
Hadrian' s Wall. Hadrian' s Wallis one of the best known Roman walls. Located in northern England, it was started by the Roman Emperor to keep the northerners out of Roman Britain.
Hadrian was born on January 24, 76 A.D. He died on July 10, 138, having been emperor since 117. He counted hisdies imperii August 11, although his predecessor had died some days earlier. During Hadrian's rule he worked on reforms and consolidated the Roman provinces. Hadrian toured his empire for 11 years.
Not all was peaceful. When Hadrian tried to build a temple to Jupiter on the site ofSolomon's temple, the Jews revolted in a war lasting three years. His relations with the Christians were generally not confrontational, but during Hadrian's stay in Greece (123-127) he was initiated into the Eleusinian Mysteries, according to Eusebius, and then, with new-found pagan zeal, persecuted local Christians.
It is claimedTrajan, his adoptive father, had not wanted Hadrian to succeed him, but was thwarted by his wife, Plotina, who covered up her husband's death until she could make sure of Hadrian's acceptance by the senate. After Hadrian became emperor, suspicious circumstance surrounded the assassination of leading military figures from Trajan's reign. Hadrian denied involvement.
Mementos of Hadrian's reign persist in the form of coins and the many building projects he undertook. Most famous is the wall across Britain that was named Hadrian's Wall after him. Hadrian's Wall was built, beginning in 122, to keep Roman Britain safe from hostile attacks from the Picts. It was the northernmost boundary of the Roman Empire until early in the fifth century.
Today many of the stones have been carted away and recycled into other buildings, but the wall is still there for people to explore and walk along, although this is discouraged.
AntonineWall. The Antonine Wall is a sixty kilometer wall north of Hadrian's Wall built by the Romans in Britian to keep the Picts at bay during the reign of Antoninus Pius (A.D. 142-155). Hadrian died in July 138. Reversing his predecessor's policy of solidification instead of expansion, Antoninus Pius ordered a northward advance and built a new wall called the Antonine Wall. It was completed by soldiers from Legions II, VI, and XX in the 140s and stretched 37 miles from the Forth to the Clyde, following Scotland's Central Valley. In front of the wall was a ditch. Forts were located at about 8 miles intervals. There are also secondary forts too small for entire regiments. Hadrian's wall is thought to have been abanoned in around 140 in favor of the Antonine Wall and then re-occupied in 158. It was then thought that the Antonine Wall was reoccupied under the other Antonine emperor, Marcus Aurelius.
The Servian Wall. The Roman King Servius Tullius is credited with building the Servian Wall in the 6th century B.C. but archaeological study of the building material suggests it actually dates to the fourth century B.C. The Servian Wall ran from theTiberto theCapitoline Hillto the Quirinal, to the valley between the Quirinal and the Pincian, towards the Esquiline, to the valley between the mons Oppius and theCaelian, along the cliffs on the south and southeast of the Caelian, then probably along the southwest side of the Palatine, then south of the forum Boarium and to the Tiber at the Sublician Bridge (pons Sublicius).
Impact of Politics and Religion on Roman Architecture
In 330 CE, about the time St Peter's Basilica was completed, the Roman Emperor Constantine I declared that the city of Byzantium (later renamed Constantinople, now Istanbul in Turkey), was to be the capital of the Roman Empire. Later, in 395 CE, following the death of Emperor Theodosius, the empire was divided into two parts: a Western half based first in Rome until it was sacked in the 5th century CE, then Ravenna; and an eastern half based in the more powerful and secure city of Constantinople. In addition, Christianity (previously a minority sect) was declared the sole official religion throughout the empire. These twin developments impacted on architecture in two ways: first, relocation to Constantinople helped to preserve and prolong Roman culture, which might otherwise have been destroyed by the barbarian invaders of Italy; second, the emergence of Christianity provided what became the dominant theme of architecture and the visual arts for the next 1,200 years.
- Adam, Jean-Pierre,Roman Building: Materials and Techniques, Indiana University Press, 1994