DoMe iN aRcHiTeCtUrE

DOME

Early dome
Domes appeared first on round huts and tombs in the ancient Near East, India, and the Mediterranean region but only as solid mounds or in techniques adaptable only to the smallest buildings. They became technically significant with the introduction of the large-scale masonry hemispheres by the Romans. Domes, like vaults, evolved from the arch, for in their simplest form they may be thought of as a continuous series of arches, with the same centre. Therefore, the dome exerts thrusts all around its perimeter, and the earliest monumental examples required heavy walls. Since the walls permitted few openings and had to be round or polygonal to give continuous support, early domes were difficult to incorporate into complex structures, especially when adjacent spaces were vaulted.


Twentieth century domes
Newer techniques, however, have added practically to the expressive advantages of domes. The reinforced-concrete slab used in vaulting can be curved in length as well as width (like an inflated handkerchief or a parachute). And in this development the distinction between vaults and domes loses significance, being based on nothing but the type of curvature in the slab. Geodesic domes, developed in the 20th century by R. Buckminster Fuller, are spherical forms in which triangular or polygonal facets composed of light skeletal struts or flat planes replace the arch principle and distribute stresses within the structure itself, as in a truss. Geodesic domes can be supported by light walls and are the only large domes that can be set directly on the ground as complete structures.

DOME IN BYZANTINE EMPIRE
Byzantine architects perfected a way of raising domes on piers instead of walls (like groin vaults), which permitted lighting and communication from four directions. The transition from a cubic plan to the hemisphere was achieved by four inverted spherical triangles called pendentives—masses of masonry curved both horizontally and vertically. Their apexes rested on the four piers, to which they conducted the forces of the dome; their sides joined to form arches over openings in four faces of the cube; and their bases met in a complete circle to form the dome foundation. The pendentive dome could rest directly on this foundation orupon a cylindrical wall, called a drum, inserted between the two to increase height.
The architecture of the Byzantine or Eastern Roman Empire which developed from Early Christian and late Roman antecedents in the 4th century, flourished principally in Greece, but spread widely and lasted throughout the Middle Ages until the fall of Constantinople to the Turks (1453). It is characterized by large pendentive-supported domes, round arches and elaborate columns, richness in decorative elements, and color. The most famous example is the Hagia Sophia in Istanbul (532–537).

The most imposing achievement of Byzantine architecture is the Church of Holy Wisdom or Hagia Sophia. It was constructed in a short span of five years (532–537) during the reign of Justinian. Hagia Sophia is without a clear antecedent in the architecture of late antiquity, yet it must be accounted as culminating several centuries of experimentation toward the realization of a unified space of monumental dimensions. Throughout the history of Byzantine religious architecture, the centrally planned structure continued in favor. Such structures, which may show considerable variation in plan, have in common the predominance of a central domed space, flanked and partly sustained by smaller domes and half-domes spanning peripheral spaces.

The chief contribution of Byzantine architects, to the repertoire of structure forms and their use–fully develop pendentives and the use of the semi domes on a scale never before attempted, to buttress a trust from above.
The innovations occurred in the construction of Hagia Sophia in Constantinople. On the smaller scale, however the pendentives become so characteristic of later Byzantine architecture. It might be regarded either as a development of small triangular infill regions by means of which earlier Roman domes were set above polygons bases or and isolated triangular portion of a dome set directly over a square bases and large enough to extend the corner of the square.

As each of a group of pendentives rises out of its gradually close in towards the adjacent ones until all four meet in complete circle. Byzantine pendentives were normally constructed of brick with some solid baking to resist subsequent outward trust. Above the final circle it was usually a cornice of stone, and on this the dome was constructed.

DOME IN ISLAMIC ARCHITECTURE

Most masonry structures of importance were in arched, vault or domes forms. Cement, plaster and stucco were used for bas-relief carving and the highly decorative muqarnas techniques employed in the arched, vault and domes.

Lead-working, bronze casting and tie used of iron were well established techniques. Domes, roof and the steeples were often weathered in lead and iron was widely used in tie bars, grills and cramps.

The skill and techniques wood working and timber engineering was used form earliest period for roof construction including early domes.

Domes, iwan, cloister or portal may be emphasized or diminished as require within its proper station, and each contains elements which display the essential structure form.

DOME IN RENAISSANCE

The dome was unsuited to the lightness and verticality of late-medieval styles but was widely used in the Renaissance and Baroque periods. Renaissance builders adapted the Gothic rib system to dome construction and found new means to reduce loads and thrust (concentric chains, etc.) that permitted high drums and variations in the curvature of the dome. The awkward, tunnel like effect produced on the interior by high domes was often hidden by an internal shell built on the same foundations (as at Florence Cathedral and St. Paul’s Cathedral, London).

The dome is used frequently, both as a very large structural feature that is visible from the exterior, and also as a means of roofing smaller spaces where they are only visible internally. Domes had been used only rarely in the Middle Ages, but after the success of the dome in Brunelleschi’s design for the Basilica di Santa Maria del Fiore and its use in Bramante’s plan for St. Peter's Basilica (1506) in Rome, the dome became an indispensable element in church architecture and later even for secular architecture, such as Palladio's Villa Rotonda. The dome of St. Peter’s applies the same techniqies to hemispherical shells, while Wren’s dome of St. Paul is a complex mixture of stone inner dome, brick intermediate cone and timber roof, and was influenced by French examplesvsuch as Les Invalides in Paris.
Renaissance architecture Elements: Domes The dome is used frequently, both as a very large structural feature that is visible from the exterior, and also as a means of roofing smaller spaces where they are only visible internally. Domes had been used only rarely in the Middle Ages, but after the success of the dome in Brunelleschi’s design for the Basilica di Santa Maria del Fiore and its use in Bramante’s plan for St. Peter's Basilica (1506) in Rome, the dome became an indispensable element in church architecture and later even for secular architecture, such as Palladio's Villa Rotonda.








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