Dome

As a dome (from the Latin cupula "little barrel" ) is called the hemispherical or bell-shaped upper part of a room, which is formed from stones, bricks or more recently of concrete and other materials. However, the actual dome is composed of wedge-shaped stones ceiling, spanning the enclosed partially or completely by walls space free.

Domes are a special form of the monastery vault with a polygonal, circular or oval floor plan - they have only one vertex and the whole extent of its ground plan as an abutment. You are an improved version of the prehistoric corbelled.

Continuously curved domes are counted engineering practice to the double-curved shells, segmented domes to the folded plates.

Designs

In addition to the cross-section, the ratio between ( imagined to ) dome floor plan, the root circle, and floor plan determines the shape of a dome. Domes over a rectangular room must be either cropped or supplemented.

• Is the most common form in the form of a hemispherical dome. When the root circle of the dome contacts the corners of the floor plan, the shell is cut vertically from the walls. This form is called pendant dome.
• If the root circle further out of the ground plan, creates a Kalottenkuppel (Flat Dome ), which is flatter than spherical cap as a pendant dome. About a square plan is created called her into a Bohemian cap, also Bohemian dome or vault Platz.
• Is the root circle of the dome the plan enrolled ( the walls as tangents ), is placed between walls and actual dome incomplete pendant dome that is trimmed horizontally and on the cutting edge of the arch rests. The four segments of the " auxiliary dome " hot Pendant, the dome shape after Pendentifkuppel.
• Frequently between pendentives and dome a drum is switched, a cylindrical wall, which is increasing the dome, often pierced with windows. The drum, as well as the subsequent dome can also accept an octagonal outline.
• Instead of Pendentifs come with the same function also squinches and (especially in the Turkish and Indian architecture) Turkish triangles that do not fill the corners with ball, but with a cone segments or pyramids.

The statics of these designs is similar, but more complex with the cross vaults, since the side pressure does not act on the corners.

Pendentifkuppel

Pendentifkuppel with Tambour

The exposure of a dome made ​​either through the oculus, the eye, an opening in the keystone at the apex, which is often covered by a durchfenstertes turrets, lantern, or through openings in the lower part of the shell. In pendentive with Tambour this is usually durchfenstert, making the dome seems to float.

History

Preforming the dome with spitzbogigem corbelled ( "false arch " ) are known since the 7th millennium BC in Cyprus and later, for example, in Assyrian, Mycenaean and Sardinian Nuraghe.

An incorrect monolithic dome has the Mausoleum of Theodoric in Ravenna. The oldest true domes with voussoirs date from the time of the Etruscans, highlights achieved the dome in ancient Roman times with the Pantheon in Rome ( see List of Roman domes ) and the Byzantine Empire with the Hagia Sophia.

In Islamic architecture, the Hagia Sophia became the prototype of the Ottoman mosque and the dome reaching a wide variety of shapes: The spectrum ranges from small ribbed domes ( Mezquita - Catedral de Córdoba, El Cristo de la Luz, Toledo ) on cupolas in the Byzantine tradition ( Dome of the Rock, Jerusalem ) to the double-shell domes of Mughal architecture in India (Taj Mahal, Agra ).

The medieval church preferred the ( cross - or barrel-vaulted ) Longitudinal front of the central building and gave the dome architecture just above the crossing certain development opportunities. The dome domed central building remained but the building type of the Baptistery, with the replicas of the Holy Sepulchre in Jerusalem, and in special cases such as the Palatine Chapel in Aachen and their Nachfolgebauten. Significant domed buildings of the Middle Ages are the Baptisteries of Parma (1196-1270), Cremona (from 1176 ) and Florence ( 11-12. Century, the largest domed building in the Middle Ages, diameter 25,60 m), all on a polygonal plan. The Baptistry of Pisa ( 1152 ) (originally with open tip) covered with a conical vault, a special form. The Byzantine cross-domed churches continued the tradition of dome vaulting, which is reflected in San Marco in Venice, where apparently inspiration for the dome domed churches of Perigord (Périgueux, Angoulême, etc.) went out.

Brunelleschi's dome of Florence ( 1420-36, diameter 45.52 m) marks a technical breakthrough and a new dimension of Wölbkunst. It is designed as double-skin brick dome. With the new style of the Renaissance is the central building and the monumental cupola drum with the new ideal. Michelangelo's St. Peter's Basilica in Rome acts well into the Baroque into it as a model. Often the externally visible dome is now significantly higher than the interior of the dome.

Especially in the 18th and 19th centuries were also secular buildings, especially government buildings domes, such as the Reichstag in Berlin or the Capitol in Washington.

Significant real domes

In order of establishment:

Through the use of reinforced concrete and steel scaffolding modern domes ( shell structures ) can be built in far bolder shapes and with greater span than stone or brick structures. Richard Buckminster Fuller geodesic domes constructed of lightweight construction.

Canopies, such as those of The O ₂ (formerly the Millennium Dome ) in London, consisting of a supported from the outside by steel cables fiber membrane, although often dome shape, but there are no domes, because they are not self-supporting, but with circus tents comparable restraints in their form will be kept.