Domical system

ancient domes building techniques

1. DOMICAL STRUCTURE BUILDING TECHNIQUES SUPERVISED BY : PROF.SHAHER RABABEH & ARCH.MOHAMMAD WALEED DONE BY: MAJD QAFISHEH, AMANI AWARTANI , HANEEN HATABEH

2. The Covered Topics: Definition Additions of Dome History of Domes Types of Domes Structural Behavior Construction techniques

3. Definitions of dome : 1- A dome is an element of architecture that resembles the hollow upper half of the sphere. 2- Dome is rounded arch made of either curved segments or a shell of revolution , meaning an arch rotated around its central axis. Rotation By 360 degree How arch is converted to a dome ?

4. Domes Additions Coffer Cupola Lantern Oculus Rotunda Tholobate/ Drum

5. • Coffer: It is a series of sunken panels . • Cupola: • A small, dome like structure on top of building Generally crowns a larger dome • Lantern: • A day lighting element above cupola • Oculus An oculus is a circular opening in the centre of a dome or in a wall

6. • Rotunda: • A circular ground plan which is covered by a dome • Tholobate / Drum: • A tholobate is the upright part of building on which dome is raised

7. HISTORY OF DOME Early and indigenous domes Roman and byzantine domes Morden period domes - the early domes were likely to be made from saplings, reeds timbers and covered with thatch tuff or skins. – Materials may have transmitted to ramed earth , mud bricks or more durable adobes as result of local conditions. - Morden period domes were made from many durable materials and in many new styles and forms. - New production techniques allowed iron, wood and many different materials to use in dome construction.. - Unique glass domes springing straight from ground level were used for green house. They are customarily hemispherical in shape on general and monumental dome in particular. - The dome of pantheon is the most important dome of roman period Largest roman concrete dome.

8. The Native Americans had Wigwams made from branches and hides, while the Inuit made Igloos from blocks of snow, and the Himba people of Namibia made a similar igloo shape out of wattle and daub as they were desert dwellers. Hut

9. The first dome in history was found in the ziggurat that cover the ceiling in the main hall.

10. Treasure of Atreus , Greece Also called false dome & beehive dome ,these are different from “ a true dome” In that they consist of purely horizontal layers . Corbel dome False Dome

11. The earliest discovered may be four small dwellings made of Mammoth tusks and bones, The first was found by a farmer in Mezhirich, Ukraine, in 1965 while he was digging in his cellar and archaeologists unearthed three more. They date from 19,280 - 11,700 BC. Roman domes are found in baths, villas, palaces, and tombs. Oculi are common features, They are customarily hemispherical in shape In order to buttress the horizontal thrusts of a large hemispherical masonry dome, the supporting walls were built up beyond the base to at least the haunches of the dome and the dome was then also sometimes covered with a conical or polygonal roof HISTORY OF DOME The Dome developed through centuries and transferred to Europe through ancient Roman Discovery of ancient roman tomb ancient roman bath

12. Roofing in Byzantine architecture The general architectural character depends on the development of the dome, introduced by the adoption of circular and polygonal plans for churches, tombs. This is in contrast with the Romanesque style, which developed the vault in Western and Northern Europe . Byzantine architecture innovated the pendentive domes Which provided the Byzantine architects with a unique way of adjusting the circular form of a dome roof to a square or polygonal

13. The church of Holly wisdom was constructed on a scale unprecedented in human history, The main ground plan of the building is a rectangle, 70 meter (230 ft) in width and 75 meter (246 ft) In length. The are covered by a central dome with a diameter of 31 meter and height of 56 meter .

14. Roman domes The Pantheon, Rome The 4,535 metric tons weight of the Roman concrete dome is concentrated with 43.3 diameter on a ring of voussoirs 9.1 metres (30 ft) in diameter that form the oculus, while the downward thrust of the dome is carried by eight barrel vaults in the 6.4 metres (21 ft) thick drum wall into eight piers. The thickness of the dome varies from 6.4 metres (21 ft) at the base of the dome to 1.2 metres (3.9 ft) around the oculus.

15. Domes are classified based on According to Geometry ) shape of the Rounded Arch) According To Structural use According To Building Construction Hemispherical Dome Compound Simple Pointed Dome Parabolic Dome Segmental Dome Corbel Geodesic Monolithic Double shell Pendentives /Squinch

16. The dome produces an thrust downward and outward and it could be supported by columns or piers , This may be due to the existence or non-existence of the transitional zone so domes can be divided into 2 kinds: simple and compound , depending on the structural use and the existing of the transition zone 1. Simple Dome : It is a type the curvature (arch) of the dome and any addition to the body of the dome are the same (No Need for transitional zone ) 2.Compound Dome : In this type the additional element and the Dome have deferent curvature. STRUCTURAL BEHAVIOUR

17. Dome loading :

18. Structural Behavior The weight of traditional domes produces downward and outward thrusts. The downward thrust must be transferred to the foundations, while the outward thrust must be resisted to prevent the dome from collapsing. This resistance can be provided by the mass of the supporting walls, by buttresses, or by a tension element such as a perimeter ring, cable or chain Thrust line obtained from given analysis Dome structural analysis

19. The Response of a Dome to loading The dome develops compressive or tensile membrane stresses along lines of latitude These are known as ‘hoop stresses’ and are tensile at the base and compressive higher up in the dome .

20. Typical Failure of Dome Local or comprehensive failure of domes may result from the masonry's inability to resist tensile or bending forces A typical failure or collapse mechanism consists of : The formation of radial cracks along it’s meridians that divides the dome into lunes , or pie-shape arch . Two hing circles form in the dome mid-section , with a third hing circle formation at or near the base , the cap of the dome will fall straight down , and the base radial cracks(lunes) will rotate outward .

21. Domes According to geometry shape of the Rounded Arch

22. True Dome False Dome False domes, achieve their shape by extending each horizontal layer of stones inward slightly farther than the lower one until they meet at the top. A false dome may also refer to a wooden dome True domes are said to be those structure is in a state of compression, with constituent elements of wedge-shaped voussoirs, the joints of which align with a central point.

23. Domes According to geometry 1.HEMISPHERICAL DOME The hemispherical dome is half of a sphere

24. 2.Pointed Dome Ex: Umbrella dome also called gadrooned ,fluted , organp , pumpkin, melon, ribbed, parachute, scalloped , or lobed domes. The ribs of a dome are the radial lines of masonry that extend from the crown down to the springing. Florence dome st peter church

25. 3. PARABOLIC DOME A parabolic dome is a unique structure in which bending stress due to the uniformly distributed load of its dead load is zero. it was widely used in buildings in ancient times , before the advent of composite structure. However if a point load is applied on the apex of a parabolic dome ,the bending stress becomes infinite . it is found in most ancient structures , the apex of the dome is stiffened or the shape modified to avoid the infinite stress.

26. 4.Segmental Dome It is a dome having the form of a segment of a sphere, with the center well below the springing line; a shallow dome. A dome that is very shallow; its radius of curvature of the dome is very large compared with its rise. They exist entirely in compression so that it can be built much thiner than other dome shapes without becoming unstable. They are more exposed to damage from movement in their supports.

27. 1- Corbelled dome As the horizontal layers get higher ,each is slightly cantilevered, or corbeled toward the center until meeting at the top . 3- According to building construction a famous example is the mycenaean treasury of Atreus

28. 2- GEODESIC DOME Honolulu Hawaii geodesic dome In the year 1957, in Honolulu Hawaii, a geodesic dome was built so quickly it only took them 22 hours after all the parts/materials were delivered. Nowadays there is over 300,000 domes around the world

29. Designing the dome is the first step to start with. The size and amount of triangles and their calculations to form the dome is needed. For example, the basic dome has equilateral 20 triangle, which then further divided into smaller triangles to form the sphere. More triangles results in bigger and more complex domes The calculation differs by class of the dome, like 2V, 3V, 4V, etc

30. The assembly should be planned according to the class and complexity of the dome constructed. It also depend on what arrangement will the triangles be, for example pentagon, hexagon. It is better to start the assembly from top pieces and gradually coming downwards. DONE BY CONNECTING THE STRUTS WITH BOLT TO CREATE TRIANGLE FORMS .

31. There are options when building the geodesic dome, you can choose to cover the triangular panels with either plastic, wood or glass, you get to decide the material according to the different categories of geodesic domes. But the most common material used to build a geodesic dome is steel as they connect the network of the beams/struts together. MATERIAL

32. BIOSPHERE DISNEY’S EPCOT CENTER

33. 3- Monolithic dome - Temple of Mercury at Baiae- The construction of the dome Its construction begins with a circular concrete foundation , the Construction technique is the centering was composed of eight equally spaced timber trusses that were supported with a central column

34. Monolithic dome is a sphere cast in one piece over a form.  A  Steel Framework  wrapped with a steel mesh like chicken wire is tied into place with wire ties.

35. The whole exterior surface gets a Coat of Polyurethane Foam. The Foam has a 10 mm Skin of Elastomeric Paint. one cast piece over the steel framework

36. - These domes were frequently constructed of bricks or of some light porous stone - Byzantine domes were constructed without temporary support or (centering ) by the simple use of large flat bricks 4 - Pendentives it is a curved support shaped like an inverted triangle -it is used to hold a dome - using pendentives , byzantine architects could build higher & wider dome - Pendentive is the term given to a construction element that allows a dome to be placed over square or rectangular spaces. THE SQUINCH (an arch in each of the corners of a square base that transforms it into an octagon ) Or THE PENDENTIVE

37. PENDENTIVE & SQUINCH ALLOWS A DOME TO REST ABOVE A SQUARE BASE

38. Dome on pendentives Dome on squinches WITH DRUM LIES IN BETWEEN PENDENTIVE DOME

39. How a Squinch Works ? A squinch is a wedge that fits on the top corners of a square space. At the point where the dome's bottom edge meets the room's upper horizontal edges, four triangular-like wedges (often similar to a small bridge or arch) are placed in the corners. How a Pendentive Works ? A pendentive also supports a dome but it's more complicated, using geometry to create a series of curving and arched supports., a pendentive is a spherical triangle that serves as an arch. Architects used four pendentives on the upper corners of a room, where they arched inward to meet the dome's circular base. One of the earliest examples of pendentives can be found in Hagia Sophia, STRUCTURAL BEHAVIOR

40. Hagia Sophia Dome is carried on four pendentives and these pendentives enable its transition into the square shape of its piers below These pendentives distribute the weight of thedome to the walls under it. HAGIA SOPHIA

41. 5- Double shell Domes were often built as semi-circles but Brunelleschi’s build an eight sided dome that will be even taller and stronger It is the largest masonry dome in the world Florence dome it has no central support system to hold it up during construction - Even worse the dome’s base an octagon with no true center To solve this there will be two domes instead of one inner & outer shell

42. Helds together by 1- giant brick arches 2- Interlocking rings of stone & wood Rings keeping the dome from expanding outward To move heavy loads hundred of feets up Brunelleschi’s design a genius machines including massive lifting devices But with no center support system …… how would he actually build it ??

43. The masonry would have to support itself during construction To do this Brunelleschi lays the brick in a herring bone pattern which spiral to the top pf the dome with vertical bricks acting to hold the others in place

44. But How to place the brick in such a precision 1- guide ropes one theory said that Ropes ran from a flower pattern in the work platform that shows exactly the were the brick should go ANOTHER has ropes running from the domes center tracing a series of cones that grew smaller as they sended to the top The eight bases meet at the top precisely

45. ONION DOME 1- Saint Basil's Cathedral, Russia(wooden framework)

46. 2- TAJ MAHAL (Islamic)

47. THE DOME • The most remarkable part of the Taj Mahal. • Enormous white onion shaped dome crowning the tomb. • Located at the exact center of the structure, the main dome is flanked by four smaller ones on it four corners. The onion shaped dome of the Taj Mahal sits on a massive drum that adds support to the circular top.

48. The weight of the dome was distributed to the building on which it was rested and then on to the iwans and arches, from which it was transferred to the foundation.

49. The dome is actually double shelled, and the interior false dome was made much smaller to be in proportion to the inner chamber. This gave the building perfect visual balance; extraordinary from the outside and comfortable small from the inside. Similar technique is used at St Paul's Cathedral in London.

50. [2] Heyman, J (1967). “On shell solutions of masonry domes.” International Journal of Solids and Structures, 3, 227-241 REFRENCES:

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