DOMES

BY-ABHINAV AGRAWAL

B.tech IIT Roorkee IIIrd year

13118001

Contents

• What are domes?• Types of Domes• Geodesic Dome• Advantages and Disadvantages of Geodesic• Monolithic Dome• Advantages and Disadvantages of Monolithic• Future of Domes

What are domes?

A dome is typically an element of architecture that resembles the upper half of a sphere. Domes are curved structures -- they have no angles and no corners -- and they enclose an enormous amount of space with the minimum of materials as they don’t require interior supports. Despite their thinness, domes are some of the strongest and stiffest structures in existence today.

There are following benefits of dome structure:-

Shake table test shows the dome shape is virtually earthquake proof: The following tests have been performed to prove this:

• INITIAL TESTS: Initially, 5.5 tons of sand bags were loaded on the top of the 24-foot diameter dome before being subjected to the four different earthquake setups. In each case, the dome sustained no damage.

• FINAL TESTS: After the passing the initial tests, the dome was loaded with an additional 10 tons of sand bags as well as 8.5 tons of steel plates for a total of 24 tons. Still, the dome did not fail.

Serenity(soundproof): Dome shaped structures are quiet. Only a very small amount of outside sound penetrates a Dome.

Stresses acting on dome shaped structures are uniformly distributed over the surface because it has no angles and corners. As a result, stress concentrations do not occur over the surface and hence crack cannot initiate and propagate easily.

Types of Domes There are various kind of Domes but I am focusing only on

two types of domes that are:• Geodesic Dome• Monolithic Dome Other domes structure are:

Corbel Dome Onion Dome Drum Dome Oval Dome Sail Dome Saucer Dome Scalloped Dome

Geodesic domes• The geodesic dome was invented in the 1950s by American

engineer and architect Buckminster Fuller. A geodesic dome is a sphere-like structure composed of a complex network of triangles. The triangles create a self-bracing framework that gives structural strength while using a minimum of material. The term geodesic is from Latin, meaning earth dividing.

•It being a collection of triangles which, by staying in a state of tension, together forms in the space a hypothetical sphere.•The structure becomes more and more sphere-like as the number of the diverse sizes of the struts increases

• One of the most fascinating facts in the geodesic dome is that in the first look it seems that all the triangles are equilateral and all the struts have the identical length. Looking better, we notice that actually the struts have lengths which are similar, but not identical, and here begin all the magic behind the complicity of realizing a geodesic dome.

Engineering Consideration

• The idea of combining triangles with the arch was first given by German engineer Dr. Walther Bauersfeld when he designed the world's first projection planetarium, built in Jena, Germany in 1922. However, it was Buckminster Fuller ("Bucky") who conceived the concept of geodesic dome homes. Fuller's first patent for a geodesic dome was issued in 1954.

Advantages of geodesic domes• Material• Stability• Structure-The geodesic dome was completely dreamed

up in Buckminster Fuller's head using his knowledge of abstract geometry. It proved to be a great surprise then when the structure was found in nature. Fullerene, or C60, a molecule named for Fuller, was discovered in 1985. It has since been found to have numerous uses in nanotechnology and materials science. One of the advantages of a geodesic dome is the simple fascination of its naturally occurring shape

Disadvantages

Unusable Space Doors and Windows-either make or special

order has to be given Permits-Building the home may also be a

challenge as drainage and fire escapes that meet code are made more difficult by the design of the home.

Financing and Resale

Monolithic Domes•The monolithic dome is made of one solid piece of material. Its construction begins with a circular concrete foundation, where a canvas "airform" is attached to the slab. The canvas is then inflated using special fans, thus forming the shape of the dome. After that, the interior is covered with a layer of polyurethane foam insulation . A steel bar is enclosed in the foam to give support to the dome. Finally, a special mix of concrete is spread over the interior of the building, reports the Architecture Week website.

• A Monolithic Dome is a super-insulated, steel-reinforced concrete structure that can be designed for virtually any use: office or business complex, school, church, temple; gymnasium or sports arena:theatre or amphitheatre, airplane hangar, factory, bulk storage facility, house or apartment complex, military installations etc

Advantages• Domes are energy efficient- With the concrete inside and

the insulation outside, the concrete is protected from the outside elements. Concrete, which conducts and holds heat easily, absorbs the differences in the interior temperature over the day. During the night, the concrete radiates energy back into the interior. This flywheel action dramatically reduces the temperature variations between the day and night.

• Durability- The dome, when finished, is earthquake, tornado and hurricane resistance. Recently, a number of monolithic domes constructed using MDI (Monolithic Dome Institute) techniques have survived major disasters

• Climate control- The spherical sections of the dome offer minimal surface area for the volume they contain, so there is less surface for heat transfer with the outside air.

Disadvantages• Unsustainable Materials-The three materials used in

monolithic domes are not the most environmentally products available. Vinyl and polyurethane are both petroleum-based and the latter emits toxins when it is burned. Shotcrete is lasting but has a large initial CO2 footprint.

• Vulnerability of the Air Form-very delicate and if damaged may cause water seeping inside and cause problem. Aluminum can be used however it will be expensive

• Poor Ventilation-Hole can be Created• Permits and Property Value• Fitting Windows and Doors

Future• In today’s world where there is risk to human life due to

various reasons and one of them is increasing natural disaster, there is urgent need to protect them as much as possible and one of the way is by living in ‘domes’• In the coming future the population is increasing at

tremendous rate and we have limited resources, therefore there is an urgent need to provide mankind with the means of sheltering himself from the elements with the least amount of materials and resources as said by THE DOME’S MASTER BUCKMINISTER FULLRENE and thus domes comes into picture.

• Domes can either be used as housing or as a container to keep toxic products out reach of humans.

• On October 17, 2015 Monolithic Domes Institutes opening two houses, the offices, their manufacturing plant, and other domes on their property for tours. From 10 AM to 4 PM on their campus in Italy, Texas.

• The domes because of its shape is self-supporting and strong enough to withstand a giant tornado, a monster hurricane or a powerful earthquake.

Reference

• Wikipedia• www.monolithic.org• www.pbs.org

THANK YOU