An air-supported (or air-inflated) structure is any building that derives its structural integrity from the use of internal pressurized

air An atmosphere () is a layer of gases that envelop an astronomical object, held in place by the gravity of the object. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. A stellar atmosph ...

to inflate a pliable material (i.e. structural fabric)

envelope An envelope is a common packaging item, usually made of thin, flat material. It is designed to contain a flat object, such as a letter (message), letter or Greeting card, card. Traditional envelopes are made from sheets of paper cut to one o ...

, so that air is the main support of the structure, and where access is via

airlock An airlock is a room or compartment which permits passage between environments of differing atmospheric pressure or composition, while minimizing the changing of pressure or composition between the differing environments. An airlock consist ...

s. The first air-supported structure built in history was the

radome A radome (a portmanteau of "radar" and "dome") is a structural, weatherproof enclosure that protects a radar antenna (radio), antenna. The radome is constructed of material transparent to radio waves. Radomes protect the antenna from weathe ...

manufactured at the Cornell Aeronautical Laboratory in 1948 by Walter Bird. The concept was implemented on a large scale by David H. Geiger with the United States pavilion at

Expo '70 The or Expo '70 was a world's fair held in Suita, Osaka Prefecture, Japan, between 15 March and 13 September 1970. Its theme was "Progress and Harmony for Mankind." In Japanese, Expo '70 is often referred to as . It was the first world's fair ...

Osaka, Japan is a designated city in the Kansai region of Honshu in Japan. It is the capital of and most populous city in Osaka Prefecture, and the third-most populous city in Japan, following the special wards of Tokyo and Yokohama. With a populatio ...

, in 1970. It is usually dome-shaped, since this shape creates the greatest

volume Volume is a measure of regions in three-dimensional space. It is often quantified numerically using SI derived units (such as the cubic metre and litre) or by various imperial or US customary units (such as the gallon, quart, cubic inch) ...

for the least amount of material. To maintain structural integrity, the structure must be pressurized such that the internal

pressure Pressure (symbol: ''p'' or ''P'') is the force applied perpendicular to the surface of an object per unit area over which that force is distributed. Gauge pressure (also spelled ''gage'' pressure)The preferred spelling varies by country and eve ...

equals or exceeds any external pressure being applied to the structure (i.e.

wind Wind is the natural movement of atmosphere of Earth, air or other gases relative to a planetary surface, planet's surface. Winds occur on a range of scales, from thunderstorm flows lasting tens of minutes, to local breezes generated by heatin ...

pressure). The structure does not have to be airtight to retain structural integrity—as long as the pressurization system that supplies internal pressure replaces any air leakage, the structure will remain stable. All access to the structure interior must be equipped with some form of airlock—typically either two sets of parallel doors or a

revolving door A revolving door typically consists of three or four doors that hang on a central shaft and rotate around a vertical axis within a cylindrical enclosure. To use a revolving door, a person enters the enclosure between two of the doors and then m ...

or both. Air-supported structures are secured by heavy weights on the ground, ground anchors, attachment to a foundation, or a combination of these. Among its many uses are: sports and recreation facilities,

warehousing A warehouse is a building for storing goods. Warehouses are used by manufacturers, importers, exporters, wholesalers, transport businesses, customs, etc. They are usually large plain buildings in industrial parks on the rural–urban fringe, out ...

, temporary shelters, and radomes. The structure can be either wholly, partial, or roof-only air supported. A fully air-supported structure can be intended to be a temporary or semi-temporary facility or permanent, whereas a structure with only an air-supported roof can be built as a permanent building.

Design

Shape

The shape of an air-supported structure is limited by the need to have the whole envelope surface evenly pressurized. If this is not the case, the structure will be unevenly supported, creating wrinkles and stress points in the pliable envelope which in turn may cause it to fail. In practice, any inflated surface involves a double curvature. Therefore, the most common shapes for air-supported structures are hemispheres, ovals, and half cylinders.

Structure

The main loads acting against the air-supported envelope are internal air pressure, wind, or weight from snow build-up. The structure is actively supported at all times by blowing in more air, which requires energy. To compensate against wind force and snow load, the structure's inflation is adjusted accordingly. Modern structures have computer controlled mechanical systems that monitor dynamic loads and automatically compensate the inflation for it. The better the quality of the structure, the higher forces and weight it can endure. The best quality structures can withstand winds up to and snow weight to 40 pounds per square yard (21.7 kilograms per square meter). Tokyo Dome 2015-5-12

The air pressure on the envelope is equal to the air pressure exerted on the inside ground, pushing the whole structure up. Therefore, it needs to be securely anchored to the ground (or to the substructure in a roof-only design). For wide span structures cables are required for anchoring and stabilization. Anchoring requires ballast (weights). Early anchoring designs incorporated sand bags, concrete blocks, bricks, or the like, typically placed around the perimeter on the seal skirt. Most modern design structures use proprietary anchoring systems. The danger of sudden collapse is nearly negligible, because the structure will gradually deform or sag when subject to a heavy load or force (snow or wind). Only if these warning signs are ignored or not noticed, then the build-up of an extreme load may rupture the envelope, leading to a sudden deflation and collapse. In hot or cold climates,

air conditioning Air conditioning, often abbreviated as A/C (US) or air con (UK), is the process of removing heat from an enclosed space to achieve a more comfortable interior temperature, and in some cases, also controlling the humidity of internal air. Air c ...

adds to the energy requirement. In venues visited by millions of people per year, energy consumption may be a couple gigajoules per square meter. A common misconception is that these structures are not meant to be permanent facilities, however all major corporations participating in this industry conform to some form of The International Building Codes. To be a permanent facility these domes have to be engineered to the same building codes as a traditional structure. Air-supported structures or domes are also commonly known as "bubbles".

Material

The materials used for air-supported structures are similar to those used in tensile structures, namely synthetic fabrics such as

fibreglass Fiberglass (American English) or fibreglass ( Commonwealth English) is a common type of fiber-reinforced plastic using glass fiber. The fibers may be randomly arranged, flattened into a sheet called a chopped strand mat, or woven into glass c ...

and

polyester Polyester is a category of polymers that contain one or two ester linkages in every repeat unit of their main chain. As a specific material, it most commonly refers to a type called polyethylene terephthalate (PET). Polyesters include some natura ...

. In order to prevent deterioration from moisture and

ultraviolet Ultraviolet radiation, also known as simply UV, is electromagnetic radiation of wavelengths of 10–400 nanometers, shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight and constitutes about 10% of ...

radiation, these materials are coated with polymers such as PVC and

Teflon Polytetrafluoroethylene (PTFE) is a synthetic fluoropolymer of tetrafluoroethylene, and has numerous applications because it is chemically inert. The commonly known brand name of PTFE-based composition is Teflon by Chemours, a spin-off from ...

. Depending on use and location, the structure may have inner linings made of lighter materials for insulation or acoustics. Materials used in modern air supported structures are usually translucent, therefore the use of lighting system inside the structure is often not required during the daytime.

Air pressure

The amount of pressure required for air-supported structures is a function of the weight of the material—and the building systems suspended on it (lighting, ventilation, etc.)—and wind pressure. This amounts to less than 1% above

atmospheric pressure Atmospheric pressure, also known as air pressure or barometric pressure (after the barometer), is the pressure within the atmosphere of Earth. The standard atmosphere (symbol: atm) is a unit of pressure defined as , which is equivalent to 1,013. ...

. Internal pressure is commonly measured in

inches of water Inches of water is a non- SI unit for pressure. It is also given as inches of water gauge (iwg or in.w.g.), inches water column (inch wc, in. WC, " wc, etc. or just wc or WC), inAq, Aq, or inHO. The units are conventionally used for measurement o ...

(inAq) and varies fractionally from 0.3 inAq for minimal inflation to 3 inAq for maximum, with 1 inAq being a standard pressurization level for normal operating conditions. In terms of the more common

pounds per square inch The pound per square inch (abbreviation: psi) or, more accurately, pound-force per square inch (symbol: lbf/in2), is a unit of measurement of pressure or of stress based on avoirdupois units and used primarily in the United States. It is the pre ...

, 1 inAq equates to a mere 0.037 psi (2.54 mBar, 254 Pa),

Notable air-supported domes

In operation

* Bennett Indoor Athletic Complex,

Toms River, New Jersey Toms River is a Township (New Jersey), township and coastal town located on the Jersey Shore in Ocean County, New Jersey, Ocean County, in the U.S. state of New Jersey. Its mainland United States, mainland portion is also a census-designated ...

, United States * Dalplex (athletics complex), Halifax,

Nova Scotia Nova Scotia is a Provinces and territories of Canada, province of Canada, located on its east coast. It is one of the three Maritime Canada, Maritime provinces and Population of Canada by province and territory, most populous province in Atlan ...

Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...

Olympic Training Center Velodrome The Olympic Training Center Velodrome, also known as the 7-11 Velodrome, is a velodrome in Colorado Springs, Colorado. Description The track is surfaced with concrete, which is unusual as Olympic-quality tracks tend to be timber or synthetics. ...

Colorado Springs, Colorado Colorado Springs is the most populous city in El Paso County, Colorado, United States, and its county seat. The city had a population of 478,961 at the 2020 United States census, 2020 census, a 15.02% increase since 2010 United States Census, 2 ...

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

* Edmonton Soccer Dome,

Edmonton Edmonton is the capital city of the Provinces and territories of Canada, Canadian province of Alberta. It is situated on the North Saskatchewan River and is the centre of the Edmonton Metropolitan Region, which is surrounded by Central Alberta ...

Alberta Alberta is a Provinces and territories of Canada, province in Canada. It is a part of Western Canada and is one of the three Canadian Prairies, prairie provinces. Alberta is bordered by British Columbia to its west, Saskatchewan to its east, t ...

, Canada * Harry Jerome Sports Center, Burnaby, British Columbia, Canada. * Krenzler Field,

Cleveland State University Cleveland State University (CSU) is a public research university in Cleveland, Ohio, United States. It was established in 1964 and opened for classes in 1965 after acquiring the entirety of Fenn College, a private school that had been in oper ...

Cleveland, Ohio Cleveland is a city in the U.S. state of Ohio and the county seat of Cuyahoga County, Ohio, Cuyahoga County. Located along the southern shore of Lake Erie, it is situated across the Canada–United States border, Canada–U.S. maritime border ...

, United States *

Tokyo Dome is an indoor stadium in Bunkyō, Tokyo, Japan. It was designed as a baseball stadium following its predecessor, Korakuen Stadium (whose former site is now occupied by the Tokyo Dome Hotel and a plaza for this stadium). In Japan, it is often us ...

Tokyo Tokyo, officially the Tokyo Metropolis, is the capital of Japan, capital and List of cities in Japan, most populous city in Japan. With a population of over 14 million in the city proper in 2023, it is List of largest cities, one of the most ...

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

University of Galway The University of Galway () is a public research university located in the city of Galway, Ireland. The university was founded in 1845 as "Queen's College, Galway". It was known as "University College, Galway" (UCG) () from 1908 to 1997 and as ...

Connacht GAA Air Dome, Carrowclogher, Mayo,

Ireland Ireland (, ; ; Ulster Scots dialect, Ulster-Scots: ) is an island in the North Atlantic Ocean, in Northwestern Europe. Geopolitically, the island is divided between the Republic of Ireland (officially Names of the Irish state, named Irelan ...

(Note: destroyed during Storm Éowyn on 24 January 2025)

Former notable domes

BC Place BC Place is a multi-purpose stadium in Vancouver, British Columbia, Canada. Located at the north side of False Creek, it is owned and operated by the BC Pavilion Corporation (PavCo), a Crown corporation of the province. The venue is currently ...

Vancouver Vancouver is a major city in Western Canada, located in the Lower Mainland region of British Columbia. As the List of cities in British Columbia, most populous city in the province, the 2021 Canadian census recorded 662,248 people in the cit ...

British Columbia British Columbia is the westernmost Provinces and territories of Canada, province of Canada. Situated in the Pacific Northwest between the Pacific Ocean and the Rocky Mountains, the province has a diverse geography, with rugged landscapes that ...

(Formerly the largest air-supported stadium in the world. The roof was changed to a retractable roof in 2011) * Greater Binghamton Sports Complex,

Binghamton, New York Binghamton ( ) is a city in the U.S. state of New York, and serves as the county seat of Broome County. Surrounded by rolling hills, it lies in the state's Southern Tier region near the Pennsylvania border, in a bowl-shaped valley at the c ...

, United States. (Roof collapsed in December 2020) * Burswood Dome,

Perth, Western Australia Perth () is the list of Australian capital cities, capital city of Western Australia. It is the list of cities in Australia by population, fourth-most-populous city in Australia, with a population of over 2.3 million within Greater Perth . The ...

(Demolition commenced June 2013) * Carrier Dome,

Syracuse, New York Syracuse ( ) is a City (New York), city in and the county seat of Onondaga County, New York, United States. With a population of 148,620 and a Syracuse metropolitan area, metropolitan area of 662,057, it is the fifth-most populated city and 13 ...

, United States (air-supported roof was deflated for the final time on March 16, 2020, with a steel frame-supported roof installed that September) * DakotaDome,

Vermillion, South Dakota Vermillion (; "The Place Where Vermilion is Obtained") is a city and the county seat of Clay County. It is in the southeastern corner of South Dakota, United States, and is the state's 12th-most populous city. According to the 2020 census, the ...

, United States (air-supported roof was replaced by a steel frame domed roof in 2001) * Donald N. Dedmon Center,

Radford, Virginia Radford (formerly Lovely Mount, Central City, English Ferry and Ingle's Ferry) is an Independent city (United States), independent city in the U.S. state of Virginia. As of 2020, the population was 16,070 by the United States Census Bureau. For ...

, United States (air-supported roof was replaced by a steel truss and fabric roof in 2009) * Hubert H. Humphrey Metrodome,

Minneapolis, Minnesota Minneapolis is a city in Hennepin County, Minnesota, United States, and its county seat. With a population of 429,954 as of the 2020 United States census, 2020 census, it is the state's List of cities in Minnesota, most populous city. Locat ...

, United States (Roof deflated January 18, 2014, demolished in February 2014) * O'Connell Center,

Gainesville, Florida Gainesville is the county seat of Alachua County, Florida, United States, and the most populous city in North Central Florida, with a population of 145,212 in 2022. It is the principal city of the Gainesville metropolitan area, Florida, Gainesv ...

, United States (air-supported roof was replaced by a steel frame-supported roof in 1998) * RCA Dome,

Indianapolis, Indiana Indianapolis ( ), colloquially known as Indy, is the List of capitals in the United States, capital and List of municipalities in Indiana, most populous city of the U.S. state of Indiana and the county seat of Marion County, Indiana, Marion ...

, United States (demolished in December 2008) *

Pontiac Silverdome The Pontiac Silverdome (also known as the Silverdome) was a stadium in Pontiac, Michigan. It opened in 1975 and sat on 199 acres (51 ha) of land. When the stadium opened, it featured a fiberglass fabric roof held up by air pressure, the fi ...

Pontiac, Michigan Pontiac ( ') is a city in and the county seat of Oakland County, Michigan, Oakland County in the U.S. state of Michigan. Located roughly northwest of downtown Detroit, Pontiac is part of the Metro Detroit, Detroit metropolitan area, and is vari ...

, United States (deflated in early January 2013; demolished December 2017) * St. Louis Science Center Exploradome,

St. Louis, Missouri St. Louis ( , sometimes referred to as St. Louis City, Saint Louis or STL) is an Independent city (United States), independent city in the U.S. state of Missouri. It lies near the confluence of the Mississippi River, Mississippi and the Miss ...

, United States (Demolished in 2013) * UNI-Dome,

Cedar Falls, Iowa Cedar Falls is a city in Black Hawk County, Iowa, United States. As of the 2020 United States census, the city population was 40,713. Cedar Falls is home to the University of Northern Iowa, a public university. Cedar Falls along with neighbori ...

, United States (air-supported Teflon/Fiberglass roof was replaced with a steel frame-supported stainless steel/fiberglass roof in 1998) * Yuengling Center (originally USF Sun Dome),

Tampa, Florida Tampa ( ) is a city on the Gulf Coast of the United States, Gulf Coast of the U.S. state of Florida. Tampa's borders include the north shore of Tampa Bay and the east shore of Old Tampa Bay. Tampa is the largest city in the Tampa Bay area and t ...

, United States (air-supported Teflon/Fiberglass roof was replaced with a steel frame-supported roof in 2012)

Similar concepts

* Blimps, the application of this technique to

airships An airship, dirigible balloon or dirigible is a type of aerostat (lighter-than-air) aircraft that can navigate through the air flying under its own power. Aerostats use buoyancy from a lifting gas that is less dense than the surrounding ai ...

, using the pressure differential between their

lifting gas A lifting gas or lighter-than-air gas is a gas that has a density lower than normal atmospheric gases and rises above them as a result, making it useful in lifting lighter-than-air aircraft. Only certain lighter-than-air gases are suitable as lift ...

and the outside atmosphere to provide structural integrity. * Balloon tanks, the application of this technique to rockets, using tank pressurization for rigidity.

References

External links

Tension Structures

DESIGN MANUAL FOR GROUND-MOUNTED AIR-SUPPORTED STRUCTURES
{cbignore, bot=medic
GUIDE FOR ESTIMATING MAXIMUM ANCHOR LOADS ON AIR-SUPPORTED STRUCTURESBubbles Biodiversity Park, an award-winning designChinese school builds clean air dome
Buildings and structures by type Tensile architecture Tensile membrane structures