A passage grave or passage tomb consists of one or more burial chambers covered in earth or stone and having a narrow access passage made of large stones. These structures usually date from the Neolithic Age and are found largely in Western Europe. When covered in earth, a passage grave is a type of burial mound[1] which are found in various forms all over the world. When a passage grave is covered in stone, it is a type of cairn.
https://en.wikipedia.org/wiki/Passage_grave
Mining is the extraction of valuable geological materials from the Earth and other astronomical objects. Mining is required to obtain most materials that cannot be grown through agricultural processes, or feasibly created artificially in a laboratory or factory. Ores recovered by mining include metals, coal, oil shale, gemstones, limestone, chalk, dimension stone, rock salt, potash, gravel, and clay. The ore must be a rock or mineral that contains valuable constituent, can be extracted or mined and sold for profit.[1] Mining in a wider sense includes extraction of any non-renewable resource such as petroleum, natural gas, or even water.
Modern mining processes involve prospecting for ore bodies, analysis of the profit potential of a proposed mine, extraction of the desired materials, and final reclamation or restoration of the land after the mine is closed.[2] Mining materials are often obtained from ore bodies, lodes, veins, seams, reefs, or placer deposits. The exploitation of these deposits for raw materials is dependent on investment, labor, energy, refining, and transportation cost.
Mining operations can create a negative environmental impact, both during the mining activity and after the mine has closed. Hence, most of the world's nations have passed regulations to decrease the impact; however, the outsized role of mining in generating business for often rural, remote or economically depressed communities means that governments often fail to fully enforce such regulations. Work safety has long been a concern as well, and where enforced, modern practices have significantly improved safety in mines. Unregulated or poorly regulated mining, especially in developing economies, frequently contributes to local human rights violations and environmental conflicts. Mining can also perpetuate political instability through resource conflicts.
https://en.wikipedia.org/wiki/Mining
A manhole (utility hole, maintenance hole,[1] or sewer hole) is an opening to a confined space such as a shaft, utility vault, or large vessel. Manholes are often used as an access point for an underground public utility, allowing inspection, maintenance, and system upgrades. The majority of underground services have manholes, including water, sewers, telephone, electricity, storm drains, district heating, and gas.
Manholes are generally found in urban areas, in streets and occasionally under sidewalks. In rural and undeveloped areas, services such as telephone and electricity are usually carried on utility poles or even pylons rather than underground.
In Australia, manhole also commonly refers to an access hatch used to get access from a room or hallway into the ceiling cavity of a building.[2][3] These manholes are typically around 450 mm × 450 mm (18 in × 18 in) square.
https://en.wikipedia.org/wiki/Manhole
An earth shelter, also called an earth house, earth bermed house, or underground house, is a structure (usually a house) with earth (soil) against the walls, on the roof, or that is entirely buried underground.
Earth acts as thermal mass, making it easier to maintain a steady indoor air temperature and therefore reduces energy costs for heating or cooling.
Earth sheltering became relatively popular after the mid-1970s, especially among environmentalists. However, the practice has been around for nearly as long as humans have been constructing their own shelters.
https://en.wikipedia.org/wiki/Earth_shelter
An underground hangar is a type of hangar for military aircraft, usually dug into the side of a mountain for protection. It is bigger and more protected than a hardened aircraft shelter (HAS).
An underground hangar complex may include tunnels containing the normal elements of a military air base - fuel storage, weapon storage, rooms for maintaining the aircraft systems, a communications centre, briefing rooms, kitchen, dining rooms, sleeping areas and generators for electrical power.
Countries that have used underground hangars include Albania, China, Italy, North Korea, Norway, Sweden, Switzerland, Taiwan, Yugoslavia, Iran, Taiwan, Vietnam, South Africa and Pakistan.
https://en.wikipedia.org/wiki/Underground_hangar
A root cellar (American English), fruit cellar (Mid-Western American English) or earth cellar (British English) is a structure, usually underground[1] or partially underground,[1] used for storage of vegetables, fruits, nuts, or other foods. Its name reflects the traditional focus on root crops stored in an underground cellar, which is still often true; but the scope is wider, as a wide variety of foods can be stored for weeks to months, depending on the crop and conditions,[1] and the structure may not always be underground.[1]
Root cellaring has been vitally important in various eras and places for winter food supply. Although present-day food distribution systems and refrigeration have rendered root cellars unnecessary for many people, they remain important for those who value self-sufficiency, whether by economic necessity or by choice and for personal satisfaction. Thus, they are popular among diverse audiences, including gardeners, organic farmers, DIY fans, homesteaders, anyone seeking some emergency preparedness (most extensively, preppers), subsistence farmers, and enthusiasts of local food, slow food, heirloom plants, and traditional culture.
https://en.wikipedia.org/wiki/Root_cellar
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Smuggling tunnels are secret passages used for the smuggling of goods and people. The term is also used where the tunnels are built in response to a siege.
https://en.wikipedia.org/wiki/Smuggling_tunnel
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Stepwells (also known as vavs or baori) are wells or ponds with a long corridor of steps that descend to the water level. Stepwells played a significant role in defining subterranean architecture in western India from 7th to 19th century.[1] Some stepwells are multi-storeyed and can be accessed by a Persian wheel which is pulled by a bull to bring water to the first or second floor. They are most common in western India and are also found in the other more arid regions of the Indian subcontinent, extending into Pakistan. The construction of stepwells is mainly utilitarian, though they may include embellishments of architectural significance, and be temple tanks.
Stepwells are examples of the many types of storage and irrigation tanks that were developed in India, mainly to cope with seasonal fluctuations in water availability. A basic difference between stepwells on the one hand, and tanks and wells on the other, is that stepwells make it easier for people to reach the groundwater and to maintain and manage the well.
The builders dug deep trenches into the earth for dependable, year-round groundwater. They lined the walls of these trenches with blocks of stone, without mortar, and created stairs leading down to the water.[2] This led to the building of some significant ornamental and architectural features, often associated with dwellings and in urban areas. It also ensured their survival as monuments.
A stepwell structure consists of two sections: a vertical shaft from which water is drawn and the surrounding inclined subterranean passageways and the chambers and steps which provide access to the well. The galleries and chambers surrounding these wells were often carved profusely with elaborate detail and became cool, quiet retreats during the hot summers.[3]
https://en.wikipedia.org/wiki/Stepwell
In subterranean civil engineering, ventilation shafts, also known as airshafts or vent shafts, are vertical passages used in mines and tunnels to move fresh air underground, and to remove stale air.[1]
In architecture, an airshaft, also known as a lightwell, is typically a small, vertical space within a tall building which permits ventilation of the building's interior spaces to the outside.[2] The floor plan of a building with an airshaft is often described as a "square donut" shape. Alternatively, an airshaft may be formed between two adjacent buildings. Windows on the interior side of the donut allow air from the building to be exhausted into the shaft, and, depending on the height and width of the shaft, may also allow extra sunlight inside.
https://en.wikipedia.org/wiki/Ventilation_shaft
Secret passages, also commonly referred to as hidden passages or secret tunnels, are hidden routes used for stealthy travel, escape, or movement of people and goods. They are sometimes inside buildings leading to secret rooms.
Others allow people to enter or exit buildings without being seen. Hidden passages and secret rooms have been built in castles and houses owned by heads of state, the wealthy, criminals, and abolitionists associated with the American Underground Railroad. They have helped besieged rulers escape attackers, including Pope Alexander VI in 1494, Pope Clement VII in 1527 and Marie Antoinette in 1789. Passages and tunnels have been used by criminals, armies (notably the Viet Cong in the Vietnam War) and political organizations to smuggle goods and people or conceal their activities.
https://en.wikipedia.org/wiki/Secret_passage
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A missile launch facility, also known as an underground missile silo, launch facility (LF), or nuclear silo, is a vertical cylindrical structure constructed underground, for the storage and launching of intercontinental ballistic missiles (ICBMs), intermediate-range ballistic missiles (IRBMs), medium-range ballistic missiles (MRBMs). Similar facilities can be used for anti-ballistic missiles (ABMs).
The structures typically have the missile some distance below ground, protected by a large "blast door" on top. They are usually connected, physically and/or electronically, to a missile launch control center.
With the introduction of the Soviet UR-100 and the U.S. Titan II missile series, underground silos changed in the 1960s. Both missile series introduced the use of hypergolic propellant, which could be stored in the missiles, allowing for rapid launches. Both countries' liquid-fueled missile systems were moved into underground silos. The introduction of solid fuel systems, in the later 1960s, made the silo moving and launching even easier.[1]
The underground missile silo has remained the primary missile basing system and launch facility for land-based missiles since the 1960s. The increased accuracy of inertial guidance systems has rendered them somewhat more vulnerable than they were in the 1960s[citation needed].
Other than underground facilities, ballistic missiles can be launched from above-ground facilities, or can be launched from mobile platforms, e.g. transporter erector launchers, railcars, ballistic missile submarines or airplanes.
https://en.wikipedia.org/wiki/Missile_launch_facility
In architecture, a semi-basement is a floor of a building that is half below ground, rather than entirely such as a true basement or cellar.
Traditionally, semi-basements were designed in larger houses where staff was housed. A semi-basement usually contained kitchens and domestic offices. The advantage over a basement is that a semi-basement can let outside light in as it can have windows, albeit ones that are often too high to enjoy a view. Historically this was an advantage as the servants, who traditionally inhabited such a floor, would not have the opportunity to waste time by looking out of the window.
The feature also has the aesthetic value of raising the ground floor, containing the building's reception rooms higher from the ground in order that they could enjoy better views, and be more free from the damp problems which always arose before the days of modern technology.
Today, London estate agents when selling former servant's rooms as modern apartments often refer to the semi-basement as the "garden floor".[1]
https://en.wikipedia.org/wiki/Semi-basement
An erdstall is a type of tunnel found across Europe.[1] They are of unknown origin but are believed to date from the Middle Ages. A variety of purposes have been theorized, including that they were used as escape routes or hiding places, but the most prominent theory is that they served a religious or spiritual purpose.[1]
https://en.wikipedia.org/wiki/Erdstall
A utility vault is an underground room providing access to subterranean public utility equipment, such as valves for water or natural gas pipes, or switchgear for electrical or telecommunications equipment. A vault is often accessible directly from a street, sidewalk or other outdoor space, thereby distinct from a basement of a building.[1][2]
Utility vaults are commonly constructed out of reinforced concrete boxes, poured concrete or brick. Small ones are usually entered through a manhole or grate on the topside and closed up by a manhole cover. Such vaults are considered confined spaces and can be hazardous to enter. Large utility vaults are similar to mechanical or electrical rooms in design and content.
https://en.wikipedia.org/wiki/Utility_vault
A dugout or dug-out, also known as a pit-house or earth lodge, is a shelter for humans or domesticated animals and livestock based on a hole or depression dug into the ground. Dugouts can be fully recessed into the earth, with a flat roof covered by ground, or dug into a hillside. They can also be semi-recessed, with a constructed wood or sod roof standing out. These structures are one of the most ancient types of human housing known to archaeologists, and the same methods have evolved into modern "earth shelter" technology.
Dugouts may also be temporary shelters constructed as an aid to specific activities, e.g., concealment and protection during warfare or shelter while hunting.
https://en.wikipedia.org/wiki/Dugout_(shelter)
Catacombs are man-made subterranean passageways for religious practice. Any chamber used as a burial place is a catacomb, although the word is most commonly associated with the Roman Empire.[1]
https://en.wikipedia.org/wiki/Catacombs
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A mausoleum is an external free-standing building constructed as a monument enclosing the burial chamber of a deceased person or people. A mausoleum without the person's remains is called a cenotaph. A mausoleum may be considered a type of tomb, or the tomb may be considered to be within the mausoleum.
https://en.wikipedia.org/wiki/Mausoleum
| Septic tank | |
|---|---|
 | |
| A septic tank being installed in the ground | |
| Position in sanitation chain | Collection and storage/treatment (on-site)[1] |
| Application level | Household or neighborhood level (schools, hotels etc.)[1] |
| Management level | Household, public, shared (most common is household level)[1] |
| Inputs | blackwater (waste), greywater, brownwater[1] |
| Outputs | Fecal sludge, effluent[1] |
| Types | Single tank or multi-chamber septic tanks (potentially with baffles)[1] |
| Environmental concerns | Groundwater pollution, water pollution e.g. during floods[1] |
A septic tank is an underground chamber made of concrete, fiberglass, or plastic through which domestic wastewater (sewage) flows for basic sewage treatment.[2] Settling and anaerobic digestion processes reduce solids and organics, but the treatment efficiency is only moderate (referred to as "primary treatment").[2] Septic tank systems are a type of simple onsite sewage facility. They can be used in areas that are not connected to a sewerage system, such as rural areas. The treated liquid effluent is commonly disposed in a septic drain field, which provides further treatment. Nonetheless, groundwater pollution may occur and can be a problem.
The term "septic" refers to the anaerobic bacterial environment that develops in the tank that decomposes or mineralizes the waste discharged into the tank. Septic tanks can be coupled with other onsite wastewater treatment units such as biofilters or aerobic systems involving artificially forced aeration.[3]
The rate of accumulation of sludge—also called septage or fecal sludge—is faster than the rate of decomposition.[2] Therefore, the accumulated fecal sludge must be periodically removed, which is commonly done with a vacuum truck.[4]
https://en.wikipedia.org/wiki/Septic_tank
A vacuum truck, vacuum tanker, vactor truck, vactor, vac-con truck, vac-con is a tank truck that has a pump and a tank. The pump is designed to pneumatically suck liquids, sludges, slurries, or the like from a location (often underground) into the tank of the truck. The objective is to enable transport of the liquid material via road to another location. Vacuum trucks transport the collected material to a treatment or disposal site, for example a sewage treatment plant.
A common material to be transported is septage (or more broadly: fecal sludge) which is human excreta mixed with water, e.g. from septic tanks and pit latrines. They also transport sewage sludge, industrial liquids, or slurries from animal waste from livestock facilities with pens. Vacuum trucks can also be used to prepare a site for installation or to access underground utilities. These trucks may use compressed air or water to break up the ground safely, without risk of damage, before installation may begin.
Vacuum trucks can be equipped with a high pressure pump if they are used to clean out sewers from sand.
https://en.wikipedia.org/wiki/Vacuum_truck
A fogou or fougou[1] (pronounced "foo-goo") is an underground, dry-stone structure found on Iron Age or Romano-British-defended settlement sites in Cornwall. The original purpose of a fogou is uncertain today. Colloquially called vugs, vows, foggos, giant holts, or fuggy holes in various dialects,[2] fogous have similarities with souterrains or earth-houses of northern Europe and particularly Scotland, including Orkney. Fewer than 15 confirmed fogous have been found.
https://en.wikipedia.org/wiki/Fogou
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| Nuclear weapons |
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| Background |
| Nuclear-armed states |
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A fallout shelter is an enclosed space specially designated to protect occupants from radioactive debris or fallout resulting from a nuclear explosion. Many such shelters were constructed as civil defense measures during the Cold War.
During a nuclear explosion, matter vaporized in the resulting fireball is exposed to neutrons from the explosion, absorbs them, and becomes radioactive. When this material condenses in the rain, it forms dust and light sandy materials that resemble ground pumice. The fallout emits alpha and beta particles, as well as gamma rays.
Much of this highly radioactive material falls to Earth, subjecting anything within the line of sight to radiation, becoming a significant hazard. A fallout shelter is designed to allow its occupants to minimize exposure to harmful fallout until radioactivity has decayed to a safer level, over a few weeks or months.
https://en.wikipedia.org/wiki/Fallout_shelter
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A borehole is a narrow shaft bored in the ground, either vertically or horizontally. A borehole may be constructed for many different purposes, including the extraction of water (drilled water well and tube well), other liquids (such as petroleum), or gases (such as natural gas). It may also be part of a geotechnical investigation, environmental site assessment, mineral exploration, temperature measurement, as a pilot hole for installing piers or underground utilities, for geothermal installations, or for underground storage of unwanted substances, e.g. in carbon capture and storage.
https://en.wikipedia.org/wiki/Borehole
| Nuclear weapons |
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| Background |
| Nuclear-armed states |
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A blast shelter is a place where people can go to protect themselves from blasts and explosions, like those from bombs, or in hazardous worksites, such as on oil and gas refineries or petrochemical facilities. It differs from a fallout shelter, in that its main purpose is to protect from shock waves and overpressure instead of from radioactive precipitation, as a fallout shelter does. It is also possible for a shelter to protect from both blasts and fallout.
Blast shelters are a vital form of protection from nuclear attacks and are employed in civil defense. There are above-ground, below-ground, dedicated, dual-purpose, and potential blast shelters. Dedicated blast shelters are built specifically for the purpose of blast protection (see bunker). Dual-purpose blast shelters are existing structures with blast-protective properties that have been modified to accommodate people seeking protection from blasts. Potential blast shelters are existing structures or geological features exhibiting blast-protective properties that have potential to be used for protection from blasts.
https://en.wikipedia.org/wiki/Blast_shelter
An underground city is a series of linked subterranean spaces that may provide a defensive refuge; a place for living, working or shopping; a transit system; mausolea; wine or storage cellars; cisterns or drainage channels; or several of these. Underground cities may be currently active modern creations or they may be historic including ancient sites, some of which may be all or partially open to the public.
The term may also refer to a network of tunnels that connects buildings beneath street level that may house office blocks, shopping centres, metro stations, theatres, and other attractions. These passages can usually be accessed through the public space of any of the buildings connecting to them, and sometimes have separate entries as well. This latter definition encompasses many modern structures, whereas the former more generally covers tunnel systems from ancient times to the present day.
Underground cities are especially functional in cities with very cold or hot climates, because they permit activities to be comfortably accessible year round without regard to the weather. Underground cities are similar in nature to skyway systems and may include some buildings linked by skyways or above-ground corridors rather than underground.
Some cities also have tunnels that have been abandoned.[1][2][3]
https://en.wikipedia.org/wiki/Underground_city
A telecommunications pedestal is a ground-level housing for a passive connection point for underground cables. Technicians require access to connection points. Placing such a point underground (e.g., in a utility vault) is expensive, so pedestals are preferred when they are an acceptable choice. Pedestals are used for CATV (known as a cable box in such a situation), telephone, passive optical networks, and other telecommunications systems.
A pedestal is generally a sheet metal or plastic housing that encloses a passive termination block. The pedestal is usually about 3 feet high and has a diameter of less than one foot, with a circular, rectangular, oval, or "rounded rectangle" cross-section. The pedestal either has an access panel or removable housing. One, two, three or (occasionally) more underground distribution cables rise from the ground into the bottom of the pedestal and the individual circuits from the cables are terminated on the termination block. In addition to distribution cables, the pedestal may terminate one or more individual underground subscriber cables. The cables are cross-connected as needed at the termination block.
https://en.wikipedia.org/wiki/Telecommunications_pedestal
A utility tunnel, utility corridor, or utilidor is a passage built underground or above ground to carry utility lines such as electricity, steam, water supply pipes, and sewer pipes. Communications utilities like fiber optics, cable television, and telephone cables are also sometimes carried. One may also be referred to as a services tunnel, services trench, services vault, or cable vault. Smaller cable containment is often referred to as a cable duct or underground conduit. Direct-buried cable is a major alternative to ducts or tunnels.
https://en.wikipedia.org/wiki/Utility_tunnel
| Permafrost | |
|---|---|
 Map showing extent and types of permafrost in the Northern Hemisphere | |
| Used in | International Permafrost Association |
| Climate | High latitudes, alpine regions |
Permafrost (from perma- 'permanent', and frost) is soil or underwater sediment which continuously remains below 0 °C (32 °F) for two or more years. Land-based permafrost can include the surface layer of the soil, but if the surface is too warm, it may still occur within a few centimeters of the surface down to hundreds of meters. It usually consists of ice holding in place a combination of various types of soil, sand, and rock, though in ice-free ground, perennially frozen non-porous bedrock can serve the same role.[1]
Around 15% of the Northern Hemisphere or 11% of the global surface is underlain by permafrost,[2] with the total area of around 18 million km2 (6.9 million sq mi).[3] This includes substantial areas of Alaska, Greenland, Canada, and Siberia. It is also located in high mountain regions, with the Tibetan Plateau a prominent example. Only a minority of permafrost exists in the Southern Hemisphere, where it is consigned to mountain slopes like in the Andes or the Southern Alps of New Zealand, and beneath the massive ice sheets of the Antarctic.[4]
https://en.wikipedia.org/wiki/Permafrost
Usage
Utility tunnels are common in very cold climates where direct burial below the frost line is not feasible (such as in Alaska, where the frost line is often more than 18 ft (5.5 m) below the surface, which is frozen year round). They are also built in places where the water table is too high to bury water and sewer mains, and where utility poles would be too unsightly or pose a danger (like in earthquake prone Tokyo). Tunnels are also built to avoid the disruption caused by recurring construction, repair and upgrading of cables and pipes in direct burial trenches.[1]
Utility tunnels are also often common on large industrial, institutional, or commercial sites, where multiple large-scale services infrastructure (gas, water, power, heat, steam, compressed air, telecommunications cable, etc.) are distributed around the site to multiple buildings, without impeding vehicular or pedestrian traffic above ground. Due to the nature of these services, they may require regular inspection, repair, maintenance, or replacement, and therefore accessible utility tunnels are preferred instead of direct burying of the services in the ground.
Utility tunnels range in size from just large enough to accommodate the utility being carried, to very large tunnels that can also accommodate human and even vehicular traffic.
https://en.wikipedia.org/wiki/Utility_tunnel
The frost line—also known as frost depth or freezing depth—is most commonly the depth to which the groundwater in soil is expected to freeze. The frost depth depends on the climatic conditions of an area, the heat transfer properties of the soil and adjacent materials, and on nearby heat sources. For example, snow cover and asphalt insulate the ground and homes can heat the ground (see also heat island). The line varies by latitude, it is deeper closer to the poles. Per Federal Highway Administration Publication Number FHWA-HRT-08-057, the maximum frost depth observed in the contiguous United States ranges from 0 to 8 feet (2.4 m).[1] Below that depth, the temperature varies, but is always above 32 °F (0 °C).
Alternatively, in Arctic and Antarctic locations the freezing depth is so deep that it becomes year-round permafrost, and the term "thaw depth" is used instead. Finally, in tropical regions, frost line may refer to the vertical geographic elevation below which frost does not occur.[2]
Frost front refers to the varying position of the frost line during seasonal periods of freezing and thawing.
https://en.wikipedia.org/wiki/Frost_line
https://en.wikipedia.org/wiki/pressure_material_age
| Authority control databases: National |
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