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Shaft (civil Engineering)
In civil engineering a shaft is an underground vertical or inclined passageway. Shafts are often entered through a manhole and closed by a manhole cover. They are constructed for a number of reasons including: * For the construction of a tunnel * For ventilation of a tunnel or underground structure, aka ventilation shaft * As a drop shaft for a sewerage or water tunnel * For access to a tunnel or underground structure, also as an escape route Construction There are a number of methods for the construction of shafts, the most significant being: * The use of sheet piles, diaphragm walls or bored piles to construct a square or rectangular braced shaft * The use of segmental lining installed by underpinning In construction or renovation, underpinning is the process of strengthening the foundation of an existing building or other structure. Underpinning may be necessary for a variety of reasons: * The original foundation isn't strong or stable enough. ... or caisson sunk to form ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Manhole
A manhole (utility hole, maintenance hole, 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. These manholes are typically around square. Construction Manhole closings are protected by a grating or manhole cover, a flat plug designed to prevent accidental or unauthoriz ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Manhole Cover
A manhole cover or maintenance hole cover is a removable plate forming the lid over the opening of a manhole, an opening large enough for a person to pass through that is used as an access point for an underground vault or pipe. It is designed to prevent anyone or anything from falling in, and to keep out unauthorized persons and material. Manhole covers date back at least to the era of ancient Rome, which had sewer grates made from stone. Description Manhole covers are often made out of cast iron, concrete or a combination of the two. This makes them inexpensive, strong, and heavy, usually weighing more than . The weight helps to keep them in place when traffic passes over them, and makes it difficult for unauthorized people without suitable tools to remove them. Manhole covers may also be made from glass-reinforced plastic or other composite material (especially in Europe, or where cover theft is of concern). Because of law restricting acceptable manual handling weights, E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ventilation (mining)
Underground mine ventilation provides a flow of air to the underground workings of a mine of sufficient volume to dilute and remove dust and noxious gases (typically NOx, SO2, methane, CO2 and CO) and to regulate temperature. The source of these gases are equipment that runs on diesel engines, blasting with explosives, and the orebody itself. The largest component of the operating cost for mine ventilation is electricity to power the ventilation fans, which may account for one third of a typical underground mine's entire electrical power cost. Types of ventilation Flow-through ventilation is the main ventilation circuit for the mine. Air enters the mine from surface via a shaft, ventilation raise or adit. The air is distributed through the mine via internal ventilation raises and ramps, and flows are controlled by regulators and permanently mounted ventilation fans. An auxiliary ventilation system takes air from the flow-through system and distributes it to the mine wor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subterranea (geography)
Subterranea are ''underground structures'', both natural (such as caves) and human-made (such as mines). Some subterranea and related topics include: Natural * Caves ** Cenote ** Ice cave ** Sea cave ** Sinkhole * Karst * Lava tube ** Lunar and Martian lava tubes * Subterranean river * Subterranean waterfall * Underground lake * Volcanic pipe Human-made or related * Borehole * Bunker * Burial vault (tomb) * Casemate * Catacombs * Cave dweller, Underground living * Cave temple * Cellar * Dungeon * Dugout (shelter) * Fogou * Mine * Rock cut architecture, rock-cut tomb * Smuggling tunnel * Tunnels (street tunnel, train tunnels) * Underground city, umbrella article for underground dwellings and facilities * Underground rapid transit system * Wine cave See also * Boring (earth) * Seattle Underground * Subterranean London Subterranean London refers to a number of subterranean structures that lie beneath London. The city has been occupied by humans for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ventilation Shaft
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. In architecture, an airshaft is a small, vertical space within a tall building which permits ventilation of the building's interior spaces to the outside. 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. See also * Ventilation (architecture) * Stack effect * Underground mine ventilation * Courtyard * Lightwell * Skylight * Atrium (architecture) In architecture, an atrium (plural: atria or atriums) is a large open-air or skylight-covered space surrounded by a building. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Slurry Wall
A slurry wall is a civil engineering technique used to build reinforced concrete walls in areas of soft earth close to open water, or with a high groundwater table. This technique is typically used to build diaphragm (water-blocking) walls surrounding tunnels and open cuts, and to lay foundations. Construction While a trench is being excavated to create a form for a wall, it is simultaneously filled with slurry (usually a mixture of bentonite and water). The dense but liquid slurry prevents the trench from collapsing by providing outward pressure, which balances the inward hydraulic forces and also retards water flow into the trench. The density of the slurry mix must be carefully monitored and adjusted to produce the correct outward pressure to prevent the trench walls from collapsing. Slurry walls are typically constructed by starting with a set of concrete guide walls, typically deep and thick. The guide walls are constructed near the ground surface to outline the desir ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Underpinning
In construction or renovation, underpinning is the process of strengthening the foundation of an existing building or other structure. Underpinning may be necessary for a variety of reasons: * The original foundation isn't strong or stable enough. * The usage of the structure has changed. * The properties of the soil supporting the foundation may have changed (possibly through subsidence) or were mischaracterized during design. * The construction of nearby structures necessitates the excavation of soil supporting existing foundations. * To increase the depth or load capacity of existing foundations to support the addition of another storey to the building (above or below grade). * It is more economical, due to land price or otherwise, to work on the present structure's foundation than to build a new one. * Earthquake, flood, drought or other natural causes have caused the structure to move, requiring stabilisation of foundation soils and/or footings. Underpinning may be accomplish ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caisson (engineering)
In geotechnical engineering, a caisson ( or ; borrowed from French ''caisson'', from Italian ''cassone'', meaning ''large box'', an augmentative of ''cassa'') is a watertight retaining structure used, for example, to work on the foundations of a bridge pier, for the construction of a concrete dam, or for the repair of ships. Caissons are constructed in such a way that the water can be pumped out, keeping the work environment dry. When piers are being built using an open caisson, and it is not practical to reach suitable soil, friction pilings may be driven to form a suitable sub-foundation. These piles are connected by a foundation pad upon which the column pier is erected. Caisson engineering has been used at least since the 18th century, and was notably used in the construction of the Brooklyn Bridge, which was completed in 1883. Types To install a caisson in place, it is brought down through soft mud until a suitable foundation material is encountered. While bedrock is pre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Civil Engineering
Civil engineering is a professional engineering discipline that deals with the design, construction, and maintenance of the physical and naturally built environment, including public works such as roads, bridges, canals, dams, airports, sewage systems, pipelines, structural components of buildings, and railways. Civil engineering is traditionally broken into a number of sub-disciplines. It is considered the second-oldest engineering discipline after military engineering, and it is defined to distinguish non-military engineering from military engineering. Civil engineering can take place in the public sector from municipal public works departments through to federal government agencies, and in the private sector from locally based firms to global Fortune 500 companies. History Civil engineering as a discipline Civil engineering is the application of physical and scientific principles for solving the problems of society, and its history is intricately linked to advances i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
