Underground hard-rock mining refers to various underground mining techniques used to excavate "hard" minerals, usually those containing metals, such as ore containing gold, silver, iron, copper, zinc, nickel, tin, and lead. It also involves the same techniques used to excavate ores of gems, such as diamonds and rubies. Soft-rock mining refers to the excavation of softer minerals, such as salt, coal, and oil sands.
A tunnel is an underground passageway, dug through surrounding soil, earth or rock, and enclosed except for the entrance and exit, commonly at each end. A pipeline is not a tunnel, though some recent tunnels have used immersed tube construction techniques rather than traditional tunnel boring methods.
Sewerage is the infrastructure that conveys sewage or surface runoff using sewers. It encompasses components such as receiving drains, manholes, pumping stations, storm overflows, and screening chambers of the combined sewer or sanitary sewer. Sewerage ends at the entry to a sewage treatment plant or at the point of discharge into the environment. It is the system of pipes, chambers, manholes, etc. that conveys the sewage or storm water.
The Kilsby Tunnel is a railway tunnel on the West Coast Main Line in England, near the village of Kilsby in Northamptonshire, roughly 5 miles (8 km) southeast of Rugby. It is 2,423 yards (2,216 m) long.
The Thames Tunnel is a tunnel beneath the River Thames in London, connecting Rotherhithe and Wapping. It measures 35 feet (11 m) wide by 20 feet (6 m) high and is 1,300 feet (396 m) long, running at a depth of 75 feet (23 m) below the river surface measured at high tide. It is the first tunnel known to have been constructed successfully underneath a navigable river and was built between 1825 and 1843 by Marc Brunel and his son Isambard using the tunnelling shield newly invented by the elder Brunel and Thomas Cochrane.
The Rotherhithe Tunnel, designated the A101, is a road tunnel under the River Thames in East London, connecting Limehouse in the London Borough of Tower Hamlets north of the river to Rotherhithe in the London Borough of Southwark south of the river. It was formally opened in 1908 by George, Prince of Wales, and Richard Robinson, Chairman of the London County Council. It is a rare example of a road tunnel where road traffic, pedestrians and cyclists all share the same tunnel bore. Transport for London took over ownership and maintenance of the tunnel in 2001.
A tunnel boring machine (TBM), also known as a "mole", is a machine used to excavate tunnels with a circular cross section through a variety of soil and rock strata. They may also be used for microtunneling. They can be designed to bore through hard rock, wet or dry soil, or sand. Tunnel diameters can range from one metre (3.3 ft) (micro-TBMs) to 17.6 metres (58 ft) to date. Tunnels of less than a metre or so in diameter are typically done using trenchless construction methods or horizontal directional drilling rather than TBMs. TBMs can be designed to excavate non-circular tunnels, including u-shaped, horseshoe, square or rectangular tunnels.
The Chicago Tunnel Company was the builder and operator of a 2 ft narrow-gauge railway freight tunnel network under downtown Chicago, Illinois. This was regulated by the Interstate Commerce Commission as an interurban even though it operated entirely under central Chicago, did not carry passengers, and was entirely underground. It inspired the construction of the London Post Office Railway.
Trenchless technology is a type of subsurface construction work that requires few trenches or no continuous trenches. It is a rapidly growing sector of the construction and civil engineering industry. It can be defined as "a family of methods, materials, and equipment capable of being used for the installation of new or replacement or rehabilitation of existing underground infrastructure with minimal disruption to surface traffic, business, and other activities."
The New Austrian tunneling method (NATM), also known as the sequential excavation method (SEM) or sprayed concrete lining method (SCL), is a method of modern tunnel design and construction employing sophisticated monitoring to optimize various wall reinforcement techniques based on the type of rock encountered as tunneling progresses. This technique first gained attention in the 1960s based on the work of Ladislaus von Rabcewicz, Leopold Müller, and Franz Pacher between 1957 and 1965 in Austria. The name NATM was intended to distinguish it from earlier methods, with its economic advantage of employing inherent geological strength available in the surrounding rock mass to stabilize the tunnel wherever possible rather than reinforcing the entire tunnel.
A cofferdam is an enclosure built within a body of water to allow the enclosed area to be pumped out. This pumping creates a dry working environment so that the work can be carried out safely. Cofferdams are commonly used for construction or repair of permanent dams, oil platforms, bridge piers, etc., built within water.
In geotechnical engineering, a caisson 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.
Shotcrete, gunite, or sprayed concrete is concrete or mortar conveyed through a hose and pneumatically projected at high velocity onto a surface, as a construction technique, first used in 1907 invented by Carl Akeley. It is typically reinforced by conventional steel rods, steel mesh, or fibers.
Shaft mining or shaft sinking is the action of excavating a mine shaft from the top down, where there is initially no access to the bottom. Shallow shafts, typically sunk for civil engineering projects, differ greatly in execution method from deep shafts, typically sunk for mining projects.
The Furka Base Tunnel is a Swiss railway base tunnel on the Matterhorn Gotthard Bahn's Furka–Oberalp line, an east-west railway connecting the cantons of Valais and Uri. Its west portal lies east of Oberwald (VS), at 1,390 m (4,560 ft) above sea level and its east portal lies south of Realp (UR), at 1,550 m (5,090 ft).
Wine caves are subterranean structures for the storage and the aging of wine. They are an integral component of the wine industry worldwide. The design and construction of wine caves represents a unique application of underground construction techniques.
A deep foundation is a type of foundation that transfers building loads to the earth farther down from the surface than a shallow foundation does to a subsurface layer or a range of depths. A pile or piling is a vertical structural element of a deep foundation, driven or drilled deep into the ground at the building site.
A well is an excavation or structure created in the ground by digging, driving, or drilling to access liquid resources, usually water. The oldest and most common kind of well is a water well, to access groundwater in underground aquifers. The well water is drawn up by a pump, or using containers, such as buckets or large water bags that are raised mechanically or by hand. Water can also be injected back into the aquifer through the well. Wells were first constructed at least eight thousand years ago and historically vary in construction from a simple scoop in the sediment of a dry watercourse to the qanats of Iran, and the stepwells and sakiehs of India. Placing a lining in the well shaft helps create stability, and linings of wood or wickerwork date back at least as far as the Iron Age.
Tunnels are dug in types of materials varying from soft clay to hard rock. The method of tunnel construction depends on such factors as the ground conditions, the ground water conditions, the length and diameter of the tunnel drive, the depth of the tunnel, the logistics of supporting the tunnel excavation, the final use and shape of the tunnel and appropriate risk management. Tunnel construction is a subset of underground construction.
Stepney Green cavern is an underground junction which contains the junction where Crossrail divides into two branches: one to Shenfield and one to Abbey Wood. It is located below Stepney Green Park. At the time of its completion in 2017, Stepney Green cavern was claimed to have been one of the largest mined caverns in Europe.
