Geotechnical engineering is the branch of civil engineering concerned with the engineering behavior of earth materials. It uses the principles of soil mechanics and rock mechanics for the solution of its respective engineering problems. It also relies on knowledge of geology, hydrology, geophysics, and other related sciences. Geotechnical (rock) engineering is a subdiscipline of geological engineering.
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.
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.
Engineering geology is the application of geology to engineering study for the purpose of assuring that the geological factors regarding the location, design, construction, operation and maintenance of engineering works are recognized and accounted for. Engineering geologists provide geological and geotechnical recommendations, analysis, and design associated with human development and various types of structures. The realm of the engineering geologist is essentially in the area of earth-structure interactions, or investigation of how the earth or earth processes impact human made structures and human 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.
In structural engineering, a shear wall is a vertical element of a system that is designed to resist in-plane lateral forces, typically wind and seismic loads. In many jurisdictions, the International Building Code and International Residential Code govern the design of shear walls.
Rock mass classification systems are used for various engineering design and stability analysis. These are based on empirical relations between rock mass parameters and engineering applications, such as tunnels, slopes, foundations, and excavatability. The first rock mass classification system in geotechnical engineering was proposed in 1946 for tunnels with steel set support.
Rock Structure Rating (RSR) is a quantitative method for describing quality of a rock mass and appropriate ground support, in particular, for steel-rib support, developed by Wickham, Tiedemann and Skinner.
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.
Blow molding is a manufacturing process for forming hollow plastic parts. It is also used for forming glass bottles or other hollow shapes.
Pietro Lunardi is an Italian politician and engineer.
The Iwate-Ichinohe Tunnel is a 25.81 km terrestrial railway tunnel in Japan — part of the Tōhoku Shinkansen, linking Tokyo with Aomori. When opened in 2002 it was the longest in-use terrestrial tunnel in world, but the title was overtaken by the Lötschberg Base Tunnel in June 2007.
Soil nailing is a remedial construction measure to treat unstable natural soil slopes or unstable man-made (fill) slopes as a construction technique that allows the safe over-steepening of new or existing soil slopes. The technique involves the insertion of relatively slender reinforcing elements into the slope – often general purpose reinforcing bars (rebar) although proprietary solid or hollow-system bars are also available. Solid bars are usually installed into pre-drilled holes and then grouted into place using a separate grout line, whereas hollow bars may be drilled and grouted simultaneously by the use of a sacrificial drill bit and by pumping grout down the hollow bar as drilling progresses. Kinetic methods of firing relatively short bars into soil slopes have also been developed.
Metro Tunneling Group or MTG is a Joint Venture (JV) of 5 companies currently working as the main contractor for the Delhi Metro Rail Corporation (DMRC). The 5 companies are DYWIDAG Systems from Germany, Larsen & Toubro from India, Samsung Corporation from South Korea, Ircon International from India, and Shimizu Corporation from Japan. DMRC is the joint venture of Government of India and Government of Delhi.
The Mt. Lebanon Tunnel is a light rail tunnel in Allegheny County, Pennsylvania, also known as the Dormont/Mt. Lebanon Transit Tunnel, part of the Pittsburgh Light Rail system.
Franz Pacher was an Austrian civil engineer and a pioneer of modern tunneling. He is one of three men who are considered to be the chief developers of the New Austrian Tunneling method (NATM).
The rock mass rating (RMR) is a geomechanical classification system for rocks, developed by Z. T. Bieniawski between 1972 and 1973. Since then it has undergone multiple modifications out of which, RMR89 is commonly used. Recently RMR14 has been proposed to improve the RMR performance by incorporating new experiences from tunnel practices. Continuous functions and a software "QuickRMR" for RMR89 and RMR14 have also been proposed by Kundu. RMR combines the most significant geologic parameters of influence and represents them with one overall comprehensive index of rock mass quality, which is used for the design and construction of excavations in rock, such as tunnels, mines, slopes, and foundations.
The Eurasia Tunnel is a road tunnel in Istanbul, Turkey, crossing underneath the Bosphorus strait. The tunnel was officially opened on 20 December 2016 and opened to traffic on 22 December 2016.
The tunnels of Gibraltar were constructed over the course of nearly 200 years, principally by the British Army. Within a land area of only 2.6 square miles (6.7 km2), Gibraltar has around 34 miles (55 km) of tunnels, nearly twice the length of its entire road network. The first tunnels, excavated in the late 18th century, served as communication passages between artillery positions and housed guns within embrasures cut into the North Face of the Rock. More tunnels were constructed in the 19th century to allow easier access to remote areas of Gibraltar and accommodate stores and reservoirs to deliver the water supply of Gibraltar.
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.
