释义 |
tunnel
tun·nel T0413900 (tŭn′əl)n.1. An underground or underwater passage.2. A passage through or under a barrier such as a mountain.3. A tube-shaped structure.v. tun·neled, tun·nel·ing, tun·nels or tun·nelled or tun·nel·ling v.tr.1. To make a tunnel through or under: tunneling the granite.2. To produce, shape, or dig in the form of a tunnel: tunnel a passageway out of prison.v.intr. To make a tunnel. [Middle English tonel, barrel, tubular net, from Old French tonnel, diminutive of tonne, tun, possibly of Celtic origin.] tun′nel·er, tun′nel·ler n.tunnel (ˈtʌnəl) n1. (Civil Engineering) an underground passageway, esp one for trains or cars that passes under a mountain, river, or a congested urban area2. any passage or channel through or under something3. a dialect word for funnel4. (Building) obsolete the flue of a chimneyvb, -nels, -nelling or -nelled, -nels, -neling or -neled5. (Civil Engineering) (tr) to make or force (a way) through or under (something): to tunnel a hole in the wall; to tunnel the cliff. 6. (intr; foll by through, under, etc) to make or force a way (through or under something): he tunnelled through the bracken. [C15: from Old French tonel cask, from tonne tun, from Medieval Latin tonna barrel, of Celtic origin] ˈtunneller, ˈtunneler ntun•nel (ˈtʌn l) n., v. -neled, -nel•ing (esp. Brit.) -nelled, -nel•ling. n. 1. an underground passage. 2. a passageway, as for trains or automobiles, through or under a mountain, river, or other obstruction. 3. an approximately horizontal gallery or corridor in a mine. 4. the burrow of an animal. 5. Dial. a funnel. v.t. 6. to construct a passageway through or under. 7. to make or excavate (a tunnel or underground passage). v.i. 8. to make a tunnel or tunnels. [1400–50; late Middle English tonel (n.) < Middle French tonele, tonnelle funnel-shaped net, feminine of tonnel cask, diminutive of tonne tun; see -elle] tun′nel•er, n. tunnel Past participle: tunnelled Gerund: tunnelling
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I tunnel | you tunnel | he/she/it tunnels | we tunnel | you tunnel | they tunnel |
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I tunnelled | you tunnelled | he/she/it tunnelled | we tunnelled | you tunnelled | they tunnelled |
Present Continuous |
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I am tunnelling | you are tunnelling | he/she/it is tunnelling | we are tunnelling | you are tunnelling | they are tunnelling |
Present Perfect |
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I have tunnelled | you have tunnelled | he/she/it has tunnelled | we have tunnelled | you have tunnelled | they have tunnelled |
Past Continuous |
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I was tunnelling | you were tunnelling | he/she/it was tunnelling | we were tunnelling | you were tunnelling | they were tunnelling |
Past Perfect |
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I had tunnelled | you had tunnelled | he/she/it had tunnelled | we had tunnelled | you had tunnelled | they had tunnelled |
Future |
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I will tunnel | you will tunnel | he/she/it will tunnel | we will tunnel | you will tunnel | they will tunnel |
Future Perfect |
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I will have tunnelled | you will have tunnelled | he/she/it will have tunnelled | we will have tunnelled | you will have tunnelled | they will have tunnelled |
Future Continuous |
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I will be tunnelling | you will be tunnelling | he/she/it will be tunnelling | we will be tunnelling | you will be tunnelling | they will be tunnelling |
Present Perfect Continuous |
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I have been tunnelling | you have been tunnelling | he/she/it has been tunnelling | we have been tunnelling | you have been tunnelling | they have been tunnelling |
Future Perfect Continuous |
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I will have been tunnelling | you will have been tunnelling | he/she/it will have been tunnelling | we will have been tunnelling | you will have been tunnelling | they will have been tunnelling |
Past Perfect Continuous |
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I had been tunnelling | you had been tunnelling | he/she/it had been tunnelling | we had been tunnelling | you had been tunnelling | they had been tunnelling |
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I would tunnel | you would tunnel | he/she/it would tunnel | we would tunnel | you would tunnel | they would tunnel |
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I would have tunnelled | you would have tunnelled | he/she/it would have tunnelled | we would have tunnelled | you would have tunnelled | they would have tunnelled | ThesaurusNoun | 1. | tunnel - a passageway through or under something, usually underground (especially one for trains or cars); "the tunnel reduced congestion at that intersection"auto, automobile, car, motorcar, machine - a motor vehicle with four wheels; usually propelled by an internal combustion engine; "he needs a car to get to work"catacomb - an underground tunnel with recesses where bodies were buried (as in ancient Rome)passageway - a passage between rooms or between buildingsrailroad tunnel - a tunnel through which the railroad track runsshaft - a long vertical passage sunk into the earth, as for a mine or tunnelunderpass, subway - an underground tunnel or passage enabling pedestrians to cross a road or railway | | 2. | tunnel - a hole made by an animal, usually for shelterburrowhollow, hole - a depression hollowed out of solid matterrabbit warren, warren - a series of connected underground tunnels occupied by rabbits | Verb | 1. | tunnel - move through by or as by digging; "burrow through the forest"burrowcut into, delve, dig, turn over - turn up, loosen, or remove earth; "Dig we must"; "turn over the soil for aeration" | | 2. | tunnel - force a way through penetrate, perforate - pass into or through, often by overcoming resistance; "The bullet penetrated her chest" |
tunnelnoun1. passage, underpass, passageway, subway, channel, hole, shaft two new railway tunnels through the Alpsverb1. dig, dig your way, burrow, mine, bore, drill, excavate The rebels tunnelled out of a maximum security jail.Translationstunnel (ˈtanl) noun a (usually man-made) underground passage, especially one cut through a hill or under a river. The road goes through a tunnel under the river. 隧道 隧道 verb – past tense, past participle ˈtunnelled , (American) ˈtunneled – to make a tunnel. They escaped from prison by tunnelling under the walls. 挖隧道 掘隧道tunnel
ear tunnel1. A short, cylindrical piece of jewelry that is fitted to one's earlobe, stretching it in such a way as to create a visible opening through the flesh. I'm in support of all forms of body modification, but the thought of getting an ear tunnel still gives me the willies.2. The visible opening through the flesh of the earlobe that results from such a piercing. I think she tried to stretch her ear tunnel too fast, and now it's pretty badly infected.See also: ear, tunnelsee the light at the end of the tunnelTo conceptualize or foresee an end to something difficult or unpleasant; to be relatively near to the end or conclusion of some problem or difficulty. I've been working on this book for over a year, but I can finally see the light at the end of the tunnel. Now that the doctors have been able to diagnose what's wrong with me, we might finally be able to see the light at the end of the tunnel.See also: end, light, of, see, tunnellight at the end of the tunnelThe end to something difficult or unpleasant. I've been working on this book for over a year, but I can finally see the light at the end of the tunnel. Now that the doctors have been able to diagnose what's wrong with me, there is finally light at the end of the tunnel.See also: end, light, of, tunneltunnel vision1. A condition in which one's field of vision narrows to a point directly in front of one's eyes, without the ability to see peripherally. I started getting tunnel vision from such a rapid change in altitude.2. A tendency, habit, or conscious decision to only focus one's energy or attention on a single particular thing or aspect, without regard for anything or anyone else. Tom tends to get tunnel vision when he starts working on a new project, so I wouldn't be surprised if we don't hear from him for a while. The only way I can complete my novels is if I have total tunnel vision while writing, which has had some disastrous effects on my relationships.See also: tunneltunnel through somethingto make a tunnel or passageway through something or a group of people. Roger had to tunnel through the crowd to get to the rest room. The workers tunneled through the soft soil to reach the buried cable.See also: through, tunneltunnel under someone or somethingto dig a tunnel under someone or something. All the time she was standing in the yard talking about the moles, they were tunneling under her. They took many months to tunnel under the English Channel.See also: tunneltunnel vision 1. Lit. a visual impairment wherein one can only see what is directly ahead of oneself. I have tunnel vision, so I have to keep looking from side to side. 2. Fig. an inability to recognize other ways of doing things or thinking about things. The boss really has tunnel vision about sales and marketing. He sees no reason to change anything.See also: tunnellight at the end of the tunnelThe end of a difficult situation or task, the solution to a difficult problem. For example, It's taken three years to effect this merger, but we're finally seeing the light at the end of the tunnel . This metaphoric expression dates from the 1800s, but became widespread only in the mid-1900s. See also: end, light, of, tunnellight at the end of the tunnel COMMON If there is light at the end of the tunnel, there is hope that a difficult situation might be coming to an end. After horrific times we are seeing light at the end of the tunnel. People feel hopeless. They don't see any light at the end of the tunnel.See also: end, light, of, tunneltunnel vision COMMON If someone has tunnel vision, they use all their energy and skill on something that is important to them and ignore other important things. Unfortunately, government departments tend to exhibit extreme tunnel vision. It is often beyond their capacity to appreciate or support something if it benefits more than one department. Note: This expression can also be used to show admiration for someone who has achieved a lot by concentrating on a single thing. They always say that you have to have tunnel vision to be a champion. You can't have any outside distractions at all. Note: You can also use tunnel-vision before a noun. The experts sometimes have a bureaucratic, tunnel-vision view of their mission. Note: Tunnel vision is a medical condition in which someone can only see things that are immediately in front of them, and cannot see things that are to the side. See also: tunnellight at the end of the tunnel a long-awaited indication that a period of hardship or adversity is nearing an end.See also: end, light, of, tunnel(see the) ˌlight at the end of the ˈtunnel (see) the possibility of success, happiness, etc. in the future, especially after a long period of difficulty: Business has been bad recently, but I think we’re beginning to see some light at the end of the tunnel.See also: end, light, of, tunnel(have) ˌtunnel ˈvision (disapproving) (have) an interest in only one small part of something instead of the whole of it: He’s got tunnel vision about music. He thinks only the classics are worth listening to.See also: tunnel light at the end of the tunnel The prospect of success, relief, or escape after strenuous effort.See also: end, light, of, tunnellight at the end of a tunnel, (see) theA solution emerges at long last. This metaphor, evoking the end of a long, dark mining or railroad tunnel, came into widespread use only in the mid-twentieth century. It was used by President John F. Kennedy in a 1962 press conference on the Vietnam War and became common throughout that conflict. However, the image was used nearly a century earlier in a letter by English novelist George Eliot, and the expression also appeared in a letter from J. Middleton Murry to his wife, Katherine Mansfield (1922): “I begin to feel that the horror may move away and that there is a big round spot of real daylight at the end of the tunnel.” See also: end, light, oftunnel visionA very narrow view, inability to see beyond a limited viewpoint. The term, dating from the mid-1900s, transfers the physiological inability to see peripheral objects to a mental outlook. For example, “Preble had the ghetto mind and the tunnel vision of a committed social climber” (T. Barling, Goodbye Piccadilly, 1980).See also: tunneltunnel
tunnel, underground passage usually made without removing the overlying rock or soil. Although tunnels are approximately horizontal, they must be built with sufficient gradient for proper drainage. Tunnels may be ventilated by shafts leading to the surface or by exhaust fans at the ends. Design and Construction Techniques Methods of tunneling vary with the nature of the material to be cut through. When soft earth is encountered, the excavation is timbered for support as the work advances; the timbers are sometimes left as a permanent lining for the tunnel. Another method is to cut two parallel excavations in which the side walls are constructed first. Arches connecting them are then built as the material between them is extracted. Portions of the unexcavated center, left temporarily for support, may be removed later. A tunnel cut through rock frequently requires no lining. Hard rock is removed by blasting. In constructing tunnels under rivers, the ordinary methods can be used as long as a stratum of impermeable material lies between the tunnel and the riverbed. In all cases, however, pumping equipment must be installed. Where mud, quicksand, or permeable earth is present in underwater tunneling, it becomes necessary to provide some means of holding back the water while the enclosing sections of the tunnel are placed in position. For this purpose the shield was devised and first used in 1825 by the French-born engineer Sir Marc I. Brunel when boring between Wapping and Rotherhithe, in England. Considered unsuccessful, the device was not employed again until 1869, when the British engineer James H. Greathead and the American inventor Alfred E. Beach developed improvements at about the same time. Their shields were metal cylinders fitting around the outside of the tunnel, the forward end closed by a diaphragm plate. As the rock or earth was cut away, the shield was shoved forward into the earth by hydraulic rams, compressed air being used to keep seepage to a minimum. The use of the pneumatic shield is now universal in tunneling under rivers. The actual cutting is performed by huge rotating cutter heads, each with up to fifty separate cutters, capable of penetrating 10 mm (1/2 in.) per revolution. River-crossing tunnels are also constructed by dredging a trench in the riverbed and then lowering prefabricated tunnel sections through the water into the trench, where they are connected to each other. The trench and tunnel are then covered over. In 1969, a tunnel was constructed across the Schelde River in Belgium, using sections 330 ft (100 m) long. Often, to speed construction, work is started at both ends. This poses no problem with the cut-and-cover method, but when the tunnel is bored from within, it must be assured that the tubes will actually meet in the center. Modern methods accomplish this with high precision. Significant Historic and Modern Tunnels The origin of tunnel building is disputed. The Egyptians built tunnels as entrances to tombs. The Babylonians built (c.2180 B.C.) a tunnel under the Euphrates using what is now called the "cut-and-cover" method; the river was diverted, a wide trench was dug across its bed, and a brick tube was constructed in it and covered up. The ancient Greeks and Romans built tunnels for carrying water and for mining purposes; some of the Roman tunnels are still in use. One of the first notable tunnels in Great Britain was part of the Grand Trunk Canal. It was nearly 2 mi (3.2 km) long and was completed in 1777. The Mont Cénis Tunnel, a railroad tunnel in the French Alps that opened in 1871 and is now 8.5 mi (13.7 km) long, was probably the first tunnel built using compressed-air drills. The first tunnel of importance in the United States was the tunnel through the Hoosac RangeHoosac Range , southern continuation of the Green Mts., NW Mass. and SW Vt., running from north to south. Its maximum height is c.3,000 ft (910 m). The Hoosac railroad tunnel, c. ..... Click the link for more information. in Massachusetts. There are hundreds of miles of tunnels in New York City and its vicinity, e.g., for subways, roads, water systems, and railroads. The Delaware AqueductDelaware Aqueduct , SE N.Y., 85 mi (137 km) long, carrying water from the Rondout Reservoir, Sullivan co., SE into the New York City water system at the Hillview Reservoir, Westchester co.; built 1937–62. ..... Click the link for more information. , which provides part of New York City's water supply, is at 105 mi (168 km) the longest continuous tunnel in the world. Road tunnels include the Holland Tunnel and the Lincoln Tunnel, which connect New York City's Manhattan Island with New Jersey, and the Hugh L. Carey (formerly Brooklyn-Battery) Tunnel, which connects Manhattan Island with Brooklyn and is the longest vehicular tunnel (1.7 mi/2.7 km) in the United States. The Anton Anderson Memorial Tunnel, also known as the Whittier Tunnel (2.5 mi/4 km), which opened in 1943 to rail traffic and in 2000 to vehicular traffic, connects Whittier, Alaska, to Anchorage and other cities; the unique single-lane tunnel allows rail or road traffic in one direction only at a time. The Chesapeake Bay Bridge-TunnelChesapeake Bay Bridge-Tunnel, officially the Lucius J. Kellam, Jr. Bridge-Tunnel, 17.6 mi (28.2 km) long, across the mouth of Chesapeake Bay, E Va., connecting Cape Charles with Norfolk, Va. ..... Click the link for more information. in Virginia, opened in 1964, has a length of 17.6 mi (28.2 km) and includes two tunnel segments over a mile long. The Simplon Tunnel (opened 1906; see under SimplonSimplon , pass, 6,590 ft (2,009 m) high, in the Lepontine Alps, Valais canton, S Switzerland. It is crossed by the Simplon Road built (1800–1806) by Napoleon I. ..... Click the link for more information. ) through the Alps was for many years the longest railway tunnel (12.3 mi/19.8 km) in the world. The Gotthard Base Tunnel (2016; see under Saint GotthardSaint Gotthard , mountain group of the Lepontine Alps, S central Switzerland, rising to Pizzo Rotondo (10,472 ft/3,192 m high). The Reuss, Rhine, Ticino, and Rhône rivers rise there. It is crossed by the Saint Gotthard Pass, 6,935 ft (2,114 m) high. ..... Click the link for more information. ), also in the Alps, is now the world's longest tunnel (35.4 mi/57 km), and the Seikan Tunnel (1988), connecting Honshu and Hokkaido, Japan, is the world's longest underwater tunnel (33.5 mi/53.6 km). The Channel TunnelChannel Tunnel, popularly called the "Chunnel," a three-tunnel railroad connection running under the English Channel, connecting Folkestone, England, and Calais, France. The tunnels are 31 mi (50 km) long. There are two rail tunnels, each 25 ft (7. ..... Click the link for more information. (1994; 31 mi/50 km) under the English Channel, however, has the longest underwater section. The world's longest vehicular tunnel, the Lærdal Tunnel (15.2 mi/24.5 km long), connects Lærdal and Aurland, Norway, and is an important overland link between Oslo and Bergen. The St. Gotthard Tunnel (10.2 mi/16.4 km long), in the Swiss Alps, was formerly the longest vehicular tunnel. Bibliography See T. M. Megaw and J. V. Bartlett, Tunnels (1981–82); B. Stack, Handbook of Mining and Tunnelling Machinery (1982); Approaching the 21st Century (1987). Tunnel a horizontal or sloping underground structure used for transportation, the moving of water, the laying of underground utility systems, and other purposes. According to use, the following types of tunnels are distinguished: railroad tunnels, vehicular tunnels, subway tunnels, tunnels at intersections of city streets and traffic arteries (seePEDESTRIAN CROSSING and ), canal tunnels, tunnels for the simultaneous passage of several types of transportation, water tunnels, municipal-service tunnels (for urban water-supply, heat- and gas-supply, sewer, and other systems), and special-purpose tunnels (for example, tunnels that are part of the underground structures of hydroelectric power plants, warehouses, and garages). According to location (Figure 1), tunnels are classified as mountain, subaqueous, and urban. Mountain tunnels are driven through ranges, divides, and individual mountains in mountainous regions; urban tunnels include subway tunnels. History. The origins of tunnel building go back to ancient times. Long before the Common Era underground work was carried out in Babylon, Egypt, Greece, and Rome, first in the mining of minerals and the construction of tombs and temples and then for water supply and transportation. Road, water-supply, and drainage tunnels—mostly arched—were driven in stable rock without reinforcement of the rock. The tunnels were cut with primitive tools. Upon the fall of the Roman Empire a period of relative stagnation in tunnel building ensued, and tunnels were built primarily for military purposes. At the end of the Middle Ages, as a result of the expansion of international trade, the building of canal tunnels that linked waterways was begun. The use of black powder to blast the rock was a prerequisite for such tunnel building. The first railroad tunnel (1.19 km long) was built in Great Britain for the Liverpool and Manchester Railway between 1826 and 1830. The invention of pyroxylin and dynamite and the successful use of drilling machines in mining made it possible to build the great Alpine tunnels between France, Italy, and Switzerland. Before World War I, 26 tunnels, each longer than 5 km, had been built, including the Simplón Tunnel (about 20 km long) between Italy and Switzerland. Among the tunnels built in the 1920’s and early 1930’s were the Apennine Tunnel (18.5 km long), which is a double-track railroad tunnel on the Florence-Bologna line in Italy, and the Rove Tunnel (more than 7 km long), which carries the Marseille-Rhône Canal in France. Together with the building of mountain tunnels, the building of subaqueous tunnels was also developed. Subaqueous tunnel building became possible through the use of tunneling shields (in combination with compressed air) and prefabricated lining. A number of major subaqueous tunnels have been driven by the shield method, for example, two vehicular tunnels (each 2.6 km long) under the Hudson River in the USA and the railroad tunnel (over 6 km long) driven under the Straits of Shimonoseki in Japan between 1936 and 1941. An important advance in the building of subaqueous tunnels was the use of sunken tube sections up to 150 m long. Figure 1. Tunnel layouts: (a) mountain tunnel, (b) subaqueous tunnel, (c) urban traffic tunnel: (1) portal, (2) ramp, (L1) length of tunnel, (L1) length of ramp, (H) depth at which tunnel lies The first railroad tunnel in Russia was the double-track Kovno Tunnel (1.28 km long), which was built in 1862. In the late 19th century many tunnels were built for railroads in the Urals, the Crimea, and the Caucasus. The largest was the Surami Tunnel (about 4 km long), which was built between 1886 and 1890. In the early 20th century a number of tunnels were built in Siberia and the Far East. Tunnel building developed considerably in the USSR as a result of intensive railroad building, the construction of a network of hydroelectric power plants, and the construction of subways and underground urban installations. Main elements of tunnels. The building of a tunnel requires an excavation, which is a cavity dug or cut in the earth’s crust in one or more stages, beginning from an adit, which is usually of trapezoidal cross section. In strong unweathered rock of uniform structure the tunnel excavation may be unsupported, but in unstable rock temporary mine supports must be installed. The temporary supports are later replaced by a permanent structure, which is called a lining and may be cast in situ or prefabricated. The lining is the most important element of a tunnel; it forms the tunnel’s inner surface, absorbs the rock pressure, and protects the tunnel against groundwater. The entrance section of a tunnel is called the portal; it assures the stability of the front and side slopes, or the preportal excavation, and gives the tunnel entrance its architectural form. Reinforced-concrete ramps, trough-shaped in cross section, are used both to prevent flooding of the entrance sections of subaqueous tunnels and to cope with mountainous conditions. Planning the route of a tunnel. The depth at which a tunnel lies, the length of the tunnel, its plan and profile, and the shape of its cross section depend on the purpose of the tunnel and on topographical, geological, and climatic conditions. During the planning and building of a tunnel, a series of surveys is carried out to select and fix the axis of the tunnel in plan and profile, to compute the geometric elements of the tunnel axis, to project the axis within the excavation, to determine the length of the axis, and to mark out the tunnel cross sections. Geological surveys are conducted along the route of the tunnel to determine, for example, the geological structure of the rock mass being cut, the nature of the rock stratification, the degree of stability and the physical and mechanical properties of the rock, the hydrogeological condition and the chemical composition of the groundwater, the presence of gases, the temperature in the excavation, and the expected rock pressure. Such data are obtained on the basis of geological exploration and hydrogeological studies using boreholes and geophysical methods; in some cases, the data are obtained from the results of exploratory tunneling. Figure 2. Tunnel construction schemes: (a) Advance in parts; (1) heading; (2), (4), (5), and (7) stages in expanding the excavation cross section; (3), (6), and (8) concreting stages, (b) Advance over the entire cross section; (1) excavation cross section, (2) lining. In plan, a tunnel may entirely or partially follow a straight line or a curve. Straight tunnels are more advantageous than curved tunnels from the viewpoints of construction and operation, because curved tunnels require a substantially larger excavation, are more difficult to build, and have poorer ventilation and visibility. Looping and spiral tunnels are sometimes built, for example, when building a railroad line through a rock mass. The longitudinal profile of a tunnel may have one or two inclines. A tunnel with two inclines slopes upward in both directions from the middle. Because of drainage requirements, tunnels cannot be strictly horizontal. When a tunnel is very long or curved, the inclination must be reduced. Tunnel materials and structures. The principal materials used for tunnel linings are concrete cast in situ, reinforced concrete cast in situ and precast, cast iron, and steel. The choice of lining material depends on the conditions in the region where the tunnel is built and the method of tunneling. Cast concrete and reinforced concrete are used primarily when tunnels are driven in regions that are not easily accessible, where it is not economically feasible to develop an industry for the production of prefabricated structures, and also in soft and weak rock, which requires that the tunnel lining be emplaced in sections. Prefabricated lining, which consists of such factory-manufactured elements as cast-iron tubing and solid or ribbed reinforced concrete blocks, is used when the rate of tunnel driving or the labor productivity must be increased. The structural shape and cross section of the lining are determined by geological conditions and the direction of the primary loads on the lining. In weak water-bearing rock and at high hydrostatic pressure a circular lining is recommended; in stable rock, where vertical stresses predominate, a horseshoe-shaped lining fully meets the requirements of clearance. Design of tunnel structures. Tunnel linings are designed for the least favorable but realistic combinations of primary, secondary, and special loads and their effects on the construction materials. Primary loads, such as rock pressure, act on the lining constantly or regularly. Secondary loads act for short times or periodically, and special loads are mainly seismic in nature. Rock pressure is determined theoretically (with allowance being made for arch formation, the mass of the “rock column, ” and other factors) or from the results of measurements made with instruments in finished excavations. Linings are designed according to limit states on the basis of the methods of structural mechanics, elasticity theory, and soil mechanics. In such designing the combined behavior of the lining and rock is regarded as that of a single elastic system. The structural model of the lining is chosen in accordance with the nature of the structure, the character of the surrounding rock, and the conditions under which the work is done; that is, the lining as a whole or its individual parts must have sufficient strength and stability in all stages of emplacement. The strength of preselected sections of concrete and cast-iron linings is tested with respect to bearing capacity in accordance with the requirements of the Construction Code. Tunnel building. Depending on the depth at which it lies, a tunnel may be built bv the cut-and-cover method or excavated from the inside. In the cut-and-cover method an excavation is dug from the surface, and the tunnel structures are built in the excavation. The excavation is then backfilled, and the disturbed surface is restored. When a tunnel is excavated from the inside, the rock is excavated, and the lining emplaced, through shafts or the tunnel portals. Many different methods are used for excavating and tunneling; the principal techniques are rock tunneling and shield tunneling. Rock tunneling entails two main stages, namely, the excavation and mucking of the rock and the emplacement of a permanent structure—the lining—in the resulting excavation. Depending on the properties of the rock, the excavation may be advanced in parts or simultaneously over the entire cross section (see Figure 2). In soft and partially consolidated rock the cross section of the excavation is divided into individual, relatively small parts that are supported by temporary, primarily wooden, bracing, which prevents the rock from caving in. In hard rock the cross section can be divided into larger units; temporary bracing is installed only along the circumference of the excavation, and the inside of the excavation is left clear. As a result, tunneling in hard rock can be mechanized to a considerable extent. As a rule, the rock is excavated by drilling and blasting with the use of high-power drilling machines and mechanized mucking; the operations along the length of the tunnel are organized in a flow-line system. Movable metal forms are used to emplace a concrete lining; such forms make it possible to employ concrete-emplacing machines. The supported-arch method has become very popular. It is used in sufficiently stable rock that is capable of withstanding the pressure of the concrete arch of the lining. In this method the excavation is cut in parts; a concrete arch supported by the rock is built first and then, depending on the extent to which the sections beneath the arch are excavated, concrete walls cast in situ are placed under the abutment of the arch. The tunnel may be driven from one or two adits. In the full-face method, which is used in the stable hard rock, the entire diameter of the excavation is cut with the use of special tunneling equipment, such as drilling platforms, jumbos, rigs, and complex units. The concrete lining is emplaced by concrete pumps or concrete-emplacing machines (see Figure 3). Figure 3. The full-face method: (1) blast holes, (2) anchor bolts, (3) movable form, (4) jumbo with car transporter, (5) mucker, (6) cars, (7) concrete pump, (W) depth of advance The shield method has been used primarily for driving tunnels in weak and unstable rock. It is based on the use of a tunneling shield (see Figure 4) as temporary bracing. The shield is a movable steel cylindrical shell that protects the workers who excavate the rock and erect the lining, which, as a rule, is circular and prefabricated. Figure 4. A tunneling shield: (1) support ring, (2) cutting edge, (3) vertical frame, (4) jumbo, (5) horizontal frame, (6) jumbo jack, (7) face jack, (8) cover plate, (9) shell, (10) propelling jack, (11) support abutment The tunnel lining is assembled by erector arms or tubing- or block-emplacing machines located directly on the shield or behind it on special movable supports. In unstable water-saturated rock, shield tunneling is combined with the use of compressed air as a means of drying the face. When excavation and lining installation are carried out at elevated air pressure, movable watertight bulkheads are used to separate the face from the rest of the tunnel. The bulkheads have airlocks for the passage of people, for mucking, and for the delivery of materials and various types of equipment. Unlike the rock methods of tunnel driving, shield tunneling does not require temporary bracing; this circumstance increases the safety and reduces the cost of tunnel driving. The tunneling shield may be adapted, by using special mechanisms, to drive through different kinds of rock, for example, plastic or friable rock and running ground. Such adaptation makes possible the total mechanization of all tunneling processes and ensures high quality and high driving rates. In the USSR, shield tunneling experienced its greatest development in the driving of subway tunnels. In addition to the rock and shield methods of tunneling, other methods, such as the immersed-tube and caisson techniques, are also used, primarily for subaqueous tunnels. Drainage systems and waterproofing. Tunnels must be protected against the penetration of surface water and groundwater. The drainage of surface water is made possible by the appropriate grading of the surface above the tunnel and by a system of open catch drains and watertight conduits for streams flowing above the tunnel. A tunnel is protected against groundwater by draining the water from the rock mass being cut or by waterproofing the lining. The groundwater is drained by using a drainage system outside the lining or by drilling wells. The most popular means of waterproofing are as follows: the use of glued waterproofing, which consists of several layers of rolled bituminized material; the pumping of cement or other solutions into the space behind the lining; and the grouting of the rock around the tunnel. Within a tunnel, chutes and pipes are provided to drain water to the portals and to discharge it outside the tunnel. Main trends in the development of tunnel-building technology. For different geological conditions, existing tunnel linings are being improved, and new types of linings are being developed. A method of emplacing linings that does not require movable forms is being introduced, and the most effective means of protecting tunnels against groundwater, especially in regions with a harsh climate, are being developed. Other trends include the introduction of efficient systems for total mechanization of tunneling and the improvement of the method of tunnel driving by drilling and blasting. REFERENCESVolkov, V. P. Tonneli, 3rd ed. Moscow, 1970. Malevich, N. A. Gornoprokhodcheskie mashiny i kompleksy. Moscow, 1971. Kompaniets, S. A., A. K. Popravko, and A. A. Bogorodetskii. Proektirovanie tonnelei. Moscow, 1973. Mostkov, V. M. Podzemnye sooruzheniia bol’shogo secheniia, 2d ed. Moscow, 1974. Tonneli i metropoliteny, 2nd ed. Edited by V. P. Volkov. Moscow, 1975. Stroitel’nye normy ipravila, part 3, sec. B, ch. 8: “Tonneli zhelezno-dorozhnye, avtodorozhnye i gidrotekhnicheskie: Pravila organizatsii stroitel’stva proizvodstva i priemki rabot.” Moscow, 1968.V. P. VOLKOV What does it mean when you dream about a tunnel?A tunnel represents transition from one set of conditions to another. The “light at the end of the tunnel” may represent relief from old conditions. With or without the presence of a train, this symbol can also have the Freudian sexual interpretation of tunnel-as-vagina. tunnel[′tən·əl] (engineering) A long, narrow, horizontal or nearly horizontal underground passage that is open to the atmosphere at both ends; used for aqueducts and sewers, carrying railroad and vehicular traffic, various underground installations, and mining. tunnel an underground passageway, esp one for trains or cars that passes under a mountain, river, or a congested urban area Tunnel (dreams)When interpreting this dream, consider all of the details and the quality of your experience. Did you see a light at the end of the tunnel, or were you trapped in a tunnel and unable to determine your location? The tunnel could represent a variety of things. If it was not an unpleasant experience, it may symbolize a transitional period and a passage into new levels of understanding or ways of living. Freud thought that any tunnel-like object represented the vagina. A tunnel in a dream may also be a symbol representing the archetype of the feminine.tunnel
tunnel [tun´el] a passageway of varying length through a solid body, completely enclosed except for the open ends, permitting entrance and exit.carpal tunnel the osseofibrous passage for the median nerve and the flexor tendons, formed by the flexor retinaculum and the carpal bones; see also carpal tunnel syndrome.flexor tunnel carpal tunnel.tarsal tunnel the osseofibrous passage for the posterior tibial vessels, tibial nerve, and flexor tendons, formed by the flexor retinaculum and the tarsal bones; see also tarsal tunnel syndrome.tun·nel (tŭn'ĕl), An elongated passageway, usually open at both ends.tun·nel (tŭn'ĕl) An elongated passageway, usually open at both ends. tunnel (tun'el) A narrow channel or passageway.CARPAL TUNNELcarpal tunnelThe canal in the wrist bounded by osteofibrous material through which the flexor tendons and the median nerve pass. Synonym: flexor tunnel See: illustrationflexor tunnelCarpal tunnel.inner tunnelThe triangular canal lying between the inner and outer pillars of Corti in the organ of Corti of the inner ear.tarsal tunnelThe osteofibrous canal in the tarsal area bounded by the flexor retinaculum and tarsal bones. The posterior tibial vessels, tibial nerve, and flexor tendons pass through this tunnel. tun·nel (tŭn'ĕl) An elongated passageway, usually open at both ends. Patient discussion about tunnelQ. I'm looking for natural/organic ways to deal with carpal tunnel syndrome. My Boss has Carpal Tunnel syndrome. I'm looking for some natural remedies to help her ease the pain.A. I have found that MSM (GNC brand) 1500mg per day works for me. I talked to an Orthopedic Surgeon asking him why it works... he said "they really don't know why it works, but it works for many of my patients". When I stop taking my MSM the symptoms return so it is not a cure. I have tried other brands of MSM and found the GNC brand works the best for me. It takes about 2 weeks to begin to see the results and several more weeks to get the full affect. Q. what can i do to help my capentunnel without surgery? A. a good friend of mine is a bike racer and did the surgery- it's not a bad solution as it seems...but you can try and put on a splint to stabilize the wrist. The splint is worn at night for several weeks. If this does not help, you may need to wear the splint during the day. Hot and cold compresses may also be recommended. There are many ergonomic devices that can be used in the workplace to reduce the stress placed on the wrist. These include special keyboards, cushioned mouse pads, and keyboard drawers. Make sure the keyboard is low enough so that the wrists aren't bent upward during typing. You may also need to make changes in your work duties or recreational activities. More discussions about tunnelAcronymsSeeTUNLtunnel Related to tunnel: Tunnel diodeSynonyms for tunnelnoun passageSynonyms- passage
- underpass
- passageway
- subway
- channel
- hole
- shaft
verb digSynonyms- dig
- dig your way
- burrow
- mine
- bore
- drill
- excavate
Synonyms for tunnelnoun a passageway through or under something, usually underground (especially one for trains or cars)Related Words- auto
- automobile
- car
- motorcar
- machine
- catacomb
- passageway
- railroad tunnel
- shaft
- underpass
- subway
noun a hole made by an animal, usually for shelterSynonymsRelated Words- hollow
- hole
- rabbit warren
- warren
verb move through by or as by diggingSynonymsRelated Words- cut into
- delve
- dig
- turn over
verb force a way throughRelated Words |