什麼是隧道

水平或接近水平的地下或水下通道。這種通道被用來採礦，尤其是作為火車或機動車的軌道來引導堤岸附近的江河、埋藏電站等機構的地下設施或引導水源等。古代人用隧道來進行灌溉或運送飲用水，在西元前22世紀，巴比倫人修建了隧道來實現幼發拉底河下的交通。羅馬人修建了輸水道隧道來用火迅速加熱岩石或用水迅速冷卻岩石，以使岩石裂開。17世紀開始使用火藥爆破後，在岩石開採上有了質的進步。較軟的岩石可以用開隧道的方法來實現，用轉動的輪子來將物質開採出來並靠傳送帶運輸出去。19和20世紀的鐵路運輸使隧道的數量和長度得到了很大提高。早期隧道主要用磚石來支撐，而現代隧道則以鋼架為支撐，直到混凝土建築的完成。一般的通道修築方法包括在開採後立刻噴制混凝土來加固等。

tunnel

Horizontal or nearly horizontal underground or underwater passageway. Tunnels are used for mining, as passageways for trains and motor vehicles, for diverting rivers around damsites, for housing underground installations such as power plants, and for conducting water. Ancient civilizations used tunnels to carry water for irrigation and drinking, and in the 22nd century BC the Babylonians built a tunnel for pedestrian traffic under the Euphrates River. The Romans built aqueduct tunnels through mountains by heating the rock face with fire and rapidly cooling it with water, causing the rock to crack. The introduction of gunpowder blasting in the 17th century marked a great advance in solid-rock excavation. For softer soils, excavation is accomplished using devices such as the tunneling mole, with its rotating wheel that continuously excavates material and loads it onto a conveyor belt. Railroad transportation in the 19th-20th century led to a tremendous expansion in the number and length of tunnels. Brick and stone were used for support in early tunnels, but in modern tunneling steel is generally used until a concrete lining can be installed. A common method of lining involves spraying shotcrete onto the tunnel crown immediately after excavation.