A tunnel is an underground or undersea passageway. It is dug through surrounding soil, earth or rock, or laid under water, and is usually completely enclosed except for the two portals common at each end, …

tunnels and underground excavations, horizontal underground passageway produced by excavation or occasionally by nature’s action in dissolving a soluble rock, such as limestone. A vertical opening is …

The meaning of TUNNEL is a covered passageway; specifically : a horizontal passageway through or under an obstruction. How to use tunnel in a sentence.

2 days ago · Explore the world’s 10 longest tunnels, record-breaking engineering marvels that push the limits of design, scale, and human ambition.

In this article, we'll explore what makes tunnels such an attractive solution for railways, roadways, public utilities and telecommunications. We'll look at the defining characteristics of tunnels and examine …

TUNNEL definition: 1. a long passage under or through the ground, especially one made by people: 2. the long passage…. Learn more.

Define tunnel. tunnel synonyms, tunnel pronunciation, tunnel translation, English dictionary definition of tunnel. n. 1. An underground or underwater passage. 2. A passage through or under a barrier such …

Tunnel definition: an underground passage.. See examples of TUNNEL used in a sentence.

Trinity Diversion Tunnel: a 10.7-mile (17.2 km) tunnel diverting water from the Trinity Basin to the Sacramento Valley. SpaceX constructed a 1.4-mile (2.3 km) test tunnel underneath the parking lot of …

Tunnels are generally grouped in four broad categories, depending on the material through which they pass: soft ground, consisting of soil and very weak rock; hard rock; soft rock, such as shale, chalk, …