Tunnle

Tunnle is commonly a misspelling of tunnel. A tunnel is a covered passageway that allows movement or passage of utilities beneath obstacles such as hills, water, or built-up areas. Tunnels are built to improve transportation, enable drainage or convey fluids, and provide shelter. They can be located underground, underwater, or beneath the seabed, and may carry roads, rail lines, pipelines, or electrical and telecommunications networks.

Construction methods vary with geology, length, and purpose. Cut-and-cover builds a trench, then covers it with soil and finishes the surface. Bored tunnels use tunnel boring machines to excavate and install a lining. Immersed-tube tunnels are constructed as segments that are floated into position and sealed underwater. Lining typically involves reinforced concrete, sometimes with steel arches, and waterproofing layers.

Design and safety: Tunnels require ventilation, lighting, drainage, and fire protection systems. Structural monitoring, seismic design, emergency egress routes, and robust communications are standard. Maintenance includes lining inspection, pump systems, and leakage control. Environmental factors, such as groundwater, mining settlements, and urban impacts, influence planning.

Types and examples: Road tunnels, rail tunnels, utility tunnels, and subsea tunnels. Famous examples include the Channel Tunnel linking the UK and France, the Gotthard Base Tunnel in Switzerland, and the Seikan Tunnel in Japan. In mining, tunnels are excavations for ore extraction and access.

Related topics include tunnel boring machines, submerged-tube tunnels, and underwater tunnels.