Tunnels are civil engineering structures that create an underground passage that may pass through a hill, under buildings or roads, under water or even under entire cities.
A tunnel is an underground passageway, dug through the surrounding soil/earth/rock and enclosed except for entrance and exit, commonly at each end. … Special tunnels, such as wildlife crossings, are built to allow wildlife to cross human-made barriers safely. Tunnels can be connected together in tunnel networks.Tunnels are civil engineering structures that create an underground passage that may pass through a hill, under buildings or roads, under water or even under entire cities. … The purpose of the tunnelling: This will influence the size and cross-section of the tunnel.
There are a wide range of methods that can used for the design and construction of tunnels, depending on the scale of the tunnel required, the specific ground and groundwater conditions, the depth, the availability of space and so on. The main considerations include:
The purpose of the tunnelling: This will influence the size and cross-section of the tunnel.
The type of ground: This will influence the selection of the route for the tunnel and whether it is economical or feasible to construct where there may be poor conditions or defects in strata.
The construction method: This will alter depending on the type of tunnel, the ground conditions, the tunnel length required and the project time pressures.
Removal of debris: The size and length of the tunnel will determine the equipment required for ‘mucking out’ debris.
Control of water: Pumping is the most common technique for dealing with the presence of water whilst tunnelling.