10-04-2017, 08:24 PM
A submerged floating tunnel (SFT), also called a suspended tunnel or Archimedes bridge, is a tunnel that floats in the water, supported by its buoyancy (specifically, using hydrostatic thrust or Archimedes' principle).
The pipe is placed under water, deep enough to avoid water and weather traffic, but not so deep that the high water pressure needs to be treated - usually 20-50 m (60-150 ft) is enough. Cables anchored to the Earth or pontoons on the surface prevent them from floating to the surface or submerging, respectively.
Building
The concept of submerged floating tunnels is based on well-known technology applied to floating bridges and offshore structures, but the construction is largely similar to that of submerged tunnels: One way is to build the pipe into sections in a dry dock; Then they float at the construction site and sink them into place, while sealed; And, when the sections are secured together, the seals are broken. Another possibility is to construct the unsealed sections, and after welding them together, pump the water.
The ballast used is calculated in such a way that the structure has an approximate hydrostatic equilibrium (ie the tunnel has approximately the same total density as the water), while the submerged tube tunnels are further lashed to weigh them to the seabed. This, of course, means that a submerged floating tunnel must be anchored to the ground or water surface to hold it in place (which depends on which side of the tunnel the tunnel is).
Applications
Submerged floating tubes allow the construction of a tunnel in extremely deep waters, where conventional bridges or tunnels are technically difficult or prohibitive. They would be able to deal easily with seismic disturbances and weather events (since they have some degree of freedom in movement), and their structural performance is independent of length (ie it can be very long without compromising its stability and resistance ).
On the other hand, they may be vulnerable when it comes to anchors or underwater traffic, so keep in mind when building one. Probable applications include fjords, deep and narrow channels and deep lakes.
The pipe is placed under water, deep enough to avoid water and weather traffic, but not so deep that the high water pressure needs to be treated - usually 20-50 m (60-150 ft) is enough. Cables anchored to the Earth or pontoons on the surface prevent them from floating to the surface or submerging, respectively.
Building
The concept of submerged floating tunnels is based on well-known technology applied to floating bridges and offshore structures, but the construction is largely similar to that of submerged tunnels: One way is to build the pipe into sections in a dry dock; Then they float at the construction site and sink them into place, while sealed; And, when the sections are secured together, the seals are broken. Another possibility is to construct the unsealed sections, and after welding them together, pump the water.
The ballast used is calculated in such a way that the structure has an approximate hydrostatic equilibrium (ie the tunnel has approximately the same total density as the water), while the submerged tube tunnels are further lashed to weigh them to the seabed. This, of course, means that a submerged floating tunnel must be anchored to the ground or water surface to hold it in place (which depends on which side of the tunnel the tunnel is).
Applications
Submerged floating tubes allow the construction of a tunnel in extremely deep waters, where conventional bridges or tunnels are technically difficult or prohibitive. They would be able to deal easily with seismic disturbances and weather events (since they have some degree of freedom in movement), and their structural performance is independent of length (ie it can be very long without compromising its stability and resistance ).
On the other hand, they may be vulnerable when it comes to anchors or underwater traffic, so keep in mind when building one. Probable applications include fjords, deep and narrow channels and deep lakes.
