Immersed Caisson Construction Technology

The submerged tunnel construction method is a technology to construct a tunnel, etc., at the bottom of the sea by immersing a submerged caisson made of concrete, steel plate, etc., as a dry dock or on land.This method has the advantage of reducing the overall length of the tunnel because it is constructed by connecting artificial islands, etc., and can reduce the overburden of the tunnel.

Outline of Immersed Caisson Construction Technology

For the location of the immersed caisson, the seabed is dredged in trenches and the foundation mound is constructed with rubble and other materials.For the construction of foundation rubble, a technique to make rubble accurately lay flat even in deep water is also used by a large SEP ship.The box of the immersed caisson is a dry dock, etc., and is made of steel plate, concrete, etc.The box blocks both sides, and water is injected into the dry dock to lift the box, which is towed by ship and transported to the installation site.The box transported to the installation position is immersed on the foundation rubble of the seabed by injecting water inside.Safe and efficient installation is also carried out using a construction support system that utilizes ICT technology. Since the box is placed in an invisible place in the sea, a positioning system using a trace ponder is also used to place the box body, and technology to accurately place the box has been developed.The box will be reclaimed and used as an undersea tunnel.