| 摘要 |
<p>A method of constructing an undersea tunnel by deploying a concrete structure (14, figure 5) on a seabed 2, where the bed is prepared by setting a caisson assembly 1 and jetting and/or excavating until an impermeable stratum 3 is reached, drilling the stratum to create a socket into which the caisson is lowered and cemented so that the caisson is sealed. Pipe assemblies 4, which facilitate remedial work on the cement, are installed within an annulus between the caisson and an external casing. Completion work is carried out on construction shafts (16, figure 6), comprising placement at an interface of the construction shafts of concrete segments (39, figure 7). Concrete segments or blocks are stacked upwards on top of a barrier 42, while slip forming is carried out externally. Further blocks are cemented on the shafts and a further barrier assembly is received on the further block to terminate the shafts.</p> |
