WORK START METHOD OF DIVING TUNNEL AND ITS DEVICE

摘要

A tunnel extending through a body of water is constructed from a dry dock (4) disposed on at least one bank of the water. Successive unit lengths (101, 102,...) of tunnel are constructed in the dry and are connected end-to-end with the existing tunnel assembly in the dry dock. The dock is then flooded and the tunnel assembly is moved out of the dock by a unit length. The dock is then emptied and the procedure is repeated until the tunnel reaches the other side or another half tunnel projecting from the other side. The water-side wall of the dry dock includes an opening which is initially closed by a sluice gate (11). Once construction has started the opening is sealed around a stationary tunnel unit by an inflatable ring seal. During movement of the tunnel assembly the seal is deflated and the tunnel moves with slight positive buoyancy and is held in position by stayed- down gantries 14. Once the tunnel is in place floats 17 which initially hold up the gantries can be removed. IMAGE