A method for construction and operation of subaqueous tunnels

摘要

A method for accelerated construction and assisted subsequent operation of a subaqueous transport tunnel connecting two land masses separated by a sea comprises tunnelling from each of the two land masses and from a position at sea intermediate the two land masses, the latter being effected by setting a bottom liner on the seabed at a location beneath which, at a suitable depth, the tunnel is to be constructed; landing a concrete or concrete/steel structure having a bore extending the full length of the structure over the bottom liner; running a tieback liner through the structure bore to the top of the bottom liner; evacuating soil and water from the bottom liner and tieback liner combination; drilling a shaft 20 from the bottom of the bottom liner to the required depth of the tunnel; the bore, bottom liner and shaft 20 being of a diameter of sufficient size to permit passage of drilling and tunnelling equipment; drilling out a cavern at the bottom of the shaft; assembling tunnelling equipment in the cavern; and constructing a tunnel emanating from the cavern. The structure serves as a support facility for tunnel operations and providing access to and egress from the tunnel for personnel and passengers, in extremis, and further as a site for equipment providing power, ventilation, pumping and maintenance over an optimised length of tunnel.