METHOD FOR REDUCING FRICTIONAL LOSSES IN TUNNELS

摘要

A method for reducing frictional loss in unlined tunnels or other tunnels with a rough wall surface and/or irregular cross section. A flexible or rigid pipe with a cross section similar to or somewhat less than the largest circular open cross section of the tunnel is introduced into the tunnel and attached continuously or at certain points to parts of the tunnel wall. Apparatus for ensuring that a superpressure occurs within the pipe relative to its outside during flow are also introduced.