GB191415801A - Improvements in or relating to the Building of Waterproof Tunnels. - Google Patents

Abstract

15,801. Hallinger, F. X., and Hallinger & Co. July 1. Tunnels; tunnelling by boring.-In building a waterproof tunnel which is driven by a shield, a protective casing is first constructed comprising an outer layer of compressible material formed by the reaction of the jacks that advance the shield, an intermediate layer of plates G, and an inner insulating-layer H of asphalt-felt board, lead, zinc, or the like, and the tunnel lining proper is subsequently constructed within the protective casing. The shield has an inner shell A within the usual shell and secured thereto by webs ; the material for the outer compressible layer of the protective casing is fed into the spaces between the shells and is compressed by the abutment plates F of the jacks E that advance the shield. The lower part of the outer compressible layer may be of sand or gravel mixed with clay and the upper part of earth ; lime or trass may also be added. The plates G may be of concrete or asphalt with an outer coat of clay, and rings Q, Fig. 6, may be embedded at their meeting edges. The lining proper may be of brick or concrete J supported by an inner tube M stayed by iron rings N. The plates G are held from movement by brackets P on a ring L removably secured to rods O embedded in the lining. The building of the upper part of the lining proper may be deferred, jacks R, Fig. 6, then being inserted temporarily. The tunnel may be of rectangular or other cross-section.