CADRE DE SOUTENEMENT DESTINE A REPRENDRE LA PRESSION DES TERRAINS EN PERCEMENT DE TUNNEL PAR LA METHODE DES ATTAQUES SUCCESSIVES

摘要

The support frame used for securing the rock during advancing crown driving by the partial-section tunnelling method is not only composed of lattice-girder segments in its crown and invert arches (1, 6) but also has crown-foot beams (3) designed as lattice girders, as a result of which the very disadvantageous cutting of the concrete shell which has occurred in the U-rails used hitherto as crown-foot beams (3) and the appearance of spray shadows are avoided. <IMAGE>