摘要 |
In a tunnel lining method an apparatus (20), comprising at least one excavation tool (25) of the chain, belt or band type or the like, is positioned to coincide with the longitudinal axis of the tunnel at a point on its extrados; the tool (25) is made to advance to a predetermined depth in a direction diverging from the tunnel axis so as to create a substantially rectangular cavity (34) from which the tool (25) is withdrawn; said cavity (34) is then filled with concrete to form a cast segment; the aforesaid stages are repeated until a frusto-conical section formed from adjacent cast segments is completed, after which the material within the formed section is excavated to a depth less than the axial length of the section, and the apparatus is advanced through a distance substantially equal to the axial length of the cast segments, the stages being repeated to form each successive section in order to form a lining in which the wider final portion of one section is superposed on the narrower initial portion of the next section; during the execution of one section of cast segments a second tool (29) associated with said first tool (25) executes consolidation/tamping injections with concrete or the like into the region which is to constitute said next section. <IMAGE> |