Tunnel structure

Claim 1

A tunnel structure or the like having a predetermined internal cross section for permanent installation in a tunnel excavation having a workface and being driven beneath the ground in a predetermined direction, said tunnel structure or the like, comprising A. a plurality of structural panel units arranged in end overlapping manner as a permanent formwork having a cross section definitive of said predetermined internal tunnel cross section; B. each of said structural panel units including a. a series of parallel, longitudinal corrugations, the walls of which define crests lying in upper planes and troughs lying in lower planes, said corrugations being transverse to the direction of driving of said tunnel; b. a series of bandlike pocket forming elements derived from portions of said crests between pairs of transverse cuts in said crests at predetermined intervals along said corrugations; c. said bandlike pocket forming elements being of nonuniform width and being depressed from the plane of said crests into a pocket forming plane bridging said corrugation; d. a series of longitudinally extending pockets having spaced upper wall portions defined by said crests and lower wall portions spaced alternately of said crests defined by said bandlike elements; e. said pocket forming elements being narrowest at the longitudinal centerline of said pockets and widest at the opposite sides of said pockets; f. said panel, in longitudinal elevation, thereby having rows of alternating wedge-shaped crest portions and wedge-shaped pocket forming elements separated by wedge-shaped gaps; g. whereby said panel is readily matable with another panel of identical configuration by nesting therewith, said nested panels forming composite longitudinal pockets, the upper walls of which are defined only by said crest portions of the underlying nested panel and the lower walls of which are defined only by said pocket forming elements of said overlying panel; C. rodlike members extending through said pockets to connect overlapped, nested end portions of said structural panel units; D. said permanent formwork being inwardly spaced from walls of said excavation and defining a predetermined gap therebetween; E. a concrete lining tightly filling said gap and pockets of said panel units, said lining comprising consecutively installed sections formed by introduction of concrete behind said formwork and vibration of said concrete in said gap to bond said lining to the walls of said excavation and said panel units; F. front formwork means disposed in each section of lining of the tunnel structure at the ends of the structural panel units which are forwardmost in sAid direction of driving to maintain said ends free of concrete, thereby accommodating connection by rodlike members with the rear ends of the structural panel units of the next section of said formwork and said lining to be installed.