Work carriage for the lining of tunnels

1 . A work carriage intended to run stepwise along a tunnel to lay a solidifiable fluid material on walls of the tunnel and allow the solidifiable fluid material to solidify for constructing a lining of the tunnel, the work carriage comprising:

a sliding formwork with an outer surface having a shape of the lining desired on the walls of the tunnel, the sliding formwork comprising a closing board for closing, radially to the tunnel,

a space between a front edge of the sliding formwork and a wall of the tunnel to be lined to form an interspace between the sliding formwork and the wall of the tunnel which is intended to accommodate the solidifiable fluid material against the wall of the tunnel,

wherein the sliding formwork further comprises dispensing ports for dispensing the solidifiable fluid material and a covering mantle intended to make a surface of the interspace that is parallel to an advancement direction of the work carriage along the tunnel,

a releasable constraint being provided between the sliding formwork and the covering mantle in order to move from a first condition, in which the covering mantle is fixed to the sliding formwork, and a second condition, in which the covering mantle slides over the sliding formwork.

2 . The work carriage of claim 1 , wherein the releasable constraint is arranged on the front edge of the sliding formwork and the covering mantle.

3 . The work carriage of claim 1 , wherein the releasable constraint is formed by a releasable connection between an edge of the covering mantle and a framework supporting the sliding formwork.

4 . The work carriage of claim 3 , wherein the releasable connection is obtained by means of the closing board.

5 . The work carriage of claim 1 , wherein the covering mantle provides holes at the dispensing ports to allow the solidifiable fluid material to pass through the covering mantle and into the interspace.

6 . The work carriage of claim 1 , wherein the covering mantle is in the form of a metal sheet.

7 . The work carriage of claim 1 , wherein the sliding formwork is formed, at least at the covering mantle, with a plurality of interconnected segments.

8 . The work carriage of claim 1 , wherein the sliding formwork further comprises an outer surface, and wherein the covering mantle rests on the outer surface.

9 . The work carriage of claim 1 , wherein the closing board is movable between an operational position close to the front edge of the sliding formwork and a non-operational position away from the front edge of the sliding formwork to open said interspace or to move closer to a rear edge of the sliding formwork.

10 . The work carriage of claim 9 , wherein for a movement of the closing board between the operational and non-operational positions there are one or more motorized systems connected between the closing board and the sliding formwork or between the closing board and a front part of the work carriage that is placed in front of the sliding formwork in the advancement direction of the work carriage.

11 . The work carriage of claim 10 , wherein the front part comprises a boring machine or a hydrodemolition machine adapted to remove material from the wall of the tunnel, and/or sections for spraying waterproofing fluid toward the wall of the tunnel, before the sliding formwork passes through for lining the wall with the solidifiable fluid material.

12 . A method for making a tunnel lining with a solidifiable fluid material by a sliding formwork with a covering mantle above the sliding formwork and releasable from the sliding formwork, the method comprising at least steps of:

a) positioning the sliding formwork along the tunnel to form an interspace between the sliding formwork and a wall of the tunnel to be lined;

b) introducing the solidifiable fluid material into said interspace;

c) waiting for an established time period for solidification of the solidifiable fluid material;

d) advancing the sliding formwork one step into the tunnel to form, with the sliding formwork, a new interspace that is confined at the rear by the solidifiable fluid material introduced in a previous interspace in step b);

e) repeating steps b) to d) to make subsequent segments of the tunnel lining,

and, if a resistance to an advancement of the sliding formwork exceeds a predetermined value,

f) releasing the covering mantle from the sliding formwork and advancing or retracting the sliding formwork to expose the covering mantle for maintenance.

13 . The method of claim 12 , wherein the maintenance comprises a step of replacing the exposed covering mantle with another covering mantle.