Precast lining element for lining a tunnel portion

Abstract

The invention relates to a precast lining element (1) for lining a vault portion of a tunnel. The element (1) comprises a central section (11), a first lateral section (12) and a second lateral section (13), wherein each of said sections (11, 12, 13) comprises a concrete shaped body (C1, C2, C3) having an intrados surface (11-1, 12-1, 13-1), an extrados surface (11-2, 12-2, 13-2) and a perimeter edge (11-3, 12-3, 13-3) connecting said intrados surface (11-1, 12-1, 13-1) with said extrados surface (11-2, 12-2, 13-2). The central section (11) is connected to the first lateral section (12) through first hinge means (21) and to the second lateral section (13) through second hinge means (22), wherein said hinge means (21, 22) allow said element (1) to change from a folded configuration, taken on before installation, to an open configuration, taken on upon installation. For each lateral section (12, 13), the element (1) comprises a foot section (12A, 13A), made of concrete, connected to the shaped body (C2, C3) of the respective lateral section (12, 13) through connection means (51-1, 51-2) allowing the foot section (12A, 13A) to slide between a retracted position, taken on before installation, and an extended position, taken on upon installation and defined by a rest plane (PO) defined by a surface of said tunnel. For each of said foot sections (12A, 13A), the element (1) further comprises locking means (61-1, 61-2) configured to lock the respective foot section (12A, 13A) in the retracted position and in the extended position, when the latter is reached.

Description

[0001] PRECAST LINING ELEMENT FOR LINING A TUNNEL PORTION

[0002] DESCRIPTION

[0003] The present invention generally relates to the field of the renovation of road works, in particular tunnels. In particular, the present invention relates to a precast element that can be used for lining an internal section of a tunnel.

[0004] BACKGROUND ART

[0005] As is known, tunnels were built, and are still built, by providing a massive internal concrete lining of considerable thickness. Over time, the quality of the lining decays due to material degradation, and in particular to deterioration of the concrete in the lining. The road and motorway network comprises several tunnel sections for which the renovation of the lining layer is now necessary. It has been observed that in many cases such an intervention also takes on a structural character. In other words, not only a renovation of the internal “skin” of the tunnel is required, but it is also necessary, as part of such an intervention, to consolidate the tunnel itself.

[0006] The renovation / restructuring of the internal lining of the tunnel involves using mechanical means for milling (or scarifying), therefore removing, a thickness portion of old concrete along the entire circumference of the radial section and over either the entire length of the existing tunnel or intervals of a specific length. The thickness scarification operation can involve only a portion of the radial section of the tunnel, i.e., not the entire tunnel arch. The scarification typically involves the tunnel arched portion that extends between the right and left walkways. In this regard, the scarification can sometimes also involve only the upper sector of the arched portion, i.e., the sector called crown, when the lateral sectors (also called sidewalls) are considered still in good conditions. For reasons related to construction site safety and management, the scarification operation is carried out along the entire tunnel or only on portions of a determined length, based on the scheduled work.

[0007] The renovation / restructuring of a tunnel involves replacing the thickness of the lining removed by the scarification operation with an equally thick layer of new and, better-quality concrete. The operations of scarification and application of new concrete must be carried out in a short time, especially when motorway tunnels are involved. Clearly, this requirement arises because of the vehicular traffic, which must be suspended as little as possible.

[0008] Different methods for renovating a tunnel are known. A first method, also aimed at consolidating the tunnel, involves, after the scarification, waterproofing the scarified portion and placing a pre-formed formwork along the longitudinal axis of the tunnel. After positioning the formwork, which step is carried out after possibly required steel reinforcements have been built, the gap between the formwork and the scarified surface ( in which said reinforcements are located) is filled by pumping fluid-phase concrete. After the concrete has hardened, therefore after a certain period of time of a few days, the method involves removing the formwork and repeating the sequence of operations until the lining is completed. This method is clearly timeconsuming and, in any case, requires almost if not completely closing the tunnel affected by renovation to the traffic.

[0009] In the context of the construction of new tunnels, US 3 373 571 A discloses a system for handling and installing formworks. Such a system comprises a plurality of hangers fastened to reinforcement beams of the tunnel under construction, in the vault region thereof, each provided with a roller assembly at a lower end thereof. The system further comprises formworks suspended from the hangers at the respective roller assemblies. The formworks have a collapsible structure formed by four annular segments connected to each other by hinges, in particular a top hinge connecting two upper segments to each other, and two side hinges connecting each upper segment to a respective lower segment. Each formwork can therefore assume a radially collapsed configuration, which allows the movement thereof along the tunnel by suspended sliding on the roller assemblies of the hangers, and a radially extended configuration, in which the formwork assumes a closed annular shape, suitable for pouring concrete into the annular gap which remains defined between the formwork and the wall of the tunnel under construction, to build a lining over a section of the wall itself. After hardening, the lined section is dismantled, returning the formwork to the collapsed configuration, in which it can be moved towards a subsequent section of the tunnel to be lined.

[0010] Another method involves applying a series of precast concrete slabs (or segments), which are precast according to the radius of the tunnel, along the scarified tunnel portion; such slabs (or segments) have a longitudinal length of between 1 and 2 metres and are installed to form a lining (called a ring) of the arched portion of the radial section. Such slabs have a certain radial thickness extending between an intrados and an extrados surface thereof. Steel reinforcements, partially buried in the radial thickness of the slabs, emerge from the extrados surface. Once installed, the slabs form a tunnel portion whose exposed, or intrados, face is formed by the precast concrete of the slabs (or segments). The thickness of said steel reinforcements creates an empty space between the intrados of the scarified area and the extrados of the precast concrete slabs (or segments). In an operation subsequent to the installation of the slabs, called backfilling, such an empty space is subsequently filled with fluid-phase concrete which is pumped through holes specifically provided in the slabs (or segments). The installation of the slabs (or segments) is performed in different ways, by means of suitably modified elevator machines or by means of specially designed machinery. To allow the backfilling to be carried out, the slabs (or segments) must be positioned and supported without any mutual movement occurring either in the radial or longitudinal direction. Therefore, this method requires the simultaneous use of different machinery. In order to prevent mutual movements between the slabs (or segments), longitudinal connection elements which improve the stability of the lining ring are also provided. Support and fastening of the slabs (or segments) necessary for carrying out the backfilling requires instead the use of removable props or mechanical support tools.

[0011] This second method therefore avoids the use of formworks and also in terms of time it certainly appears more advantageous than the previous one. However, as explained above, it requires the simultaneous use of different machinery and equipment, which are difficult to manage in a limited space such as that inside a tunnel, as well as a large number of operators. In any case, this method also requires the complete closure to traffic.

[0012] In the context of the construction of new tunnels, BE 1 015 837 A3, US 4 124 985 A, JP 2002 121997 A, and FR 2 574 111 Al disclose collapsible precast lining sections for building tunnel linings. The lining sections described in such documents consist of a plurality of precast arched elements (segments) connected to each other by hinges so as to form a closed ring. The lining sections can take on a collapsed configuration, suitable for transporting the sections themselves up to their intended installation position in a tunnel, where they can then be installed by bringing them into an erect or expanded configuration, so as to form an annular section of the lining of the tunnel under construction.

[0013] In view of the above, a need arises for new technical solutions that allow implementing a more effective and faster method for renovating the lining of an existing tunnel than those currently used.

[0014] SUMMARY

[0015] The main task of the present invention is to provide a new precast lining element intended in particular for renovating linings of existing tunnels, which allows the above-mentioned drawbacks to be overcome or at least reduced.

[0016] Within the scope of this task, a first object of the present invention is to provide a precast lining element ready for installation on site. Another object is to provide a precast lining element that allows a tunnel section to be lined in less time as compared to the traditional techniques and that requires less traffic interruption than that required by the traditional techniques. Another object is to provide a precast lining element which requires a limited number of machines for its positioning and at the same time does not require to be supported at the intrados for carrying out the backfilling step. Yet another object of the present invention is to provide a precast lining element which, if necessary, can allow for structural consolidation of the tunnel. Not least object of the present invention is to provide a lining element which is reliable and easy to manufacture at competitive costs.

[0017] Such objects are achieved by a precast lining element for lining a vault portion of a tunnel having the characteristics respectively set forth in appended claims 1 and 12.

[0018] In its most general form, the invention relates to a precast lining element for lining a vault portion of a tunnel, comprising: a structural section comprising a concrete shaped body having an intrados surface, an extrados surface, and a perimeter edge connecting the intrados surface with the extrados surface and comprising a pair of long sides and a pair of short sides, wherein said shaped body comprises at least one hole connecting the intrados surface with the extrados surface; two foot sections made of concrete, each foot section being connected with an end of the shaped body through connection means allowing the foot section to slide between a retracted position and an extended position, wherein in the retracted position the foot section is adjacent to the respective end of the shaped body, and in the extended position the foot section is distal from the respective end of the shaped body, wherein said extended position is defined by a rest plane defined by a surface of said tunnel upon installing the lining element, wherein said lining element comprises, for each of said foot sections, locking means configured to lock the respective foot section in said retracted position and in said extended position, when the latter is reached.

[0019] According to a preferred embodiment, the structural section of said lining element comprises a central section, a first lateral section and a second lateral section, each comprising a respective concrete shaped body having an intrados surface, an extrados surface and a perimeter edge connecting said intrados surface to said extrados surface, said perimeter edge comprising a pair of long sides and a pair of short sides, said shaped body comprising at least one hole connecting the intrados surface with the extrados surface.

[0020] In this case the lining element also comprises first hinge means connecting said central section with said first lateral section and second hinge means connecting said central section with said second lateral section, wherein said hinge means allow said element to change from a folded configuration, taken on before installation, and an open configuration, taken on upon installation.

[0021] Furthermore, said foot sections are respectively connected with one end of the shaped body of each of the lateral sections of the structural section through said connection means and can slide between a retracted position and an extended position, wherein in said retracted position the foot sections are adjacent to the respective lateral section and in said extended position the foot sections are distal from the respective lateral section, said extended position being established by a rest plane defined by a surface of said tunnel upon installing the lining element.

[0022] Preferably, the structural section or at least one of said central section and said lateral sections comprises a perimeter gasket extending along the perimeter edge of the respective shaped body. Preferably, the structural section or at least one of said central section and said lateral sections comprises mechanical joining devices arranged along said long sides of the perimeter edge of the respective shaped body.

[0023] According to a possible embodiment, the structural section or at least one of said central section and said lateral sections comprises a metal reinforcement emerging from the extrados surface of the respective shaped body.

[0024] Conveniently, the lining element comprises first anti-rotation means for preventing the rotation of said first lateral section relative to said central section when said element reaches said open configuration, and second anti-rotation means for preventing the rotation of said second lateral section relative to said central section when said element reaches said open configuration.

[0025] Preferably, said first hinge means and said second hinge means are connected with said central section and with the respective lateral section at the respective intrados surfaces and close to the respective short sides so as to define a rotation axis substantially parallel to said respective short sides.

[0026] Conveniently, said first hinge means and said second hinge means are removably connected with said central section and with the respective lateral section.

[0027] Preferably, each of said lateral sections comprises at least one attachment bracket fastened to the respective intrados surface, wherein said attachment bracket is removably connectable to an end of an extendable arm of an equipment for installing said element.

[0028] According to a preferred embodiment of the lining element, for at least one of said foot sections: said connection means comprise a metal plate fastened, by means of first fastening screws, to an intrados surface of the foot section so as to be integral therewith as it slides from the retracted to the extended position, and wherein said metal plate has a plurality of straight slots, and said locking means comprise second fastening screws for connecting said plate with said intrados surface of the respective lateral section, wherein each of said second screws is inserted in one of said slots so that said plate is interposed between said intrados surface and a head of said second screws.

[0029] Preferably, the connection means further comprise: at least one male pipe partially buried into the body of said foot section and emerging from a surface of said body facing the respective lateral section, and at least one internally hollow female pipe buried into the shaped body of the respective lateral section, each male pipe being inserted in a corresponding female pipe so as to define a telescopic coupling.

[0030] Preferably, the locking means are also configured so as to develop, further to reaching said extended position, a friction force between said male pipe and said female pipe, wherein said friction force prevents a mutual displacement of said telescopically coupled pipes.

[0031] LIST OF FIGURES

[0032] Further features and advantages of the invention shall become more apparent from the following detailed description of preferred embodiments thereof, provided below, for indicating and non-limiting purposes, with reference to the attached drawings, in which:

[0033] - Figs 1, 1A are perspective views from different observation points of a possible embodiment of a lining element according to the invention in a folded configuration;

[0034] - Figs IB and 1C are front views of the element of Figures 1 and 1A in another folded configuration and in an open configuration, respectively;

[0035] - Figs 2 and 2A are views from different observation points of another embodiment of a lining element according to the invention;

[0036] - Figs 3A and 3B are perspective views from different observation points of a central section of the lining element of Figures 1 and 1A;

[0037] - Figs 4A and 4B are perspective views from different observation points of the lateral sections of the lining element of Figures 1 and 1A;

[0038] - Figs 5A, 5B and 5C are perspective views from different observation points of hinge means of the element of Figures 1 and 1A, where such means are shown in different operating positions;

[0039] - Figs 6A, 6B and 6C are respectively a perspective view, a lateral view, and a sectional view of a foot section of the lining element of Figures 1 and 1 A in a first operating position;

[0040] - Figs 7A, 7B and 7C are respectively a perspective view, a lateral view, and a further perspective view of the foot section of Figures 6A, 6B and 6C in a second operating position;

[0041] - Figs 8A and 8B are sectional views each related to a possible embodiment of locking means of a foot section of a lining element according to the invention;

[0042] - Figs 9 to 18 show operating steps related to the transport and installation of a lining element according to the invention;

[0043] - Figs 19, 20, 21 refer to another possible embodiment of a lining element according to the invention.

[0044] The same reference numerals and letters in the figures identify the same elements or components.

[0045] DETAILED DESCRIPTION

[0046] The present invention thus relates to a precast lining element which, once installed, allows lining a section of a tunnel, wherein by ’’section ” it is meant a portion of the tunnel vault of a certain length (for example 1 or 1.5 metres).

[0047] Figures 1 to 2A refer to embodiments of a lining element according to the invention (generally indicated by reference 1 ) comprising a structural section formed by three sections 11, 12, 13: a central section 11 (hereinafter also indicated by the expressions central section 11 or crown 11 ) and two lateral sections 11, 12 (hereinafter also indicated as sidewalls 11, 12). As better indicated below, the sections 11, 12, 13 of the element 1 are mutually connected by hinge means 21, 22 which allow the element 1 to take on a folded configuration (see for example Figures 1 and 1A), convenient for its transport and installation, and an open configuration (see Figures 1C, 2 and 2A), taken on when the installation is completed.

[0048] Figures 3 A and 3B show, from different angles, the central section 11 (crown 11 ) of the element 1 also shown in Figures 1, 1A, IB, 1C separated from the sidewalls 12, 13. The two sidewalls 12, 13 of the same element 1 are instead shown in Figures 4A and 4B.

[0049] With reference to Figures 3 A and 3B, the central section 11 comprises a concrete shaped body Cl having an intrados surface 11-1, an extrados surface 11-2 opposite said intrados surface 11- 1, and a perimeter edge 11-3 connecting the intrados surface 11-1 to the extrados surface 11-2. The perimeter edge 11-3 comprises a pair of long sides, i.e., faces, Al and a pair of short sides, i.e., faces, Bl. Upon completion of the installation of the element 1, the long sides extend along an arch portion when viewing the tunnel frontally, while the short sides Bl extend axially, i.e., in the longitudinal direction of the tunnel.

[0050] The shaped body Cl of the crown 11 comprises at least a first through hole 11-5 formed in a central position (i.e., on the plane R-R indicated above) and connecting the intrados surface 11- 1 with the extrados surface 11-2 to allow backfilling operations as better specified below. Preferably, the shaped body Cl comprises one or more through holes 11-6 in a non-central position also for backfilling operations. In general, said holes 11-5, 11-6 can be used for both pumping concrete material and as air vent holes.

[0051] The central section or crown 11 is provided with a perimeter gasket 91-1 extending along the perimeter edge 11-3, preferably at a same height relative to the surfaces 11-1, 11-2 indicated above. Such a gasket 91-1 is aimed at ensuring hydraulic sealing. Such a gasket 91-1 comprises a pair of portions (arranged on the short sides Bl ) each intended to contact (when the element 1 takes on the open configuration) a gasket portion arranged on one of the sidewalls 11, 12 of the same lining element 1. The gasket 91-1 further comprises another pair of portions ( arranged on the long sides Al ) each intended to contact a corresponding portion arranged on a long side of a crown of another adjacent lining element. In this way possible water leaks in the tunnel can be avoided. The gasket 91-1 of the crown 11 can be provided while making the shaped body Cl according to a procedure normally used to make lining segments for tunnels.

[0052] With reference again to Figures 3 A and 3B, the central section or crown 11 also comprises mechanical joining devices 92-1 provided along the long sides Al of the perimeter edge 11-3 to allow the mechanical connection with a crown of a lining element already installed and / or with an element that will be installed subsequently. Such mechanical joining devices 92-1 can be of the type described in patent application IT102023000023139.

[0053] In a possible embodiment, further joining devices (not shown in the figures) could be provided at the short sides B l of the perimeter edge 11-3 to mechanically connect such sides with corresponding short sides A2, A3 (indicated in Figures 4 A, 4B) of the lateral sections or sidewalls 12, 13.

[0054] The element shown in Figures 2 and 2A can be used for renovating the tunnel surface (i.e., for the restoration of the skin layer only, without any structural consolidation purpose). As can be seen from such figures, the crown 11 can advantageously comprise a metal reinforcement 95-1 which emerges from the extrados surface 11-2 and is buried in, and therefore stably connected to the concrete of the shaped body Cl. In a possible, and therefore non-exclusive, embodiment shown in the figures, the metal reinforcement 95-1 comprises a reinforcing lattice made up of, e.g., metal rods bent with a curvature corresponding to the extrados surface 11-2 and supported by metal elements having a triangular arrangement (see Figure 2A).

[0055] The element shown in Figures 1, 1A, IB, 1C can instead be used for consolidating a tunnel. In this case, the crown 11 lacks the metal reinforcement emerging from the extrados surface 11-2, however the thickness of the shaped body Cl (i.e., the distance between the intrados surface 11-1 and the extrados surface 11-2) can be suitably increased as compared to the thickness of a crown 11 serving as a lining only (like the one shown in Figures 2 and 2A).

[0056] With reference to Figures 4A, 4B, similarly to the crown 11, each sidewall 12, 13 comprises a concrete shaped body C2, C3 having an intrados surface 12-1, 13-1 and an extrados surface 12- 2, 13-2 opposite said intrados surface 12-1, 13-1. For each sidewall 12, 13 the respective shaped body C2, C3 further comprises a perimeter edge 12-3, 13-3 connecting the intrados surface 12- 1, 13-1 to the extrados surface 12-2, 13-2. A pair of long sides, i.e., faces, A2, A3 and a pair of short sides, i.e., faces, B2, B3 can be identified also for the shaped body C2, C3 of each abutment 12, 13.

[0057] For each sidewall 12, 13 the respective shaped body C2, C3 comprises at least a first through hole 12-5, 13-5 connecting the intrados surface 12-1, 13-1 to the extrados surface 12-2, 13-2 for backfilling. Preferably, at least a second through hole 12-6, 13-6 is provided, serving initially as an air vent while pumping concrete material through the first hole 12-5, 13-5, and subsequently for pumping cementitious material.

[0058] For each sidewall 12, 13, the respective shaped body C2, C3 is provided with a perimeter gasket 91-2, 91-3 extending along the perimeter edge 12-3, 13-3 preferably at a same height relative to, for example, the intrados surface 12-1, 13-1. The perimeter gasket 91-2, 91-3 has the same function and operates according to the same principle as the perimeter gasket 91-1 provided for the shaped body Cl of the crown 11.

[0059] Still with reference to Figures 4A and 4B, similarly to the crown 11, each sidewall 12, 13 is provided with mechanical joining devices 92-2, 92-3 arranged at least along the long sides A2, A3 of the perimeter edge 12-3, 13-3 of the respective shaped body for mechanical connection with another sidewall of a lining element already installed and / or of another lining element that will be installed subsequently. The mechanical joining devices 92-2, 92-3 of the sidewalls 12, 13 can also be of the type described in patent application IT102023000023139 mentioned above.

[0060] Referring again to Figures 2 and 2A, when the element 1 is intended for renovating the tunnel surface, the sidewalls 12, 13 can comprise respective metal reinforcements 95-2, 95-3 which emerge from the respective extrados surfaces 12-2, 13-2 for purposes similar to those of the metal reinforcement 95-1 provided for the crown 11. Preferably, such reinforcements 95-2, 95- 3 have the same shape as the metal reinforcement 95-1 provided for the crown 11.

[0061] Similarly to what explained above for the crown 11 with reference to Figures 4A and 4B, in the case where the element 1 is required to have a permanent structural consolidation function, the sidewalls 12, 13 can lack metal reinforcements emerging from the respective extrados surfaces 12-2, 13-2 (visible instead in Figures 2 and 2A). The shaped bodies C2, C3 of the sidewalls 12, 13 will be then properly sized for the consolidation function.

[0062] With regard to the configuration of the sections 11, 12, 13 constituting the lining element 1, it is observed that the short sides B l of the crown 11 and the short sides B2, B3 of the sidewalls 12, 13 have the same length, so that all sections 11, 12, 13 equally line the same longitudinal length of the tunnel. If the tunnel has curved sections, the lining elements will have a trapezoidal shape, wherein such a shape is evaluated on the reference plane R-R defined above. In the embodiments shown in the figures, the crown 11 has a substantially symmetrical shape relative to reference plane R-R (indicated in Figures 1 and IB). At the same time, the two sidewalls 12, 13 have substantially the same shape and are also specular relative to the reference plane R-R when the element 1 takes on the open configuration (Figure 2). However, in an alternative embodiment, still falling within the scope of the present invention, the two sidewalls

[0063] 12, 13, at least with reference to their long sides A2, A3, could have a different shape. In this case, thus, the crown section 11, as well as the lining element 1 as a whole, may not have the symmetry shown in the figures. The possible asymmetry could be dictated by the different heights of the scarified surfaces of the tunnel defining the rest planes PO for the sidewalls 12,

[0064] 13.

[0065] With reference to Figures 1, 1A, IB and 1C, the element 1 comprises first hinge means 21 connecting the crown 11 to the first sidewall 12 and second hinge means 22 connecting the crown 11 to the second sidewall 13. As indicated above the hinge means 21, 22 generally connect the sections 11, 12, 13 of the element 1 so as to allow the latter to change from a folded configuration (Figures 1, 1C and IB) before being installed, to an open configuration (Figure 1C) in which, when reached, the sections thereof are locked in the mutual position so achieved. In particular, with reference to Figure 1C, the open configuration is substantially “arched” when seen on the trans verse / frontal plane of the tunnel, whereby the element 1 has, as a whole, an intrados surface 1-IN and an extrados surface 1-OUT respectively defined by the combination of the three intrados surfaces 11-1, 12-1, 13-1 and by the combination of the three extrados surfaces 11-2, 12-3, 13-2 of the sections 11, 12, 13 forming the element. In the case shown in the figures, the arched configuration is perfectly and preferably symmetrical relative to a central reference plane R-R.

[0066] Preferably, the element 1 is provided with first anti-rotation means 31 and second anti-rotation means 32 (shown for example in Figure 1A) configured to mechanically lock the sections 11, 12, 13 of the element 1 when it takes on the open configuration. In particular, the first antirotation means 31, further to their activation, prevent the rotation of the first sidewall 12 relative to the crown 11, while the second anti-rotation elements 32, further to their activation, prevent the rotation of the second sidewall 13 relative to the crown 11.

[0067] Figures 5 A to 5C show a possible embodiment of the first hinge means 21 which are connected to the central section 11 and to the first sidewall 12 at the respective intrados surface 11-1, 12- 1 and close to a respective short side B l, B2, so as to define a rotation axis 101-A substantially parallel to the short sides B l, B2. In general, the first hinge means 21 are removably connected to the intrados surfaces 11-1, 12-1 of said two sections 11, 12, i.e., in such a way that they can be disconnected at the end of the installation, preferably after the backfilling operation and hardening of the material used for the backfilling.

[0068] In the illustrated embodiment, the first hinge means 21 comprise a first plate 211 and a second plate 212. The first plate 211 is fastened by means of screws to the intrados surface 11-1 of the central section 11 close to a first short side B l thereof. The second plate 212 is fastened by means of screws to the intrados surface 12-1 of the first sidewall 12 close to a first short side B2 thereof. The first plate 211 supports two aligned hinge female parts 218-A (indicated in Figure 5A), while the second plate 212 supports two aligned hinge male parts 218-B (indicated in Figure 5B). The hinges male parts 218-B are mechanically coupled with the female parts 218-A and define through such a coupling a first rotation axis 101-A (indicated in Figure 1A and Figure 5B ).

[0069] Preferably, the second hinge means 22, also removable, are configured in the same manner as the first hinge means 21 for defining a corresponding second rotation axis 101-B between the second sidewall 13 and the crown 11. Therefore, as to the second hinge means 22, particularly their structure and connection method, reference can be made, mutatis mutandis, to the description of the first hinge means 21 provided above.

[0070] The cited Figures 5A to 5C also show a possible embodiment of the first anti-rotation means 31 which prevent the rotation between the central section 11 and the first sidewall 12 when the element 1 takes on the open configuration. Specifically, the first anti-rotation means 31 comprise a pair of guide profiles 311 integral with the first plate 211 of the hinge means 21. Each guide profile 311 houses a sliding piston 312 and a spring 313 that permanently pushes the sliding piston 312. For each guide profile 311, the respective piston element 312 takes on a first position (i.e., is in a deactivated state) relative to the guide profile 311 when the lining element 1 is in a partially folded configuration (Figure 5A). For this purpose, a stop element 315 is provided which locks the piston element 312 in said first position, wherein the latter partially protrudes from the guide profile 311 resting on or extending above the surface of the first plate 211 (Figures 5 A and 5B).

[0071] Once the open configuration has been reached (further to the mutual rotation of the first sidewall 12 relative to the crown 11 indicated by W1 in Figure 5B), removing the corresponding stop 315 of each profile 311 causes the respective piston element 312, pushed by the respective spring 313, to be released (activated state) thereby snapping into a second position in which it also extends onto the second plate 212 of the first hinge means 21 (see Figure 5C). In this condition the piston elements 312 lock, or in any case prevents, the rotation about axis 101-A of the two sections 11, 12 of the element 1 connected by the first hinge means 21. Advantageously, the first anti-rotation means 31 described above are integral with the first plate 211 of the first hinge means 21. Therefore the first anti-rotation means 31 can be removed together with the first hinge means 21 from the intrados surface 1-IN once the latter has been installed and consolidated. Preferably, the second anti-rotation means 32 are configured in the same manner as the first anti-rotation means 21. Therefore, as to the second anti-rotation means 32, reference can be made, mutatis mutandis, to the description of the first anti-rotation means 31 provided above.

[0072] As apparent, for example, from Figures 1, 1A and 5B, preferably each of the sidewalls 12, 13 is provided with one or more attachment brackets 40 removably fastened to the respective intrados surface 12-1, 13-1. As better explained below, during installation, the end of an extendable arm 610 (see Figures 11 to 18) provided on a dedicated equipment is connected to the attachment brackets 40 of each sidewall 12, 13. By acting on the attachment brackets 40, the extendable arms 610 cause the rotation of the respective sidewall 12, 13, by means of the rotation axes 101-A, 101-B, relative to the crown 11 until reaching the open configuration.

[0073] In accordance with the present invention, the lining element 1 further comprises two concrete foot sections 12A, 13A, slidably connected to the structural section of the element 1 at transversely opposite ends thereof, which in this embodiment are defined by the free ends of the two lateral sections or sidewalls 12, 13 of the structural section itself. In more detail, each foot section 12A, 13A is connected in a sliding manner to the concrete shaped body C2, C3 of the respective sidewall 12, 13, in particular at the short side B2, B3 of the perimeter edge 12-3, 13-3 opposite the short side at which the respective hinge means 21, 22 are installed.

[0074] In particular, for each sidewall 12, 13, the relative foot section 12A,13A is connected to the respective shaped body C2, C3 through connection means 51-1, 52-1 which allow it to slide between a retracted position and an extended position. In the retracted position, the foot section 12A, 13A is adjacent to (substantially in contact with) the shaped body C2, C3 of the respective sidewall 12, 13. In the extended position, the foot section 12A, 13A is instead distal from the same shaped body C2, C3 and contacts the rest plane PO defined by the tunnel, in particular by a scarified horizontal surface thereof (coinciding with or adjacent to a tunnel walkway). Each foot section 12A, 3A is therefore extendable from the retracted to the extended position, the latter being defined by said rest plane PO.

[0075] For each foot section 12A, 13A, the element 1 comprises locking means 61-1, 61-2 which lock the respective foot section 12A, 13A in the retracted position and in the extended position so as to prevent relative movements between the foot section 12 A, 13A and the corresponding sidewall 12, 13. As better described below, for installation, the element 1 is brought from a folded configuration to an open configuration inside the tunnel. In this step, the foot sections 12A, 13A are locked in their retracted position. Once the rotation of the sidewalls 12, 13, carried out by means of a lifting equipment 600, is completed, the element 1 is axially connected to another element already installed. At this point, the foot sections 12A, 13A are unlocked (deactivation of the locking means 61-1, 61-2) and reach the rest plane PO defined by the scarified horizontal surface of the tunnel (i.e., they reach the extended position) by gravity. Once the respective extended position has been reached, the foot sections 12A, 13A are locked again (re-activation of the locking means 61-1, 61-2) relative to the respective sidewall 12, 13. In particular, this locking is such as to allow the foot sections 12A, 13A to support the other sections (crown 11, sidewalls 12,13) of the lining element 1 when the lifting equipment 600 is removed.

[0076] Advantageously, the sliding of the foot sections 12A, 13A relative to the related sidewall 12, 13 allows the element 1 in the open configuration to be adapted to the tunnel vault, in fact providing the proper support for the arch formed by the lining element 1. Furthermore, by positioning the two foot sections 12A, 13A in the retracted position, the rotation of the sidewalls 12, 13 relative to the crown 11, i.e., the transition to the open configuration, can be carried out with the minimum scarification diameter foreseen for the tunnel. Basically, the positioning in the retracted position ensures that the rotation of the sidewalls 12, 13 is possible without affecting, for this purpose, the scarification diameter.

[0077] Figures 6A, 6B, 6C, 7A, 7B, 7C refer to a possible embodiment of a foot section 12A slidably connected to the shaped body C2 of the first sidewall 12. The two foot sections 12A, 13A preferably have the same structure and the same operating principle. Therefore, the following solutions and explanations referred to the foot section 12A, the connection means 51-1, and the locking means 61-1 operatively associated with the first sidewall 12 are also valid for the foot section 13A, the connection means 51-2, and the locking means 61-2 operatively associated with the second sidewall 13.

[0078] Figures 6A, 6B and 6C show the foot section 12A in the retracted position, while in Figures 7A, 7B, 7C the same foot section 12A is shown in the extended position. The foot section 12A comprises a base surface 141 that contacts the rest plane PO in the extended position. Furthermore, the foot section 12A has an intrados surface 142, an extrados surface 143, and an internal surface 144, which is located opposite the base surface and remains adjacent to (in contact with) a short side B2 of the shaped body C2 when the foot section 12A is in the retracted position. Preferably, a sealing gasket 141A (indicated in Figure 6C) can be secured to the base surface 141 which is then pressed between the rest plane PO and the base surface 141 itself. The connection means 51-1 comprise a metal plate 155 (removably) fastened to the intrados surface 142 of the foot section 12A so as to be integral with the latter during its sliding from the retracted to the extended position. In particular, such a metal plate 155 is fastened to the intrados surface 142 of the foot section 12A through first fastening screws 151. The metal plate 155 has straight grooves 153 (or slots 153).

[0079] Second fastening screws 152 are provided for connecting the metal plate 155 to the intrados surface 12-1 of the second sidewall 12. In particular, each of the second screws 152 is inserted into one of the grooves 153 so that the metal plate 155 remains between the above-mentioned intrados surface 12-1 and the head of the second screws 152. When the foot section 12A is in the retracted position, the second screws 152 are located in the slots 153 in a first position close to the foot section (Figure 6A). As indicated below, in the extended position of the foot section 12A, the second screws 152 are located in the slots 153 in a more distal position relative to the same foot section 12A.

[0080] The connection means 51-1 further comprise a pair of male pipes 157 (solid or hollow) partially buried in the body of the foot section 12A and emerging from said internal surface 144. The connection means 51-1 further comprise a pair of female pipes 156 (internally hollow pipes), each buried into the shaped body C2 of the first sidewall 12 (see sectional view of Figure 6C). A corresponding male pipe 157 is inserted into each of the female pipes 156 so as to define a telescopic coupling. Therefore, in the illustrated embodiment at least two telescopic couplings are provided.

[0081] Starting from the retracted position (Figures 6A, 6B, 6C), after loosening the second screws 152, the foot section 12A moves by gravity relative to the first sidewall 12 guided by the two telescopic couplings configured as described above and by the above-mentioned slots 153. Such a sliding is completed when the rest plane PO is reached (Figures 7 A, 7B, 7C). In such a condition, the second screws 152, being fastened to the first sidewall 12, are farther away from the foot section 12A than they were in the retracted position ( compare, for example, Figures 6A and 7A). Once the extended position is reached, the second screws 152 are tightened again so as to lock the metal plate 155 again against the intrados surface 12-1 of the first sidewall 12.

[0082] As apparent from Figures 7A and 7C, when the distal position is reached, the internal surface 144 of the foot section 12A is facing, but distal from the short side B2 of the shaped body C2 of the first sidewall 12. The distance between the two surfaces (144, B2) will depend on the position of the rest plane PO relative to the first sidewall 12 and therefore can be different each time depending on the portion of the tunnel to be lined. Within the locking means 61-1 provided for the foot section 12A, the second screws 152 described above define first locking means which, further to their tightening, develop a friction force between the intrados surface 12-1 of the first sidewall 12 and the metal plate 155 such as to prevent the mutual movement between the two parts (12-1, 155).

[0083] In accordance with a preferred embodiment, second locking means configured to lock each male pipe 157 inside the corresponding female pipe 156 are preferably provided for the foot section 12 A. In particular, such second locking means are configured to develop a friction force between the male pipe 157 and the corresponding female pipe 156 which prevents the mutual displacement between the two elements (155-156). Such a friction force advantageously combines with the friction force developed by the first locking means so as to allow the structural sections of element 1 (i.e., the sections 11, 12, 13) to be supported relative to the foot section 12 A.

[0084] Figures 8A and 8B are sectional views showing two possible embodiments of the second locking means. In the embodiment of Figure 8A they comprise a cylindrical bushing 154 arranged (buried) in the body C2 of the second sidewall 12 between the intrados surface 12-1 of the first sidewall 12 and the surface of the respective female pipe 156. The cylindrical bushing 154 (indicated in Figure 8A) is internally threaded and one of the second screws 152 is screwed therein. The latter comprises a head 152A facing the metal plate 155 and an end 152B, opposite the head 152A, which lies on the external surface of the male pipe 157 arranged inside the female pipe 156. A nut 153A is also provided which is screwed onto the second screw 152 below the head 152A, wherein such a nut 153A lies directly on the surface of the metal plate 155.

[0085] Tightening the nut 153A against the metal plate 155 develops a friction force (indicated by Fl) between the metal plate 155 and the intrados surface 12-1 of the first sidewall 12. The nut 153A essentially performs the above-mentioned function of the first locking means. Instead, following the tightening of the screw 152, applied on its head 152A, the end 152B pushes the male pipe 157 against the female pipe 156, developing a friction force ( indicated with F2 ) which locks the telescopic coupling in the achieved configuration.

[0086] Overall, for both foot sections 12A-13A the action of the second locking means combines with the action of the first locking means. Considering both the sidewalls 12, 13, the combined action of the first locking means and the second locking means is such as to allow the sections 11, 12, 13 of the lining element 1 to remain supported above the foot sections 12A-13A.

[0087] In the embodiment shown in Figure 8B, the second locking means comprise a wedge element 158 arranged within a conical seat 159 defined at the base of the female pipe 156. The wedge element 158 is crossed by the male pipe 157. When the foot section 12A is released from the retracted position, the male pipe 157 is dragged along the female pipe 156 and tends to drag the wedge element 158, which is permanently pushed in the opposite direction by a spring 159-B. Due to the coupling with the conical surface 159, the action of the spring 159-B, and the hindered axial movement, the wedge 158 develops a friction force on the outside of the male pipe 157 which prevents a return (movement) thereof towards the inside of the female pipe 156. Also in this case, the friction forces developed by the second locking means are synergistic to those developed by the first locking means (i.e., by the second screws 152) for supporting of the sections 11, 12, 13 above the foot sections 12A, 13A.

[0088] With reference to the metal plate 155, it is noted that the same acts advantageously as a formwork in the backfilling operation. In fact, upon completion of the installation of the lining element 1, for each sidewall 12, 13, the respective metal plate 155 allows filling the space between the sidewall itself and the respective foot section 12A, 13A with concrete material, wherein such a space is generated when the latter reaches the extended position. Furthermore, upon completion of the backfilling and after the hardening of the concrete material introduced with the backfilling, the metal plate 155 can be advantageously removed and reused for assembling further lining elements 1.

[0089] The sections 11, 12, 13 of the element 1 can be easily produced through production processes similar to, or linked to, those normally used for the production of concrete segments used for the final lining of tunnels. The assembly of the element 1, i.e., the connection of the sections 11, 12, 13 through the hinge means 21, 22 and the provision of the other functional elements (anti-rotation means 31, 32, attachment brackets 40, connection means 51-1, 52-1 of the foot sections 12-13 A, etc.) can take place in a site adjacent to or even remote from the tunnel for which the element 1 is intended.

[0090] In fact, in any case, when assembled, element 1 can be easily transported, in a folded configuration, through a self-propelled vehicle 500 provided with a loading platform 501 (see Figures 9 to 18). Figures 1 and 1A show the lining element 1 in a folded configuration (hereinafter referred to as closed configuration) particularly suitable for transport. The loading platform 501 will have a length L2 (indicated in Figure 9) greater than the distance between the rotation axes 101 A, 101B defined by the hinge means 21, 22 (distance measured orthogonally to the reference plane R-R indicated in Figure 1). The loading platform 501 will also have a width L2 (indicated in Figure 10) greater than the width LI of the element 1 indicated above. As shown in Figures 9 to 18, for supporting the folded element 1 during its transport and for its subsequent positioning, an equipment 600 is preferably used comprising a frame 601 mounted on a fifth wheel 602 installed on the platform 501 of the self-propelled vehicle 500 and configured so as to allow a rotation of the frame 601 relative to the platform 501 of at least 90°. The fifth wheel 601 is mounted on a longitudinal slide 603 which allows the movement of the fifth wheel itself and of the equipment 600 in the longitudinal direction of the self-propelled vehicle 500.

[0091] The equipment 600 comprises a turret 605 which is movable relative to the frame 601 in a vertical direction, parallel to the axis of the fifth wheel 602. The equipment 600 further comprises two extendable arms 610 located on opposite sides of the turret 605. Each extendable arm 610 comprises a first end hinged to the turret 605 and a second end intended to be fastened to the attachment brackets 40 of one of the two sidewalls 12, 13 of the folded element 1. Said second end will comprise suitable means for attachment to / release from the attachment brackets 40.

[0092] For transport, the folded element 1 is mounted in the closed configuration (shown in Figure 1 ) on the platform 501 as shown in Figure 10, i.e., in such a way that the short sides Bl, B2, B3 of the three sections 11, 12, 13 are orthogonal to the longitudinal plane of the self-propelled vehicle 500. Considering the self-propelled vehicle 500 in a plan view, the element 1 thus remains within the perimeter of the loading plane 501. This feature ensures transportability on roads and motorways while at the same time allowing the self-propelled vehicle 500 to enter tunnels (see Figures 9 and 10).

[0093] During transport, each extendable arm 610 of the movable turret 605 is connected a its second end to the attachment brackets 40 of a respective sidewall 12, 13. As apparent from Figure 9, during transport, the extendable arms 610 are arranged along the longitudinal plane of the self- propelled vehicle 500.

[0094] Figures 9 to 18 allow understanding the installation steps of a lining element 1 carried out using the equipment 600 described above. With reference to Figure 9, the element 1 is brought close to the scarified tunnel portion of 700 to be lined, which has already been subjected to the preparatory scarification step. Once the position intended for installation has been reached (position adjacent to a lining element 1A already installed), the self-propelled vehicle 500 is stopped and preferably secured to the ground by means of suitable telescopic feet 615 ( indicated in Figure 11 ). Subsequently, the frame 601 (and thus also the turret 605) is rotated, through the fifth wheel 602, by 90° (Figure 12) so that, further to such rotation, the rotation axes 101-A, 101-B of the hinge means 21, 22 are oriented parallel to the axis of the tunnel (condition in Figure 13). At this point, the turret 605 is lifted relative to the frame 601 (see again Figure 13) until the crown 11 of the element 1 is brought into the position intended for installation (Figure 14). Subsequently, the extendable arms 610 are activated, thereby causing the rotation of the sidewalls 12, 13 relative to the crown 11 (Figures 15 and 16) until reaching the open configuration (Figure 17). In this regard, in order to reduce operating times, the extendable arms 610 can also be activated while lifting of the movable turret 605, i.e., while the crown 11 is being brought to the installation position.

[0095] In any case, when the open configuration is reached (Figure 17) the anti-rotation means 31, 32 are activated so as to prevent at least the closing of the sidewalls. Subsequently, the fifth wheel 602 and the frame 601 are translated axially (arrow A in Figure 17) along the slide 603 so as to connect the element 1 in the open configuration with the lining element 1 already installed (Figure 18). Further to such movement, the long sides Al, A2, A3 of each section 11, 12, 13 of the element 1A contact the long sides of the sections of the element 1A already installed. The activation of the joining devices 92-1, 92-2, 92-3 generates a stable connection between the two lining elements 1,1 A in question.

[0096] Subsequently, for each sidewall 12, 13 the corresponding foot section 12A, 13A is released so that it can move down and reach the rest surface PO (Figure 18). Once the movement is completed, the foot section 12A, 13A is locked in the extended position (resting on the plane PO), by acting on the (first and second) locking means described above. Once the tightening is completed, the sections 11, 12, 13 are connected to the respective sections of the element 1A already installed and at the same time supported by the foot sections 12 A, 13 A. In this condition the extendable arms 610 can be disconnected from the respective sidewalls 12, 13 and retracted. The self-propelled vehicle 500 can leave the tunnel for receiving a new load.

[0097] When the positioning of the element 1 is completed, backfilling can be carried out to fill the empty gap between the extrados surface 1-OUT and the scarified surface 700 of the tunnel vault facing it. The backfilling can be carried out after installing each individual lining element, or alternatively after installing two or three adjacent lining elements.

[0098] Upon completion of the backfilling and after hardening of the concrete material in the gap, it is possible to remove all functional elements installed on the intrados surface 1-IN of the lining elements. As to the backfilling, it is noted that the pumping of concrete material is started at the base of the sidewalls 12, 13, continues upwards, and is completed above the crown 11.

[0099] Figures 19 to 21 show another possible embodiment of a lining element (indicated by reference 1 ’) according to the invention. In this case the element 1 ’ comprises a structural section 11 ’ made of a single piece. In particular, the structural section 11 ’ of the element 1 ’ corresponds to the central section or crown 11 of the element 1 previously described with reference to Figures 1 to 8 A. Therefore, as compared to the element 1 described above, the element 1 ’ lacks the two sidewalls 11, 12. The element 1’ can be used to line only the upper portion of the tunnel vault, therefore in those cases where the lateral portions of the vault are considered intact.

[0100] The structural section 11’ of the element 1’ has a concrete shaped body C having substantially the same shape as that described above with reference to the crown 11 of the element 1 described above, namely it comprises an intrados surface 111, an extrados surface 112, an edge portion 113 with long sides A and short sides B , and at least one hole 115 connecting the intrados surface 111 with the extrados surface 112 (in any case, reference is made, mutatis mutandis, to the description provided above for the body Cl of the crown 11 shown in Figures 3 A and 3B). Preferably, the element 1’ comprises a pair of gaskets 911 arranged on the long sides A of the body C of the structural section 11’. On the same long sides A, mechanical joining devices 92- 1 are provided for connecting the structural section 11’ to another structural section of another, similar, lining element already installed. With reference to Figure 21, the structural section 11’ can comprise a metal reinforcement 95-1 emerging from the extrados surface 112 if the element 1’ is intended only for the renovation of the tunnel skin. If the element 1’ has a structural function, then the metal reinforcement 95-1 might not emerge from the intrados surface.

[0101] The lining element 1’ comprises two foot sections 1A, IB, each connected to the structural section 11’ at an end 11 A, 11B thereof. For this purpose, connection means 511, 512 (indicated in Figure 20) are provided at each end 11 A, 11B which allow the foot sections 1A, IB to slide between a retracted position and an extended position, wherein in the retracted position the foot sections 1A, IB are adjacent to the respective end 11 A, 11B, whereas in the extended position the foot sections 1A, IB are distal from the respective end 11 A, 11B. The connection means 511, 512 are therefore configured according to the same principle and have the same function as those (51-1, 52-1) described above and provided for the movement of the foot sections 12A, 13A of the element 1 shown in Figures 1 to 8. Therefore, the connection means 511, 512 are structurally and functionally similar to those described above with reference to Figures 6A to 7C.

[0102] For each of the foot sections 1A, IB, the element 1’ comprises locking means configured to lock the respective foot section 1A, IB in the retracted position and in the extended position, when this is reached. Such locking means are not shown in Figures 19 to 21, but they are preferably similar to those already described with reference to Figures 6A to 8B. Therefore, the solutions and explanations presented with reference to Figures 6A to 8B are to be considered valid, mutatis mutandis, also for the element 1 ’ . In practice, the same solutions described with reference to Figures 6A to 8B can be used for slidingly connecting and for locking the foot sections 1A, IB. Figure 19 shows the element 1’ positioned in the scarified seat 700 of a tunnel, with the foot sections 1A, IB in the extended position. Figure 20, instead, shows the element 1’ with the foot sections 1A, IB in the retracted position. For each foot section 1A, IB the extended position is therefore determined by the rest plane PO1 defined by a scarified surface of the tunnel (in this case not adjacent or coinciding with the walkway plane). The sliding allowed to the foot sections allows the element 1’ to be perfectly fit in the scarified seat 700 of the tunnel.

[0103] With reference to Figure 21, preferably first attachment brackets 40’ and second attachment brackets 40” are provided on the intrados surface 111, in a position close to the first end 11A and the second end 11B of the shaped body, respectively. The ends of an extendable arm 610 of an equipment 600 for installing the lining element 1’ can be connected to each of these attachment brackets 40’, 40”. Advantageously, the same equipment 600 described above for installing the lining element 1 provided with sidewalls 12, 13 can be used.

[0104] The element 1, 1’ according to the invention allows the intended task and objects to be fully accomplished. In particular, such an element is relatively easy to make and install. Advantageously, the installation requires less time and fewer workers than those required by traditional methods adopted for skin or structural renovation of a tunnel. Furthermore, the operations can be carried out in predetermined time slots, for example during the night, without blocking daytime traffic. In fact, the installation and support of the lining element according to the invention do not require the positioning of vehicles and equipment on the roadway.

Claims

CLAIMS1) Precast lining element (1) for lining a vault portion of a tunnel, characterized by comprising: a central section (11), a first lateral section (12), and a second lateral section (13), wherein each of said sections (11, 12, 13) comprises a concrete shaped body (Cl, C2, C3) having an intrados surface (11-1, 12-1, 13-1), an extrados surface (11-2, 12-2, 13-2), and a perimeter edge (11-3, 12-3, 13-3) connecting said intrados surface (11-1, 12-1, 13-1) with said extrados surface (11-2, 12-2, 12-3), said perimeter edge comprising a pair of long sides (Al, A2, A3) and a pair of short sides (Bl, B2, B3), said shaped body (Cl, C2, C3) comprising at least one hole (11-5, 11-6, 12-5, 12-6, 13-5, 13-6) connecting the intrados surface (11-1, 12-1, 13-1) with the extrados surface (11-2, 12-2, 13-2); first hinge means (21) connecting said central section (11) with said first lateral section (12) and second hinge means (22) connecting said central section (11) with said second section (13), wherein said hinge means (21, 22) allow said element (1) to change from a folded configuration, taken on before installation, and an open configuration, taken on upon installation, a foot section (12A, 13A), made of concrete, for each of said lateral sections (12, 13), wherein each foot section (12A, 13A) is connected with the respective shaped body (C2, C3) through connection means (51-1, 51-2) allowing said foot section (12A, 13A) to slide between a retracted position and an extended position, wherein in said retracted position said foot section (12A, 13A) is adjacent to the respective lateral section (12, 13) and wherein in said extended position said foot section (12A, 13A) is distal from the respective lateral section (12, 13), wherein said extended position is defined by a rest plane (PO) defined by a surface of said tunnel upon installing said element (1); wherein said lining element (1) comprises, for each of said foot sections (12A, 13A), locking means (61-1, 61-2) configured to lock the respective foot section (12A, 13A) in said retracted position and in said extended position, when the latter is reached.2) Element (1) according to claim 1, wherein at least one of said sections (11, 12, 13) comprises a perimeter gasket (91-1, 91-2, 91-3) extending along the perimeter edge (11- 3, 12-3, 13-3) of the respective shaped body (Cl, C2, C3).3) Element (1) according to any one of the previous claims, wherein at least one of said sections (11, 12, 13) comprises mechanical joining devices (92-1, 92-2, 92-3) arranged along said long sides (Al, A2, A3) of the perimeter edge (11-3, 12-3, 13-3) of the respective shaped body (Cl, C2, C3).4) Element (1) according to any one of the previous claims, wherein at least one of said sections (11, 12, 13) comprises a metal reinforcement (95-1, 95-2, 95-3) emerging from the extrados surface (11-2, 12-2, 13-2) of the respective shaped body (Cl, C2, C3).5) Element (1) according to any one of the previous claims, wherein said element (1) comprises first anti-rotation means (31) for preventing the rotation of said first lateral section (12) relative to said central section when said element (1) reaches said open configuration, and second anti-rotations means (32) for preventing the rotation of said second lateral section (12) relative to said central section (11) when said element (1) reaches said open configuration.6) Element (1) according to any one of the previous claims, wherein said first hinge means (21) and said second hinge means (22) are connected with said central section (11) and with the respective lateral section (12, 13) at the respective intrados surfaces (11-1, 12-1, 13-1) and close to the respective short sides (B l, B2, B3) so as to define a rotation axis (101-A, 101-B) substantially parallel to said respective short sides.7) Element (1) according to claim 6, wherein said first hinge means (21) and said second hinge means (22) are removably connected with said central section (11) and with the respective lateral section (12, 13).8) Element (1) according to any one of claims 1 to 7, wherein each of said lateral sections (12, 13) comprises at least one attachment bracket (40) fastened to the respective intrados surface (12-1, 13-1), wherein said attachment bracket (40) is removably connectable to an end of an extendable arm (610) of an equipment (600) for installing said element (1).9) Element (1) according to any one of the previous claim, wherein for at least one of said foot sections (12A, 13A)- said connection means (51-1, 51-2) comprise a metal plate (155) fastened, by means of first fastening screws (151), to an intrados surface (142) of the foot section (12A) so as to be integral therewith as it slides form the retracted to the extended position, and wherein said metal plate (155) has a plurality of straight slots (153), and- said locking means (61-1, 61-2) comprise second fastening screws (152) for connecting said plate (155) with said intrados surface (12-1, 13-1) of the respective lateral section (12, 13), wherein each of said second screws (152) is inserted in one of said slots (153) so that said plate (155) is interposed between said intrados surface (12-1, 13-1) and a head of said second screws (152).10) Element (1) according to claim 9, wherein said connection means (51-1, 51-2) further comprise:- at least one male pipe (157) partially buried into the body of said foot section (12A, 13A) and emerging from a surface (144) of said body facing the respective lateral section (12, 13),- at least one internally hollow female pipe (156) buried into the shaped body (C2, C3) of the respective lateral section (12, 13), each male pipe (157) being inserted in a corresponding female pipe (156) so as to define a telescopic coupling.11) Element (1) according to claim 9 or 10, wherein said locking means are also configured so as to develop, further to reaching said extended position, a friction force between said male pipe (157) and said female pipe (156), wherein said friction force prevents a mutual displacement of said telescopically coupled pipes (157, 156).12) Precast lining element (1’) for lining a vault portion of a tunnel, characterized by comprising: a structural section (11’), comprising a concrete shaped body (C) having an intrados surface (111), an extrados surface (112), and a perimeter edge (113) connecting the intrados surface (111) with the extrados surface (112), said perimeter edge (113) comprising a pair of long sides (A) and a pair of short sides (B), said shaped body (C) comprising at least one hole (115) connecting the intrados surface (111) with the extrados surface (112); two foot sections (1A, IB), made of concrete, each foot section (1A, IB) being connected with an end (11 A, 11B) of the shaped body (C) through connection means (511, 512) allowing said foot section (1A, IB) to slide between a retracted position and an extended position, wherein in said retracted position said foot section (1A, IB) is adjacent to the respective end (11 A, 1 IB) and wherein in said extended position said foot section (1A, IB) is distal from the respective end (11 A, 1 IB), wherein said extended position is defined by a rest plane (PO) defined by a surface of said tunnel upon installing said element (1’); wherein said lining element (1’) comprises, for each of said foot sections (1A, IB), locking means (61-1, 61-2) configured to lock the respective foot section (1A, IB) in said retracted position and in said extended position, when the latter is reached.13) Element (1’) according to claim 12, wherein said structural section (11’) comprises a perimeter gasket (911) extending along the perimeter edge (113) of said shaped body (C).14) Element (1’) according to claim 12 or 13, wherein said structural section (11’) comprises mechanical joining devices (92-1) arranged along said long sides (Al) of said perimeter edge (113) of the respective shaped body (C).5) Element (1’) according to any one claims 12 to 14, wherein said structural section (11’) comprises a metal reinforcement (95-1) emerging from the extrados surface (112) of said shaped body (C).

Images