PREFABRICATED TUNNEL LINING SHANK WITH CIRCUMFERENTIAL TRACTION GEAR

Description

DESCRIPTION of the industrial invention entitled: "Prefabricated ashlar of a tunnel lining with circumferential traction devices" of: MACCAFERRI TUNNELING Srl, of Italian nationality, with headquarters in Bologna Designated Inventor: Cristiano BONOMI filed on: May 9, 2024 * * * Field of invention The present invention relates to the field of the production of tunnels and, in particular, the construction of lining structures for tunnels using prefabricated segments. More specifically, the invention relates to a prefabricated block for the construction of tunnel lining structures made up of pre-cast concrete blocks adjacent buildings in such a way as to obtain pre-compression of the ashlars same. Technological background As is known, one of the fundamental operations in the creation of tunnelling by underground excavation is the creation of one or more layers of lining to stabilize and contain the walls that are exposed by the excavation I want. A well-known type of lining for natural tunnels is made of prefabricated concrete elements known as “quoins”. This type coating typology is typically achieved by creating progressive mind, as the excavation progresses, casing rings that extend no on the entire perimeter of the excavation section, each formed by a pl- PROVVISIONATO & CO reality of these blocks, placed next to each other. This type of coating is normally used in galleys made using so-called mechanized techniques. In this case the works basic underground excavation operations, removal of excavated material the excavation walls are lined and lined continuously and simultaneously, by means of large, specially designed machines, called TBM (“Tunnel Boring Machines”). These machines carry out excavation in integral and continuous manner and at the same time provide for the evacuation removal of excavated material from the excavation face and the construction of the revetment tunnel extension as the excavation face advances. In the case of tunnels built using this mechanized technique are normally foreseen a single layer of cladding made up of the aforementioned prefabricated blocks. Cladding structures made of prefabricated blocks can however be adopted also in the context of the construction of natural tunnels, va- that is to say tunnels dug underground, using the so-called traditional technique the, in which the above-mentioned fundamental operations are carried out in a discontinuous, largely in succession, rather than simultaneously, and re- repeated cyclically until the tunnel is completed. In this case, the prefabricated blocks are used to create the definitive cladding of the tunnel, replacing the alternative construction which provides the use of formwork and the subsequent pouring of concrete on site. To ensure the stability of the cladding, the ashlars that form a ri- gallery dressing are typically connected to each other by joining systems. In particular, each segment is connected to the adjacent segments both in a circumferential, or perimeter, direction of the covering PROVVISIONATO & CO ment, that is to say with the adjacent ashlars belonging to the same ring of ashlars, both in a longitudinal direction of the cladding, i.e. with the adjacent ashlars belonging to immediately adjacent ashlar rings to the ring containing the stone in question. Exposition of the invention In light of the above, the main purpose of the present invention is to create a perfected system for pre-tensioning in a effective and optimal in the circumferential direction the rings formed by the ashlars for tunnel lining. Another purpose is to make available a prefabricated block to create tunnel linings that can be put under compression in the circumferential direction. A further object of the present invention is to make available a prefabricated block of the above type which can be manufactured in mo- do simple and at competitive costs and can be used without limitations to create coverings in the context of the construction of tunnels both with mechanized technique as well as traditional technique. In accordance with the present invention, these objects are achieved through prefabricated segments having the characteristics indicated in the claims tions that follow. The object of the invention is also a covering ring to for galleries made up of ashlars. According to a first aspect, a prefabricated block of a tunnel lining, having an intrados face, a extrados, opposite the intrados face, and a perimeter wall which connects the intrados face and the extrados face. In the ashlar it is re- a tubular conduit shaped like an arch was dug out which opened onto two sides PROVVISIONATO & CO opposite sides of the perimeter wall intended to be placed side by side to correspond teeth faces of adjacent ashlars that form the same ring of tunnel lining segments. The tubular duct is designed for the introduction of at least one flexible elongated element used for the pre-tensioning of the ring of segments. The tubular duct is preferably made using a tube rigid which is placed in the formwork of the ashlar before pouring the concrete which, once solidified, will form the ashlar. The tubular conduit it preferably has an arched shape concentric to the curvature of the extrados and intrados of the ashlar. Preferably, even if not li- In a typical way, the tubular duct is arranged on a median plane of the con- that is, perpendicular to the faces onto which the tubular duct opens. With such a configuration of the ashlar, it is possible to make a ring- tunnel lining, also the subject of the present invention, com- taking a plurality of ashlars placed next to each other in such a way that the the openings of the tubular duct on the adjacent voussoirs coincide with each other. In this way, a continuous and overall tubular duct is formed. circumferentially along all the ashlars that form the cladding ring tunnel chin. At least one outlet segment is drilled an opening on the intrados that communicates with the tubular duct. Please note that in this description, the term “circumferential le” is used in a broad sense and is not limited to defining a configuration circular, but includes any closed ring configuration, such as example also polycentric. At least one flexible elongated traction element, which may be PROVVISIONATO & CO for example a wire rope, is inserted along the tubular duct so such that its ends protrude from at least one opening on the intrados of the said outlet ashlar. In this way it is possible to exert a traction of the at least one flexible elongated element so as to pre-compress around referring to the tunnel lining ring. According to a preferred aspect, on said at least one outlet ashlar two openings are made, from each of which one of the two comes out end of the at least one flexible elongated tensile member which per- the circumferential tubular duct runs. According to a particularly advantageous aspect, they can be pre- seen, along the same tunnel lining ring, two or more of the said outlet segments being provided with openings for the exit of respective flexible elongated elements, or ends of sections of one or more elongated elements flexible gates, so as to divide the tubular duct into several sections king. Preferably, two or three of said outlet ashlars can be provided, in such a way as to divide the circumferential tubular duct into two or three respective sections of tubular duct, preferably angularly equal spaced along the extension of the tunnel lining ring. Traction organs of at least one ele- flexible elongated chin strap, the ends of which can then be locked in traction through locking organs. According to another advantageous aspect, between adjacent ashlars are pre- move sealing gaskets to seal the tubular duct from the environment external in the areas of juxtaposition between adjacent ashlars. In this way prevents dirt, debris or moisture from entering the tubular duct, at all PROVVISIONATO & CO to the advantage of resistance over time, especially to corrosion, of the at least one flexible elongated traction element. Brief description of the drawings Further features and benefits will be detailed in the description. cut that follows a preferred form of embodiment, with reference to the di- attached signs, given as a non-limiting example, in which: - Figure 1 is a schematic perspective view of a tunnel lining formed by rings of adjacent ashlars; - figure 2 is a section along line II-II of figure 1; - Figure 3 is a perspective view of a ring outlet ashlar ashlars of figure 1, provided with openings on the intrados for the exit of the ends of a circumferential prestressing rope of the con- ring there; and - figure 4 is an enlarged scale view of a detail of a section longitudinal centerline of the outlet segment in figure 3. Detailed description Referring now to the figures, a tunnel lining 10 is realised made by means of prefabricated segments 1. The segments 1 are arranged in such a way as to form- have a plurality of rings 2 of closed circular shape, mutually adjacent centi in a longitudinal development direction of the tunnel, so as to known self. The segment 1 consists of a prefabricated element, for example of reinforced concrete, configured as a cylindrical crown segment or cylindroid, having a rectangular perimeter shape or, as in the ca- I know of the so-called "keystone" and of the two stones circumferentially surrounding it. PROVVISIONATO & CO adjacent mind of each ring of the tunnel lining, trapezoidal. Therefore, segment 1 has a curvature in one of the two directions of extension. in particular the direction of greatest extension, corresponding to the curvature of the rings constituting the cladding. The segment 1 comprises then an intrados face 11, which, in the condition put in place of the ashlar 1, faces towards the inside of the tunnel and one extrados face 12 opposite the intrados face 11. The ashlar 1 also includes a perimeter wall 13, which connects the intrados face 11 and the face of extrados 12 and is formed by a pair of faces 13a, opposite each other parallels, which define the corresponding portion of the two faces of the tunnel lining ring. The faces 13a are generally more long of the other pair of faces 13b of the perimeter wall 10 plus short. The shorter faces 13b can each lie on a parallel plane to the longitudinal direction XX, such as planes passing through the cen- tro or for one of the centers of the covering ring, or on skewed planes in the case of keystones and those circumferentially adjacent to them you. In the following description, the direction parallel to the shorter sides 13b, which is parallel to the longitudinal direction XX of development of the coating of the tunnel, will be conventionally defined as the longitudinal direction the hips in relation to the single ashlar. The ashlar 1 can be provided, in a manner known per se, with a seal perimeter sealing nition 14, which extends along the entire perimeter wall 13, preferably near the extrados face 12, to rea- to create a seal at the joint spaces that are they are formed between adjacent segments in the tunnel lining 10. PROVVISIONATO & CO Inside the voussoirs 1 that form each cladding ring 2 a tubular duct 15 is obtained which runs from a short face 13b to the fac- short cia 13b opposite, flowing onto them with an opening 15a which is aligned- to a corresponding opening 15a obtained on the short face 13b of the con- that is adjacent, so that, as visible in the section of figure 2, a tubular duct is formed inside the lining ring 2 continuous circumferential king. A gasket is preferably placed between one segment and the next. 21 sealing that seals the joining area of ​​the openings 15a of the ducts on adjacent segments, to prevent moisture or dirt from penetrating into the duct citia, or debris generated during the galley lining process ria. The openings 15a of the stored and transported segments are protected with sacrificial gaskets made of polystyrene or other similar elements. On an outlet 1', the tubular duct 15 is diverted, to starting from the two ends on the short sides 13b of the 1' ashlar, to flow into two respective openings 16, 17 obtained at the intrados 11' of the ashlar 1'. In this way, the tubular duct runs continuously along the lining ring to 2, starting from one of the two openings, for example opening 16, running circumferentially in the cladding ring 2 inside the voussoirs 1 and emerging into the other of the two openings, for example opening 17 on the same now I'm going to have to work 1'. A flexible transmission element is inserted into the tubular duct 15. tion, for example a rope 18, preferably, but not limited to a wire rope. Rope 18 is long enough for its ends 18a, 18b can come out from the openings 16, 17 respectively. In corre- PROVVISIONATO & CO edge of the openings 16, 17, the ends of the rope 18 pass through so retention plates 19 with conical coupling 20 of generally- known. The ends of the rope 18 can be tensioned by means of systems known in the steel wire rope tensioning sector. To make a lining ring with the previously described blocks of the laying of the blocks, placing them next to each other to form the ring. At least one of the voussoirs is the outlet voussoir 1' on which are foreseen the openings on the intrados where the two ends of the tu- duct flow into 15. When the lining ring 2 is completed, in the tubular duct through the opening 15, for example, the rope 18 is introduced which pro- progressively the sacrificial gaskets, if any, at the ends 15a of the duct on the faces of each ashlar. Once the circumferential turn is completed, ferential in the tubular duct that runs along the entire lining ring then, the end of the rope 18 is extracted from the other opening 17 inside hump 11' of the 1' ashlar. In case more than one segment is foreseen in the cladding ring 2 of outlet 1', each of which is equipped with openings on the intrados, po- multiple ropes or sections / pieces of rope can be used to create the tie rod circumferential, gradually introducing each rope into an opening of a outlet 1' to get it out of the opening of an outlet quoin 1' next along the extension of the lining ring 2. For example, in case three outlet segments are foreseen in the cladding ring 2 1' with respective openings 16, 17 on the intrados, three can be introduced ropes or sections / pieces of rope, each of which occupies a respective section of tubular duct, from opening 16 of an outlet 1' to the opening PROVVISIONATO & CO 17 of the next 1' outlet segment. The sections / pieces of rope can then be put under tension by acting in traction on their ends which protrude come out from the openings on the outlet voussoirs 1'. By pulling the rope or ropes or sections / pieces of rope, depending on the configurations of the ashlars adopted, which determine the single or sectional path of the tubular duct, compression is obtained circumferential to the cladding ring 2 of ashlars. Of course, variations of the above implementation form are possible. described. The rope can be not only metallic, but also textile, made with polymeric fibers or a combination of polymeric fibers and metal fibers liche. After the rope 18 has been inserted into the tubular duct 15, it can be fill the duct with a material that fills it without leaving spaces voids. The filling material can be a cement mortar, a ma- stice, a polymer foam material or other functional filler materials ultimately similar. The filling material can protect the rope from corrosion, preventing it from coming into contact with any moisture that might penetrate through the joints of the tubular duct at the walls put some ashlars side by side. As previously indicated, more than one ashlar can be foreseen 1' outlet on which to make openings for the ends of the rope to come out, for example to use several shorter sections of rope to com- complete the circumferential path of the lining ring. It is also possible to foresee more tubular ducts that run to example between them parallel inside the ashlars, both to increase the strength of PROVVISIONATO & CO traction that can be exerted on the covering ring, both for redundancy, in the case where a tubular duct becomes blocked, for example by debris that have accidentally penetrated the tubular duct during the installation of the tanneries. Furthermore, nothing excludes the possibility of using more than one rope in the same tubular duct, compatible with the transverse dimensions of the ropes and of the duct, respectively. The tubular duct (or each of the tubular ducts, if any) (there are more than one) can have a cross-section of any kind, pre- preferably circular or oval, although the possibility of realizing it is not excluded create tubular ducts of different cross-sections, for example square or polygonal. Naturally, without prejudice to the principle of the invention, the forms of at- The situation and the construction details may vary widely. with respect to what is described and illustrated, without thereby departing from the scope of the present invention. PROVVISIONATO & CO

Claims

1. Prefabricated segment (1) for the construction of an annular tunnel lining (10), having an intrados face (11), an extrados face (12) opposite the intrados face, and a perimeter wall (13) connecting the intrados face (11) and the extrados face (12), in the segment being made a tubular conduit shaped like an arch and opening onto two opposite faces of the perimeter wall intended to be placed next to corresponding faces of adjacent segments which are part of the same ring of segments of the annular tunnel lining (10), the tubular conduit being prepared for the introduction into it of at least one flexible elongated traction element for the pre-tensioning of the ring of segments.

2. Prefabricated ashlar according to claim 1, wherein the arched shape of the tubular duct is concentric with the curvature of the extrados and intrados of the ashlar.

3. Tunnel lining ring, comprising a plurality of segments (1, 1') according to claim 1 or claim 2, wherein each segment is placed next to two adjacent segments in such a way that the openings of the tubular duct on the adjacent segments coincide so as to form a continuous and overall circumferential tubular duct which runs through all the segments forming the tunnel lining ring, at least one opening being made on its intrados on at least one outlet segment (1') of the plurality of segments, said at least one opening being in communication with the tubular duct, at least one flexible elongated traction element being inserted along the tubular duct with its ends protruding from the at least one opening on the intrados of said at least one outlet segment (1'),to exert traction on the at least one flexible elongated traction element so as to circumferentially pre-compress the tunnel lining ring (2)., 4. Tunnel lining ring according to claim 3, wherein two openings are made on said outlet segment (1'), each intended for the exit of a respective end of the at least one flexible elongated traction element which runs along the circumferential tubular duct.

5. Tunnel lining ring according to claim 3 or claim 4, comprising two or more of said outlet segments (1') provided with openings for the exit of the ends of respective flexible elongated traction elements or the ends of sections of one or more flexible elongated traction elements, said outlet segments (1') being arranged in the ring of segments in such a way as to divide the circumferential tubular duct into several sections.

6. Tunnel lining ring according to claim 5, comprising two or three of said outlet segments (1'), for dividing the circumferential tubular duct into two or three tubular duct sections respectively, wherein said two or three outlet segments (1') are preferably equally spaced angularly along the extension of the tunnel lining ring. PROVVISIONATO & CO - 13 PI2936 7. Tunnel lining ring according to any of claims 4 to 6, wherein traction members are provided, the at least one flexible elongated traction element whose ends can be locked in tension by means of locking members.

8. Tunnel lining ring according to any of claims 4 to 7, wherein sealing gaskets are provided between adjacent segments to seal the tubular duct from the external environment in the areas where adjacent segments meet.

9. Tunnel lining ring according to any of claims 4 to 8, wherein the at least one flexible elongated traction element is a wire rope.