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EP-4558705-B1 - TUNNEL CONSTRUCTION METHOD AND MACHINE

EP4558705B1EP 4558705 B1EP4558705 B1EP 4558705B1EP-4558705-B1

Inventors

  • BONOMI, CRISTIANO

Dates

Publication Date
20260506
Application Date
20230718

Claims (12)

  1. Method for constructing natural tunnels, wherein a tunnel (1) under construction comprises an excavation front (EF), a final lining front (FLF) upstream of the excavation front (EF) in an excavation advance direction (A), and a work region located between the excavation front (EF) and the final lining front (FLF), comprising the steps: a) advancing the excavation front (EF) by a predetermined advance length by means of point excavation with one or more self-propelled excavating machines (100); b) removing excavated material from the work region by means of one or more dump trucks (500); c) applying a primary lining (2) onto walls exposed by the excavation at the advance length of the excavation front (EF); d) advancing the final lining front (FLF) by a predetermined advance length by creating a final lining (4) onto the primary lining (2) applied at the same advance length in a previous advance cycle; e) repeating steps a) to d) until the tunnel (1) is completed, wherein step d) of advancing the final lining front (FLF) comprises assembling at least one full ring (42') of prefabricated segments (41) and is carried out simultaneously with step a) of advancing the excavation front (EF), wherein step d) of advancing the final lining front (FLF) is carried out by means of a segment placing machine (200) having a tubular frame (201), and wherein the passage or displacement of operating machines (100, 600, 700, 800), vehicles (500, 900), or equipment from/to said work region during step b) of removing excavated material and step c) of applying the primary lining (2) takes place through the tubular frame (201) of the segment placing machine (200).
  2. Method according to claim 1, wherein assembling the at least one full ring (42') of segments (41) by means of the segment placing machine (200) comprises repeatedly moving a robot arm (203) along a circular path between a segment taking position and a plurality of segment placing positions distributed along said circular path.
  3. Method according to any one of the previous claims, wherein the excavation front (EF) and the final lining front (FLF) are respectively advanced substantially by a same advance length.
  4. Method according to any one of the previous claims, further comprising, after step d) of advancing the final lining front (FLF), advancing the segment placing machine (200) on the previously created final lining (4), preferably by a length equal to the advance length of the final lining front (FLF).
  5. Method according to any one of the previous claims, further comprising moving a self-propelled service platform (400) for transferring operating machines (100, 600, 700, 800, 1000), vehicles (300, 500, 900) or equipment in a tunnel portion between a rear end of the segment placing machine (200) and a carriageway plane front (CF) of the tunnel (1) located upstream of the segment placing machine (200).
  6. Self-propelled segment placing machine (200) for placing prefabricated segments (41) of a final lining (4) of a natural tunnel (1), comprising: - a longitudinally extended tubular frame (201) having transverse dimensions which allow operating machines (100, 600, 700, 800, 1000), vehicles (500, 900), or equipment used during the construction of the tunnel (1) to pass or be displaced through the tubular frame (201), and - segment handling means (203) associated with the tubular frame (201) and displaceable relative to the tubular frame (201) between a segment taking position and a plurality of segment placing positions for assembling full rings (42, 42') of segments (41) at walls of the tunnel (1), wherein in a rest configuration of the segment placing machine (200) the tubular frame (201) is freely practicable by said operating machines (100, 600, 700, 800, 1000), vehicles (500, 900), or equipment, and wherein the tubular frame (201) comprises a plurality of anchoring devices (206) which can be radially extended therefrom for temporarily anchoring the segment placing machine (200) to walls of the tunnel (1).
  7. Segment placing machine (200) according to claim 6, wherein the segment handling means (203) comprise a robot arm (203) displaceable along a circular guide rail (205) integral with the tubular frame (201) and arranged perpendicularly to a direction of longitudinal extension of the tubular frame (201).
  8. Segment placing machine (200) according to claim 7, wherein in a rest configuration of the segment placing machine (200) the robot arm (203) is extended substantially parallel to the tubular frame (201) along an inner side thereof, preferably in a vault region thereof.
  9. Segment placing machine (200) according to claim 7 or 8, wherein in a work configuration of the segment placing machine (200) the robot arm (203) projects at least partially longitudinally and/or transversally form the tubular frame (201).
  10. Segment placing machine (200) according to any one of claims 6 to 9, further comprising at least one movable bridge (204) for establishing a motorable connection between the segment placing machine (200) and a work region of the tunnel (1).
  11. Segment placing machine (200) according to claim 10 when dependent on claim 7, wherein the movable bridge (204) is displaceable along the circular guide rail (205) of the robot arm (203), in coordination with the robot arm (203).
  12. Segment placing machine (200) according to any one of claims 6 to 11, wherein the anchoring devices (206) are located so as to form at least one ring around the tubular frame (201).

Description

The present invention falls generally within the technical field of construction of natural tunnels. In particular, the invention relates to a method and a machine for constructing natural tunnels by means of excavation with "traditional" technique. In very general terms, the construction of natural tunnels by means of excavation essentially comprises three operations: underground excavation, removal of the excavated material and application of one or more lining layers to stabilize and consolidate the excavation walls. These operations form the basis of the techniques most widely used today to construct natural tunnels by excavation, namely the "traditional" technique and the "mechanized" technique. According to the "traditional" technique, the above-mentioned basic operations are carried out discontinuously, largely in succession, and repeated cyclically until the tunnel is completed. Each of them requires a direct and substantial workforce intervention and the use of a plurality of operating machines, vehicles, and equipment, which have to pass or be moved repeatedly along the tunnel during the construction thereof to reach a respective working front or region. In further detail, in an embodiment typical of known methods for constructing natural tunnels by means of excavation with "traditional" technique, each advance cycle comprises firstly advancing an excavation front of the tunnel by a predetermined advance length. The excavation front is point-excavated by means of conventional excavating machines. Simultaneously with and/or subsequently to the excavation, the excavated material is removed by means of dump trucks that transport the excavated material outside the tunnel under construction, passing through it repeatedly. Once the tunnel length just excavated has been freed of the excavated material, a primary lining, also known as first phase lining or temporary lining, having the purpose of stabilizing the cavity in the short term, so as to allow the workers to operate therein safely, is applied onto walls exposed by the excavation, in particular onto the radial walls. The primary lining is usually made of shotcrete. Often, before applying shotcrete, large metal reinforcement profiles, called ribs, are laid. Such reinforcement profiles are shaped according to the excavation cross-sectional profile and are arranged longitudinally at regular intervals along the excavation. In this case, the shotcrete is subsequently applied onto the intrados of the ribs and between the ribs themselves, thus incorporating them in one single structure. For these operations, suitable operating machines, such as pumping machines for applying the shotcrete and machines for lifting and laying the ribs, and related service vehicles, such as concrete mixers and load trucks for transporting the ribs and other materials, are used, which shall be able to pass through the tunnel under construction as far as the newly excavated tunnel length. Other work fronts upstream - with reference to the direction in which the excavation is advanced - of the excavation front are then advanced, at which works are made aimed at creating a final lining of the tunnel, also known as second phase lining, which is required for ensuring the long-term stability thereof. In particular, at a first work front upstream of the excavation front, two lateral shoulders, also known in the art as kerbs, made of reinforced concrete and parallel to each other, are further built on opposite sides of the tunnel base. At a second work front, upstream of the advance front of the kerbs, an inverted arch, also made of reinforced concrete, is built at the bottom of the tunnel, between the two kerbs previously built. Lastly, at a third work front upstream of the advance front of the inverted arch, the final lining of the tunnel is built at the vault and the sidewalls. Typically, this operation comprises laying waterproofing sheets on the corresponding surfaces, building a steel reinforcement framework and concrete casting with radial thickness varying from 30 cm to 120 cm with the aid of a large monolithic formwork, transversally shaped according to the final tunnel cross-sectional profile and having length of, e.g., 10 m, which can be moved along the tunnel on rails temporarily laid on the previously built kerbs. The operations linked with casting of the final lining at the vault and sidewalls, and of the inverted arch on the bottom, significantly obstruct or totally block the passage of operating machines, vehicles, or equipment through the tunnel sections involved and therefore the passage thereof from/to the excavation front. During said operations, which in the case of the final lining can take up to 10-12 hours, it is not possible to advance the excavation. The latter is resumed in a subsequent advance cycle, when the tunnel sections involved in the advance of the final lining or the inverted arch are free again. From the above it is apparent that the excavation adv