Classifications

• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
  • E21D9/00—Tunnels or galleries, with or without linings; Methods or apparatus for making thereof; Layout of tunnels or galleries
  • E21D9/005—Tunnels or galleries, with or without linings; Methods or apparatus for making thereof; Layout of tunnels or galleries by forcing prefabricated elements through the ground, e.g. by pushing lining from an access pit

Definitions

• the present invention relates to a method for the realization of a passage or tunnel reserved for the circulation of pedestrians or vehicles under a railway line or a road or motorway pavement in activity, which requires only a limited interruption in time traffic on this lane, the structure defining the passage to be built being prefabricated, if necessary made next to the lane before it is momentarily cut to allow the excavation of the ground forming the support slope of this lane , said work being then set up in the excavation thus created before the road or the roadway is reconstituted on the top of this work.
• the invention is more particularly a method which, once the excavation cleared after severing the track, to bring the work under the location of the latter in extremely short time, while allowing a remarkable accuracy of its positioning the sub-layers or the ballast are then reconstituted on the structure before the track is reformed, allowing the immediate resumption of traffic.
• the invention relates to a construction method in which the work to be done in under the track consists of a means of one or two frames, hollow and concrete, developed in situ, the frame being arranged in the first case on one side of the slope carrying the track and in the case of two homologous frames symmetrically to each other on each side of the median plane of this slope, parallel to the track, the single frame being placed transversely in the excavation or the two frames meeting in the median plane so as to ensure continuity of passage under the path from one frame to another.
• the European patent EP-A-0 611 848 is known on behalf of the applicant, a process known as autoripage, allowing the supply of a work developed in situ reinforced concrete through a slope supporting a railway, an active road or highway pavement.
• This method uses, for moving bridges or structures developed in-situ reinforced concrete, at least one base plate support and guide for a concrete frame.
• the frame is carried by the raft and is provided laterally with anchor points for traction cables.
• the traction cables are secured at the front of the guide raft to at least one fixed anchoring point, while the other end is engaged with cylinders carried by the frame, so that the tensile force exerted on the cables by the jacks is reflected, as a result of reaction, a sliding of the frame on the floor and then on the ground.
• the main disadvantage of this method lies particularly in the fact that it is insufficient to move large volume structures. Indeed, the anchoring points which are located laterally and at the front of the guide raft in a spade, tend to bend and tear from the ground under the effect of the traction of the jacks and because of the friction important between the contacting faces respectively of the frame, the floor and the floor.
• the present invention aims to overcome these disadvantages, by proposing a method that allows on the one hand, to distribute the tensile force on multiple anchor points judiciously distributed at the end of the front of the guide raft in at least one spade buried in the ground perpendicular to the axis of traction, and secondly, advantageously, to distribute with the aid of a fluid mattress, contained between the slab of the structure and the sole of the raft or the ground, the pressure of this work on the support.
• the flat guide bed is arranged so as to make it comprise at least one boss or solid constituting the passive anchor point of the traction cables, this boss being disposed in the vicinity of the end of the guide raft directed towards the inside of the excavation, at the level of at least one transverse spade.
• the method consists in associating via the passive and active anchoring points, each structure supported by the base of the frame to at least one or more parallel cables, extending below the latter at the level of longitudinal passages made within the guide raft.
• the anchoring protrusions of the cables are formed in the front part of the guide raft, closer to the sides of the excavation in the embankment, the traction cylinders being mounted on the base of the frame.
• the active anchoring bosses comprise, at the level of the zones of attachment of the cylinders, orifices whose penetration axis is inclined relative to the horizontal by an angle ⁇ , by means of deflectors, so as to deflect the traction cables towards the bottom of the frame raft, in the grooves of reservation of the guide raft.
• the passive anchor bosses located in the "spade" zone of the guide raft, at the zones of fastening of the ends of the cables comprise orifices whose penetration axis is inclined relative to horizontally at an angle ⁇ , so as to deflect the traction cables running in the guide raft to the "spade" zone.
• the cables used are multi-wire cables, the strands of which are secured at one of their ends to a bearing plate abutting the opposite face of the anchoring boss.
• the realization of such a passage is carried out as follows, the example given below being relative to the implementation of a passage consisting of two prefabricated concrete frames, homologous and arranged symmetrically on both sides of the slope, these frames meeting substantially in the median longitudinal plane of the slope extending parallel to the track.
• the method applies just as well when the passage to be made is constituted by means of a single frame which extends entirely through the slope to form alone the passage in question.
• two support and guide rafts 1 are built on either side of the embankment, these rafts being arranged opposite one another with respect to the median plane of the track. .
• Each guide raft 1 consists of a concrete flat sole 2, preferably cast in situ and having projecting parts such as extending under this sole 2 to form spades 3 for immobilizing the raft 1 in the ground .
• the slab is associated with tie rods whose one end is secured to the edge of the slab and the other, which is buried in the ground, is locked relative to the latter being embedded in a solid mass of concrete.
• the sole 2 comprises flanges 4 whose role will be specified later.
• the sole 2 is provided with a plurality of reservation grooves 5 which are adapted to allow the passage of traction cables 6. These reservation grooves 5 are arranged along the longitudinal axis of the guide raft 1, they allow the horizontal path traction cables 6 between the two ends 7, 8 facing deviators 9, 10 respectively from active anchoring points 11 and passive 12.
• a hollow frame 13 forming the framework of the concrete structure, generally of rectangular cross section and comprising a lower slab 14, on the sides 15 and an upper slab 16, parallel to the lower slab 14, the width of the frame 13 being substantially equal to that which separates, on the guide slab 1, the flanges 4 thereof, so that once the frame cast on the guide raft 1, this frame 13 can slide on the latter 1, this sliding can be facilitated in particular by an injection between the sole 2 and the slab 14, between their opposite faces, a lubricating agent , in particular a bentonite slurry or other similar product, providing a lubrication that may be useful during the relative displacement of the frame 13 on the guide slab 1, and then on the ground, in front of the slab as and when as the frame 13 moves away from it, as explained hereinafter.
• a lubricating agent in particular a bentonite slurry or other similar product
• the lubrication agent injection wells open into a plurality of ⁇ sections placed in directions substantially transverse to the direction of movement of the structure.
• annular belt 17 is produced on the slab 14 of the slab of the frame 13, at the level of the face opposite the guide slab 1.
• the latter is intended to receive a bladder 18 or chamber preferably made of a deformable material, in particular of the plastic material type, under the action of a fluid under pressure.
• the material reserve forming the annular belt 17 is filled by a chamber 18 which is filled with a fluid under pressure. incompressible type of water, so as to expand it in the volume of the annular belt 17 and to form a mattress that will be able to withstand the compressive forces during the pouring of concrete from the structure on the base of the frame 13.
• the fluid contained in the bladder 18 is driven out and is replaced by a gaseous fluid under pressure (compressed air).
• the face of the bladder 18 facing the face of the guide raft 1 has a plurality of raised areas 19, so as to form a lip which retains the fluid which is injected between the sole 2 and the slab lower 14.
• the pressure of the structure on the guide raft 1, then on the ground, taking into account the order of magnitude of the facing surfaces, is maintained, thanks to this device, in a very reasonable range, of the order of 0.3 to 1.5 bar, which allows the lifting of the structure for a fluid injection pressure, on the one hand inside the chamber 18 (of the order of 1.5 to 2 bars), and secondly between the lower slab 14 and the sole 2, the intensity of the injection pressure of the lubricating agent being of the order of 0.3 to 1.5 bar.
• the cables 6 may, depending on the case, be manufactured on site or may be prefabricated and brought already trained on site.
• the lateral sides 15 of each frame 13 may optionally also comprise external bosses 11, arranged above the flanges of the guide raft 1 when the frame 13 rests on it, being in these conditions substantially vis-à- screw and in the extension of the passive anchoring bosses 12 of the guide raft 1, provided at the end of the flanges at the end of the slab facing the slope.
• the active bosses 11 of the frame 13 are arranged so as to allow the mounting and the support of hydraulic jacks 21, intended to cooperate with traction cables 6 such that each of the possible lateral cables and cables located between the base of the frame 13 and the guide raft 1, respectively along the lateral sides and the front edge of the frame, having an end fixed on the one hand to the corresponding passive anchor 12 buried in the ground at the spade 3 and being engaged with secondly with the jack 21 so that the tensile force on the cable 6 exerted by this jack 21 causes, by reaction on the frame 13, a corresponding displacement of the latter vis-à-vis the guide slab 1 in direction of the slope.
• the cables 6 are multi-wire cables, formed of a plurality of strands arranged such that, at the end of the cable in the passive anchor 12, they develop in a recess thereof to be fixed to the means of locking keys on a support plate 22, ensuring a suitable distribution of the forces created by the corresponding traction cylinder 21.
• the zone of expansion of the cable 6 inside an orifice 23 made in the passive anchor 12 is effected within a trumpet 24.
• the main axis of this orifice 23 is inclined by an angle ⁇ relative to the horizontal axis, this angle being between 5 and 15 ° and preferably close to 10 °.
• each orifice 24 through which each pulling cable 6 opens is inclined at an angle ⁇ with respect to the horizontal axis, this angle being between 5 and 15 ° and preferably close to 10 °.
• each of the orifices 23, 24 made within the active anchoring points 11 and passive 12 is provided with a deflector 23 '.
• This deflector 23 ' is made from a tube, in particular metal, which is additionally bent.
• the frame 13 cast on its guide raft 1, with a similar arrangement on each side of the slope in the example especially considered, being again recalled that the same process can be implemented with a single frame and a single slab laid out of one side of the embankment, we proceed then to the momentary sectioning of the track and to the realization across the embankment of a excavation whose dimensions transversely are substantially those of the frames which, once put in place in this excavation, will delimit the passage realized under the track.
• Each of these frames 13 is progressively and mutually ripened towards each other on the guiding rafts 1 which support them, until such time as these cables, which run horizontally within the reservation grooves 5, meet in the median plane of the embankment, ensuring continuity of passage underlayers or ballast on top of the upper slab 16 of each frame 13 can be quickly replaced, before the track is reconstituted to allow recovery traffic that was only interrupted during the skipping operations of frames 13, as indicated above.
• the ground pressure due to the frames 13 sliding on their guide rafts 1 is less than that created by the mass of soil removed in the excavation, the risk of soil compaction as they are encountered in a process of shifting frames on longrins previously made across this excavation, are eliminated, which allows a safer implementation of the frames.
• this guide groove in the base of the frame 13 is formed by the assembly of angles previously secured to the guide bed 1, using plastic screws which will be cut during the movement of the work, these angles being coated with a metal section which is welded to them after having walked in the housing delimited by the two lateral angles, the strands of the cables 6.

Landscapes

• Engineering & Computer Science (AREA)
• Mining & Mineral Resources (AREA)
• Environmental & Geological Engineering (AREA)
• Life Sciences & Earth Sciences (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Geochemistry & Mineralogy (AREA)
• Geology (AREA)
• Pit Excavations, Shoring, Fill Or Stabilisation Of Slopes (AREA)
• Railway Tracks (AREA)
• Road Paving Structures (AREA)
• Underground Structures, Protecting, Testing And Restoring Foundations (AREA)
• Conveying And Assembling Of Building Elements In Situ (AREA)
• Rod-Shaped Construction Members (AREA)
• Bridges Or Land Bridges (AREA)
• Machines For Laying And Maintaining Railways (AREA)
• Piles And Underground Anchors (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=9525596

Family Applications (1)

Country Status (6)

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Family Cites Families (3)

• 1998
  • 1998-04-23 FR FR9805104A patent/FR2777924B1/fr not_active Expired - Lifetime
• 1999
  • 1999-04-22 AT AT99400990T patent/ATE263307T1/de not_active IP Right Cessation
  • 1999-04-22 DE DE69915920T patent/DE69915920T2/de not_active Expired - Lifetime
  • 1999-04-22 PT PT99400990T patent/PT952307E/pt unknown
  • 1999-04-22 EP EP99400990A patent/EP0952307B1/fr not_active Expired - Lifetime
  • 1999-04-22 ES ES99400990T patent/ES2216458T3/es not_active Expired - Lifetime

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