Method for repairing a civil engineering structure

Abstract

A repair method for a civil engineering work. The method includes the depositing, directly onto a portion of the work to be repaired, of a reinforcing structure formed from one or more successive layers of at least one reinforcing material which are each extruded in contact with the surface onto which the material is to be deposited, using a robot system, with the material being extruded in strips.

Claims

1. A repair method for a civil engineering work, comprising depositing, directly onto a portion of the work to be repaired, a reinforcing structure formed from one or more successive layers of at least one reinforcing material which are each extruded in contact with a surface onto which the material is to be deposited, using a robot system, the material being extruded in strips and deposited with the aid of at least one extrusion head of the robot system having a slot-shaped outlet orifice for the material.

2. The method as claimed in claim 1, comprising smoothing the structure before the structure sets with the aid of a tool of the robot system.

3. The method as claimed in claim 2, said tool of the robot system being a spreading blade.

4. The method as claimed in claim 2, said tool being carried by an arm of the robot system carrying the at least one extrusion head.

5. The method as claimed in claim 1, comprising acquisition of relief data of a zone onto which the material is to be deposited and automatic pilot-controlling of the at least one extrusion head at least based on these relief data.

6. The method as claimed in claim 5, the relief data being acquired with the aid of an acquisition system of the robot system.

7. The method as claimed in claim 6, said acquisition system of the robot system being carried by an arm of the robot system carrying the at least one extrusion head.

8. The method as claimed in claim 7, in which the work contributes to guide the robot system mechanically by pressing the robot system against at least one surface defined by a girder of the work.

9. The method as claimed in claim 5, the acquisition of relief data comprising acquisition of relief data in real time, simultaneously with the extrusion.

10. The method as claimed in claim 5, the acquisition of relief data comprising acquisition of relief data prior to the extrusion.

11. The method as claimed in claim 5, the relief data being acquired with the aid of at least one optical sensor, by scanning with ultrasound or millimetric waves, and/or with the aid of at least one mechanical probe.

12. The method as claimed in claim 1, said at least one extrusion head being guided so as to respect a preprogrammed algorithm for said at least one reinforcing material.

13. The method as claimed in claim 1, the number of deposited layers lying between 2 and 100, and the thickness of each layer between 1 and 30 mm.

14. The method as claimed in claim 1, in which the number of layers deposited and/or the thickness of the layers deposited varies so as to produce a reinforcing structure with an inertia that varies.

15. The method as claimed in claim 1, the reinforcing structure being ribbed.

16. The method as claimed in claim 1, the reinforcing structure being a girder.

17. The method as claimed in claim 1, the reinforcing structure being a shell.

18. The method as claimed in claim 1, the reinforcing structure being a knob for distributing concentrated force.

19. The method as claimed in claim 18, the reinforcing structure being an anchor block for cables and/or tendons.

20. The method as claimed in claim 19, the reinforcing structure being an anchor knob for additional prestressing cables, for deviating external prestressing cables, support cables, or cables for anchoring damping devices.

21. The method as claimed in claim 1, the reinforcing structure being produced with one or more blockouts by adapting the location of the deposited layers.

22. The method as claimed in claim 1, in which the work contributes to guide the robot system mechanically as the robot system moves along the work when producing the reinforcing structure.

23. The method as claimed in claim 22, in which the work contributes to guide the robot system mechanically by pressing the robot system against at least one surface of the work.

24. The method as claimed in claim 1, the accuracy of the depositing of the reinforcing structure being greater than +/−0.5 cm in terms of thickness and/or in a direction parallel to the underlying surface of the work onto which the material is to be deposited.

25. The method as claimed in claim 1, the extruded material being a concrete.

26. The method as claimed in claim 25, the extruded material being a fiber-reinforced concrete.

27. The method as claimed in claim 25, the extruded material being a high-performance or ultra-high-performance concrete.

28. The method as claimed in claim 1, the extruded material comprising a resin.

29. The method as claimed in claim 1, the work being an arched roof.

30. The method as claimed in claim 29, the work being an arched roof of a tunnel or dome.

31. The method as claimed in claim 1, the work being a bridge.

32. The method as claimed in claim 31, the portion of the work to be repaired being part of the deck of the bridge.

33. The method as claimed in claim 1, the work being a pipe or a mast.

34. The method as claimed in claim 33, the robot system traveling along and inside of this pipe or this mast.

35. The method as claimed in claim 1, the work being made from masonry and the deposited structure being used for repointing.

36. The method as claimed in claim 1, the majority of the portion of the work to be repaired being made from concrete.

37. The method as claimed in claim 1, the portion of the work to be repaired being metal.

38. The method as claimed in claim 1, the portion of the work to be repaired being made from wood.

39. A repair method for a civil engineering work, comprising depositing, directly onto a portion of the work to be repaired, a reinforcing structure formed from one or more successive layers of at least one reinforcing material which are each extruded in contact with a surface onto which the material is to be deposited, using a robot system, the material being extruded in strips and deposited with the aid of at least one extrusion head of the robot system, said at least one extrusion head being guided so as to respect a preprogrammed algorithm for said at least one reinforcing material.

40. The method as claimed in claim 39, at least one extrusion head having a slot-shaped outlet orifice for the material.

Description

(1) The invention will be better understood on reading the following description of non-limiting exemplary embodiments of said invention and on examining the attached drawings, in which:

(2) FIG. 1 shows schematically and partially an example of a robot system according to the invention, used when reinforcing an arched roof,

(3) FIGS. 2A and 2B show separately schematically and partially the extrusion head during the extrusion of the material,

(4) FIG. 3 illustrates the juxtaposition of stacks of extruded strips which have been superposed as the production of the reinforcing structure progresses,

(5) FIG. 4 is an example of a reinforcing structure produced with the aid of the robot system in FIG. 1,

(6) FIG. 5 illustrates the possibility of varying the inertia of the reinforcing structure produced with the aid of the robot system in FIG. 1,

(7) FIG. 6 shows another example of a reinforcing structure produced along a girder,

(8) FIG. 7 illustrates the possibility of varying the inertia of the reinforcing structure in FIG. 5,

(9) FIG. 7A illustrates a detail from FIG. 7,

(10) FIG. 8 shows schematically and partially another example of a robot system according to the invention, used when reinforcing a pipe,

(11) FIG. 9 shows an example of a reinforcing structure produced with the aid of the robot system in FIG. 8,

(12) FIG. 10 shows schematically and partially examples of a robot systems according to the invention, used for producing knobs on a work such as a bridge,

(13) FIG. 11 shows a knob produced with the aid of the method according to the invention, after strapping to the structure of the work,

(14) FIGS. 12 and 13 show a longitudinal cross-section of examples of profiles which may be given to the knobs,

(15) FIG. 14 shows schematically and partially another example of a robot system used to reinforce masonry,

(16) FIG. 15 is a block diagram illustrating the connection between different components of the robot system, and

(17) FIG. 16 illustrates the possibility of equipping the robot system with attached tools such as finishing tools like a spreading blade.

(18) A first example of a motorized system 10 according to the invention, used to reinforce a civil engineering work comprising an arched roof V, for example that of a tunnel, is shown in FIG. 1.

(19) The robot system 10 comprises a movable platform 11 which can move along the arched roof V.

(20) The robot system 10 comprises an articulated arm 12 which may comprise one or more segments depending on the number of degrees of freedom required to produce the depositing of the material. This arm 12 may be articulated about an axis parallel to a generatrix of the arched roof.

(21) In the example illustrated, the arm comprises three articulated segments but the invention encompasses all types of deformable and/or orientable structures adapted to the reinforcement operation to be performed.

(22) The arm carries an extrusion head 13 which makes it possible to deposit multiple successive layers of a reinforcing material, for example a cement-based one.

(23) The extrusion head 13 comprises, as can be seen in FIG. 2A, a nozzle 14 through which the reinforcing material is extruded in a fluid state.

(24) This extrusion takes place first, during a first pass of the extrusion head, in contact with the outer surface S of the work in order to form a first strip layer C.sub.1, as illustrated in FIG. 2A, then, during a subsequent pass, in contact with the previously deposited layer C.sub.1, in order to form the second strip layer C.sub.2, as illustrated in FIG. 2B, and so on according to the number of layers to be deposited in order to form the desired reinforcing structure. A layer is preferably deposited on the previous layer before the setting of the previous layer is complete so as to have the best possible adhesion between the layers.

(25) After a portion of the reinforcing structure has been formed of width w corresponding to that of a strip, the following portion is produced. This portion may be formed as an extension of the previous one, with no overlap of the strips, as illustrated in FIG. 3. When the successive strips are juxtaposed but the material has not set yet, the strips can join at their contact edges such that, after the material has set, the final reinforcing structure is continuous in a direction transverse to the strips. Three successive stacks in the longitudinal direction of the work have been shown in FIG. 3, each stack comprising four superposed strips of material, labeled C.sub.1,1 to C.sub.4,1 for the first stack, C.sub.1,2 to C.sub.2,4 for the second stack, and C.sub.1,3 to C.sub.4,3 for the third stack.

(26) The outlet orifice of the nozzle 14 preferably has a cross-section of a shape that is elongated along a longitudinal axis X, for example is rectangular, this longitudinal axis X preferably being oriented perpendicularly to the direction D in which the nozzle 14 moves to deposit each of the layers in strips of reinforcing structure.

(27) The thickness e of each layer which is deposited is, for example, substantially constant for each of the layers of the reinforcing structure and the number of deposited layers is adapted locally to give the reinforcing structure the desired thickness at each point.

(28) e lies, for example, between 1 and 30 mm and the width w of the strips is between 3 and 50 mm. The thickness can depend on the rheology of the material used, and the thickness which is deposited is preferably chosen so that the layer adheres completely to the surface on which it is deposited without losing its cohesion.

(29) The number of superposed layers locally depends on the thickness that the reinforcing structure needs to have at this point.

(30) When extruding a layer, the distance d of the nozzle 14 from the surface onto which the material is deposited is preferably equal to e. This allows adhesion of the material to the surface on which it is deposited even when the extrusion takes place with the axis of the nozzle 14 pointing upward.

(31) The extrusion head 13 is advantageously equipped with a seal (not shown) which closes when there is no extrusion, for example when the extrusion is locally interrupted because the reinforcing material has not been deposited, for example because the extrusion head 13 is too far from the work to extrude thereon the reinforcing material in contact with it or because the number of layers which has already been deposited corresponds to the desired thickness for the reinforcing structure in the zone where the nozzle 14 is situated.

(32) The nozzle 14 is supplied with reinforcing material through each duct, the feed pressure of the reinforcing material being chosen depending on its rheology and on the outlet rate of the nozzle.

(33) The reinforcing material is preferably pumped from a tank which can be stationary relative to the work, in which case a flexible pipe is provided between this tank and the platform 11. The tank can also move with the robot system 10, in particular when the quantity of reinforcing material to be deposited allows it.

(34) The robot system 10 comprises, in the example illustrated, a system 30 for acquiring relief data, shown schematically in FIG. 15, which enables it to determine the relief of the surface of the work on which the reinforcing structure needs to be produced so as to control the movement of the arm 12 and the platform 11 so that the reinforcing material may be deposited as desired.

(35) This acquisition system 30 can be stationary or movable with respect to the arm 12 and/or the platform 11. It can also be external to the platform 11 and/or the arm 12, for example situated on a different machine, the positioning of which relative to the platform 11 and/or the arm 12 is known with sufficient accuracy.

(36) The acquisition system 30 comprises, for example, one or more cameras and/or one or more radiofrequency devices, for example of the Lidar type.

(37) The robot system 10 comprises a calculator 31 which receives the data generated by the acquisition system 30 and pilot-controls the platform 11, the arm 12, and the extrusion of the material accordingly.

(38) This pilot-control takes place such that it respects a predefined algorithm for depositing the reinforcing material on the work.

(39) As illustrated in FIG. 4, a reinforcing structure 100 is, for example, produced in the form of a shell with a thickness that reduces toward the edges, in a section made perpendicularly to the longitudinal direction of the work.

(40) This algorithm for depositing reinforcing material is chosen depending on the mechanical stresses to which the work is exposed; the invention makes it possible, by virtue of the controlled extrusion, to deposit locally only the amount of reinforcing material required to provide the required mechanical strength at each point of the work such that a saving in material is made compared with some known repair techniques.

(41) The robot system may comprise a human/machine interface 32 which makes it possible to input the depositing algorithm to be respected; this depositing algorithm can result from a prior analysis of the flaws in the work which need to be corrected.

(42) The calculator 31 is preferably programmed such that the operation of depositing the reinforcing structure takes place independently with no human intervention to pilot-control the necessary movements of the extrusion nozzle 14.

(43) The relief data are advantageously used in real time to ensure that the depositing of the first layer of material takes place properly, following the relief of the portion of the work to be reinforced and, for each subsequent layer, that of the relief of the last deposited layer, such that the depositing of a new layer on one or more previously deposited layers can result in the desired final geometry.

(44) A layer is deposited on the previous one preferably depending on the acquisition of real-time data relating to the relief of the portion of the work already produced so as to be able to accordingly adapt the position of the nozzle.

(45) The different layers are thus preferably deposited with the possibility of correcting in real time the trajectory of the nozzle 14 using the relief data.

(46) The robot system 10 may thus be produced so as to be able to adapt itself to its surroundings. Deploying the robot system is then facilitated.

(47) The reference numeral 34 in FIG. 15 refers to all of the actuators of the robot system, the functioning of which is controlled by the calculator 32 so as to perform the depositing of the reinforcing structure according to the desired geometry.

(48) The movement of the platform 11 may be controlled based on the same relief data as those used to determine the movements of the arm 12. As an alternative, the acquisition of the relief data serves only to pilot-control the movements of the arm relative to the platform and the movement of the latter takes place independently of the relief of the portion of the work on which the reinforcing structure is produced.

(49) The platform is, for example, moved in increments along the work, with the surface of the work being swept each time the platform halts by the nozzle 14 in order to deposit thereon a layer of reinforcing material depending on the geometry to be produced. The sweeping takes place the number of times needed to deposit the number of layers that allow the maximum desired thickness to be obtained.

(50) During this sweeping, real-time acquisition of the relief data makes it possible to determine the movements of the arm which are required to move the nozzle at a predefined distance from the surface in contact with which the extrusion is to take place.

(51) Once all the layers have been deposited, the platform is moved by a further increment. This movement may correspond to the width of an extruded strip so as to make it possible to obtain a continuous reinforcing structure along the work, as explained above.

(52) When the platform 11 is on wheels or tracks, the calculator 31 can control the driving motor or motors of said platform so as to follow a predefined trajectory. This trajectory can be corrected by any means.

(53) Guiding the platform 11 during its movement along the work may also be ensured mechanically by one or more rails or by guide wires.

(54) The movement of the platform 11 may be assisted by an optical system, for example by means of one or more cameras, in particular different cameras from those used to reconnoiter the topology of the surface on which the reinforcing material is to be deposited.

(55) Where appropriate, markers are positioned along the work in order to help the robot system to locate itself along the work. These markers may be produced so as to be detected by the relief data acquisition system. They may be passive or active optical markers.

(56) The platform 11 may also be guided with the aid of a satellite locating system, for example of the DGPS type, and/or by land- or sea-based pseudolites.

(57) Where appropriate, one or more RFID tags or other location transmitters, or one or more optical markers, may be arranged at at least one predefined point of the work and preferably at multiple points, which give the robot system a positional reference point and/or are capable of, for example, delimiting a zone of action of the robot system or helping it to orient itself.

(58) Several locating techniques may, where appropriate, be combined for greater accuracy.

(59) The robot system 10 preferably comprises an inertial platform and/or an odometer helping it to determine the position and/or the orientation of the platform 11 over time when it moves.

(60) The invention makes it possible to produce reinforcing structures of any geometry adapted to the type of work to be repaired.

(61) It is thus possible to produce the reinforcing structure with a variable inertia, for example which is greater where the stresses are highest.

(62) For example, in the case of strengthening an arched roof, as illustrated in FIG. 5, the inertia may be varied along the work by producing ribs 101 spaced apart along the work.

(63) Illustrated in FIG. 6 is the possibility of strengthening a girder P with the aid of the reinforcing structure 100. The reinforcing structure 100 is itself, for example, in the form of a girder, for example with an I-section, the base flange being wider than the top flange.

(64) The inertia of the reinforcing structure is varied along the girder, as illustrated in FIG. 7, with for example limited portions of reduced inertia 102 in the base flange. The transition 103 between the portions of greater inertia and those of lower inertia may be substantially linear on the scale of the work, a wide variety of transition profiles being achievable according to the invention. If the reinforcing structure 100 is observed closely, a graduated relief with steps of width w can be seen, as illustrated in FIG. 7A, because the depositing takes place in strips of width w. The height between two successive steps corresponds substantially to the difference in the number of layers deposited to produce the two corresponding stacks.

(65) The dimensions and/or the morphology of the robot system 10 may be adapted depending on the geometry of the work to be repaired.

(66) In the example of a pipe D, which may or may not be capable of being visited, and which may or may not be buried, as illustrated in FIG. 8, the platform 11 can have wheels which are oriented so that they bear against the inner surface of the pipe so as to move along it. The arm 12 may be telescopic and comprise a segment which can rotate about an axis that coincides with that of the pipe. The nozzle 14 can be moved radially so as to be brought to the desired distance from the surface onto which the reinforcing material is to be extruded. Each strip is deposited on all or part of the circumference.

(67) In such a case, the acquisition of the relief data may be limited, for example, to the acquisition of the distance from the axis of the pipe, in the radial direction, of the inner surface of the pipe S.

(68) Where appropriate, a reinforcing rib 105 may be formed, projecting from the inner surface of the pipe, as illustrated in FIG. 9. Where appropriate, the robot system may make several passes in the pipe.

(69) Illustrated in FIG. 10 is the repair of a bridge with the aid of two robot systems working in parallel, one to produce a reinforcing structure 100 in the form of a knob outside the work, the other working inside the work.

(70) When the reinforcing structure is a knob, the latter may be produced with a passage 108 which enables a prestressing cable PC to be anchored with the aid of a bearing block, as illustrated in FIG. 12, or with a passage 109 with a splayed shape at its ends in order to deviate a prestressing cable PC.

(71) Once the knob has been produced, it can furthermore be strapped to the work, as illustrated in FIG. 11. In this case, the layers are deposited by extrusion so as to create holes for the subsequent installation of the strapping system.

(72) Illustrated in FIG. 14 is the repair of masonry with the aid of a robot system 10 according to the invention. The robot system is then used for the repointing, between the stones R. Where appropriate, the robot system may be equipped with a tool for scraping out the existing joints before new joints are put in place by extrusion.

(73) The robot system may be equipped with other tools and, for example, with a spreading blade 17, as illustrated in FIG. 16, so as to, for example, smooth the reinforcing material deposited by extrusion before it sets.

(74) The invention is not of course limited to the examples which have just been given.

(75) All types of civil engineering work can be repaired by virtue of the invention.