Method for constructing a buried wall using a prefabricated concrete brick and prefabricated concrete brick for this purpose

Abstract

The invention relates to a method for constructing an underground structure (20), the method comprising steps of: presenting a prefabricated brick (B2) comprising a longitudinal through channel (11, 12) in which is engaged a section of auger comprising a lower end equipped with a retractable drill head configured to present a retracted position in which the drill head with the auger section can slide in the channel; and rotating the drill head in a deployed position about an axis of rotation, in order to form an excavation and drive the brick into the excavation as it is formed, the excavation having a cross-section in a first plane perpendicular to the axis of rotation, determined by the width of the deployed drill head, the brick having a cross-section in the first plane, inscribed in the cross-section of the excavation. Figure 1

Description

Title of the invention: Method for constructing a buried wall using a prefabricated concrete brick and prefabricated concrete brick for this purpose Technical field

[0001] The present invention relates to the construction of a buried wall, in particular for producing civil engineering works such as a well, a retaining wall, an open trench for road or railway use, a metro station, an underground car park or a water retention basin. State of the art

[0002] Generally, the construction of a buried wall is carried out by juxtaposing laterally successively reinforced concrete panels having the height of the buried wall to be constructed. For this purpose, an excavation of the ground having the shape of a panel is carried out, for example using a drilling machine. To maintain the opening of the excavation, it is filled with bentonite mud. A metal reinforcement having the shape of the panel to be produced is then introduced into the excavation through the bentonite mud using a lifting machine. Then, the excavation is filled with concrete by means of a tube immersed in the bentonite mud. Thus, the walls of the excavation in natural soil serve as a mold for the formation of the panel. The construction of an adjacent panel is carried out by the same process by forming an excavation in the continuity of the panel already produced.

[0003] This method of constructing a buried wall has many disadvantages. Indeed, despite the presence of bentonite mud, there is a high risk of collapse of the excavation floor, both during the construction of the excavation, during the introduction of the metal reinforcement and during the pouring of the concrete. In addition, these collapses can cause settlement of the surface ground, which raises risks of cracking for any buildings located nearby.

[0004] This process can lead to sealing defects between the panels. Using the walls of the excavation as a mold to form each panel can also lead to defects in the concrete thus poured. The use of bentonite mud can also affect the adhesion of the concrete to the metal reinforcement and therefore affect the strength of the wall thus produced. The construction of such a buried wall also raises risks for workers who can fall into the excavation, and when lifting the reinforcement to introduce it into the excavation, the reinforcement can be several tens of meters high.

[0005] Due to ground collapses, concrete consumption may be higher. bearing capacity as required. This process also requires a significant amount of bentonite sludge, which results in significant costs, including transportation, on-site management, and recycling. This process also requires a large volume of water, which raises wastewater management issues.

[0006] It is therefore desirable to be able to simplify the construction of a buried wall, while reducing costs, the risks of defects forming and the risks of accidents for personnel present on the site and damage to any buildings in the vicinity. Summary

[0007] Embodiments relate to a method of constructing a buried structure, the method comprising steps of: a) presenting a first prefabricated brick comprising at least one longitudinal through channel in which is engaged an auger section comprising a lower end equipped with a retractable drilling head configured to present an extended position and a retracted position in which the drilling head with the auger section can slide in the channel;and b) rotating the upper end of the auger section to rotate the drill head in the deployed position about a drilling rotation axis, in order to form an excavation by drilling a well, to raise drilling residues by the auger section and to drive the first brick into the excavation as the excavation is formed, the excavation having a section in a plane perpendicular to the drilling rotation axis, determined by the width of the drill head in the deployed position, the first brick having a section in the plane perpendicular to the drilling rotation axis, inscribed in the section of the excavation. ;

[0008] Thanks to these provisions, it is possible to form a pile or a buried wall in a single operation consisting of digging and driving the concrete brick forming the pile or the buried wall. This avoids having to maintain an empty excavation which risks collapsing during its formation, requiring the use of bentonite mud and leading to accident risks for personnel present on the site and risks for any buildings located nearby. As the brick is prefabricated, it also avoids structural defects which can appear when the concrete is poured into the excavation. In addition, the presence of the channel makes it possible to reduce the quantity of concrete used without affecting the strength of the structure thus produced. Indeed, the central zone of the brick contributes only to a small extent to the strength of the structure.

[0009] According to one embodiment, the method further comprises steps consisting of: c) presenting a second prefabricated brick above the first brick, the second brick having a section in the plane perpendicular to the axis of rotation of drilling identical to that of the first brick and comprising a longitudinal channel in which an auger section is engaged; d) coupling the lower end of the auger section of the second brick to the upper end of the auger section of the first brick; and e) rotating the upper end of the auger section of the second brick to rotate the auger sections and the drilling head in the deployed position, in order to continue the formation of the excavation, to bring up drilling residues by the auger sections, and to push the first and second bricks into the excavation as the excavation is formed.

[0010] Thus, the depth of the pile or panel is not limited by the height of the brick.

[0011] According to one embodiment, the method comprises a step of fixing by means of screws introduced into through holes, from the second brick to the first brick after the presentation of the second brick above the first brick and before the rotation of the upper end of the worm section of the second brick, the fixing step being carried out by means of screws introduced into through holes formed in the bricks.

[0012] In this way, the bricks are fixed to each other and correctly aligned before being driven into the excavation.

[0013] According to one embodiment, the method comprises steps of repeating steps c) to e) several times to form a panel of bricks juxtaposed one above the other in the excavation, the panel comprising the first brick and several copies of the second brick.

[0014] Thus, it is possible to form a pile or a panel of great depth.

[0015] According to one embodiment, the method comprises, following the formation of the panel, steps consisting of introducing a cable or a rigid rod into aligned through-holes, formed in the first and second bricks forming the panel, and if a cable is introduced into through-holes, locking one end of the cable in the first brick, putting the cable under tension from another end of the cable and locking the other end of the cable in an upper brick forming the panel.

[0016] Thus, it is possible to apply a prestress to the panel, in particular to ensure that the thrust forces from the adjacent ground are taken up.

[0017] According to one embodiment, a sealing joint is arranged between each pair of bricks juxtaposed one above the other.

[0018] Thus, it is possible to form a waterproof panel.

[0019] According to one embodiment, the method comprises steps consisting of repeating steps a) to c) or a) to e) several times to form a buried wall formed of bricks juxtaposed laterally.

[0020] This technique of forming a wall does not impose any limit on the width and depth of the wall thus produced.

[0021] According to one embodiment, step a), when carried out to lay a new brick juxtaposed laterally to the panel, comprises the insertion of a guide provided on a lateral face of the new brick into a guide of complementary shape provided on a lateral face opposite each brick of the panel.

[0022] The guides thus ensure correct positioning of the bricks of two panels juxtaposed laterally.

[0023] According to one embodiment, each brick comprises several longitudinal through channels in each of which is engaged a worm screw section, each worm screw section of the first brick comprising a lower end equipped with the drilling head, the excavation being formed by the rotation of the drilling heads associated with the first brick.

[0024] This form of brick allows a wider panel to be produced in a single operation and a very wide panel or wall to be formed more quickly. The presence of the longitudinal channels makes it possible to reduce the quantity of concrete used without affecting the strength of the structure thus produced. In fact, the central area of ​​the brick including the channels, even if these were omitted, only contributes to a small extent to the strength of the structure.

[0025] According to one embodiment, each of the bricks of at least a portion of the first and second bricks comprises a lateral housing 12, 12' for receiving a lateral sealing joint to ensure sealing with a laterally juxtaposed brick.

[0026] Thus, it is possible to form a watertight wall.

[0027] According to one embodiment, step b) and / or e) comprises a step of coupling a free upper end of each worm screw section to a rotary.

[0028] According to one embodiment, the rotary machines are slidably mounted on a chassis between a high position allowing the presentation of one of the first or second bricks and a low position where each endless screw of the brick coupled to the rotary machines can be coupled or decoupled from the rotary machines and the rotary machines raised to the high position to allow the presentation of the second or another second brick.

[0029] Embodiments may also relate to a prefabricated concrete brick, comprising: longitudinal through channels, longitudinal through holes for receiving prestressing cables, a groove along an upper face for receiving a seal for providing a seal with a juxtaposed brick arranged above, a guide along a side face for assembling with a guide of complementary shape of an adjacent brick arranged laterally, and a longitudinal groove along the side face to receive a seal.

[0030] According to one embodiment, the brick has at least one of the following characteristics: the channels open into a lower face of the brick through a channel portion having a flared shape, one of the orifices contains a threaded sleeve, to receive a threaded rod for fixing the brick to another brick juxtaposed below, the longitudinal groove is formed by one of the channels which has an opening opening onto the lateral face of the brick, the brick comprises cannulas opening into the upper face to fill the orifices with concrete after insertion of cables, the orifices each comprise a cable locking device for longitudinally locking a cable subjected to a tensile force, the upper face has two grooves for respectively receiving two sealing joints, the channels opening into the upper face between the two grooves,the upper and lower faces of the brick have complementary shapes which fit together when the brick is placed on another brick juxtaposed below, the brick includes a front face and / or a back face having undulations following the shape of the channels. Brief description of the figures,

[0031] The present invention will be better understood with the aid of the following description of exemplary embodiments with reference to the appended figures, in which identical reference signs correspond to structurally and / or functionally identical or similar elements.

[0032] [Fig-1] Figure 1 is a schematic perspective view of a wall formed in ace appearing to be several bricks, according to one embodiment,

[0033] [Fig.2] Figure 2 is a schematic perspective view from below of one of the bricks, according to one embodiment,

[0034] [Fig.3] Figure 3 is a schematic perspective view from below of another of the bricks, according to one embodiment,

[0035] [Fig.4] Figure 4 is a schematic perspective view from above of one of the bricks, according to one embodiment,

[0036] [Fig.5] Figure 5 is a detailed schematic top view of a portion of two adjacent bricks assembled laterally, according to one embodiment,

[0037] [Fig.6] Figure 6 is a schematic top view of a wall formed from several bricks or panels assembled laterally, according to one embodiment,

[0038] [Fig.7] Figure 7 is a schematic top view of one of the bricks, according to another embodiment,

[0039] [Fig.8] Figure 8 is a detailed schematic top view of a portion of two adjacent bricks assembled laterally, according to the embodiment of Figure 7,

[0040] [Fig.9] Figure 9 is a schematic side view of a drilling head in a locked deployed position, according to one embodiment,

[0041] [Fig. 10] Figure 10 is a schematic side view of the drilling head in a retracted position, according to one embodiment,

[0042] [Fig. 11] Figure 11 is a more detailed side schematic view of the drill head in a locked deployed position, according to one embodiment,

[0043] [Fig. 12] Figure 12 is a more detailed side schematic view of the drill head in a retracted position, according to one embodiment,

[0044] [Fig. 13] Figure 13 is a schematic view from below of the drilling head in the locked deployed position, according to one embodiment,

[0045] [Fig. 14] Figure 14 is a schematic view in radial section of two parts of bricks assembled laterally, according to one embodiment,

[0046] [Fig. 15] Figure 15 is a schematic view in radial section of two parts of bricks assembled laterally, according to another embodiment,

[0047] [Fig. 16] Figure 16 is a schematic view in longitudinal section of one of the bricks, in which are positioned drilling heads each associated with a section of worm screw, according to one embodiment,

[0048] [Fig. 17] Figure 17 is a schematic perspective and sectional view of a construction site for a buried wall, according to one embodiment. Detailed description

[0049] Figure 1 shows a prefabricated brick B1, in particular for constructing a buried wall 60 formed from several juxtaposed panels PI, P2, P3, each panel being formed from bricks arranged one above the other. Brick B1 comprises a plurality of parallel through channels 11 extending between an upper face 10c and a lower face 10d of the brick.

[0050] According to one embodiment, brick B1 is made of concrete, for example fiber-reinforced concrete.

[0051] According to one embodiment, the channels 11 each have a cylindrical shape. According to one embodiment, the thickness of the brick around each of the channels 11 is constant, so that a front face 10a and a rear face 10b of the brick have a wavy shape.

[0052] According to one embodiment, one 12 of the channels located at one end of the side of the lateral face 10f of the brick is open laterally over its entire length.

[0053] Figure 2 shows in particular the lower face 10d of a brick B2 intended to be driven first into the earth. Brick B2 differs from brick B1 in that each of the channels 11, 12 opens into the lower face 10d of the brick through a part 18 of truncated cone or funnel shape to channel the drilling debris towards channel 11.

[0054] Figure 3 shows in particular the lower face 10d of the brick B1 intended to be driven into the ground following the brick B2 or another brick identical to the brick B1. Figure 4 shows in particular the upper face 10c of the brick B1 or B2. According to one embodiment, the lower face 10d of the bricks B1 comprises an assembly form 16 intended to cooperate with a complementary assembly form 17 formed in the upper face 10c of the bricks B1, B2. The assembly forms 16, 17 are arranged in such a way that when a brick B1 is superimposed and assembled with another brick B1 or B2, the longitudinal axes of the channels 11, 12 of the two superimposed bricks coincide. The assembly shapes 16, 17 are provided by embedding effect to define a preferred superposition position making it possible to ensure the continuity of the channels 11, 12 between the bricks of a panel.The assembly shapes 16, 17 also prevent the bricks of the panel from sliding relative to each other and thus contribute to the strength of the structure of the panel.

[0055] Furthermore, the upper face 10c of the bricks B1, B2 is equipped with sealing joints 13 making it possible to ensure sealing between the faces 10c, 10d opposite two bricks B1, B2 assembled one above the other.

[0056] In the example of Figures 3 and 4, the assembly shape made in the lower face 10d of the bricks B1 comprises studs 16. The assembly shape made in the upper face 10c of the bricks B1, B2 comprises cavities 17 arranged to receive the studs 16. The studs 16 and the cavities 17 may be of complementary shapes. The studs 16 and the cavities 17 may be formed between each channel mouth 11, 12 in the faces 10c, 10d, or only between some of these mouths. Of course, other assembly shapes may be provided. For example, the cavities 17 may be formed in the face 10d and the studs 16 may be formed in the face 10c. According to another example, a stud 16 may alternate with a cavity 17 on each of the faces 10c, 10d.

[0057] According to a first example of embodiment, the bricks B1, B2 have a height of 2 m, a length of 2.70 m and a maximum thickness of 0.6 m and comprise six longitudinal channels of 0.3 m in diameter, for a mass of 5 t of fiber concrete.

[0058] According to a second embodiment, the bricks B1, B2 have a height of 3 m, a length of 3.60 m and a maximum thickness of 0.6 m and comprise eight longitudinal channels of 0.3 m in diameter, for a mass of 10 t of fiber-reinforced concrete.

[0059] Figure 5 shows the upper face 10c of parts of two adjacent bricks Bl or B2 juxtaposed laterally, according to one embodiment. The lateral faces 10e, 10f of the bricks Bl, B2 are equipped with guides 14a, 14b making it possible to ensure correct positioning of two bricks Bl, B2 juxtaposed laterally. In the example of figure 5, the guides 14a, 14b have a profile configured so that they can be assembled by interlocking and slide into one another. Furthermore, the channel 12 is provided to receive a seal 21 which is inserted into the channel 12 by sliding. According to one embodiment, the seal 21 is inflatable and inflated for example by a cement grout, following its placement in the channel 12 of several bricks B1, B2 juxtaposed one above the other.

[0060] Figure 6 shows several bricks B5-B8 which may be identical to bricks B1, B2, juxtaposed laterally, to illustrate different modes of lateral assembly of bricks to form a buried wall. Figure 6 shows juxtaposition modes at 90°, 180° and in "T". In the juxtaposition mode at 180°, the lateral face lOf of brick B6 is placed opposite the lateral face 10e of brick B7. In the juxtaposition mode at 90°, the lateral face lOf of a brick B5 is placed opposite the rear face of brick B6 along a channel 11 adjacent to the lateral face 10e of brick B6. In the "T" juxtaposition mode, the side face lOf of the brick B7 is placed opposite the front or rear face 10a, 10b of the brick B8 along a channel 11 not adjacent to one of the side faces 10e, lOf of the brick B8.

[0061] Figures 7 and 8 show a brick B10 according to another embodiment. Brick B10 differs from brick B1 or B2 in that it only comprises closed channels 11. The lower face 10d of brick B10 may be like that of brick B1 or B2. The lateral face 10e of brick B10 comprises a longitudinal groove 12' provided to receive a sealing joint 21'. Furthermore, brick B10 comprises guides 14a', 14b' provided to engage and slide one inside the other. In the example of Figures 7 and 8, the guide 14b' is arranged in a longitudinal recess formed on the face lOf and comprises a longitudinal groove, and the guide 14a' has the shape of a tongue extending along the face 10e and configured to engage in the guide 14b' by longitudinal sliding. The lateral face lOf of the brick B10 has a longitudinal flare.

[0062] Figures 9 to 13 show a retractable drilling head 30 for drilling a well. The drilling head 30 comprises in particular a body 33 forming a central block of the drilling head 30. The drilling head is coupled to a worm screw section 40. In Figure 9, the drilling head 30 is shown in the deployed position locked at the lower end of a brick B20 comprising a longitudinal channel 11 in which the worm screw section 40 is inserted. In Figure 10, the drilling head 30 is shown in the retracted position in the channel 11 of the brick B20. The brick B20 may have a tubular shape with a single channel 11 or correspond to the bricks B1, B2, B10 with several longitudinal through channels 11, 12.

[0063] In Figures 10 to 12, the drilling head 30 comprises a body 33 provided with two arms 31, 32 for drilling the ground when the drilling head 30 is rotated in locked deployed position, around a drilling rotation axis A coinciding with the longitudinal axis of the worm screw section 40. The diameter DI of the drilling head 30 in the retracted position and the diameter of the worm screw 40 are less than the width or internal diameter D4 of the channels 11, 12 (figure 10). The drilling head 30 in the retracted position and the worm screw 40 can therefore slide freely in the channels 11, 12. According to one embodiment, the two arms 31, 32 are identical. Each arm 31, 32 comprises a plurality of teeth 34, for example made of tungsten, the geometry of which is known to those skilled in the art. Each arm 31, 32 has substantially a blade shape comprising one end fixed to the body 33, by means of a respective deployment rotation shaft 35.Thus, each arm 31, 32 is rotatable around the deployment rotation shaft 35 between a retracted position, visible in Figures 10 and 12, and a locked deployed position, visible in Figures 9, 11 and 13. Each arm 31, 32 has, opposite the deployment rotation shaft 35, a free end 36 which is provided with a drilling projection 361.

[0064] In the example of figures 11 to 13, each arm 31, 32 comprises two substantially planar faces 311, 312 extending along an axis perpendicular to the deployment rotation axis 33. Each arm 31, 32 has a thickness, along the deployment rotation axis 35, which is constant and along an axis perpendicular to the deployment rotation axis 35, decreasing between the deployment rotation axis 35 and the free end 36.

[0065] According to one embodiment, the deployment rotation axis 35 is positioned in a plane forming an angle of between 50° and 110°, preferably of between 80° and 100°, and in particular equal to 90° with the drilling rotation axis A.

[0066] According to one embodiment, the deployment rotation axis 35 does not intersect the drilling rotation axis A. Thus, there is a non-zero distance d between the deployment rotation axis 35 and the drilling rotation axis A.

[0067] In the retracted position (figure 12), each arm 31, 32 forms with the drilling rotation axis A an angle a included in a first angle value range. The first angle value range extends from 0° to 60°, preferably from 0° to 30°. According to one example, the angle a is equal to 24°. Thus, the drilling head 30 in the retracted position has a diameter DI hereinafter called "handling diameter".

[0068] In the locked deployed position (figure 11), the arm 31, 32 forms an angle [3 with the drilling rotation axis A included in a second angle value range. The second angle value range extends from 60° to 130°, preferably from 80° to 100°. According to one example, the angle [3 is equal to 90°, that is to say that each arm 31, 32 extends perpendicular to the drilling rotation axis A. Thus the diameter D2 of the drilling head in the locked deployed position corresponds to the drilling diameter D2 which is greater than the handling diameter DI.

[0069] The drilling head 30 is configured so that in the deployed position, the deployment rotation axis 35 of each arm 31, 32 and the free end 36 of each arm are positioned on either side of a median plane M of the body 33 (figure 13). The median plane M of the body 33 passes through the drilling rotation axis A of the drilling head 30 and is parallel to the deployment rotation axis 36. Preferably, the plane M separates the drilling head into two substantially identical, or symmetrical, zones. Thus, each arm 31, 32 comprises on its face 312 a contact portion configured to be in contact with the body 33, and a drilling portion at the free end 36 making it possible to increase the drilling diameter D2 in the deployed position. The specific position of the deployment rotation axis 35 of each arm 31, 32 makes it possible to increase the contact surface of each arm on the body 33 and thus promote the transmission of cutting forces to the end 36 of the arm 31, 32.

[0070] The specific geometry of the drilling head allows a ratio of the diameter D2 of the drilling head in the deployed position to the diameter DI of the drilling head in the retracted position of between 1 and 5, preferably between 1 and 3, and in particular equal to 2.

[0071] The drilling head 30 also comprises a fixing base 37 configured to fix the drilling head 1 to a section of worm 40. The worm 40 comprises a rod extending along an elongation axis, one orientation of which indicates the orientation of the well to be drilled. The elongation axis of the worm 40 therefore corresponds to the drilling rotation axis A. The worm 40 makes it possible to transmit to the drilling head 30 a rotational movement around the drilling rotation axis A, and at the same time to ensure the evacuation of the drilling residues torn from the ground by the drilling head.

[0072] The fixing base 37 is a mechanical part intended to be fixed in a removable manner to the worm screw section 40 so that there is no possible relative movement between the fixing base and the worm screw section. Alternatively, the fixing base 37 is fixed in a non-removable manner to the worm screw section 40, for example by welding.

[0073] According to one embodiment, the base 37 extends substantially in a first plane forming an angle with the drilling rotation axis A of between 60 and 120°, preferably between 80° and 100°, and in particular 90°.

[0074] The body 33 is movably fixed to the base 37, and more particularly is rotatably movable.

[0075] The drilling head 30 may also comprise a device for locking the arms 31, 32 in the deployed position. According to one embodiment, a locked position of each arm 31, 32 is obtained by a rotation of the body 33 relative to the base 37. The locked position is obtained by a rotation of between 30° and 150°, preferably between 60° and 120°, and in particular 70°.

[0076] According to one embodiment, the base 37 comprises a locking surface 38 configured to come into contact with each arm 31, 32 in the locked position. The rotation of the body 33 relative to the base 37 is carried out by means of the worm screw 40. The rotation is therefore carried out along the drilling rotation axis A. During the rotation, the locking surface 38 is moved in order to be positioned in contact with the arm 31, 32. The latter is then locked in the deployed position. Thus, the locking device is simple to implement. The locking is carried out by a rotation of the worm screw 40 in a drilling direction, while the unlocking is carried out by a rotation in the opposite direction of the worm screw 40.

[0077] According to one embodiment, the diameter DI of the drilling head 30 in the retracted position is less than or equal to that of the base 37. Thus, in the retracted position, the diameter DI of the drilling head 30 can correspond to that of the base 37, that is to say the diameter of the circle drawn by the base when the latter is rotating along the drilling rotation axis A.

[0078] The drilling head 30 is more particularly intended to allow the insertion of a brick B1, B2 or B10 by carrying out an excavation by drilling adjacent wells in a ground which may have significant mechanical resistance. For this purpose, a drilling head 30 in the retracted position, coupled to a worm screw section 40, is inserted into each of the channels 11, 12 of the brick B2, as illustrated in FIG. 16. In order to be able to rotate all the drilling heads 30 at the same time and to avoid collisions between the drilling heads, these are arranged in two different planes, perpendicular to the drilling rotation axes A and sufficiently spaced from each other. For this purpose, the drilling heads are respectively coupled to worm screw sections 40 having two different alternating lengths.Thus, the worm screw sections 40 in the first, third and fifth channels 11 have a first length, and the worm screw sections 40 in the second, fourth and sixth channels 11, 12 have a second length having with the first length a gap providing sufficient space for each drilling head to rotate freely without risk of hitting an adjacent drilling head. In the example of [Fig. 16], the second length is greater than the first length.

[0079] Figure 14 shows two parts of bricks B1 or B2 juxtaposed laterally, and in particular the interface between the two bricks with the guides 14a, 14b fitted into each other, and the joint 21 engaged in the open channel 12 of one of the bricks. As illustrated by Figure 14, the drilling diameter D2 of the drilling heads 30 associated with the channels 11, 12 is such that the section of the excavation S2 corresponding to the combined drilling surface made by the drilling heads covers the entire section S1 of the brick B1, B2, including the guides 14a, and is tangent to the guide 14b of the adjacent brick. In other words, the drilling diameter D2 is greater than the width or diameter D3 of brick Bl, B2, B20.

[0080] Figure 15 shows two parts of bricks B10 or B10 juxtaposed laterally, and in particular the interface between the two bricks with the guides 14a', 14b' fitted into one another, and the joint 21' engaged in the groove of the lateral face 10e of one of the bricks. As illustrated by Figure 14, the drilling diameter D2 of the drilling heads associated with the channels 11, 12 is such that the section of the excavation S2 corresponding to the combined drilling surface made by the drilling heads covers the entire section SI' of the brick B10, the guide 14a being completely embedded in the brick B10. Here again, the drilling diameter D2 is greater than the width D3 of the brick B10.

[0081] A second brick B1, B10 can then be driven into the ground above brick B2, B10. For this purpose, an auger section 40' is inserted into each of the channels 11, 12 of brick B1, B10 (Figure 16). Brick B1, B10 is positioned above brick B2, B10 which has already been driven into the ground. The lower end of each of the auger sections 40' in brick B1 is coupled to the upper end of one of the auger sections 40 in brick B2. For this purpose, the upper end of each auger section 40 comprises a coupling device 41 configured to cooperate with a coupling device 42 of complementary shape arranged at the lower end of each of the auger sections 40'.

[0082] According to one embodiment, the bricks B1, B2, B10 associated with drilling heads 30 and the worm screw sections 40, 40' are used in a method of constructing a buried wall. This method illustrated by FIG. 17 comprises a first step consisting of presenting, for example by means of a lifting device 55, a first prefabricated brick B (B2, B10). For this purpose, the lifting machine 55 takes a brick B from a stock of bricks 56 and positions it in a device 50 comprising a chassis 53, a block of motorized rotary machines 51 for actuating the drilling heads 30 associated with the brick and a block 52 for coupling the rotary machines to the worm screw sections of the brick positioned in the device 50. The block of rotary machines 51 and the coupling block 52 are mounted to move in translation in the chassis 53 between high and low positions to follow the movement of driving the bricks and accommodate a new brick to be driven.The device 50 can be placed on guide walls 56, 57, for example made of concrete, extending along opposite edges of the excavation to be carried out and ensuring that the chassis is kept oriented along the axis of the drilling. The function of the block 52 is to hold a brick on the surface in the position for introduction into the excavation and to ensure the vertical translation of the rotary block 51 and the held brick.

[0083] The brick B taken from the stock 56 comprises a section of worm screw 40 whose lower end is equipped with the drilling head 30, engaged in each of the parallel longitudinal channels 11, 12 of the brick. The drilling heads 30 are re towable and configured to have a deployed position and a retracted position in which the drilling head can slide in each of the channels 11, 12. The drilling heads 30 can be locked in the deployed position by rotating the upper end 41 of the worm sections 40. The coupling device 41 at the upper end of each of the worm sections 40 engaged in the brick B is coupled to the rotary block 51.

[0084] In a second step of the method, the rotary block 51 is activated to rotate the drilling heads 30 in the deployed position, in order to carry out an excavation by drilling adjacent wells, to raise drilling residues by the worm sections 40. During drilling, the coupling block 52 moves in translation in the direction of the drilling rotation axes A and exerts pressure on the drilling heads and pushes the brick B into the excavation as the latter is formed. The excavation thus produced has a maximum width determined by the width D2 of the drilling heads 30 in the deployed position, and a length depending on the number of channels 11, 12 of the brick and therefore on the number of drilling heads 30. The brick B can have a section SI inscribed in the section of the excavation S2.

[0085] In a third step, the coupling block 52 is decoupled from the worm sections 40 of the first brick B and the rotary block 51 is placed in the high position. Then, a second brick B (B1, B10) is presented above the first brick in the device 50, by means of the lifting machine 55. A worm section 40' being engaged in each of the parallel longitudinal channels 11, 12 of the second brick B.

[0086] In a fourth step, the coupling device 42 at the lower end of each of the worm screw sections 40' of the second brick B is coupled to the coupling device 41 at the respective upper end of one of the worm screw sections 40 of the first brick B. The second brick B may also be fixed to the first brick B. For this purpose, each of the bricks B may have through holes 19' opening into the upper 10c and lower 10d faces of the bricks in which threaded rods 20 are engaged, the upper end of which is engaged in a threaded sleeve capable of receiving the threaded rod 20 of a brick arranged above. Holes 19' of the first brick B may house a threaded sleeve for receiving the threaded rods 20 of the second brick arranged above.

[0087] In a fifth step, the coupling devices 41 at the upper ends of the worm screw sections 40' of the second brick B are coupled to the rotary block 51 and set in rotation, to rotate all of the worm screw sections 40, 40' and the drilling heads 30 in the deployed and locked position, in order to continue drilling the excavation, to raise drilling residues through the sections of endless screw. During drilling, the drilling heads 30, the first and the second brick move in translation, sinking into the excavation as it is formed.

[0088] The third to fifth steps can be repeated several times to form a panel PI of juxtaposed bricks B comprising the first brick B and several second bricks B arranged one above the other in the excavation. Once the panel PI is produced, the drilling head is placed in its retracted position, for example by a reverse rotational movement of the worms 40, 40', then the rotary block 51 is raised by the block 52 to extract the worm sections of the upper brick of the panel. These worm sections are blocked and decoupled from the rotary block 51 and from the worm sections of the adjacent brick located below. Then, the worm sections thus detached are removed from the device 50.The rotary block 51 is then lowered by the block 52 and coupled to the remaining worm sections 40, 40' in the channels 11, 12 of the bricks of the PL panel. These operations are repeated to remove all the worm sections 40, 40' and the drilling heads 30 located in the PL panel.

[0089] A prestress can be applied to the bricks forming the panel PI by inserting cables or strands, for example made of steel, into the through holes 19 from the upper brick B to the first brick B forming the panel PL. Once inserted into the holes 19, the cables are blocked in the first brick B, then tensioned by applying a tensile force to the upper end of each cable. The cables can be blocked in the first brick B, for example, by pouring cement or by a suitable blocking device provided in the first brick B. To maintain the cables in tension in the holes 19 after the tensile force has disappeared, the upper brick of the panel comprises cable blocking devices to prevent the cables from losing their tension and retracting into the panel. Depending on the desired strength of the panel PI, one or more cables can be tensioned in each hole 19.To seal the strands in the bricks, the holes 19 can then be filled with a cement grout, for example using cannulas 23 made during the manufacture of the bricks (figure 5).

[0090] Alternatively, rigid rods or reinforcements, for example made of steel, can be simply introduced and sealed in the orifices 19, without applying prestress.

[0091] The third to fifth steps are optional, knowing that a panel may only have one first brick B.

[0092] Then, the first and second steps or first to fifth steps can be repeated several times to form a buried wall 60 composed of several panels PI, P2, P3, P4 juxtaposed laterally each comprising a first brick B and possibly one or more second bricks B juxtaposed one above the other. When forming the second panel P2 and the following panels P3, P4, the device 50 is moved along the guide walls 56, 57 which thus have a guiding function for the device 50. The guides 14b, 14b' of each brick of the following panel can be successively engaged in the guides 14a, 14a' of each brick of the adjacent panel previously buried in the excavation. Thus, the guides ensure correct positioning of the bricks of a panel with the bricks of the adjacent buried panel. During the sinking of the bricks of a panel, the guides 14b, 14b' slide in the guides 14a, 14a' of the bricks of the adjacent panel previously buried.

[0093] It will be clear to those skilled in the art that the present invention is susceptible to various variant embodiments and various applications. In particular, the invention is not limited to a brick comprising several longitudinal channels. The brick may comprise only one longitudinal channel (case of brick B20), in particular to produce a buried pile, or a wall formed from several piles juxtaposed laterally. The invention is also not limited to the formation of a pile or a wall comprising two or more bricks juxtaposed one above the other. Indeed, it may be useful to produce a wall comprising only bricks juxtaposed laterally.

[0094] Furthermore, the present invention includes all possible combinations of the embodiments defined in the preceding description and the following claims. Thus, the bricks assembled to form a panel or a wall are not necessarily identical. It is simply important that two bricks arranged one above the other have respectively upper and lower facing faces which correspond. Similarly, it is simply important that bricks juxtaposed laterally have lateral faces which correspond.

[0095] Furthermore, the brick B20 with a single longitudinal channel may have one or two grooves on its upper face 10c to receive a sealing joint ensuring a seal with an identical brick placed above. The groove may surround the mouth of the channel or pass through the brick as for the bricks B1, B2, so as to coincide with the end of a groove of an identical or non-identical brick juxtaposed laterally. The brick B20 may also have lateral guides to ensure correct positioning of a brick juxtaposed laterally in order to form a wall.

Claims

Claims

1. 1. A method of constructing a buried structure (20), the method comprising steps consisting of: a) presenting a first prefabricated brick (B, B2, B10, B20) comprising at least one longitudinal through channel (11, 12) in which is engaged a worm screw section (40) comprising a lower end equipped with a retractable drilling head (30) configured to have a deployed position and a retracted position in which the drilling head with the worm screw section can slide in the channel; and b) rotating the upper end (41) of the auger section to rotate the drilling head in the deployed position around a drilling rotation axis (A), in order to form an excavation by drilling a well, to raise drilling residues by the auger section and to push the first brick into the excavation as the excavation is formed, the excavation having a section (S2) in a plane perpendicular to the drilling rotation axis, determined by the width of the drilling head in the deployed position, the first brick having a section (SI, SI') in the plane perpendicular to the drilling rotation axis, inscribed in the section of the excavation.

2. 2. The method of claim 1, further comprising steps consisting of: c) presenting a second brick (B, B1, B10, B20) prefabricated above the first brick (B, B2, B10, B20), the second brick having a section (SI, SI') in the plane perpendicular to the drilling rotation axis (A) identical to that of the first brick and comprising a longitudinal channel (11, 12) in which a section of worm screw (40') is engaged; d) coupling the lower end (42) of the auger section of the second brick to the upper end (41) of the auger section of the first brick; and e) rotating the upper end of the auger section of the second brick to rotate the auger sections (40, 40') and the drilling head (30) into the deployed position, in order to continue forming the excavation, to bring up drilling residues through the auger sections, and to drive the first and second bricks into the excavation as the excavation is formed.

3. Method according to claim 2, comprising a step of fixing by means of screws (20) introduced into through holes (19'), the second brick to the first brick after the presentation of the second brick (B, B2, B10, B20) above the first brick (B, B1, B10, B20) and before the rotation of the upper end of the worm section of the second brick, the fixing step being carried out by means of screws (20) introduced into through holes (19') formed in the bricks.

4. 4. Method according to one of claims 1 to 3, comprising steps consisting of repeating steps c) to e) several times to form a panel (PI) of bricks (B, B1, B2, B10, B20) juxtaposed one above the other in the excavation, the panel comprising the first brick (B, B2, B10, B20) and several copies of the second brick (B, B1, B10, B20).

5. A method according to claim 4, comprising, following the formation of the panel (PI), steps of introducing a cable or a rigid rod into aligned through-holes (19) formed in the first and second bricks (B, B1, B2, B10, B20) forming the panel, and if a cable is introduced into through-holes (19) locking one end of the cable in the first brick (B, B2, B10, B20), tensioning the cable from another end of the cable and locking the other end of the cable in an upper brick (B, B1, B10, B20) forming the panel.

6. 6. Method according to claim 4 or 5, in which a sealing joint (13) is arranged between each pair of bricks (B, B1, B2, B10, B20) juxtaposed one above the other.

7. 7. Method according to one of claims 2 to 6, comprising steps consisting of repeating steps a) to c) or a) to e) several times to form a buried wall (60) formed of bricks (B, B1, B2, B10, B20) juxtaposed laterally.

8. A method according to claim 7, wherein step a), when carried out to lay a new brick (B, B1, B2, B10, B20) juxtaposed laterally to the panel (PI), comprises inserting a guide (14a, 14a') provided on a lateral face (10e) of the new brick into a guide (14b, 14b') of complementary shape provided on an opposite lateral face (10f) of each brick of the panel.

9. 9. Method according to one of claims 1 to 8, in which each brick (B, Bl, B2, B10) comprises several longitudinal through channels (11, 12) in each of which is engaged a worm section (40, 40'), each worm section (40) of the first brick (B, B2, B10) comprising a lower end equipped with the drilling head (30), the excavation being formed by the rotation of the drilling heads associated with the first brick.

10. 10. A method according to claim 8 or 9, wherein each of the bricks of at least a portion of the first and second bricks (B, B1, B2, B10, B20) comprises a lateral housing (12, 12') for receiving a lateral seal (21, 21') for sealing with a laterally juxtaposed brick.

11. 11. Method according to one of claims 1 to 10, in which step b) and / or e) comprises a step of coupling a free upper end (41) of each worm screw section (40, 40') to a rotary (51).

12. 12. Method according to claim 11, in which the rotary machines (51) are slidably mounted on a frame (53) between a high position allowing the presentation of one of the first or second bricks (B, B1, B2, B10, B20) and a low position where each endless screw (40, 40') of the brick coupled to the rotary machines can be coupled or decoupled from the rotary machines and the rotary machines raised to the high position to allow the presentation of the second or another second brick.

13. 13. Method according to one of claims 1 to 12, in which each brick (Bl, B2, B10) prefabricated in concrete, comprises at least one of the following elements: several longitudinal through channels (11, 12), longitudinal through orifices (19, 19') for receiving prestressing cables, a groove along an upper face (10c) for receiving a sealing joint (13) for providing a seal with a juxtaposed brick arranged above, a guide (14a, 14a') along a lateral face (10e, 10f) for assembling with a guide (14b, 14b') of complementary shape of an adjacent brick (Bl, B2, B10) arranged laterally, a longitudinal groove (12, 12') along the lateral face for receiving a sealing joint (21, 21'), several longitudinal through channels (11, 12) opening into a lower face (10d) of the brick via a channel part (18) having a flared shape, at least one longitudinal through orifice (19') containing a threaded sleeve, to receive a threaded rod (20) to fix the brick to another brick juxtaposed below, a longitudinal groove (12) formed by one of the channels which has an opening opening onto the lateral face (10f) of the brick, cannulas (23) opening into the upper face (10c) to fill longitudinal through orifices (19) with concrete after insertion of cables, longitudinal through holes (19) each comprising a cable locking device (22) for longitudinally locking a cable subjected to a tensile force, an upper face (10c) comprising two grooves for receiving two sealing gaskets (13) respectively, each channel opening into the upper face between the two grooves, upper (10c) and lower (10d) faces of the brick having complementary shapes to fit with another brick arranged respectively under and on another brick, several longitudinal through channels (11, 12), and a front face (10a) and / or a rear face (10b) having undulations following the shape of the channels.

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