Machine for producing a double-diameter pile in the ground

Abstract

The invention relates to a machine (10) for producing a double-diameter pile in the ground, the machine comprising: a casing (12) having a first diameter, the casing having a casing axis and a lower portion comprising a first cutting member, the casing being rotatable about the casing axis and translatable along the casing axis; an auger (20) having a second diameter smaller than the first diameter and being coaxial with the casing, the auger having an auger axis and being rotatable about the auger axis and translatable along the auger axis, the auger having a lower portion provided with an injection port (30); a coupling device (40) arranged in the lower portion of the machine, comprising a free position in which the auger can rotate and translate relative to the casing, and a coupled position in which the auger is rigidly attached to the casing such that rotation of the auger causes concomitant rotation of the casing about the casing axis and translation of the auger causes concomitant translation of the casing along the casing axis; and an injection device (32) for injecting a binder into the ground, via the injection port.

Description

[0001] DESCRIPTION

[0002] Title: Machine for driving a two-diameter pile into the ground

[0003] Technical Field

[0004] The present invention relates to the field of producing dual-diameter piles in the ground in the context of geotechnical works such as foundations.

[0005] Previous Technique

[0006] As is known, a two-diameter pile comprises an upper portion and a lower portion arranged in continuity with each other, the diameter of the upper portion being greater than the diameter of the lower portion.

[0007] The first section is carried out to a depth of around 5 metres to allow for the absorption of horizontal forces. The length of the lower section is sized to obtain the desired vertical lift.

[0008] The advantage of a dual-diameter pile, compared to a single-diameter pile whose diameter corresponds to the diameter of the upper portion, lies in the savings in concrete that are made.

[0009] The construction of a dual-diameter pile makes it possible to reduce by approximately 20 to 40% the quantity of concrete required to obtain the desired mechanical properties.

[0010] The use of dual-diameter piles therefore has the effect of reducing the environmental impact of the foundation.

[0011] Statement of the invention

[0012] One aim of the invention is to propose a machine for producing a dual-diameter pile.

[0013] The invention achieves its aim by a machine for producing a two-diameter pile in the ground comprising: a casing having a first diameter, the casing having a casing axis and a lower part comprising a first cutting member, the casing being movable in rotation around the casing axis and movable in translation along the casing axis; an auger having a second diameter, smaller than the first diameter, and being coaxial with the casing, the auger having an auger axis and being movable in rotation around the auger axis and movable in translation along the auger axis, the auger having a lower part provided with an injection orifice;a coupling device, arranged in the lower part of the machine, comprising a free position in which the auger can rotate and translate relative to the casing and a coupled position in which the auger is secured to the casing so that the rotation of the auger causes the concomitant rotation of the casing around the casing axis and the translation of the auger causes the concomitant translation of the casing along the casing axis; and an injection device for injecting a binder into the ground via the injection orifice.;

[0014] It is understood that when the auger is coupled to the casing, the latter is mechanically linked to the auger. The casing being integral with the auger, when the coupling device is in the coupled position, the movement of the auger causes the same movement of the casing in rotation and / or in translation along the casing axis.

[0015] Preferably, the casing axis is vertical.

[0016] The vertical movement of the auger in the ground, in the coupled position, has the effect of driving the assembly consisting of the casing and the auger into the ground. This movement therefore has the effect of drilling a first hole in the ground having the diameter of the first diameter of the casing.

[0017] It is also understood that, in the free position, the auger is mobile in rotation and translation relative to the casing.

[0018] The auger has in particular a retracted position in which the casing is located axially in the lower part of the auger. Preferably, the machine is arranged so that the transition between the coupled position and the free position takes place when the auger is in the retracted position.

[0019] In the retracted position the auger can be completely retracted into the casing or extend slightly beyond the lower end of the casing along the casing axis, particularly when the lower end of the auger is fitted with a cutting element.

[0020] In the free position of the coupling device, the auger can be extended axially beyond the lower end of the casing. This allows the auger to be driven into the ground without the casing remaining at the same depth.

[0021] The binder, for example concrete, can be injected through the injection port as the auger rises so as to initially fill the second hole in order to form the lower portion of the bi-diameter pile. Then the auger is again coupled to the casing and the auger together with the casing are raised together while injecting the binder into the first hole in order to form the upper portion of the bi-diameter pile, thus creating the bi-diameter pile.

[0022] It is understood that the coupling device has the function of coupling in rotation the auger and the casing so that the rotation of the auger causes the rotation of the casing in the same direction and at the same rotation speed.

[0023] The auger comprises a tubular auger body and at least one helical blade extending along the auger body. The lower end of the auger preferably comprises a second cutting member.

[0024] The tubing is preferably without a helical blade.

[0025] The injection device preferably comprises a binder supply line which is connected to an upper end portion of the auger.

[0026] Preferably, but not exclusively, the auger comprises a dip tube which is housed in the auger body. The dip tube is movable in translation relative to the auger body and comprises the injection orifice in its lower part. Such a dip tube is known elsewhere. To carry out the injection, the dip tube is deployed relative to the auger body so as to uncover the injection orifice. During drilling, the dip tube is retracted so as to mask the injection orifice.

[0027] Advantageously, the machine according to the invention further comprises a lining tube having a third diameter which is greater than the second diameter and less than the first diameter, the lining tube being arranged in the casing while being coaxial with said casing, while the auger is movable in rotation and in translation in the lining tube.

[0028] The third diameter of the liner tube is slightly larger than the second diameter of the auger. Preferably, the third diameter is less than 105% of the second diameter.

[0029] During the drilling stage, the cuttings are brought to the surface by circulating vertically between the auger and the lining tube.

[0030] Advantageously, the lining tube is rotatable relative to the casing around the casing axis.

[0031] According to a preferred embodiment, the lining tube is fixed relative to the ground. To do this, the machine further comprises a locking member for blocking the rotation of the lining tube relative to the ground.

[0032] The locking member prevents the casing tube from rotating with the auger during the drilling stage, whether the auger is coupled in rotation to the casing or not. This facilitates the lifting of the cuttings.

[0033] In the absence of a locking member, the possible rotation of the lining tube with the rotating auger may result from the friction induced by the cuttings in the lining tube during the rotation of the auger, the cuttings having the effect of coupling the lining tube in rotation with the auger. The inventor has found that rotation of the lining tube in the same direction of rotation as the auger generally has the disadvantage of preventing the cuttings from rising, creating a blockage.

[0034] According to a preferred embodiment, the blocking member comprises at least one wing arranged in the upper part of the lining tube, the wing cooperating with an object stationary relative to the ground.

[0035] The stationary object on the ground may be, for example, a part of a tracked carrier, for example the mast, which carries the machine according to the invention. The wing abuts against the mast, whereby the lining tube does not rotate when the auger rotates.

[0036] More preferably, the coupling member comprises two wings arranged on either side of the lining tube.

[0037] The casing remains mobile in rotation relative to the lining tube. It is understood that when the auger is coupled to the casing, the assembly consisting of the auger and the casing rotates relative to the lining tube.

[0038] Preferably, the lining tube moves in translation with the assembly consisting of the auger and the casing, when the coupling device is in the coupled position.

[0039] To achieve this, the liner tube is connected to the casing by means of a pivot connection. This pivot connection has the dual function of guiding the rotation of the casing relative to the liner tube and of translationally coupling the liner tube with the casing, whereby the liner tube is driven in translation during the translational movement of the casing.

[0040] Advantageously, the coupling device is located in the lower part of the casing. Preferably, the coupling device is arranged near the lower end of the casing, at the lower part of the casing.

[0041] According to an exemplary embodiment, the coupling device comprises a clamping element arranged to clamp the auger. Preferably, the clamping element is arranged to clamp blades of the auger.

[0042] Advantageously, the machine further comprises a sealing device arranged between the lining tube and the clamping element to prevent the entry of cuttings between the casing and the lining tube.

[0043] The coupling device further comprises an actuator for actuating the clamping element.

[0044] Advantageously, the auger comprises a main blade and a secondary blade, and the clamping element is arranged to press radially on diametrically opposite portions of the main and secondary blades.

[0045] Preferably, the clamping element comprises a chuck.

[0046] More preferably, the mandrel comprises two jaws mounted on the casing in a pivoting manner around at least one axis of rotation parallel to and distant from the casing axis, the jaws being arched and arranged on either side of the auger.

[0047] According to a preferred variant, each of the two jaws is pivotally mounted around an axis of rotation. Preferably, but not exclusively, the internal surface of the jaws is corrugated or provided with protrusions in order to increase the coefficient of friction between the mandrel and the auger.

[0048] According to an exemplary embodiment, the jaws are actuated by an actuator connecting two ends of the jaws opposite the axis of rotation. This actuator may be a hydraulic cylinder. Deployment of the cylinder causes the mandrel to open, while retraction of the cylinder causes the mandrel to close and the auger to be locked relative to the casing.

[0049] Preferably, the first cutting member extends annularly at the lower end of the casing.

[0050] More preferably, the lower end of the casing comprises an opening whose diameter is slightly greater than the diameter of the auger. The first cutting member extends annularly around said opening. The first cutting member preferably comprises several cutting tools.

[0051] The invention further relates to an installation for producing a bi-diameter pile in a ground, comprising a machine according to the invention and a carrier provided with a mast from which the machine is suspended, the carrier comprising a drive device for driving the auger in rotation around the auger axis and in translation along the auger axis.

[0052] The drive device comprises a rotation drive device and a translation drive device along the auger axis, which is substantially vertical.

[0053] In the embodiment where the machine comprises a lining tube, the wing of the locking member, when present, comes to bear against the mast of the carrier, which constitutes a stop preventing rotation of the lining tube relative to the ground.

[0054] The invention also relates to a method for producing a dual-diameter pile in a ground, in which: a machine according to the invention is provided, the coupling device is brought into the coupled position so as to secure the casing to the auger; the auger is rotated using the drive device so as to drive the assembly consisting of the auger and the casing into the ground to a first depth, whereby a first hole having a first diameter is drilled in the ground to a first depth; then the coupling device is brought into the free position so as to detach the casing from the auger; the auger is driven into the ground to a second depth, so as to drill a second hole in the ground in continuity with the first hole, the second hole having a second diameter smaller than the first diameter;a binder is injected into the ground through the auger orifice while raising the auger to the first depth so as to fill the second hole; the coupling device is brought into the coupled position so as to secure the casing to the auger; the auger is continued to rise, together with the casing, while continuing to inject binder into the ground so as to fill the first hole; then the machine is removed from the ground.;

[0055] The bi-diameter pile is therefore made up of the first and second holes filled with binder. The first hole filled with binder constitutes the upper portion of the pile while the second hole filled with binder constitutes the lower portion of the pile.

[0056] The two-diameter pile is made in a substantially vertical direction.

[0057] The upper portion of the dual-diameter pile allows for the absorption of horizontal forces, which are greater at the top of the pile. The lower portion has a smaller diameter but is generally longer in order to ensure the pile's load-bearing capacity.

[0058] Preferably, at least one rebar cage is inserted into at least one of the first and second binder-filled holes after removal from the machine.

[0059] Advantageously, the machine further comprises a lining tube having a third diameter greater than the second diameter and less than the first diameter, the lining tube being coaxial with the casing and the auger being slidable in the lining tube, and in which the auger rotates relative to the lining tube when drilling the first and / or second holes.

[0060] Preferably, the liner tube is locked against rotation relative to the ground during drilling of the first and / or second holes.

[0061] Advantageously, the rotational coupling of the auger with the casing is achieved by tightening the auger blades.

[0062] Description of the drawings

[0063] The invention will be better understood on reading the following description of an embodiment of the invention given by way of non-limiting example, with reference to the appended drawings, in which:

[0064] [Fig. 1] Figure 1 illustrates, in a perspective view, an exemplary embodiment of the machine according to the invention, and more particularly its lower part;

[0065] [Fig. 2] Figure 2 is a front view of the machine of Figure 1;

[0066] [Fig. 3] Figure 3 is a longitudinal sectional view of the machine of Figure 2;

[0067] [Fig. 4] Figure 4 illustrates the machine of Figure 3 without the casing housing, showing the mandrel;

[0068] [Fig. 5] Figure 5 illustrates the installation according to the invention and a first step of the method according to the invention in which the casing and the auger are driven into the ground concomitantly so as to drill a first hole, the lining tube being blocked in rotation by the mast of a carrier and the auger being coupled with the casing;

[0069] [Fig. 6] Figure 6 illustrates a second step of the method according to the invention in which the auger is decoupled from the casing and drills a second hole below the casing;

[0070] [Fig. 7] Figure 7 illustrates the injection of binder into the second hole during the ascent of the auger;

[0071] [Fig. 8] Figure 8 illustrates the injection of binder into the first hole during the raising of the casing and the auger, coupled to each other; and

[0072] [Fig. 9] Figure 9 illustrates the two-diameter pile, equipped with a reinforcement cage, produced by the method according to the invention. Detailed description

[0073] In Figure 5, an example of an installation 100 according to the invention is illustrated for producing a bi-diameter pile P in a soil S, comprising a machine 10 according to the invention, and a carrier 110 provided with a mast from which the machine is suspended. In this example, the carrier 110 is a tracked carrier.

[0074] In this example, the mast is substantially vertical and the machine 10, which will be described in more detail below, is carried by a carriage 114 which is movable in translation along the mast 112.

[0075] The actuating system of the carriage 114 is known elsewhere and will not be described in more detail here.

[0076] Referring to Figures 1 to 3, it can be seen that the machine 10 according to the invention comprises a casing 12 having a generally cylindrical shape having a first diameter DI and a casing axis A. In this example, the casing axis is substantially vertical.

[0077] In Figures 1 to 3, for the sake of readability, only the lower portion 14 of the casing 12 has been shown. The casing 12 also comprises a cylindrical casing body 11, visible in Figures 3 and 6, which is connected to the lower portion 14.

[0078] The casing 12 comprises a lower portion 12a which is provided with a first cutting member 18. In this example, the first cutting member 18 consists of a plurality of cutting tools 19 which extend annularly at the lower end 13 of the casing. The first cutting member is located at the lower end 13 of the casing, on a lower annular face 22 of a circular plate 15 of the casing.

[0079] In this example, the outer wall 12b of the casing is substantially flat and devoid of a helical blade.

[0080] The diameter of the first cutting member 18 is substantially equal to or slightly greater than the first diameter D1.

[0081] As will be explained in more detail below, the casing 12 is movable in rotation around the casing axis A and movable in translation along the casing axis A.

[0082] The machine 10 according to the invention further comprises an auger 20 having a second diameter D2, smaller than the first diameter D1. The auger 20 has an auger axis B and comprises a tubular body 22, a main blade 24 which is helical and which surrounds the tubular body 22, as well as a secondary blade 26 located in the lower part 20a of the auger. The secondary blade 26 is angularly offset by 180° relative to the main blade 24.

[0083] The second diameter D2 corresponds to the outside diameter of the main blade 24.

[0084] The auger 20 comprises a second cutting member 28 comprising a first part 28a arranged at the lower end of the main blade 24, a second part 28b arranged at the lower end of the secondary blade 26 and a third part 28c arranged at the lower end 22a of the tubular body 22.

[0085] As can be seen in Figure 3, the auger 20 is coaxial with the casing 12.

[0086] The auger 20 is movable in rotation around the auger axis B and movable in translation along the auger axis B.

[0087] The auger 20 further comprises an injection orifice 30 which is connected to an injection device 32 for injecting a binder into the soil S. This binder may be a concrete grout or a mortar for example. The auger 20 is hollow so that the binder flows into the auger as far as the injection orifice 30. Without departing from the scope of the present invention, the auger may comprise several injection orifices. In this example, the auger 20 comprises a dip tube 23, known elsewhere, which is movable in translation relative to the tubular body 22 and the injection orifice is provided at a lower end portion of the dip tube. In a known manner, to carry out the injection, the dip tube 23 is deployed axially out of the tubular body in order to uncover the injection orifice. During drilling, the dip tube 23 is retracted into the tubular body, as illustrated in Figure 3, in order to mask the injection port.

[0088] The installation 100 further comprises a drive device 130, arranged in the carriage 114, for driving the auger 20 in rotation around the auger axis B and in translation along the auger axis B.

[0089] Furthermore, the tubing 12 can also be guided in translation and rotation relative to the mast via a guide member 132.

[0090] The machine 10 further comprises a coupling device 40, arranged in the lower part of the machine, comprising a free position in which the auger can rotate and translate relative to the casing 12, and a coupled position in which the auger is blocked relative to the casing so that the rotation of the auger 20 causes the concomitant rotation of the casing around the casing axis, and the translation of the auger causes the concomitant translation of the casing along the casing axis A. In this example, the coupling device 40 is located at the lower part of the casing 12.

[0091] The coupling device 40 is controllable so that it can be placed in the free (or decoupled) position and in the coupled position.

[0092] In this example, when the coupling device is in the coupled position, the auger is secured to the casing.

[0093] Still in this example, the coupling device 40 is located in the lower part of the casing. As seen in Figure 3, the coupling device 40 is arranged inside the lower part 14 of the casing. The coupling device 40 is arranged above the circular plate 15. It comprises a clamping element 42 arranged to pinch the auger 20. The pinching of the auger by the clamping element 42 has the effect that the casing becomes integral with the auger. Consequently, the movement of the auger, by translation and / or rotation, is accompanied by the concomitant movement of the casing. In other words, the movement of the casing is controlled by the auger when the coupling device is in the coupled position.

[0094] The clamping element 42 is arranged to press simultaneously and radially on diametrically opposite portions of the main and secondary blades 24, 26.

[0095] In this example, the clamping element 42 comprises a mandrel 44 which consists of two jaws 46 which are mounted on the plate 15 of the casing 12 in a pivoting manner around axes of rotation XI, X2 parallel and distant from the casing axis A.

[0096] As seen in Figure 4, the jaws are arched and arranged on either side of the auger so as to be able to radially pinch the main and secondary blades. To do this, the jaws 46 are actuated by an actuator 48, in this example a jack, which connects the two ends of the jaws which are opposite the axes of rotation XI, X2.

[0097] It is understood that the deployment of the cylinder has the effect of opening the jaws, that is to say of moving them apart from each other, while the retraction of the cylinder has the opposite effect of closing the jaws. When the auger is retracted into the casing 12, the pinching zone of the main and secondary blades is located substantially at the same axial level as the clamping element 42. The coupling of the auger with the casing preferably takes place when the auger is retracted.

[0098] Advantageously, the machine 10 further comprises a lining tube 60 having a tube axis C and having a cylindrical shape of diameter D3.

[0099] The lining tube is arranged inside the casing 12 while being coaxial with said casing. The lining tube is rotatable relative to the casing around the casing axis A. In this example, the lining tube is connected to the body of the casing 11 by means of a pivot connection 17 which has the function of guiding the rotation of the lining tube 60 relative to the casing 12, while blocking the translation of the lining tube 60 relative to the casing 12. The pivot connection 17 comprises an annular guide part 17a secured to the inner wall of the casing, and two annular portions 17b, 17c, fixed to the outer wall of the lining tube and enclosing the annular guide part. Rollers 17d, mounted along the two annular portions, facilitate the rotation of the annular part relative to the lining tube. The pivot connection thus provides a translational coupling, along the casing axis A, of the lining tube 60 relative to the casing 12.Consequently, the translational movement of the casing along the casing axis A causes the translational movement of the casing.

[0100] The third diameter D3 of the lining tube 60 is greater than the second diameter D2 of the auger but less than the first diameter DI of the casing.

[0101] It is therefore understood that the lining tube is arranged inside the casing and that the auger is arranged inside the lining tube.

[0102] The machine further comprises a sealing device 57, visible in FIG. 3, arranged between the lining tube 60 and the clamping element 42 to prevent the entry of excavation spoil between the casing and the lining tube. In this example, the sealing device 57 is arranged at the lower end of the lining tube and comprises an annular seal 59 which bears on the upper face of the jaws 46. The third diameter D3 of the lining tube is slightly greater than the second diameter D2 of the auger.

[0103] The auger 20 is movable in rotation and translation relative to the lining tube 60. When the coupling device is in the free position, the auger can translate and rotate relative to the lining tube. The auger can also rotate in the lining tube when the coupling device is in the coupled position.

[0104] The machine 10 further comprises a locking member 62 for locking the rotation of the lining tube relative to the ground S, particularly during the drilling operation. In this example, the locking member comprises two wings 62 arranged in the upper part of the lining tube 60. The wings project radially relative to the lining tube.

[0105] It can be seen in Figure 5 that one of the wings 62 cooperates with the mast 112 of the carrier. The mast is stationary relative to the ground so that the latter acts as a stop for the wing, which has the effect of blocking the rotation of the lining tube around the casing axis.

[0106] The locking member ensures that the liner tube does not rotate with the auger. As a result, when drilling, the auger rotates relative to the liner tube around the auger axis, which facilitates the lifting of the cuttings by the rotation of the auger.

[0107] Using figures 5 to 9, we will now describe a method of implementing the process for producing a two-diameter pile P in the ground S.

[0108] According to this method, a machine according to the invention is provided, such as that described above.

[0109] First, the installation 100 is positioned at the location where the pile P is to be made.

[0110] The coupling device 40 is brought into the coupled position so as to secure the casing 12 to the auger 20. The auger 20 is rotated about the auger axis using the drive device 130. Since the auger 20 is secured to the casing 12, it is understood that the rotation of the auger has the effect of rotating the casing. The assembly consisting of the auger and the casing rotates as a single piece about the casing axis. This rotating assembly is then driven into the ground S to a first depth PI, so as to drill a first hole of length L1 in the ground S, the diameter of which is the first diameter DI of the casing 12.

[0111] In this example, the machine 10 further comprises a lining tube 16 having a third diameter greater than the second diameter and less than the first diameter. The lining tube 16 is coaxial with the casing and the auger is slidably mounted in the lining tube.

[0112] The lining tube 16 is locked in rotation relative to the ground during the drilling of the first and second holes. In this example, the auger 20 is locked in rotation relative to the ground, during the rotation of the auger, thanks to the wing 62 which rests on the mast 112. The locking in rotation of the lining tube makes it easier to raise to the surface the spoil excavated by the auger 20.

[0113] After reaching the first depth PI, the coupling device 40 is brought into the free position so as to detach the casing 12 from the auger 20, as a result of which the auger 20 can move, in translation and in rotation, relative to the casing 12.

[0114] As illustrated in Figure 6, the auger 20 is driven into the ground to a second depth P2, so as to drill a second hole in the ground in continuity with the first hole.

[0115] The second hole has a generally cylindrical shape which extends over a length L2 and whose diameter is the second diameter D2. In the figures of the example, the second hole has at its lower end a small third hole whose diameter is less than the diameter of the auger. This third hole has a low vertical height relative to the length L2 of the second hole.

[0116] As illustrated in Figure 7, a binder, for example concrete, is then injected into the soil S through the orifice 30 of the auger 20 while raising the auger to the first depth PI so as to fill the second hole with binder. The third hole, when present, is also filled with binder.

[0117] In this example, the plunger tube 23 is axially deployed out of the body 22 of the auger so as to uncover the injection orifice 30.

[0118] Once the auger has risen substantially to the first depth PI, the coupling device is brought into the coupled position so as to secure the casing 12 to the auger 20. The auger 20 is then continued to rise, which in its vertical movement drives the casing 12, while continuing to inject binder into the ground so as to fill the first hole. This is illustrated in Figure 8. Finally, the machine is removed from the ground.

[0119] Before the binder solidifies, a reinforcement cage 70 is inserted into the first and second holes so as to obtain the reinforced pile P illustrated in figure 9.

Claims

CLAIMS 1. Machine (10) for producing a two-diameter pile (P) in a ground (5) comprising: a casing (12) having a first diameter (Dl), the casing having a casing axis (A) and a lower part (12a) comprising a first cutting member (18), the casing being movable in rotation about the casing axis (A) and movable in translation along the casing axis; an auger (20) having a second diameter (D2), smaller than the first diameter (Dl), and being coaxial with the casing (12), the auger having an auger axis (B) and being movable in rotation about the auger axis and movable in translation along the auger axis, the auger having a lower part (20a) provided with an injection orifice (30);a coupling device (40), arranged in the lower part of the machine, comprising a free position in which the auger can rotate and translate relative to the casing and a coupled position in which the auger is integral with the casing so that the rotation of the auger causes the concomitant rotation of the casing around the casing axis and the translation of the auger causes the concomitant translation of the casing along the casing axis; and an injection device (32) for injecting a binder into the ground via the injection orifice.; 2. Machine according to claim 1, further comprising a lining tube (60) having a third diameter (D3) which is greater than the second diameter (D2) and less than the first diameter (D1), the lining tube being arranged in the casing while being coaxial with said casing, while the auger is movable in rotation and in translation in the lining tube.

3. Machine according to claim 2, in which the lining tube is rotatable relative to the casing around the casing axis.

4. Machine according to claims 2 or 3, further comprising a locking member (62) for locking the rotation of the lining tube relative to the ground.

5. Machine according to claim 4, in which the locking member (62) comprises at least one wing arranged in the upper part of the lining tube (60), the wing cooperating with an object stationary relative to the ground.

6. Machine according to any one of claims 1 to 5, in which the coupling device (40) is located in the lower part of the tubing.

7. Machine according to claim 6, wherein the coupling device (40) comprises a clamping element (42) arranged to clamp the auger.

8. Machine according to claim 7, in which the auger comprises a main blade (24) and a secondary blade (26), and the clamping element is arranged to press simultaneously on diametrically opposite portions of the main (24) and secondary (26) blades.

9. Machine according to claim 7 or 8, in which the clamping element (42) comprises a chuck (44).

10. Machine according to claim 9, in which the mandrel (44) comprises two jaws (46) mounted on the casing in a pivoting manner around at least one axis of rotation parallel and distant from the casing axis, the jaws being arcuate and arranged on either side of the auger.

11. Machine according to claim 10, in which the jaws are actuated by an actuator (48) connecting two ends of the jaws opposite the axis of rotation.

12. Machine according to any one of the preceding claims, in which the first cutting member extends annularly at the lower end (13) of the tubing.

13. Machine according to any one of the preceding claims, in which the auger has a lower end provided with a second cutting member.

14. Installation (100) for producing a two-diameter pile in a ground, comprising a machine (10) according to any one of the preceding claims, a carrier (110) provided with a mast (112) from which the machine is suspended, the carrier comprising a drive device for driving the auger in rotation around the auger axis and in translation along the auger axis.

15. A method of producing a two-diameter pile in a ground, in which: a machine according to any one of claims 1 to 13 is provided, the coupling device is brought into the coupled position so as to secure the casing to the auger; the auger is rotated so as to drive the assembly consisting of the auger and the casing into the ground to a first depth, whereby a first hole having a first diameter is drilled in the ground to a first depth; then the coupling device is brought into the free position so as to detach the casing from the auger; the auger is driven into the ground to a second depth, so as to drill a second hole in the ground in continuity with the first hole, the second hole having a second diameter smaller than the first diameter; a binder is injected into the ground through the orifice of the auger while raising the auger to the first depth so as to fill the second hole; the coupling device is brought into the coupled position so as to secure the casing to the auger; the auger is continued to rise, together with the casing, while continuing to inject binder into the ground so as to fill the first hole; then the machine is removed from the ground.

16. The method of claim 15 wherein at least one reinforcing cage (70) is inserted into at least one of the first and second binder-filled holes after removal from the machine.

17. The method of claim 15 or 16, wherein the machine further comprises a liner tube (60) having a third diameter greater than the second diameter and less than the first diameter, the liner tube being coaxial with the casing and the auger being slidable in the liner tube, and wherein the auger rotates relative to the liner tube when drilling the first and / or second hole.

18. Method according to claim 17, in which the lining tube is locked in rotation relative to the ground during the drilling of the first and / or second hole.

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