A probe designed to be inserted into a borehole formed in the ground to measure at least one parameter of said ground, and the associated method.
Patent Information
- Application Number
- FR2023000517
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2023-01-19
- Publication Date
- 2025-03-07
- Estimated Expiration
- 2043-01-19
Smart Images
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Abstract
Description
Title of the invention: PROBE INTENDED TO BE INSERTED INTO A BOREHOLE FORMED IN SOIL TO MEASURE AT MINUS ONE PARAMETER OF SAID SOIL AND ASSOCIATED PROCESS FIELD OF INVENTION
[0001] The present invention relates to the field of soil characterization.
[0002] In particular, the invention relates to a probe intended to be inserted into a borehole formed in soil, to measure at least one parameter of said soil and the method of implementing said probe. STATE OF THE ART
[0003] The invention applies in particular to borehole expansion tests for determining in-situ the mechanical characteristics of the soil, such as resistance or deformability. This data is particularly useful for designing geotechnical structures.
[0004] The expansion test carried out with a Ménard pressuremeter is the reference test in France. It is implemented using a Ménard pressuremeter which classically comprises a probe intended to be inserted into a borehole made in the ground, a pressure-volume controller (PVC) left on the surface and means of connection between the probe and the PV.
[0005] The probe of the Ménard pressure gauge consists of a metal cylinder with a central cell covered by an elastic rubber membrane. The central cell is configured to deform under the pressure of a fluid such as water. The probe is further protected by another deformable membrane.
[0006] The CPV comprises a fluid-filled reservoir and is connected to a compressed gas source such as a compressed gas cylinder. It is connected to the probe using the connection means.
[0007] In practice, the probe is installed either by drilling a borehole, for example using tools adapted to the soil being studied, or by driving or hammering the pressuremeter probe, protected by a lantern tube, to the desired depth.
[0008] The fluid is pressurized at the CPV using compressed gas and is then injected into the central cell via the connection means, in order to expand the central cell. The volume of the expanded probe and the corresponding pressure exerted on the borehole walls are thus recorded.
[0009] Although Ménard pressuremeters are the standard for in-situ expansion tests, they are mechanically complex. Furthermore, Ménard pressuremeters require the presence of a gas cylinder. compressed, which leads to handling problems due to the transport of the bottles in the field and risks of bursting of the tubing transporting the pressurized fluids during the testing phases.
[0010] In addition, the probes of Ménard pressuremeter devices are often subject to repeated bursting, due to the low resistance of the deformable membrane surrounding the probe.
[0011] Finally, pressure losses occur in the tubing during significant creep in the ground. These pressure losses disrupt, or even distort, the measurement of the fluid pressure contained in the probe.
[0012] The invention aims to solve the aforementioned problems. DETAILED DESCRIPTION
[0013] To solve these problems, the invention relates to a probe intended to be inserted into a borehole drilled in soil, to measure at least one parameter of said soil. The probe comprises:
[0014] - a cylindrical body having an axis. The cylindrical body comprises a plurality of chambers, of which at least one first chamber and at least one second chamber. The at least one first chamber opens from the cylindrical body in a first direction perpendicular to the axis, and the at least one second chamber opens from the cylindrical body in a second direction perpendicular to the axis, distinct from the first direction;
[0015] - a plurality of pistons, of which at least one first piston is contained in the at least a first chamber and at least one second piston contained in at least one second chamber;
[0016] - a fluid supply circuit configured to supply the chambers with fluid under pressure so as to move each piston between a retracted position, in which the piston is inside the chamber, and an extended position, in which at least one end of the piston protrudes from the chamber. At least one first piston is movable in the first direction and at least one second piston is movable in the second direction;
[0017] - a plurality of arms, including at least a first arm and at least a second arm. The arms are configured to exert a load on a borehole wall. At least one first arm is mounted at the end of at least one first piston so as to be movable in the first direction, and at least one second arm is mounted at the end of at least one second piston so as to be movable in the second direction.
[0018] In other words, the invention relates to a probe that replaces Ménard probes, while overcoming their drawbacks. To this end, in the probe of The invention consists of jacks, arranged along the body of the probe, which exert the necessary force on the wall of the borehole.
[0019] The cylinder chambers are filled only with a fluid such as oil to actuate the pistons, thus eliminating the need for a compressed gas cylinder. The probe of the invention is mechanically simpler than Ménard probes, and the associated risks are significantly reduced. Indeed, there is no longer any risk of bursting.
[0020] Finally, since the fluid flow rate between the CPV and the probe is low, the pressure loss problems are solved.
[0021] The probes of the invention are therefore safer and more precise than the Ménard probes of the prior art.
[0022] In practice, the chambers provided in the cylindrical body are aligned along the axis of the cylindrical body.
[0023] According to the invention, the alignment of the chambers means that in all planes of the cylindrical body perpendicular to the axis, there is only one single chamber. In other words, there are no multiple chambers positioned on the same axis perpendicular to the axis of the cylindrical body.
[0024] Aligning the chambers along the axis maximizes the size of the chambers within the cylindrical body. These chambers can extend across the entire width of the cylindrical body, thus maximizing the stroke of the cylinders. The probe can therefore expand over a greater width than Ménard probes, for example, going from an initial diameter of 58 mm to a final diameter of 92 mm.
[0025] More specifically, the chambers are contiguous in pairs along the axis. The chambers have a bottom and at least one side wall, and two contiguous chambers share at least a portion of their side wall.
[0026] Advantageously, two adjacent chambers open respectively in the first and second directions. This allows for an alternating arrangement of cylinders configured to deploy in the first and second directions. The arms are thus configured to be deployed uniformly from the cylindrical body.
[0027] According to an advantageous embodiment, the first direction is opposite to the second direction. In other words, the invention is then a probe comprising cylinders arranged in a staggered pattern along the cylindrical body of the probe. In particular, the probe has arms that extend symmetrically on each side of the cylindrical body.
[0028] In practice, the probe further comprises a membrane surrounding the cylindrical body and the arms. The membrane is configured to deform during the movements of the arms. Such a membrane prevents the gaps created between the cylindrical body of the probe and the arms when the latter are spread apart do not fill with soil or debris, which could prevent them from returning to their initial position and thus hinder the extraction of the probe from the borehole at the end of the test.
[0029] In addition, unlike Ménard probes, the membrane of the probe of the invention is not at risk of bursting because the stroke of the pistons is better controlled compared to the pressure exerted by a fluid directly on the membrane.
[0030] According to an advantageous embodiment, each piston includes a fastening means and each arm includes on an inner face at least one bore, each bore being configured to cooperate with a fastening means of one of the pistons, so as to fix the arm on said piston.
[0031] In other words, the arms are attached to the ends of the pistons by means of a bore in the arms with fastening means located at the ends of the pistons. Advantageously, several pistons are evenly distributed under an arm and work together to deploy the arm. The unit force exerted by each piston is thus homogenized by the presence of the arms, and the force exerted on the borehole wall is therefore better distributed.
[0032] According to another aspect, the invention relates to a pressure gauge comprising:
[0033] - a probe as described above,
[0034] - a pressure-volume controller intended to be left on the surface, and
[0035] - means for connecting the probe and the pressure-volume controller.
[0036] According to another aspect, the invention also relates to a method for implementing the probe comprising the following steps:
[0037] - insertion of the probe into a borehole formed in the ground, and
[0038] - supplying fluid to the chambers to move the pistons into the position deployed in order to exert stress on the borehole wall via the arms.
[0039] Advantageously, the process further includes a step of measuring a soil parameter. DESCRIPTION OF THE FIGURES
[0040] [Fig. 1] [Fig. 1] is an exploded perspective view of the probe according to one embodiment of the invention,
[0041] [Fig.2] [Fig.2] is a perspective view of the probe body according to the embodiment of [Fig.1], in which the arms are deployed,
[0042] [Fig.3] The [Fig.3] is a perspective view of the probe body according to the embodiment of the [Fig.1],
[0043] [Fig.4] The [Fig.4] is a cross-sectional view of the probe body of the [Fig.3],
[0044] [Fig. 5] Fig. 5 is a perspective view from above of the probe body along the embodiment of [Fig. 1], in which the pistons are in the deployed position,
[0045] [Fig.6] [Fig.6] is a perspective view of one end of the probe body according to the embodiment of [Fig.1], in which the pistons are in the deployed position,
[0046] [Fig.7] [Fig.7] is a front view of the probe body according to the embodiment of [Fig.1], in which the pistons are in the deployed position,
[0047] [Fig.8] [Fig.8] is a front view of a portion of the probe body according to the embodiment of [Fig.1], in which a first piston is in the deployed position and a second piston is in the retracted position.
[0048] [Fig.9] Fig.9 is a perspective view of the top of a piston according to one embodiment of the invention,
[0049] [Fig. 10] [Fig. 10] is a perspective view of the underside of the piston of [Fig. 9], and
[0050] [Fig. 11] [Fig. 11] is a schematic front view of a pressure gauge. including a probe of the invention. ILLUSTRATIVE METHODS OF IMPLEMENTATION OF THE INVENTION
[0051] The detailed description that follows will be better understood in the light of the drawings. For illustrative purposes, the device is shown in a preferred embodiment. It should be understood, however, that the application is not limited to the specific arrangements, structures, features, embodiments, and aspects shown. The drawings are not drawn to scale and are not intended to limit the scope of the claims to the embodiment shown. Therefore, it should be understood that where the features mentioned in the appended claims are followed by reference numerals, these numerals are included solely for the purpose of improving the intelligibility of the claims and do not in any way limit the scope of the claims.
[0052] The probe 100 of the invention is equipped with cylinders configured to exert pressure on the wall 301 of a borehole 300 by means of arms.
[0053] As illustrated in [Fig. 1 1], the probe 100 of the invention is intended to be used in conjunction with a pressure-volume controller (PVC) 200, which is left on the surface. The probe 100 is connected to the PV 200 with connection means 400 such as hydraulic hoses.
[0054] The CPV 200 includes in particular a fluid reservoir intended to supply the cylinders of the probe 100. The connection means 400 are thus configured to bring the fluid to the probe 100. The fluid is for example a hydraulic oil or a hydraulic fluid based on polyethylene oxide.
[0055] The probe 100 is installed either by drilling a borehole 300 using tools adapted to the soil 500 being studied, or by driving or hammering the probe 100 to the desired depth. The drilling method depends on the nature of the soil 500, its condition, and the possible presence of a water table. The borehole 300 preferably has a diameter between 40 and 70 mm, more preferably 64 mm. It can be made with the same tools as those used for Ménard probes, which requires little adaptation to transition to a 100 probe according to the invention.
[0056] As illustrated in [Fig.1], the probe 100 of the invention has a cylindrical body 10 having arms 20, 20a, 20b movable between two positions: a retracted position, in which the arms are in contact with the cylindrical body 10, and a deployed position, illustrated in [Fig.2], in which the arms 20, 20a, 20b are moved away from the cylindrical body 10 and exert a pressure force against the wall 301 of the borehole 300.
[0057] The probe is controlled either by constant pressure steps or by progressively increasing the probe volume while providing a constant fluid flow rate. A pressure step corresponds to a given position of the arms 20, 20a, 20b at the spacing. In one particular implementation example, the probe 100 remains in the position of a pressure step for a period of between 1 and 2 minutes. The test may include between 2 and 10 pressure steps. For a given pressure, the CPV 200 provides the position of the arms 20, 20a, 20b at the spacing. The test is continued until a limit pressure is reached. This limit pressure characterizes the phase of large borehole displacements or the failure of the soil 500.
[0058] During a test where the volume of the probe is gradually increased, a constant flow of fluid is injected into the probe and the pressure is continuously measured as a function of the spacing of the arms.
[0059] At the end of the test, the arms can be retracted without making a stop.
[0060] In a particular example, the cylindrical body 10 has a length between between 300 mm and 450 mm. When arms 20, 20a, 20b are retracted, the diameter of the cylindrical body 10 can be between 40 mm and 70 mm, more preferably 48 mm. When arms 20, 20a, 20b are extended, the diameter of the cylindrical body 10 can be between 80 mm and 100 mm, more preferably 84 mm.
[0061] The cylindrical body 10 preferably has a circular cross-section, but alternatively, the section can be elliptical, polygonal and be in the form of a triangle, a square, a hexagon, or other.
[0062] The cylindrical body 10 has a longitudinal axis A extending along the length of the cylindrical body 10. The axis A is an axis of revolution of the cylindrical body 10 in the case where the section of the cylindrical body 10 is a circle.
[0063] The cylindrical body 10 is preferably made of a metal, such as steel.
[0064] As illustrated in [Fig. 2], the central part of the cylindrical body 10 comprises a plurality of cylinders configured to move arms 20, 20a, 20b.
[0065] As illustrated in Figures 3 and 4, the cylinders comprise a plurality of Chambers 40, 40a, 40b are formed within the cylindrical body 10. Preferably, these chambers have a cylindrical shape with a circular cross-section, extending across the width of the cylindrical body 10. Alternatively, the chambers may have an elliptical, polygonal, or other cross-section. For example, chambers 40, 40a, 40b may have a height between 40 mm and 60 mm and a width between 20 mm and 50 mm.
[0066] In practice, the chambers 40, 40a, 40b have a bottom 41 and at least one wall 42, thus forming a receiving cavity configured to be filled with fluid. In the case where the chambers 40, 40a, 40b are cylindrical, the wall 42 is a circular wall.
[0067] First chambers 40a are distinguished, which can open in a first direction DI, and second chambers 40b, which can open in a second direction D2. The first chambers 40a and the second chambers 40b can be aligned along the axis A. In this case, as illustrated in [Fig. 4], two contiguous chambers 40a, 40b share at least a portion of their lateral wall 42.
[0068] The chambers 40, 40a, 40b are preferably regularly distributed along axis A. For example, they may be spaced from each other by a distance of between 1 cm and 5 cm. Preferably, the cylindrical body 10 has an alternation of first chambers 40a and second chambers 40b. In other words, the cylindrical body 10 has a first chamber 40a opening along direction DI and a second chamber 40b, positioned directly next to the first chamber 40a along axis A, opening in direction D2. Directions DI and D2 may be defined by vectors having a direction and a sense. The angle defined between the two vectors is between 1 and 180°.
[0069] Preferably, the vectors of DI and D2 have opposite directions and are separated by an angle of 180°. Thus, the first chambers 40a and the second chambers 40b preferably open on either side of the cylindrical body 10.
[0070] The invention is not limited to two directions D1, D2. Indeed, the chambers 40 can open in any direction forming an angle between 1 and 180° with the directions D1 or D2. Preferably, the cylindrical body 10 comprises between 4 and 20 chambers 40, 40a, 40b, and more preferably 10 chambers 40, 40a, 40b. Preferably, the number of first chambers 40a is equal to the number of second chambers 40b.
[0071] As illustrated in figures 5 to 8, each chamber 40; 40a, 40b receives a piston 30, 30a, 30b. Thus, we distinguish between first pistons 30a, which can extend in the first direction D1 and second pistons 30b, which can extend in the second direction D2.
[0072] As illustrated and shown in Figures 9 and 10, a piston 30, 30a, 30b comprises a body 33 designed to slide in a chamber 40; 40a, 40b, while ensuring The sealing of chamber 40, 40a, 40b. To this end, the body 33 has a shape complementary to the cavity formed by chamber 40, 40a, 40b and the same dimensions as chamber 40, 40a, 40b. Thus, for example, if the chamber is cylindrical with a circular cross-section, the body 33 of piston 30, 30a, 30b is also cylindrical with a circular cross-section. The bodies 33 of pistons 30, 30a, 30b have, for example, a height between 40 mm and 60 mm and a diameter between 20 mm and 50 mm.
[0073] Advantageously, a scraper seal 39 is positioned in the chamber 40; 40a, 40b so as to ensure the sealing of the cylinders.
[0074] The body 33 of the piston 30, 30a, 30b further has an upper opening 31, with a diameter, for example, between 8 mm and 16 mm, and a lower opening 32, with a diameter, for example, between 1 mm and 8 mm. Preferably, the diameter of the upper opening 31 is larger than the diameter of the lower opening 32.
[0075] In practice, the body 33 of the piston 30, 30a, 30b is traversed through by a recess which opens at the level of the upper opening 31 and lower opening 32. The recess has a narrowing 78 in its lower part so that the lower opening 32 has a diameter smaller than the upper opening 31. The upper opening 31 advantageously has a thread.
[0076] The upper opening 31 is filled by a threaded element 35 so as to ensure the sealing of the upper opening 31. The threaded element 35 has a body 36 having the thread and adapted to cooperate with the tapped hole of the upper opening 31. The threaded element 35 also has a head having a recess 38 intended to cooperate with a tool such as a wrench or screwdriver in order to screw the threaded element 35 into the upper opening 31. The threaded element 35 has, for example, a height of between 5 mm and 15 mm and may protrude from the body 33 of the piston 30, 30a, 30b by a height of between 1 mm and 5 mm.
[0077] The lower opening 32 is traversed by a screw 75. The screw 75 has a head 77 configured to fit into the constriction 78, and a threaded body 76 configured to cooperate with a tapped opening 45 in the cylindrical body of the probe 10. The screw 75 also has a recess 79 for cooperating with a tool such as a wrench or screwdriver to screw the screw 75 into the tapped opening 45. The screw 75 has, for example, a height of between 10 mm and 30 mm and may protrude from the body 33 of the piston 30, 30a, 30b by a height of between 5 mm and 15 mm.
[0078] In practice, the piston 30, 30a, 30b is first inserted into the chamber 40, 40a, 40b, so as to align the lower opening 32 of the piston 30, 30a, 30b with the threaded opening 45. The screw 75 is then inserted through the upper opening 31 and screwed through the lower opening 32 into the threaded opening 45. The screw 75 is screwed in so that when the piston 30, 30a, 30b is at the end of its stroke, the head 77 comes to rest in the narrowing 78. The body 76 then protrudes from the bottom 41 of the chamber 40, 40a, 40b. Next, the threaded element 35 is screwed into the upper opening 31.
[0079] The piston 30, 30a, 30b is thus movable between a retracted position and an extended position. In the retracted position, the piston 30, 30a, 30b is completely retracted into the chamber 40, 40a, 40b, and the head 79 of the screw 75 is then abutted against the threaded element 35. In the extended position, the body 33 of the piston 30, 30a, 30b protrudes from the chamber 40, 40a, 40b, and the head 79 of the screw 75 is then abutted against the narrowing 78. The recess of the piston 30, 30a, 30b thus slides around the body 76 of the screw 75.
[0080] In a particular example, the pressure to be applied to the wall 301 of the borehole 300 can reach 3 MPa, which, for 10 cylinders and the chosen arm geometry, represents a force of 62 kN exerted by each cylinder. The cross-section of each cylinder allows it to operate at typical hydraulic pressures in industry, on the order of 200 bar.
[0081] As illustrated in [Fig. 6], the movements of the pistons 30, 30a, 30b are ensured by filling the chambers 40, 40a, 40b with fluid. The more the chamber 40, 40a, 40b is filled, the more the piston 30, 30a, 30b extends. The fluid supply is provided by a supply circuit comprising a first conduit 51 whose inlet is located at the end of the cylindrical body 10. The inlet is connected to the CPV 200 via at least one hydraulic hose.
[0082] A second conduit 52 passes through the cylindrical body 10 along axis A. In practice, this second conduit 52 is made by drilling, then sealed at each end by a sealing screw after machining to ensure the sealing of the supply circuit.
[0083] A third conduit 53 connects the first conduit 51 with the second conduit 52. In practice, the third conduit 53 is made by drilling the cylindrical body 10. It is sealed after machining by a sealing screw to ensure the sealing of the supply circuit.
[0084] A fourth conduit 54 allows communication from the second conduit 52 with the bottoms 41 of chambers 40, 40a, 40b. This fourth conduit 54 is made by drilling and sealed, after machining, by a sealing screw to ensure the sealing of the supply circuit.
[0085] During maintenance operations, the sealing screws can thus be removed to clean the conduits 51-54.
[0086] Thus, to supply each cylinder, the fluid passes through the first conduit 51 then the third conduit 53 then the second conduit 52 then the fourth conduit 54 before opening into the chambers 40, 40a, 40b and allowing them to fill and push the pistons 30, 30a, 30b out of the chambers 40, 40a, 40b in the directions DI and D2.
[0087] A plurality of arms 20, 20a, 20b are attached to the ends of the pistons 30, 30a, 30b and are configured to exert a stress on the wall 301 of the borehole 300.
[0088] As illustrated in [Fig.2], the probe 100 can comprise two arms 20, a first arm 20a and a second arm 20b. The first arm 20a is fixed to the end of the first pistons 30a and can thus extend along the first direction D1, while the second arm 20b is fixed to the end of the second pistons 30b and can thus extend along the second direction D2.
[0089] Alternatively, several first arms 20a can be fixed to the ends of the first pistons 30a so as to extend along the first direction D1. Similarly, several second arms 20b can be fixed to the ends of the second pistons 30b so as to extend along the second direction D2. An arm 20, 20a, 20b can, for example, cooperate with between 1 and 10 pistons 30, 30a, 30b.
[0090] According to another embodiment each piston 30 can cooperate with its own arm 20 so that there are as many arms 20 as piston 30.
[0091] The arms 20, 20a, 20b are metal plates of substantially parallelepiped shape, for example made of steel, with a length between 300 mm and 400 mm, a width between 3 cm and 7 cm, and a thickness between 1 mm and 5 mm. Advantageously, the shape of the arms 20, 20a, 20b is adapted to follow the shape of the cylindrical body 10. Thus, for example, if the cylindrical body 10 has a circular cross-section, the arms 20, 20a, 20b have a convex shape to adapt to the curvature of the cylindrical body 10.
[0092] The arms 20, 20a, 20b are for example fixed to the ends of the pistons 30, 30a, 30b by means of bores 21 machined to bear against the head of the threaded element 35 which emerges from the body 33 of the pistons 30, 30a, 30b.
[0093] As illustrated in [Fig. 1], the cylindrical body 10 is preferably covered by a membrane 60 surrounding the cylindrical body 10 and the arms 20, 20a, 20b. The membrane 60 comprises a sheath 61, made of an elastic and deformable material such as rubber, configured to deform during the movements of the arms 20, 20a, 20b. The sheath 61 has a thickness of between 1 and 5 mm, preferably 3 mm. The membrane 60 also comprises sealing elements 62-66 for closing the membrane 60 around the cylindrical body and thus ensuring that no external element disturbs or blocks the movement of the cylinders. These sealing elements 62-65 are, for example, seals such as O-rings 64, 65 and / or tapered rings 62, 63.The conical rings 62, 63 are held by nuts 56 of the cylindrical body 10, which are movable on a thread 55 of the cylindrical body 10 in order to adjust the position and tightening of the nuts 56. Finally, a protective shoe 66 protects the thread 55 of the cylindrical body 10 when it is inserted into the soil 500.
[0094] The invention thus makes it possible to obtain a probe which allows for the safe and precise measurement of various soil parameters.
Claims
1. Claims Probe (100) intended to be inserted into a borehole (300) formed in a soil (500), to measure at least one parameter of said soil (500), the probe comprising: - a cylindrical body (10) having an axis (A), the cylindrical body (10) comprising a plurality of chambers (40, 40a, 40b) including at least one first chamber (40a) and at least one second chamber (40b); the at least one first chamber (40a) opening out of the cylindrical body (10) in a first direction (D1) perpendicular to the axis (A), and the at least one second chamber (40b) opening out of the cylindrical body (10) in a second direction (D2) perpendicular to the axis (A), distinct from the first direction (D1); - a plurality of pistons (30, 30a, 30b) including at least one first piston (30a) contained in the at least one first chamber (40a) and at least one second piston (30b) contained in the at least one second chamber (40b); - a fluid supply circuit (51-54) configured to supply the chambers (40, 40a, 40b) with pressurized fluid so as to move each piston (30, 30a, 30b) between a retracted position in which the piston (30, 30a, 30b) is retracted into the chamber (40, 40a, 40b) and a deployed position, in which at least one end of the piston (30, 30a, 30b) protrudes from the chamber (40, 40a, 40b); the at least one first piston (30a) being movable in the first direction (D1) and the at least one second piston (30b) being movable in the second direction (D2); - a plurality of arms (20, 20a, 20b) including at least one first arm (20a) and at least one second arm (20b), the arms (20, 20a, 20b) being configured to exert a force on a wall (301) of the borehole (300), the at least one first arm (20a) being mounted at the end of the at least one first piston (30a) so as to be movable in the first direction (D1), and the at least one second arm (20b) being mounted at the end of the at least one second piston (30b) so as to be movable in the second direction (D2), characterized in that the chambers (40, 40a, 40b) are contiguous two by two according to the axis (A), the chambers (40, 40a, 40b) having a bottom (41) and at least one side wall (42), two contiguous chambers (40, 40a, 40b) sharing at least a portion of their side wall (42), two contiguous chambers (40, 40a, 40b) opening respectively in the first direction (D1) and the second direction (D2), the first direction (D1) being opposite the second direction (D2), the chambers (40, 40a, 40b) having a height extending over an entire width of the cylindrical body (10).
2. A probe according to claim 1, wherein the chambers (40, 40a, 40b) are aligned along the axis (A).
3. Probe according to one of claims 1 or 2, in which the probe (100) further comprises a membrane (60) surrounding the cylindrical body (10) and the arms (20, 20a, 20b), the membrane (60) being configured to deform during movements of the arms (20, 20a, 20b).
4. Probe according to one of claims 1 to 3, in which each piston (30, 30a, 30b) comprises a fixing means and each arm (20, 20a, 20b) comprises on an internal face at least one bore (21), each bore (21) being configured to cooperate with a fixing means of one of the pistons (30, 30a, 30b), so as to fix the arm (20, 20a, 20b) on said piston (30, 30a, 30b).
5. A probe according to one of claims 1 to 4, wherein the arms (20, 20a, 20b) are configured to be deployed uniformly from the cylindrical body (10).
6. Pressure meter apparatus comprising: - a probe (100) according to one of claims 1 to 5, - a pressure-volume controller intended to be left on the surface, and - connection means between the probe (100) and the pressure-volume controller.
7. Method of implementing the probe according to one of claims 1 to 6, the method comprising the following steps: - inserting the probe (100) into a borehole (300) formed in the ground (500), and - supplying the chambers (40, 40a, 40b) with fluid to move the pistons (30, 30a, 30b) into the deployed position in order to exert a stress on the wall (301) of the borehole (300) via the arms (20, 20a, 20b).
8. The method of claim 7, wherein the method further comprises a step of measuring a soil parameter (500).