Device and method for forming a floor element

Abstract

The invention relates to a device and a method for forming a soil element in the ground with a drilling device with a drill drive, by which a drill screw with a hollow inner tube can be driven in a rotating manner, wherein a borehole in the ground can be created by the drill screw while removing soil material, a feeding device for feeding a curable mass through the hollow inner tube and an outlet opening at a lower end region of the drill screw into the borehole when the drill screw is withdrawn from the borehole, a pressure sensor for detecting the pressure of the curable mass during feeding and a control device for controlling a withdrawal movement of the drill screw when feeding the curable mass.According to the invention, the pressure sensor is arranged at the lower end region of the auger, in particular at the outlet opening for the curable mass, the control unit has a storage unit in which at least one setpoint for a pressure is stored as the target pressure in the area of ​​the outlet opening for the curable mass during feeding, and the control unit is connected to the pressure sensor and is designed to control the retraction movement of the auger and / or the feeding of curable mass by the feeding device in such a way that, during retraction, the pressure of the curable mass in the area of ​​the pressure sensor corresponds to the predetermined target pressure.

Description

[0001] The invention relates to a device for forming a soil element in the ground, comprising a drilling device with a drilling drive, by means of which a drilling auger with a hollow core tube can be driven in rotation, wherein a bore in the ground can be created by the drilling auger while removing soil material, a feed device for feeding a hardenable mass through the hollow core tube and an outlet opening at a lower end region of the drilling auger into the bore when the drilling auger is withdrawn from the bore, a pressure sensor for detecting the pressure of the hardenable mass during feeding, and a control device for controlling a retraction movement of the drilling auger when feeding the hardenable mass, according to the preamble of claim 1.

[0002] The invention further relates to a method for forming a soil element in the ground, wherein a drilling auger with a hollow core tube is driven in rotation by the drill drive of a drilling device, wherein a bore is created in the ground by the drilling auger while removing soil material, a hardenable mass for forming the soil element is fed into the bore through the hollow core tube and an outlet opening at a lower end region of the drilling auger by means of a feed device when the drilling auger is withdrawn from the bore, the pressure of the hardenable mass is detected by means of a pressure sensor during feeding, and a retraction movement of the drilling auger is controlled by means of a control device when the hardenable mass is fed, according to the preamble of claim 9.

[0003] Such a soil element can be, for example, a foundation pile, a retaining pile or a column that serves, for example, to improve the soil.

[0004] A generic device and method are disclosed in EP 0 842 329 B1. To create a soil element in the ground, a borehole is first created using an auger. The auger serves to remove the soil material and simultaneously transport the removed soil material upwards. This known method allows for uncased drilling, since the borehole wall is supported by the auger with the drill spirals filled with soil material during drilling.

[0005] After reaching a final depth, the auger is retracted axially with the filled screw flights, while simultaneously, concrete is introduced into the space below the auger through a hollow core tube of the auger to form the soil element. EP 0 842 329 B1 teaches the use of a computer to control the retraction speed of the auger depending on the concrete flow rate. This is intended to ensure that concrete mass is supplied as needed, so that the area of ​​the borehole currently exposed by the auger is immediately filled with concrete mass, and the borehole wall is directly supported by the introduced concrete mass as the auger is retracted.

[0006] In this known method, the control system determines a volume to be filled by an inflow of concrete mass, depending on the geometric conditions of the auger, in particular the auger diameter and the resulting borehole diameter, and the retraction speed of the auger. To measure the inflow of concrete, the known drilling device features a flow meter for measuring the concrete flow on the feed hose to the auger, and a pressure sensor for measuring the concrete pressure is arranged above the drill drive for driving the underlying auger.

[0007] This well-known method generally delivers good results under stable soil conditions. However, problems can arise if the borehole passes through one or more soil layers made of permeable soil material or containing cavities. In such soil conditions, filling a borehole may require significantly more hardening compound, as a significant portion of the hardening compound will flow out of the borehole area and penetrate into adjacent soil layers. This can result in a soil element being constructed incorrectly and possibly with defects, which impairs the load-bearing capacity of the soil element. This can lead to the need for additional foundation piles or the costly removal and replacement of a defective soil element.

[0008] In practice, a certain excess of concrete is added during the construction of a foundation pile to avoid voids. This can lead to undesirable swelling of the soil and excessive consumption of concrete, although the risk of voids cannot be completely eliminated.

[0009] The invention is based on the Task The aim is to provide a device and a method with which a soil element can be created in the ground in a particularly reliable and economical manner.

[0010] The object is achieved, on the one hand, by the device having the features of claim 1 and, on the other hand, by a method having the features of claim 9. Preferred embodiments of the invention are specified in the dependent claims.

[0011] The device according to the invention for forming a soil element in the ground is characterized in that the pressure sensor is arranged at the lower end region of the auger, in particular at the outlet opening for the hardenable mass, that the control device has a memory unit in which at least one setpoint value for a pressure is stored as the setpoint pressure in the region of the outlet opening for the hardenable mass during feeding, and that the control device is connected to the pressure sensor and is designed to control the retraction movement of the auger and / or a feed of hardenable mass by the feed device in such a way that, during retraction, a pressure of the hardenable mass in the region of the pressure sensor corresponds to the predetermined setpoint pressure.

[0012] A basic idea of ​​the invention is that the pressure of the concrete mass, specifically at the lower end of the auger, is decisive for determining the actual requirement for hardenable mass to form the soil element. The pressure of the hardenable mass is detected directly in the lower end of the auger and is a measure of whether the borehole area is actually filled or whether hardenable mass is flowing into a possibly existing cavity in the ground. In the latter case, the pressure is noticeably lower than a target pressure, as is particularly the case when creating the soil element under stable geological conditions. This actual pressure in the borehole area cannot be detected with a pressure sensor located far away, such as on the drill drive.For typical auger lengths between 15m and 25m, the pressure measured at the upper end of the auger does not allow sufficient conclusions to be drawn about the pressure at the lower end of the auger due to wall friction effects of the hardenable mass in the correspondingly long core tubes of the augers.

[0013] According to a further aspect of the invention, the pressure sensor is connected to the control device, which is designed to control the retraction movement of the auger and / or the supply of hardenable compound through the supply device such that the pressure measured by the pressure sensor corresponds to a predetermined target pressure stored in the control device. Within the meaning of the invention, the correspondence to a target pressure is to be understood as a target pressure range that includes a certain upper and lower pressure tolerance.

[0014] If, for example, concrete mass flows into a cavity in an adjacent soil layer during the construction of a soil element, the device according to the invention can be used to reduce the retraction movement of the auger or, in extreme cases, to stop it, and / or to increase the supply of hardenable mass through the feed device until the pressure sensor measures a pressure corresponding to the specified target pressure. The control system can then increase the retraction movement again or reduce the supply of hardenable mass through the feed device. In particular, the retraction movement of the auger and / or the supply of hardenable mass is controlled depending on the pressure of the hardenable mass.

[0015] Overall, the invention allows for the creation of a high-quality floor element without defects through the appropriate use of a hardenable mass, particularly a concrete mass. The hardenable mass is a suspension of liquid and solids, preferably a cement-based suspension.

[0016] A soil element within the meaning of the invention can, in particular, be a foundation pile, a retaining pile, or a column that contributes to improving a property of the soil or subsoil, in particular to improving its load-bearing capacity and / or stability. The soil element can, in particular, serve as a foundation element or other structural element in the soil and be designated as such.

[0017] A preferred embodiment of the invention is that the at least one target value is formed by a target value curve in which the target pressure depends on the depth position of the outlet opening. In particular, the target pressure achieved during construction of the soil element can increase with increasing depth, since increased pressure on the concrete mass can be exerted from above. As the auger is withdrawn upwards from a final depth of the soil element, the target pressure to be achieved can thus gradually decrease. This applies in particular if the pressure sensor is arranged in the region of the core tube at the lower end of the auger.

[0018] For a preferred control system, according to a further development of the invention, the control device detects a depth position of the outlet opening. This can be determined, for example, by detecting the position of the drill drive along the mast, since the length of the auger is a known, fixed value. Depending on the depth position of the outlet opening on the auger, the current setpoint for the pressure at the given depth can be determined and specified in the control device via a stored control program. A depth-dependent setpoint is advantageous for a demand-based supply of the hardenable mass.

[0019] A further advantageous embodiment of the invention is that the predetermined target pressure depends on the type of soil layer in which the outlet opening of the auger is located. If the outlet opening is located in the area of ​​a soft soil layer, it may be expedient to reduce the target pressure in this area in order to avoid or limit the unnecessary displacement of hardening mass into a soft soil layer. The geology of the soil and in particular the structure of the soil layers in which the soil element is created can be stored in the control system. The geology of the soil, in particular a soil profile, is usually determined in advance by a soil report on construction sites where foundation piles are required. These values ​​can be entered from a control center via remote data transmission or directly by a machine operator.The control device can determine a setpoint curve for the target pressure depending on the soil profile.

[0020] A particularly preferred embodiment of the invention is that the control device is configured to detect soil layers, particularly their layer thicknesses and types, during the drilling process. In a first step, the drill hole is created using the auger to create the soil element. During the drilling process, a torque, a feed force, a rotational speed, and / or a feed rate can be detected. Based on these detected parameters, conclusions can be drawn regarding the structure of the soil and the strength of individual soil layers.

[0021] Based on comparative data, which can be stored in a data storage device of the control unit, a soil profile with the soil layers can be determined for each specific borehole and saved in the control unit. This can preferably also be done in combination with a previously stored soil profile, whereby a particularly precise determination of the layer boundaries for the specific borehole can be determined. This soil structure, determined during the borehole creation process, can be directly taken into account in the second process step of creating the soil element by introducing the hardenable mass at an adjusted target pressure.

[0022] According to a further embodiment of the invention, it is advantageous for the control device to have a storage unit in which data on soil layers, in particular their layer thicknesses and types, are stored. Such a storage unit or database can be used in particular for evaluating the data acquired during drilling and assigning them to specific soil layers. This allows a specific soil profile with the individual soil layers, as well as their layer thicknesses and type or composition, to be determined particularly reliably for each borehole.

[0023] According to a further embodiment of the invention, it is preferred that a support unit is provided with a mast, along which the auger drive is movably mounted and guided for rotationally driving and moving the auger. The mast can, in particular, be a so-called leader with a linear guide for a guide carriage on which the auger drive is arranged. The auger drive below can be rotationally driven and moved axially, in particular vertically, by the auger drive. In particular, a feed movement and a retraction movement of the auger drive and thus of the auger can be controlled via the guide carriage and a corresponding travel drive.

[0024] The invention further comprises a method for forming a soil element in the ground, which is characterized in that the pressure sensor is arranged at the lower end region of the auger, in particular at the outlet opening for the hardenable mass, that the control device has a memory unit in which at least one setpoint value for a pressure is stored as the setpoint pressure in the region of the outlet opening for the hardenable mass during feeding, and that the control device is connected to the pressure sensor and controls the retraction movement of the auger and / or a feed of hardenable mass by the feed device in such a way that during retraction a pressure of the hardenable mass in the region of the pressure sensor corresponds to the predetermined setpoint pressure.

[0025] The method can be carried out, in particular, with the device described. The advantages described can be achieved.

[0026] A preferred embodiment of the invention is that the control device controls the retraction movement of the auger and / or the supply of hardenable mass through the supply device depending on the depth position of the outlet opening. This allows for a variation in suspension pressure over depth to be taken into account, allowing for a particularly needs-based supply of the hardenable mass.

[0027] According to a further method variant of the invention, it is preferred that the control device controls the retraction movement of the auger and / or the supply of hardenable mass through the supply device depending on the type of soil layer. A target value can be specified not only by a depth, but also by the type of soil layer present in the area of ​​the outlet opening. Particularly in the case of a soft soil layer, reducing the target pressure value can be useful in order to counteract excessive displacement of hardenable mass into the soft soil layer. This allows for particularly economical use of the hardenable mass.

[0028] The soil layers can be stored in the control device, in particular as data relating to a soil profile. According to a further development of the invention, a particularly preferred embodiment variant consists in the control device detecting soil layers, in particular their layer thicknesses and types, when the borehole is being drilled in the ground. Already when the borehole is being drilled, the control system can detect certain operating parameters, in particular a torque and a feed force on the drill drive as well as the rotational speed and feed rate set on the auger. The control device is designed with a corresponding program and a database for comparison data so that a soil profile can be created over the borehole depth based on the detected operating parameters. This can be taken into account to determine a target value curve in the subsequent method step of introducing the hardenable mass.

[0029] The recording and determination of a soil profile by the control device can also be used in combination and for comparison with the data already stored for a soil profile.

[0030] The invention is described below with reference to preferred embodiments, which are schematically illustrated in the drawings. In the drawings: Fig. 1 is a highly schematic side view of a device according to the invention; Fig. 2 is a schematic representation of a first method step in carrying out a method according to the invention; and Fig. 3 is a representation corresponding Fig. 2 to a further method step of the method according to the invention for creating a soil element in the ground.

[0031] According to Fig. 1A device 10 according to the invention is shown with a drilling rig 12, which is preferably designed with a mobile carrier unit 14. In the embodiment shown, the carrier unit 14 can have a crawler track with a superstructure rotatably mounted thereon.

[0032] The drilling rig 12 can be provided with a mast 16 via a linkage mechanism 18, which is preferably vertically oriented during operation. A linear guide 17 can be formed along the front of the mast 16, along which a drive carriage 22 with a drilling drive 20 can be guided. The drive carriage 22 with the drilling drive 20 can be moved along the mast 16 via an actuator 24. The actuator 24 can be designed as a winch device for an upper and lower cable for moving the drive carriage 22. In addition, a further winch 26 can be arranged to support the drive carriage.

[0033] Mounted beneath the drill drive 20 is a drilling auger 30, which can be driven in rotation via the drill drive 20. The drilling auger 30 has a central hollow core tube 32, along the outside of which a screw flight 34 is arranged. The drilling auger 30 can also be referred to as a so-called continuous auger.

[0034] At the lower end of the auger 30, an auger device 36 is arranged for removing soil material 6. The rotational movement of the auger 30 transports the removed soil material 6 upward through the auger flight 34.

[0035] At a lower end region, at least one outlet opening 38 is arranged on the auger 30. A feed device 40, which in the illustrated embodiment is arranged on the drilling device 12 but can also be arranged separately, can convey a hardenable mass 9 via a schematically indicated feed line 42 through the drill drive 20 and the core tube 32 to the outlet opening 38, wherein the hardenable mass 9 can exit from the outlet opening 38 and enter the region of a bore 8.

[0036] Furthermore, a pressure sensor 50 is arranged at the lower end of the auger 30, particularly near the outlet opening 38, and is designed to detect the pressure of the hardenable mass 9 in this area. The pressure sensor 50 is connected via a line (not shown) to a control device 45, which, in the illustrated embodiment, is arranged on the drilling rig 12. The control device 45 is also connected to the drilling drive 20 and the actuator 24 for moving the drive carriage 22 with the drilling drive 20.

[0037] The control device 45 is designed according to the invention to control a retraction movement of the drilling auger 30 and / or a supply of hardenable mass 9 by the supply device 40, which may comprise a peristaltic pump, such that during retraction the actual pressure of the hardenable mass 9 in the region of the pressure sensor 50 corresponds to a predetermined target pressure.

[0038] A first method for creating a soil element in the soil 5 with the previously described device 10 according to a method according to the invention is described in Fig. 2 According to the presentation by Fig. 2 The auger 30 with the core tube 32 and the auger flight 34 has already drilled into the ground 5 to a final depth, creating a borehole 8. Material from the ground 5 is removed by the removal device 36 at the lower end of the auger 30 and can be transported upwards by the auger 30, whereby removed soil material 6 can accumulate on the surface of the ground 5.

[0039] After reaching the final depth, hardenable mass 9 can now flow through the hollow core tube 32 through the auger 30 to the lower outlet opening 38 and fill the bore 8 to form the soil element, as clearly shown in Fig. 3 is shown.

[0040] The device 10 retracts the auger 30 from the bore 8 in a controlled manner, with hardenable mass 9 simultaneously flowing into the bore 8 from the outlet opening 38. With the method according to the invention, a retraction movement of the auger 30 and / or a supply of the hardenable mass 9 is controlled depending on the measured pressure at the lower region of the auger 30 such that hardenable mass 9 fills the cavity released in the bore 8 as needed when the auger 30 is retracted.

Claims

1. A device for forming a soil element in the ground (5) comprising - a drilling device (12) with a drilling drive (20), by means of which a drilling auger (30) with a hollow core tube (32) can be driven in rotation, wherein a bore in the ground (5) can be created by the drilling auger (30) while removing soil material (6), - a feed device (40) for feeding a hardenable mass (9) through the hollow core tube (32) and an outlet opening (38) at a lower end region of the drilling auger (30) into the bore when the drilling auger (30) is retracted from the bore (8), - a pressure sensor (50) for detecting the pressure of the hardenable mass (9) during feeding, and - a control device (45) for controlling a retraction movement of the drilling auger (30) when the hardenable mass (9) is fed, characterized by - that the pressure sensor (50) is arranged at the lower end region of the auger (30), in particular at the outlet opening (38) for the hardenable mass (9), - thatthe control device (45) has a memory unit in which at least one setpoint value for a pressure is stored as the setpoint pressure in the region of the outlet opening (38) for the hardenable mass (9) during feeding, and - that the control device (45) is connected to the pressure sensor (50) and is designed to control the retraction movement of the drilling auger (30) and / or a supply of hardenable mass (9) by the supply device (40) in such a way that, during retraction, a pressure of the hardenable mass (9) in the region of the pressure sensor (50) corresponds to the predetermined target pressure.

2. Device according to claim 1, characterized by that the at least one setpoint value is formed by a setpoint curve in which the setpoint pressure depends on a depth position of the outlet opening (38).

3. Device according to claim 1 or 2, characterized by thata depth position of the outlet opening (38) is detected by the control device (45).

4. Device according to one of claims 1 to 3, characterized by that the predetermined target pressure depends on the type of soil layer in which the outlet opening (38) of the auger (30) is located.

5. Device according to one of claims 1 to 4, characterized by that the type of soil layer in which the outlet opening (38) is currently located can be detected by the control device (45).

6. Device according to one of claims 1 to 5, characterized by that the control device (45) is designed to detect soil layers, in particular their layer thicknesses and types, when creating the borehole (8) in the ground (5).

7. Device according to one of claims 1 to 6, characterized by thatthe control device (45) has a storage unit in which data on soil layers, in particular their layer thicknesses and types, are stored.

8. Device according to one of claims 1 to 7, characterized by that a support unit (14) with a mast (16) is provided, along which the drilling drive (20) is movably mounted and guided for rotatingly driving and moving the drilling auger (30).

9. A method for forming a soil element in the ground (5), in particular with a device (10) according to one of claims 1 to 8, wherein - a drilling auger (30) with a hollow core tube (32) is driven in rotation by a drilling drive (20) of a drilling device (12), wherein a bore (8) is created in the ground (5) by the drilling auger (30) while removing soil material (6), - a hardenable mass (9) for forming the soil element is fed into the bore (8) through the hollow core tube (32) and an outlet opening (38) at a lower end region of the drilling auger (30) by means of a feed device (40) during retraction of the drilling auger (30) from the bore (8), - the pressure of the hardenable mass (9) during feeding is detected by means of a pressure sensor (50), and - a retraction movement of the drilling auger is controlled by means of a control device (45). (30) is controlled when the hardenable mass (9) is fed in, characterized by - thatthe pressure sensor (50) is arranged at the lower end region of the auger (30), in particular at the outlet opening (38) for the hardenable mass (9), - that the control device (45) has a memory unit in which at least one setpoint value for a pressure is stored as the setpoint pressure in the region of the outlet opening (38) for the hardenable mass (9) during feeding, and - that the control device (45) is connected to the pressure sensor (50) and controls the retraction movement of the drilling auger (30) and / or a supply of hardenable mass (9) by the supply device (40) in such a way that, during retraction, a pressure of the hardenable mass (9) in the region of the pressure sensor (50) corresponds to the predetermined target pressure.

10. Method according to claim 9, characterized by thatthe control device (45) controls the retraction movement of the drilling auger (30) and / or the supply of hardenable mass (9) by the supply device (40) depending on a depth position of the outlet opening (38).

11. Method according to claim 9 or 10, characterized by that the control device (45) controls the retraction movement of the auger (30) and / or the supply of hardenable mass (9) by the supply device (40) depending on the type of soil layer.

12. Method according to one of claims 9 to 11, characterized by that the control device (45) detects soil layers, in particular their layer thicknesses and types, when creating the borehole (8) in the ground (5).

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