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inner tube and an outlet opening at a lower end region of the drill screw into the borehole when the drill screw is withdrawn from the borehole, a pressure sensor for detecting the pressure of the curable mass during feeding and a control device for controlling a withdrawal movement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 with a drilling rig with a drill drive, by which a drill auger with a hollow inner tube can be driven in a rotating manner, wherein a borehole can be created in the ground by the drill auger 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inner tube and an outlet opening at a lower end region of the drill auger into the borehole when the drill auger is withdrawn from the borehole, a pressure sensor for detecting the pressure of the curable mass during feeding and a control device for controlling a withdrawal movement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 auger when feeding the curable mass, according to the preamble of claim 1. A device of the same type is known, for example, from US 6,116,819 A.

[0002] The invention further relates to a method for forming a soil element in the ground, wherein a drill auger with a hollow inner tube is driven by a drilling drive of a drilling rig, wherein a borehole is created in the ground by the drill auger while removing soil material, a curable mass for forming the soil element is fed into the borehole through the hollow inner tube and an outlet opening at a lower end region of the drill auger by means of a feeding device when the drill auger is withdrawn from the borehole, the pressure of the curable mass is detected by means of a pressure sensor during feeding, and a withdrawal movement of the drill auger is controlled by means of a control device when feeding the curable mass, 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, which serves, for example, to improve the soil.

[0004] A generic device and a generic 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 to convey the removed soil material upwards. With this known method, uncased drilling can be carried out, since the borehole wall is supported during drilling by the auger's auger, which is filled with soil material.

[0005] After reaching a final depth, the auger with its filled flight coils is retracted axially. Simultaneously, concrete is injected through a hollow inner tube of the auger into the space below it to form the base element. EP 0 842 329 B1 describes how a computer can be used to control the auger's retraction speed based on the concrete flow rate. This ensures that the concrete is supplied as needed, so that the area of ​​the borehole currently exposed by the auger is immediately filled with concrete. As the auger retracts, the borehole wall is directly supported by the injected concrete.

[0006] In this known method, the control system determines a volume to be filled by an inflow of concrete, depending on the geometric characteristics of the auger, in particular the auger diameter and the resulting borehole diameter, and the auger's retraction speed. To detect the concrete flow, the known drilling device incorporates a flow meter on the feed hose to the auger to measure the concrete flow, and a pressure sensor above the drill drive, which drives the auger below, to measure the concrete pressure.

[0007] The established method generally yields good results under stable soil conditions. However, problems can arise if the borehole passes through one or more layers of permeable soil or soil containing cavities. In such soil conditions, a significantly higher amount of curing compound may be required to fill the borehole, as a considerable portion of the compound flows out of the borehole area and into adjacent soil layers. This can lead to an improperly constructed soil element with defects, thus impairing its load-bearing capacity. This may necessitate the installation of additional foundation piles or the costly removal and reconstruction of a defective soil element.

[0008] In practice, to avoid defects when constructing a foundation pile, a certain excess of concrete is added. This can lead to undesirable soil swelling and excessive concrete consumption, although the risk of defects is not completely eliminated.

[0009] The invention is based on the Task The aim is to specify 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 problem is solved, firstly, by the device with the features of claim 1 and, secondly, by a method with 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 soil 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 curable mass, that the control device has a storage unit in which at least one setpoint for a pressure as the target pressure in the area of ​​the outlet opening for the curable mass during feeding is stored, 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 feeding of curable mass by the feeding device in such a way that, during retraction, a pressure of the curable mass in the area of ​​the pressure sensor corresponds to the predetermined target pressure.

[0012] A fundamental aspect of the invention is that the pressure of the concrete mass at the lower end of the auger is crucial for determining the actual amount of curing material required to form the floor element. This pressure is measured directly at the lower end of the auger and indicates whether the borehole is actually filled or whether curing material is flowing into any existing void in the ground. In the latter case, the pressure is significantly lower than the target pressure, which is particularly relevant when constructing the floor element under stable geological conditions. This actual pressure at the borehole cannot be measured by a pressure sensor located far away, such as on the drill drive.With typical auger lengths between 15m and 25m, due to wall friction effects of the curable mass in the correspondingly long inner tubes of the augers, a pressure measured at the upper end of the auger does not allow for a sufficient conclusion to be drawn about the pressure at the lower end of the auger.

[0013] According to a further aspect of the invention, the pressure sensor is connected to the control unit, which is configured to control the retraction movement of the auger and / or the feeding of curable material by the feed device in such a way that the pressure measured by the pressure sensor corresponds to a predetermined setpoint pressure stored in the control unit. For the purposes of the invention, "corresponding to a setpoint pressure" is to be understood as a setpoint pressure range that includes a certain pressure tolerance both above and below this range.

[0014] For example, if concrete flows into a cavity in an adjacent soil layer during the construction of a floor element, the device according to the invention can reduce or, in extreme cases, stop the retraction movement of the auger and / or increase the supply of curing material through the feed device until the pressure sensor measures a pressure corresponding to the predetermined target pressure. The control system can then increase the retraction movement again or reduce the supply of curing material through the feed device. In particular, the retraction movement of the auger and / or the supply of curing material are controlled based on the pressure of the curing material.

[0015] According to the invention, a high-quality, defect-free floor element can be achieved through the appropriate use of a curing compound, in particular a concrete compound. The curing compound 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 the ground, especially 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 consists in the at least one setpoint being formed by a setpoint curve in which the setpoint pressure depends on the depth position of the outlet opening. In particular, the setpoint pressure achieved during the creation of the base element can increase with increasing depth, since increased pressure may be exerted on the concrete mass from above. When the auger is withdrawn upwards from a final depth of the base element, the setpoint pressure to be achieved can thus gradually decrease. This applies particularly when the pressure sensor is arranged in the area of ​​the liner tube at the lower end of the auger.

[0018] For a preferred control system, a further development of the invention provides that the control unit detects the 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 control unit can determine and set the current target value for the pressure at the given depth using a stored control program. A depth-dependent target value is advantageous for supplying the curing material according to demand.

[0019] Another advantageous embodiment of the invention lies in the fact that the predetermined target pressure depends on the type of soil layer in which the auger's outlet opening is located. If the outlet opening is located in a soft soil layer, it may be advantageous to reduce the target pressure in this area to avoid or limit the unnecessary displacement of curable material into the soft soil layer. The control system can store information about the soil geology, and in particular the soil layer structure of the soil in which the soil element is created. The soil geology, especially a soil profile, is typically determined in advance by a soil survey at construction sites where foundation piles are required. These values ​​can be entered from a central control unit via remote data transmission or directly by a machine operator.The control unit can determine a target value curve for the target pressure that depends on the ground profile.

[0020] A particularly preferred embodiment of the invention consists in the control device being designed to detect soil layers, especially their thicknesses and types, during the drilling process. In a first step, the auger is used to create the borehole for the soil element. During drilling, torque, feed force, rotational speed, and / or feed rate can be detected. Based on these detected parameters, conclusions can be drawn about the soil structure and the strength of individual soil layers.

[0021] Based on comparative data, which can be stored in the control unit's data memory, a soil profile with its soil layers can be determined for each specific borehole and stored in the control unit. This can preferably be done in combination with a pre-stored soil profile, allowing for a particularly precise determination of the layer boundaries for the specific borehole. This soil structure, determined during borehole creation, can then be directly incorporated into the second process step of creating the soil element by introducing the curable material at an adjusted target pressure.

[0022] According to a further embodiment of the invention, it is advantageous that the control unit has 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 recorded during drilling and assigning it to specific soil layers. This allows a specific soil profile with the individual soil layers, their layer thicknesses, and type or composition to be determined with particular reliability for each borehole.

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

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

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

[0026] A preferred embodiment of the invention consists in the control device controlling the retraction movement of the auger and / or the supply of curable material through the feed device depending on the depth position of the outlet opening. This allows for consideration of a suspension pressure that changes with depth, thus enabling a particularly demand-oriented supply of the curable material.

[0027] According to a further variant of the process, it is preferred that the control device regulates the retraction movement of the auger and / or the supply of curable material by the feed device depending on the type of soil layer. A setpoint can be specified not only for a depth but also for the type of soil layer present in the area of ​​the discharge opening. Particularly in the case of a soft soil layer, a reduction of the setpoint for the pressure can be advantageous in order to counteract excessive displacement of curable material into the soft soil layer. This results in a particularly economical use of the curable material.

[0028] The soil layers can be stored in the control unit, particularly as soil profile data. A particularly preferred embodiment of the invention consists in the control unit recording soil layers, especially their thicknesses and types, during the drilling process. Even during drilling, the control unit can record certain operating parameters, in particular the torque and feed force at the drill drive, as well as the rotational speed and feed rate of the auger. The control unit is equipped with a corresponding program and a database of comparative data, enabling the creation of a soil profile across the drilling depth based on the recorded operating parameters. This can be used to determine a target value profile for the subsequent process step of introducing the curing compound.

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

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

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

[0032] The drilling rig 12 can be equipped with a mast 16 via a linkage mechanism 18, which is preferably oriented vertically 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 by means of 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. An additional winch 26 can also be arranged for support.

[0033] Below the drill drive 20, a drill auger 30 is mounted, which can be rotated by the drill drive 20. The drill auger 30 has a central hollow inner tube 32, along the outside of which a helix 34 is arranged. The drill auger 30 can also be described as a so-called continuous auger.

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

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

[0036] Furthermore, a pressure sensor 50 is arranged at the lower end of the auger 30, particularly near the outlet opening 38, which is designed to detect the pressure of the curable mass 9 in this area. The pressure sensor 50 is connected via a line (not shown) to a control unit 45, which in the illustrated embodiment is arranged on the drilling rig 12. The control unit 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 auger 30 and / or a supply of curable mass 9 by the supply device 40, which may include a peristaltic pump, in such a way that during retraction the actual pressure of the curable mass 9 in the area of ​​the pressure sensor 50 corresponds to a predetermined target pressure.

[0038] A first method description for creating a floor element in the ground 5 with the previously described device 10 according to a method according to the invention is in Fig. 2 clarifies. According to the representation of Fig. 2 The auger 30, with its inner tube 32 and auger helix 34, has already been drilled into the soil 5 to a final depth, creating a borehole 8. The removal device 36 at the lower end of the auger 30 removes material from the soil 5, which can then be conveyed upwards by the auger 30, allowing the removed soil material 6 to accumulate on the surface of the soil 5.

[0039] Once the final depth is reached, the curable mass 9 can now flow through the hollow inner tube 32, through the auger 30, to the lower outlet opening 38 and fill the bore 8 to form the base element, as illustrated in Fig. 3 is shown.

[0040] The device 10 retracts the auger 30 from the bore 8 in a controlled manner, while simultaneously curable mass 9 flows into the bore 8 from the outlet opening 38. The method according to the invention controls the retraction movement of the auger 30 and / or the supply of the curable mass 9 based on the measured pressure at the lower region of the auger 30, such that the curable mass 9 fills the cavity created in the bore 8 as required when the auger 30 is retracted.

Claims

1. Device for forming a ground element in the ground (5), comprising - a drilling implement (12) comprising a drill drive (20), by means of which an auger (30) comprising a hollow stem (32) can be rotatably driven, wherein a borehole can be made in the ground (5) by the auger (30) by removing ground material (6), - a supply apparatus (40) for supplying a curable mass (9) through the hollow stem (32) and an outlet opening (38) on a lower end region of the auger (30) into the borehole while withdrawing the auger (30) from the borehole (8), - a pressure sensor (50) for detecting the pressure of the curable mass (9) while it is being supplied, and - a controller (45) for controlling a withdrawal movement of the auger (30) while supplying the curable mass (9), characterised in that - the pressure sensor (50) is arranged on the lower end region of the auger (30), in particular on the outlet opening (38) for the curable mass (9), - in that the controller (45) comprises a memory unit, in which at least one target value for a pressure is stored as a target pressure in the region of the outlet opening (38) for the curable mass (9) while it is being supplied, and - in that the controller (45) is connected to the pressure sensor (50) and is designed to control the withdrawal movement of the auger (30) and / or a supply of curable mass (9) by the supply apparatus (40) such that, during the withdrawal, a pressure of the curable mass (9) in the region of the pressure sensor (50) corresponds to the predetermined target pressure.

2. Device according to claim 1, characterised in that the at least one target value is formed by a target value progression in which the target pressure is dependent on a depth position of the outlet opening (38).

3. Device according to claim 1 or 2, characterised in that a depth position of the outlet opening (38) is detected by the controller (45).

4. Device according to any of claims 1 to 3, characterised in that the predetermined target pressure is dependent on the type of ground layer in which the outlet opening (38) of the auger (30) is located.

5. Device according to any of claims 1 to 4, characterised in that the type of ground layer in which the outlet opening (38) is currently located can be detected by the controller (45).

6. Device according to any of claims 1 to 5, characterised in that the controller (45) is designed to detect ground layers, in particular their layer thicknesses and types, while the borehole (8) is being made in the ground (5).

7. Device according to any of claims 1 to 6, characterised in that the controller (45) comprises a memory unit in which data relating to ground layers, in particular their layer thicknesses and types, are stored.

8. Device according to any of claims 1 to 7, characterised in that a carrier unit (14) comprising a mast (16) is provided, along which the drill drive (20) is movably mounted and guided to rotatably drive and move the auger (30).

9. Method for forming a ground element in the ground (5), in particular using a device (10) according to any of claims 1 to 8, wherein - an auger (30) comprising a hollow stem (32) is rotatably driven by a drill drive (20) of a drilling implement (12), wherein a borehole (8) is made in the ground (5) by the auger (30) by removing ground material (6), - by means of a supply apparatus (40), a curable mass (9) for forming the ground element is supplied through the hollow stem (32) and an outlet opening (38) on a lower end region of the auger (30) into the borehole (8) while withdrawing the auger (30) from the borehole (8), - by means of a pressure sensor (50), the pressure of the curable mass (9) is detected while it is being supplied, and - by means of a controller (45), a withdrawal movement of the auger (30) is controlled while supplying the curable mass (9), characterised in that - the pressure sensor (50) is arranged on the lower end region of the auger (30), in particular on the outlet opening (38) for the curable mass (9), - in that the controller (45) comprises a memory unit, in which at least one target value for a pressure is stored as a target pressure in the region of the outlet opening (38) for the curable mass (9) while it is being supplied, and - in that the controller (45) is connected to the pressure sensor (50) and controls the withdrawal movement of the auger (30) and / or a supply of curable mass (9) by the supply apparatus (40) such that, during the withdrawal, a pressure of the curable mass (9) in the region of the pressure sensor (50) corresponds to the predetermined target pressure.

10. Method according to claim 9, characterised in that the controller (45) controls the withdrawal movement of the auger (30) and / or the supply of curable mass (9) by the supply apparatus (40) depending on a depth position of the outlet opening (38).

11. Method according to claim 9 or 10, characterised in that the controller (45) controls the withdrawal movement of the auger (30) and / or the supply of curable mass (9) by the supply apparatus (40) depending on the type of ground layer.

12. Method according to any of claims 9 to 11, characterised in that the controller (45) detects ground layers, in particular their layer thicknesses and types, while the borehole (8) is being made in the ground (5).

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