EP2998037A1 - Cleaning device for cleaning a base of a borehole and method for creating a foundation element - Google Patents

Abstract

The invention relates to a cleaning device (10) for cleaning a sole (6) of a borehole (2) in the ground and to a method for creating a bored pile in a borehole. The cleaning device has a pumping device (14) through which sedimented soil material in the region of the bottom of the borehole can be sucked off via a suction opening (16) and can be discharged from the borehole via a suction line (20). At least one rinsing nozzle (34) is provided, through which a rinsing jet can be generated, which emerges from the cleaning device and rinses sedimented soil material from the bottom of the borehole. A bored pile can then be produced in a well that has been cleaned in this way.

Description

The invention relates to a cleaning device for cleaning a sole of a borehole in the ground, having a pumping device through which sedimented soil material in the region of the bottom of the wellbore can be sucked out of the borehole and via a suction line, according to the preamble of claim 1.

The invention further relates to a method for creating a foundation element, in which a borehole is introduced in a soil, which is filled with a curable suspension, which cures to the foundation element, wherein before a hardening of the foundation element, a cleaning device is lowered to the bottom of the wellbore, through which sedimented soil material in the region of the sole is sucked off and removed via a suction opening, according to the preamble of claim 10.

In particular for the foundation of structures, bored piles are produced in the soil. Here, a borehole is first created in the soil, which is filled with a suspension during drilling or only after completion of the drilling. Optionally, this suspension can be hardened by addition of binders or exchange with a curable medium downhole to the bored pile.

The load capacity of a bored pile is significantly influenced by the boundary layer between the bored pile and the adjacent soil. It is known that loose soil material, which sediments when creating the borehole to the bottom of the wellbore, negatively affected the footprint and thus the sustainability of the bored pile.

To remove such loose soil from the bottom of the well, it is known to scrape a submersible pump as a cleaning device after completion of the well into the well filled with drilling, with which the loose soil is sucked from the sole and removed from the well via a suction line.

In such a cleaning device, it may happen that as the distance from the suction opening loose soil material remains on the bottom hole. Thus, no comprehensive cleaning of the bottom hole is effected with such a cleaning device.

Furthermore, it is known to remove loose soil material, for example, by a box drill mechanically from the bottom hole. However, in this mechanical excavation process, a certain amount of loose soil material may remain at the bottom of the wellbore.

From the EP 1 491 716 A2 a drilling tool with a pumping device is known, with which removed soil material can be conveyed into a collecting container of the drilling tool.

An apparatus and method for filtering suspensions in boreholes is known from US Pat DE 28 07 917 A1 out. Filtered soil material is taken up in a collecting container within the filter device.

The invention has for its object to provide a cleaning device for cleaning a sole of a borehole and a method for creating a bored pile, with which loose soil material is removed from a bottom hole particularly reliable and efficient, and so a high-quality foundation element can be created economically.

The object is achieved on the one hand by a cleaning device with the features of claim 1. On the other hand, the object is achieved by a method having the features of claim 10. Preferred embodiments of the invention are specified in the respective dependent claims.

The cleaning device according to the invention is characterized in that at least one rinsing nozzle is provided, through which a rinsing jet can be generated, which exits the cleaning device and flushes sedimented soil from the bottom of the wellbore.

A basic idea of the invention is not simply to suck off sedimented soil material at the borehole bottom or to mechanically remove it. Rather, a purge steel or a plurality of purge jets is generated by the cleaning device, which rinse the sedimented soil material from the bottom hole and whirl up. The so stirred up into the liquid in the wellbore soil material can be easily sucked through the suction opening of the cleaning device and discharged from the wellbore. This flushing of the bottom hole allows a very clean interface between the wellbore and the solid, pending soil to be achieved. As a result, a foundation element with a defined footprint and with good and reliable load-bearing capacity can subsequently be created.

The foundation element may for example be an approximately cylindrical bored pile or an approximately cuboidal diaphragm wall segment. Accordingly, according to the invention, a borehole is not meant to be narrow in the sense of a cylindrical bore. Rather, the term "borehole" also includes any other forms of holes in the ground, in particular an elongated Frässchlitz.

In principle, one or more central rinsing nozzles can be provided on the cleaning device. A particularly good rinsing is achieved according to a development of the invention in that at least one rinsing arm is provided on which the at least one rinsing nozzle is arranged. The elongated flushing arm may extend laterally or radially away from the cleaning device. In this way, the rinsing arm can rinse particularly reliably of deposited soil material, in particular the corner region, at which the borehole bottom merges into the substantially vertical borehole wall. These corner regions are of particular importance for the stability and load-bearing capacity of a bored pile to be formed.

A further improvement of the rinsing results according to a variant embodiment of the invention in that a plurality of rinsing arms are provided which extend radially extend to a central axis. Along a rinsing arm, one or more rinsing nozzles can be rectified or arranged with different jet angles.

A further improvement in the bottom hole cleaning results according to an embodiment of the invention in that the at least one rinsing arm is arranged on a rotor which is rotatably mounted and driven about a central axis. The one or more rinse arms on the rotor can thus move over a circular disc-shaped bottom hole and rinse off with a particularly high reliability deposited, loose soil material.

According to a further preferred embodiment it is provided that at least one rinsing nozzle is arranged on at least one roller body, which is rotatably mounted about an axis of rotation. The axis of rotation may preferably be arranged approximately horizontally. This allows holes with an elongated or angular layout to be cleaned. Instead of an elongated roller body, a plurality of disc-shaped roller bodies may be mounted along the axis of rotation. In this case, the rinsing nozzles can be directed so that the rinsing jets emerge radially or tangentially.

In principle, it is possible that the rotational movement of the rotor or the roller body is generated by a separate rotary motor, such as an electric motor or a hydraulic motor. A structurally particularly robust and simple solution is achieved according to a development of the invention in that a rotational movement of the rotor or of the roller body is produced by a purging jet. At about vertical axis of rotation at least one purge jet is not aligned vertically alone, but in a circumferential direction. In particular, a rinsing jet or several rinsing jets can be arranged in the horizontal direction in the circumferential direction, that is to say approximately at right angles to a radial rinsing arm. Due to the recoil principle, the rotor or the roller body can thus be set into rotary motion by the exiting purge jet. A separate rotary motor with a corresponding power supply can thus be dispensed with.

Preferably, the pumping device or a separate pumping unit is also used to generate the spray jet. A preferred embodiment of the invention is in particular that the pumping device sedimented soil material sucked together with liquid in the borehole, wherein a portion of the sucked liquid is discharged via a branch line to the at least one rinsing nozzle for forming the rinsing jet. The pumping device in the cleaning device thus does not generate a suction flow alone, with which deposited soil material is sucked together with liquid and discharged from the borehole via a corresponding suction line. Rather, according to the invention in this embodiment, the central pumping device is also used to produce the or the Spülstahlen. For this purpose, a portion of the upwardly directed liquid flow is branched off from the suction line via a branch line or a bypass line and returned to the at least one rinsing nozzle. The control can be effected for example by a slide, by which a distribution of the liquid flow is adjustable. In the region of the branch, a separating or filtering device can be present, by means of which it is prevented that coarse soil material enters the branch line and thus could block the rinsing nozzles.

According to a further embodiment of the invention, it is advantageous that a spacer ring is provided, which surrounds the rotor or the roller body. The cleaning device is arranged approximately centrally in the borehole above the sole. In a rotor this is rotatably mounted about a central axis on the cleaning device. In order to avoid damaging the rotor with the rinsing nozzles by contact with the borehole wall, a drum-shaped spacer ring is provided, which is attached via connecting struts to the housing of the cleaning device. The spacer ring has a larger diameter than the rotor and is arranged concentrically to this. In this way, unwanted collisions of the rotor with the upcoming soil material can be prevented. For other types of wellbore, the spacer ring can also be designed angular.

According to one embodiment of the invention, it is further expedient that the pumping device is arranged in a housing which can be lowered to the bottom of the wellbore. On the housing, a connection device for attachment to a drill string or a hoist rope is provided. As a result, the housing can be lowered to the bottom of the wellbore. Alternatively, the pumping device of the cleaning device can also be arranged outside the borehole, wherein the pumping device is then connected via a suction line to the housing and the suction opening.

Furthermore, it is advantageous according to the invention that the at least one rinsing nozzle and / or the at least one rinsing arm are adjustable. So the rinsing nozzles can be changed in their rinsing direction. The rinse arms can be radially telescoped, so that the cleaning device can be adapted to different borehole diameter.

The object stated in the introduction is achieved with regard to the method in that a cleaning device with at least one rinsing nozzle is used, through which a rinsing jet is generated, through which sedimented soil material is rinsed by the bottom of the borehole.

To carry out this method, it is possible in particular to use a cleaning device as has been described above. With the method according to the invention, a foundation element with particularly good bearing capacity can be created due to the reliable cleaning of a bottom hole of sedimented loose soil material. Since in a bored pile, the footprint contributes a significant portion of the load capacity of a bored pile, bored piles can be created with increased carrying capacity by the inventive method without much economic effort.

A preferred embodiment of the invention is that the at least one rinsing nozzle is moved over the sole of the borehole, in particular driven in rotation. In this way, a reliable flushing and cleaning of the bottom hole can be achieved with a single flush nozzle or with a relatively small number of flushing nozzles.

A particularly economical method implementation results according to a development of the invention in that a movement of the at least one rinsing nozzle is effected via a recoil of the rinsing jet. There is thus no high expenditure on equipment in carrying out the process necessary.

Fig. 1:

eine schematische Querschnittsansicht einer erfindungsgemäßen Reinigungsvorrichtung in einem Bohrloch;

Fig. 2:

eine perspektivische Ansicht der Reinigungsvorrichtung von Fig. 1;

Fig. 3:

eine perspektivische Ansicht von unten auf die erfindungsgemäße Reinigungsvorrichtung der Figuren 1 und 2;

Fig. 4:

eine Seitenansicht der Reinigungsvorrichtung von Figuren 1 bis 3;

Fig. 5:

eine herkömmliche Reinigungsvorrichtung nach dem Stand der Technik in einem Bohrloch in Seitenansicht; und

Fig. 6:

eine perspektivische Draufsicht der Reinigungsvorrichtung von Fig. 5 von oben.

The invention will be further explained with reference to a preferred embodiment, which is shown schematically in the accompanying drawings. In the drawings show:

Fig. 1:

a schematic cross-sectional view of a cleaning device according to the invention in a borehole;

Fig. 2:

a perspective view of the cleaning device of Fig. 1 ;

3:

a perspective view from below of the cleaning device according to the invention of Figures 1 and 2 ;

4:

a side view of the cleaning device of FIGS. 1 to 3 ;

Fig. 5:

a conventional cleaning device according to the prior art in a borehole in side view; and

Fig. 6:

a perspective top view of the cleaning device of Fig. 5 from above.

In the FIGS. 5 and 6 a cleaning device 110 is shown in the generic state of the art. The cleaning device 110 is essentially a submersible pump, which is sunk into a borehole 2, which is filled with a liquid support suspension. When creating the borehole 2, soil material falls off in particular from the wall 4 and forms a layer of sedimented soil material 8 on a bottom 6 of the borehole 2. By lowering the cleaning device 110 into the region of the bottom 6, the sedimented soil material 8 is sucked off and, as schematically is shown with arrows, conveyed away via a suction 120 from the borehole 2.

With increasing distance from the cleaning device 110, the suction power decreases, so that in particular in edge or corner regions of the sole 6 of the wellbore 2 sedimented soil material 8 can remain to some extent. This unspooled sedimented soil material 8 affects the footprint of a foundation element to be formed in the wellbore 2 and thus its carrying capacity.

An improved cleaning of the bottom 6 of the wellbore 2 of sedimented soil material 8 is achieved by a cleaning device 10 according to the invention, as exemplified in the FIGS. 1 to 4 is shown for a cylindrical borehole 2 and explained below.

The cleaning device 10 according to the invention has a central, drum-shaped housing 12, in which a pumping device 14 is arranged. Via a suction opening 16 on the underside of the housing 12, as in the preceding prior art, suspension in the borehole 2 together with sedimented soil material is sucked in by the bottom 6 of the borehole 2 and via an only partially shown suction line 20 upwards, in particular outside the borehole 2, discharged. At the top of the housing 12, a suspension device 18 is provided, with which the cleaning device 10 is suspended on a rope and lowered into the borehole 2 created by drilling. In addition, a power supply, in particular electrical energy or hydraulic energy, can be supplied via the suspension device 18 via a supply line (not shown).

For improved cleaning of the sole 6 of the borehole 2, a rotor 30 with three uniformly distributed and radially directed flushing arms 32 is formed below the suction opening 16, each having a plurality of flushing nozzles 34. The rotor 30 is rotatably mounted on the housing 12 via a connecting device, not shown.

About a branch line 22, a portion of the liquid stream is branched off in the suction line 20 and guided down to a hub 31 of the rotor 30. The distribution of the current is adjustable via a slide 24 in the suction line 20. From the central hub 31, the branched liquid is passed through the hollow rinsing arms 32 to the rinsing nozzles 34. By a corresponding adjustment of slide 24 and pumping device 14, the branched liquid exits the rinsing nozzles 34 under pressure and forms rinsing jets 35. In this case, a substantial part of the rinsing nozzles 34 is arranged so that the rinsing jets directed to the sole 6 with the sedimented soil material 8 are to rinse the sole 6 of the sedimented soil material 8. The so rinsed and whirled up soil material 8 is sucked through the suction opening in the housing 12 and discharged via the suction line 20 from the borehole 2.

On the rotor 30, two flushing nozzles 34 are arranged at the outer free ends of the flushing arms 32 so that they are directed in the circumferential direction. By means of these circumferentially directed flushing nozzles 34 pointing in the circumferential direction rinsing jets 35 are generated, as shown schematically in FIG Fig. 3 is shown. By the recoil principle, the rotor 30 is thus counter-clockwise in a rotational movement, as indicated by the arrow in Fig. 2 is shown.

To protect the rotor 30, a cylindrical spacer ring 40 is attached via retaining struts 42 to the housing 12 so as to protectively surround the rotor 30. The wall of the spacer ring 40 is formed by a sheet in which a plurality of through holes is introduced. The outer diameter of the annular spacer ring 40 is slightly smaller than the bore diameter of the cylindrical bore. 2

Claims (13)

Cleaning device for cleaning a sole (6) of a borehole (2) in the ground, with a pumping device (14), through which sedimented soil material in the region of the sole (6) of the borehole (2) via a suction opening (16) sucked and via a suction line (20) is dischargeable from the wellbore (2),
characterized,
in that at least one rinsing nozzle (34) is provided, through which a rinsing jet (35) can be generated which emerges from the cleaning device (10) and rinses sedimented soil material (8) from the bottom (6) of the borehole (2). Cleaning device according to claim 1,
characterized,
in that at least one rinsing arm (32) is provided on which the at least one rinsing nozzle (34) is arranged. Cleaning device according to claim 2,
characterized,
in that a plurality of rinse arms (32) are provided, which extend radially to a center axis. Cleaning device according to claim 2 or 3,
characterized,
in that the at least one flushing arm (32) is arranged on a rotor (30) which is mounted and driven to rotate about a center axis. Cleaning device according to one of claims 1 to 4,
characterized,
in that at least one rinsing nozzle (34) is arranged on at least one roller body which is rotatably mounted and driven about an axis of rotation. Cleaning device according to claim 4 or 5,
characterized,
that a rotational movement of the rotor (30) or the roll body by a flushing jet (35) can be generated. Cleaning device according to one of claims 1 to 6,
characterized,
in that the pumping device (14) sucks sedimented soil material (8) together with liquid in the borehole (2), wherein a portion of the aspirated liquid is discharged via a branch line (22) to the at least one rinsing nozzle (34) for forming the rinsing jet (35) , Cleaning device according to one of claims 4 to 7,
characterized,
that a spacer ring (40) is provided which the rotor (30) or the roll body surrounds. Cleaning device according to one of claims 1 to 8,
characterized,
that the pumping device (14) is arranged in a housing (12) which can be lowered to the sole (6) of the borehole (2). Cleaning device according to one of claims 1 to 9,
characterized,
the at least one flushing nozzle (34) and / or the at least one spray arm (32) are adjustable. Method for creating a foundation element, in which a borehole (2) is introduced in a soil, which is filled with a curable suspension, which cures to the foundation element, wherein before cleaning of the foundation element a cleaning device (10) is lowered to the bottom (6) of the borehole (2) through which sedimented soil material (8) in the region of the sole (2) is sucked off and removed via a suction opening (16),
characterized,
in that a cleaning device (10) is used with at least one rinsing nozzle (34) with which a rinsing jet (35) is produced, through which sedimented soil material (8) is rinsed by the sole (6) of the borehole (2). Method according to claim 11,
characterized,
the at least one flushing nozzle (34) is rotationally driven in particular via the sole (6) of the borehole (2) moves. Method according to claim 12,
characterized,
that a movement of the at least one rinsing nozzle (34) is effected via a recoil of the rinsing jet (35).

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