METHOD AND DEVICE FOR PRODUCING A FOUNDATION ELEMENT IN THE GROUND FROM A SOIL MORTAR

Description

The invention relates to a method for creating a foundation element in the ground from a soil mortar, having a soil removal device with at least one rotationally driven processing tool, wherein the at least one processing tool is moved substantially vertically to the ground and soil material is removed by the at least one rotationally driven processing tool by forming a hole in the ground, a settable suspension is fed into the hole and the removed soil material remains at least partially in the hole and is mixed in situ by the at least one rotationally driven processing tool with the supplied suspension to form the soil mortar, wherein the soil mortar formed, after the at least one rotationally driven processing tool has been withdrawn from the hole, hardens to the foundation element in the soil, wherein at least the vertical movement of the at least one processing tool, the rotational movement of the at least one processing tool, the supply of suspension and at least one dimensioning of the foundation element represent method parameters, according to the preamble of claim 1.

The invention also relates to a device for creating a foundation element in the ground from a soil mortar, having a soil removal device with at least one rotationally driven processing tool, wherein the device is configured to move the at least one processing tool substantially vertically to the ground and to remove soil material by the at least one rotationally driven processing tool by forming a hole in the ground, to feed a settable suspension into the hole by means of a feeding device and to mix the fed suspension with removed soil material in situ in the hole by the at least one rotationally driven processing tool to form the soil mortar, wherein the formed soil mortar hardens in the soil after the withdrawal of the at least one rotationally driven processing tool from the hole to the foundation element, wherein at least the vertical movement of the at least one processing tool, the rotational movement of the at least one processing tool, the supply of suspension and at least one dimensioning of the foundation element represent method parameters, according to the preamble of claim 10.

Foundation elements made from a soil mortar are particularly economical and ecological. In contrast to a conventional mortar, in which a binder is mixed with a liquid and a supplied aggregate, in particular sand or gravel, the aggregate used in a soil mortar is the soil material produced directly during the soil processing. This can save costs for the extraction of the aggregate and the transport of the aggregate from outside to the construction site. By using the soil material produced directly during soil cultivation for the soil mortar, the disposal costs for removing excavated material from the construction site and for dumping removed soil material are also reduced accordingly.

However, creating a foundation element, in particular a foundation pile or a diaphragm or sealing wall, in the ground from a soil mortar requires increased effort when forming the foundation element, in order to ensure a sufficient quality of execution and to avoid unnecessary additional consumption of settable suspension. In addition, a machine operator is particularly challenged when creating a hole in the ground in which the foundation element is produced in situ from the soil mortar formed directly in the hole. In particular, sufficient rotational speeds of the processing tool and an adapted delivery rate for supplying the settable suspension must be ensured for a high quality finish of the foundation element from the soil mortar. These can vary depending on the local conditions and also on the respective working depth. This requires a high concentration and a great experience on the part of the machine operator.

EP 1 452 645 B2 describes a generic method for creating a diaphragm wall in the ground, in which a diaphragm wall milling machine with rotationally driven milling wheels is lowered into the ground, wherein soil material is removed and comminuted. The removed soil material is mixed with a settable suspension inside the milling slot, wherein soil mortar is formed. Before the soil mortar hardens, the diaphragm wall milling machine is withdrawn again from the milling slot filled with soil mortar. It is also possible to insert support beams into the soil mortar by using a crane before the soil mortar hardens.

Such a method for producing a retaining wall in the ground from a soil mortar is also known as the CSM™ method.

It is known from DE 10 2004 005 967 A1, for example, to use a drilling and mixing auger and, in particular, an arrangement of drilling and mixing augers arranged parallel next to each other to form a supporting or drilling wall in the ground from a soil mortar in a similar way. Here, the soil material removed during drilling is mixed with a settable liquid in the borehole to form a soil mortar. Such a method is known in particular under the name MIP™.

The invention addresses the problem of specifying a method and a device with which a foundation element in the ground can be produced from a soil mortar particularly efficiently and with a high quality of workmanship.

The problem is solved, on the one hand, by a method having the features of claim 1 and, on the other hand, by a device having the features of claim 10. Preferred embodiments of the invention are given in the dependent claims.

The method according to the invention is characterised in that the method is carried out automatically with a control device at least in portions, wherein at least one method parameter is entered into the control device as a default value and in that at least one remaining method parameter is set and controlled by the control device in dependence on the at least one default value entered.

A basic idea of the invention resides in, not to leave the method for creating a foundation element in the ground from a soil mortar solely to the experience of a machine operator, but to provide a control device with which the method can be carried out partially or completely automatically. For this, the control device is configured in such a way that at least one default value is specified by the machine operator or a control centre as a method parameter, while the remaining essential method parameters are then determined and controlled by the control device in accordance with a control program. The control device can preferably be configured in such a way that, depending on the construction site and, in particular depending on the specifications of the machine operator or a control centre, it is possible to freely set which method parameter or parameters serve(s) as the default value(s) and which method parameters are determined and readjusted by the control device depending on this.

A control logic or a control program of the control device can be formed by storing formulas or, in particular, by pre-calculated tables that are stored in the control device. For example, when specifying a vertical movement and/or a rotational speed of the processing tool as a default value, a feed quantity of settable suspension can be controlled. Alternatively, a feed quantity or feed rate of settable suspension can also be specified, while a suitable rotational speed and/or a suitable vertical movement of the processing tool is controlled by the control device. In the case of a vertical movement, the control device can control lowering, pulling or preferably both.

By using the method according to the invention, foundation elements can be created from a soil mortar particularly efficiently and with a high and largely consistent quality of execution. Here, in the context of the invention, the term “foundation elements” is to be understood generally and includes not only foundation elements but also sheeting, sealing, supporting and block elements as well as other elements which are created in the ground. Such foundation elements made of soil mortar can also be referred to as soil mixing elements.

Essential general method parameters for creating a foundation element from a soil mortar can be, in particular, the vertical movement of the at least one processing tool, a rotary movement of the at least one processing tool, the supply of suspension and at least one dimensioning of the foundation element.

According to a development of the invention is provided that the method parameters comprise or additionally have at least one of the following parameters: rotational speed of the processing tool, direction of rotation of the processing tool, torque of the processing tool, number of rotations per depth stroke of the processing tool, vertical movement speed or vertical feed force when lowering or pulling the processing tool, feed rate of suspension, feed quantity of suspension or a combination of these parameters. The parameters “rotational speed of the machining tool, direction of rotation of the machining tool, torque of the machining tool and number of rotations per depth stroke of the machining tool” represent, for example, specifics of the general held method parameter “rotational movement of the at least one machining tool”. The parameters “vertical movement speed or vertical feed force when lowering or pulling the machining tool” are to be assigned to the method parameter “vertical movement”. For this, the control device can be connected to corresponding sensors for directly detecting or determining the method parameters and to corresponding adjustment devices on the drilling device, in particular to actuate and influence corresponding drive devices, such as a feed drive, a rotary drive, a feed pump, etc. The parameters “feed rate of suspension and feed quantity of suspension” refer to the general method parameter “feed of suspension”. The method parameter “dimensioning of the foundation element” can relate to a diameter of the foundation element, its axial length/depth, special outer contours, such as cylindrical, conical or with a disc-shaped contact surface.

A further preferred embodiment of the invention resides in that the at least one rotationally driven machining tool comprises a drilling tool which is rotationally driven about a substantially vertically directed drilling axis, wherein the hole is created by drilling. In particular, the drilling axis and the direction of advance are in the same direction. Here, the method can be carried out by using a sufficiently well-known earth drilling rig with one or more rod-shaped processing tools that are aligned parallel next to each other and are configured for removal and mixing.

Alternatively, an advantageous configuration of the invention resides in that the at least one rotationally driven machining tool comprises a milling wheel which is driven in rotation about a substantially horizontally oriented milling wheel axis, wherein the hole is created by milling. The horizontal milling wheel axis and the vertical direction of advance are transverse to each other. In particular, the at least one milling wheel can be arranged on a so-called diaphragm wall milling machine. Preferably, two milling wheels are arranged as a pair of milling wheels on a common end shield, which is located between the two milling wheels. Further preferably, two such pairs of milling wheels are arranged on the underside of a support frame of a diaphragm wall milling machine, so that an approximately rectangular milling hole is created when the diaphragm wall milling machine is lowered or sunk into the ground.

The milling device can preferably be lowered into the ground via a suspension cable based solely on the weight of the milling device or via a guide rod, by means of which a feed force can preferably be exerted. Preferably, the settable suspension is introduced into the formed milling slot in the area of the at least one milling wheel. The rotation of the at least one milling wheel removes and comminutes the existing soil material and mixes it with the supplied suspension to a soil mortar.

A preferred variant of the method according to the invention resides also in that at least one rotationally driven processing tool has at least one removal element, by means of which soil material is removed and comminuted, and/or at least one mixing element, by means of which removed soil material is mixed with the supplied suspension. The at least one additional mixing element can be a mixing paddle or a mixing blade on a vertically oriented drill rod or on the outer circumference of the at least one milling wheel. The drill rod is configured preferably tubular, wherein a central feed channel is formed for feeding the suspension. In the case of a diaphragm wall milling machine, scraper elements can also be arranged on the frame, which are in meshing contact with the removal teeth on the circumference of the milling wheel in order to achieve in this way a particularly good mixing effect.

According to a development of the invention, it is preferable that a supply of suspension into the hole and a movement of the at least one rotationally driven processing tool are entered into the control device as default values, and that a substantially vertical movement of the at least one rotationally driven processing tool is set by the control device depending on the default values entered. The rotation of the processing tool can relate to a rotational speed, a torque and/or a specific ratio between rotational speed and propulsion. If the ground is loose, for example, a greater vertical movement can be set or achieved with a certain rotational movement. Conversely, if the ground is firmer, an axial advance must be reduced accordingly in order to maintain a desired rotational movement, in particular a set rotational speed.

A further preferred embodiment of the invention can be seen in the fact that a vertical lowering of the at least one rotationally driven machining tool is set by the control device, if this is not a default value, and/or a vertical pulling of the at least one rotationally driven machining tool is set, if this is not a default value. Depending on, for example, a predetermined rotational speed or a predetermined torque, the control device can set a suitable vertical lowering of the rotationally driven machining tool. The vertical lowering can refer to a ratio between a lowering and a supplied suspension quantity. The same applies to vertical pulling of the rotationally driven processing tool, so that a qualitative high-quality soil mortar of consistent quality can be produced when the method is carried out.

In particular, according to a development of the method according to the invention, it is preferred that a rotation of the processing tool and/or a feed rate and/or a feed quantity of suspension is set by the control device, if these are not default values. In particular, a particularly high and consistent mortar quality can be achieved by controlling and setting these parameters by the control device.

To control and set the rotary movement of the machining tool, a rotary drive in particular, can be controlled by the control device. With regard to the vertical movement, a vertical drive, in particular an actuating cylinder or a cable pull mechanism for vertical movement, can be controlled by the control device.

With regard to the control of the suspension quantity, it is advantageous according to one embodiment of the invention that a suspension pump is controlled by the control device, through which suspension is fed into the hole. Here, the suspension pump can be a positive displacement pump, in particular a peristaltic or screw pump. In particular, the control device is connected to this end to the pump drive so that the amount of suspension to be supplied can be adjusted directly depending on the movement of the processing tool.

The invention further comprises a device for creating a foundation element in the ground from a soil mortar, which is characterised in that a control device is provided and configured with which the creation of the foundation element can be carried out automatically at least in portions, wherein at least one method parameter is entered into the control device as a default value, and a substantially vertical movement of the at least one rotationally driven processing tool is set by the control device in dependence on the default values entered.

The device is configured, in particular for carrying out the method according to the invention described above. The advantages described above can be achieved with the device.

In principle, the device for creating a foundation element can be configured in any suitable form. According to one embodiment of the invention, it is advantageous that the device is configured as a drilling device in which the at least one rotationally driven processing tool comprises a drilling tool which is driven in rotation about a substantially vertically directed drilling axis. In a simple case, the drilling tool can be a continuous drilling auger. Preferably, the drilling tool can have a removal device on its underside for removing soil material and, following this upwards, further elements, such as mixing paddles, for conveying and/or mixing the removed soil material with suspension. Preferably, the drilling tool can comprise a central feed channel through which suspension can be fed from above and introduced into the surrounding borehole via at least one lower outlet opening and/or at least one lateral outlet opening along the central drill string.

According to a development of the invention, it is particularly preferable for the drilling device to have several drilling tools which are arranged parallel next to each other. In this way, elongate boreholes can be created in the ground in a transverse direction. The individual drilling tools can be configured and matched to one another in such a way that the individual boreholes at least partially overlap in order to form an elongate drilling slot.

Alternatively, according to one embodiment variant of the device according to the invention, it is preferred that the device is configured as a milling machine, in particular as a diaphragm wall milling machine, in which the at least one rotationally driven processing tool has a milling wheel which is driven in rotation about a substantially horizontally directed milling axis. Milling teeth and preferably also mixing elements are arranged on the outer circumference of a milling wheel hub, so that soil material can be removed by the milling wheel and mixed with the supplied settable suspension to the soil mortar. The suspension is preferably fed close to the at least one milling wheel.

It is particularly advantageous in this case for the milling machine to have several milling wheels, in particular two pairs of milling wheels, which are arranged parallel next to each other. In particular, with two such pairs of milling wheels on the underside of a support frame of a milling device, an approximately rectangular milling hole can such be created in the ground when the milling device is lowered vertically, which milling hole extends vertically downwards into the ground. The milling machine or milling device is thus configured as a so-called diaphragm wall milling machine. By lining up correspondingly produced milling holes, a milling slot of almost any length can be created in the ground, which is filled with soil mortar to form a diaphragm wall.

The device can be configured stationary or mobile. In a mobile embodiment, the device has a chassis, in particular a crawler chassis. Preferably, a mast can be arranged on a rotatably mounted superstructure, along which the processing tool can be guided in a vertically displaceable manner.

A preferred embodiment of the invention further resides in that a suspension pump is arranged for feeding suspension into the hole, wherein the suspension pump is controlled by the control device. By means of the suspension pump, settable suspension can be fed from a surface of the ground, for example from a preparation plant or a reservoir, to the processing tool in the ground. In particular, the control device can control both a rotating drive for the processing tool and a drive for the suspension pump in a coordinated manner, so that a needs-based supply of settable suspension into the hole for producing soil mortar is always ensured. In principle, the control device can also be connected to a preparation system for preparing the suspension, which is connected upstream of the suspension pump. In this way, the control device as a whole can control the device for creating a foundation element, the suspension pump and the preparation system in a coordinated manner, so that demand and/or capacity-oriented preparation and feeding of suspension into the ground is achieved for the efficient creation of a foundation element.

To illustrate the invention and the method according to the invention, the following preferred exemplary embodiments are cited when creating a foundation pile from a soil mortar.

A suspension quantity of 980 l/m (litres per metre) of the foundation element to be installed is specified as a default value for creating the foundation element and for forming the necessary soil mortar. Another specified method parameter is a maximum advance or extraction speed of the soil processing tool, in particular a drilling tool, of 0.5 m/min (metres per minute). Another present method parameter is a maximum delivery rate of a suspension pump of 525 I/min (litres per minute). In order to ensure the suspension quantity of 980 I/m of the foundation element to be installed, the feed rate is set to 0.43 m/min by the control device, so that the maximum advance speed is not exhausted but the maximum delivery rate of the suspension pump is used and the specified suspension quantity per metre is ensured.

If, on the other hand, the suspension quantity to be installed is only 450 I/m of the foundation element in another exemplary embodiment, a maximum pump delivery rate of 425 I/min would result in a theoretically conceivable advance speed of 0.94 m/min, but the control device sets the advance or feed rate to 0.5 m/min in accordance with the default value of the maximum advance speed of 0.5 m/min for the existing device, i.e. the maximum possible advance rate for the device, while the delivery rate is adjusted accordingly so that the target quantity is achieved.

The invention is explained further hereinafter with reference to preferred exemplary embodiments, which are shown schematically in the drawings. The drawings show:

FIG. 1 a perspective view of a first embodiment of a device according to the invention, which is configured as a milling device;

FIG. 2 an enlarged detailed view of the milling machine of the device of FIG. 1 in partially sectioned side view;

FIG. 3 a schematic representation of the production of a foundation element in the ground by using the milling machine shown in FIG. 2;

FIG. 4 a schematic side view of the device in FIG. 1 when creating a foundation element in the ground;

FIG. 5 a side view of a further device according to the invention, which is configured as a drilling device;

FIG. 6 an enlarged front view of the drilling tools which are used in the device shown in FIG. 5; and

FIG. 7 a schematic screen representation of a control device for the invention.

A device 30 according to the invention for creating a foundation element in the ground, which is specifically configured as a diaphragm wall milling machine 50, is shown in FIG. 1. The device 30 can preferably have a carrier 32 with an undercarriage 33, which can in particular be configured as a crawler chassis. Preferably, a superstructure 34 can be arranged on the undercarriage 30 and can preferably be mounted rotatably about a vertical axis of rotation. A substantially vertical mast 35 can be attached to the carrier 32, in particular the superstructure 34, during operation.

In the device 30, which is configured as a diaphragm wall milling machine 50, a milling machine 60 with a guide rod 52 is displaceably arranged along the mast 35 as a soil removal device 40. This machining device 40 can have milling wheels 64 as a machining tool 42 for removing soil material, as will be explained in greater detail hereinafter in conjunction with FIG. 2.

The milling machine 60 according to FIG. 2 has a compact frame 61, which is smaller in cross-sectional dimensions than the cross-section of the milling hole produced by the milling machine 60. Two plate-shaped end shields 62 are attached to the underside of the frame 61, one next to the other, and milling wheels 64 are mounted on each of their side surfaces.

The milling wheels 64 on an end shield 62 are each coaxial to one another, so that a pair of milling wheels is formed on each end shield 62. Along the outer circumference of each milling wheel 64, removal elements are configured in a fundamentally known manner for removing, in particular milling off, soil material. The milling wheels 64 are each driven in pairs via an associated drive 63, wherein the two drives 63 provided are preferably arranged in the housing-like frame 61 of the milling machine 60.

The frame 61 is attached to a guide rod 52, in which a suspension feed 54 runs to feed a settable suspension. The tubular suspension feed 54 opens out below the frame 61 between the two pairs of milling wheels 64. In a milling operation, the soil material removed by the milling wheels 64 can thus be mixed directly in the area of the milling wheels with the settable suspension flowing out of the suspension feed 54 by the movement of the milling wheels and a soil mortar can be formed in situ. The radially protruding removal elements 66 can here also serve directly as mixing elements for mixing the milling cuttings with the suspension. Preferably, additional paddle-like mixing elements can also be arranged on the milling wheels 64.

Mixing can also be supported by plate-like scrapers 68, which are attached to the underside of the frame 61 and can reach into the area of the row-like arranged removal elements 66 for scraping off adhering soil material. The rotary movement of the milling wheels 64 and the arrangement of the scrapers 68 can in particular assist in conveying the mixture of the milling cuttings and the suspension upwards past the frame 61 into a rear area of the milling slot.

The process and the method for forming a foundation element 8 in the ground 1 is further illustrated schematically in FIGS. 3 and 4. The milling machine 60 with the rotationally driven milling wheels 64 is lowered substantially vertically into the ground 1 via the guide rod 52, wherein a hole 3 is created in the ground 1 by the rotating milling wheels 64. The soil material removed during milling is mixed in situ in the hole 3 by the milling wheels 64 with the settable suspension supplied via the suspension feed 54 to a soil mortar 5, which flows past the frame 61 of the milling machine 60 and can thus fill out and support the hole 3 in the soil 1, as illustrated clearly in FIG. 3.

After reaching a final depth, further homogenisation of the soil mortar 5 in the hole 3 can be carried out if necessary by moving the milling machine 60 vertically up and down in the hole 3. After completion of the processing, the milling machine 60 is withdrawn from the hole 3, as shown in FIG. 4. The soil mortar 5 in the hole 3 can set up to the foundation element 8.

As also can be seen in FIG. 4, the milling machine 60 can be guided by the guide rod 52 along the mast 35 on the carrier 32 of the device 30.

A feed device 20, which may, in particular comprise a suspension pump 22, is used to convey a settable suspension, such as a cement suspension, from a reservoir (not shown) or a mixing and preparation plant to the upper end of the guide rod 52 into the tubular suspension feed 54 via a feed line 24, which is only partially shown in FIG. 4. A vertical travelling movement of the milling machine 60, a rotary movement of the milling wheels 64 and a conveying capacity of the feed device 20 can be coordinated and controlled as required via a control device (not shown).

In conjunction with FIGS. 5 and 6, a further embodiment of the device 50 according to the invention is explained, which is configured as a drilling device 70. The drilling device 70 can also preferably have a carrier device 32 with an undercarriage 30, which can in particular be configured as a crawler-type undercarriage. A superstructure 34 can preferably be arranged on the undercarriage 30 and can preferably be mounted rotatably about a vertical axis of rotation. A substantially vertical mast 35 can be attached to the carrier 32, in particular the superstructure 34, during operation.

A drilling carriage 72 can be mounted and guided in a linearly displaceable manner along the mast 35. A soil removal device 40 can be arranged on the drilling carriage 72, and in the illustrated embodiment example is configured for example as a drilling device 80 with three drilling tools 82 arranged next to each other. The drilling tools 82 can each have a rod-shaped design with a lower drilling head for removing soil material and an adjoining conveying and mixing auger. Other embodiments of the at least one drilling tool 82 are possible, for example with separate conveying and mixing segments.

The preferably three drilling tools 82 arranged next to each other can be used to create an elongate borehole 3 in the ground 1.

The soil material removed by the respective drill heads is conveyed upwards by the augers into a rear area of the hole 3. The drilling tools 82 can be configured with a hollow core barrel, through which settable suspension can flow down to a lower area of the drilling tools 82 and flow out into the hole 3 via outlet openings (not shown). The suspension is fed via a hose-like feed line 24 from the carrier 32 to the upper end of the drilling tools 82 in the area of the drill drives 83. Further outlet openings for the suspension can also be designed along the rod-shaped drilling tools 82 for discharge in the area of the feed screws.

The removed soil material, which is at least partially conveyed upwards by the drilling tools 82, can thus be mixed with the supplied settable suspension to the soil mortar 5 by the rotary movement of the drilling tools 82 and, in particular, the augers. The soil mortar 5 produced in situ in this way can harden in the produced drilled hole to a desired foundation element 8.

According to FIG. 7, a possible representation 90 on a screen or a possible protocol graph is shown as an example. This can be displayed to a device operator on a screen of the machine and/or printed out by the control device of the device 50 when carrying out the method according to the invention. In a left-hand first portion 91 of the representation 90, a depth progression of the machining tool 42 over time can be shown. Specifically, it can be seen from the representation 90 according to FIG. 7 that the processing tool 42 is sunk largely uniformly from the surface to a depth of approximately 12 metres within approximately 50 minutes and is then withdrawn again from the final depth to the surface in the subsequent approximately 20 minutes.

In the subsequent second portion 92, the respective depth can be used to display the amount of suspension that has been introduced and worked into hole 3 in which depth portion. The amount of suspension incorporated in each case is shown as bar 95 in depth portions of 0.5 metres each, wherein the second portion 92 refers to the introduction of suspension during the sinking of the processing tool.

On the other hand, in the subsequent third portion 93, the amount of suspension incorporated in each depth portion, which is also 0.5 metres in each case, can be displayed as bar 95 when the machining tool is pulled.

Furthermore, the total quantity of suspension incorporated over each depth portion during sinking and during pulling of the processing tool 42 can be shown in the subsequent right-hand fourth portion 94. It should be noted that in FIG. 7 the quantity scale with respect to the X-axis is different in portions 92, 93 and 94, while the depth portions with respect to the Y-axis may be the same in portions 91, 92, 93 and 94.

The control system can be used to seek that the same amount of suspension in each depth portion or a predetermined amount of suspension, which differs for each depth portion, is introduced after sinking and pulling. With the help of the evaluation software, comparable graphs can also be generated for the executed tool rotations per metre of ground depth. During execution, the machine operator is shown comparable diagrams for the suspension quantity and, depending on the process, additionally also tool rotations on the work screen in the machine.