Patent Application
20250171978
The invention relates to a drilling unit for producing a foundation in the ground and a foundation in the ground under water. Furthermore, the invention relates to a corresponding method, a device comprising such a drilling unit and a cutting ring of such a drilling unit.
When constructing structures of various types and purposes, the structure is usually anchored to the ground in the installation area in order to ensure safe operation during the intended service life of the structure. The connection of the structure to the ground is created by laying a foundation at the installation site.
Suitable foundations are often embodied by so-called pile foundations, wherein steel or concrete piles are first inserted into the ground and then firmly connected to the ground. Such pile foundations may consist of one or more piles to which the future structure is fixed. The diameter and length of these piles depend on the structural requirements and the respective geological conditions at the insertion site. Pile foundations are used both on land and at sea. The diameters on land are often a few decimeters, while offshore they are often over 3 m with insertion lengths in the ground of over 10 m. Similar piles are used in the construction of shafts. In this application, too, the pile generally remains in the ground after it has been inserted.
A common operating method of inserting such piles for foundations and shafts in loose rock is the so-called driving method. On land, these can be so-called sheet piles or pipes, in the maritime sector mainly hollow components such as round pipes or square pipes. This is a quick and cost-effective construction method, but has a strong impact on the environment, especially on fauna (noise emissions with high sound pressure levels). The driving work comes to an end as soon as the geological formation contains not only loose rock, but also boulders or hard rock banks or solid hard rock.
Alternatively, piles may be inserted into the ground using a drilling method, wherein the piles are often only inserted into the borehole as prefabricated piles or as reinforced in-situ concrete after the borehole has been completed. In the case of prefabricated piles, the so-called annular space between the pile and the borehole walls is grouted with a suitable grouting agent. This creates a force-fit connection between the drilling pile and the borehole. In a variant of the method, drilling is carried out using a hollow pile that follows the drilling front in the bottom downwards during drilling, wherein the drilling instrument is arranged in or around the hollow pile and can be recovered after the deepening process.
The document DE 10 2013 012 279 A1 describes a method for producing a foundation in the ground using a hollow pile.
The document DE 101 17 111 A1 describes an alternative method for producing a foundation in the ground, wherein foundation bodies are introduced into annular foundation trenches.
The known drilling methods typically also allow foundations to be produced in harder soils or soils with harder boulders such as stones and chunks. Although the known drilling methods have clear ecological and geological advantages compared to the conventional driving method, they are generally much more time-consuming and costly.
It is an object of the present invention to provide devices and methods for the improved creation of a foundation in the ground, which is in particular environmentally friendly, safe, fast and cost-effective.
The technical object is achieved by a device according to the features of the independent claims. Advantageous embodiments are claimed in the dependent claims.
A first aspect of the invention relates to a drilling unit for producing a foundation in a ground and/or a foundation under water, wherein the drilling unit comprises a drive unit and a cutting ring, wherein the cutting ring is rotatably mounted on the drilling unit and can be driven by means of the drive unit, wherein the drilling unit is configured such that it can be detachably arranged and fastened to an end of a drilling pile, in particular facing the ground, for sinking, preferably vertically, into the ground.
A second aspect of the invention relates to a device for producing a foundation in the ground 2 and/or a foundation under water, including a drilling pile and a drilling unit.
The device according to the invention is a drilling pile including a clamping area, a drilling unit, feed and conveyor lines, a cutting ring and a bearing for the cutting ring.
The clamping area is configured such that, via said clamping area, the axial forces (pressing and pulling forces) required for a drilling process can be introduced into the drilling pile and the torques generated during the insertion process can be absorbed by the clamping device. The clamping area is preferably located in the upper third of the drilling pile, but at least in the part of the drilling pile that is not to be inserted into the ground. The clamping area may be located on the inside, the outside or both the inside and the outside of the drilling pile. The clamping effect is preferably generated by frictional engagement, but can also be achieved by form-fit engagement or a combination of these two types of force transmission with an appropriate configuration.
The drive unit is driven by at least one motor/gear unit, the torque of which is transmitted to the cutting ring via a gearing. The drive unit is located above the bearing and can be attached to the inner and outer area of the drilling pile. The drive unit is fixed to the drilling pile in a form-fitting and/or force-fitting manner during the sinking process in order to transmit the torque from the drive unit through the drilling pile into the clamping area. The drive unit should have a diameter that is as small as possible compared to the ring cut diameter of the cutting ring. The cutting ring is configured such that the resulting annular heading is so large that the drilling pile cannot be clamped during the sinking process. The drive unit is provided with at least one drive pinion which engages in a gear ring on the cutting ring and thereby transmits the torque required for the cutting process from the motor/gear unit. Via the bearing, the cutting ring is mounted at the lower end of the drive unit and sealed off from the drive unit by means of seals.
The feed line is used to transport the drilling fluid required for the drilling process to the cutting ring. For this purpose, the feed line is provided in the outer or inner area of the annular heading. The feed line is hollow on the inside so that the drilling fluid can be pumped through the feed line to its lower end by the flushing pump. The feed line is fixed to the drive unit and tends to have a smaller diameter than the conveyor line. Preferably, the conveyor line will run inside the drilling pile as close to the wall of the drilling pile as possible. At least one feed and conveyor line should be installed on the circumference of the drilling pile. In order to ensure that the waste is removed over the entire surface, it will be useful to install a plurality of conveyor and feed lines. Since the feed line is fixed (not rotating) in an advantageous embodiment, the corresponding fixation of the feed line to the drive unit may be made solid. The feed line may also be recovered and reused when the drive unit is recovered. The conveyor line can either be recovered or remain in the annular heading area to be used to pump the grouting material.
A third aspect of the invention relates to a cutting ring for producing a foundation in the ground and/or a foundation under water for use with a device including a drilling unit and/or a drilling unit, wherein the cutting ring has foldable sub-segments, which are preferably configured as ring segments.
A cutting ring in the sense of the invention is preferably an annular body that is equipped with cutting tools. The cutting ring also preferably has a U-shaped cross-section. In contrast to a cutting disk, which machined the entire cross-section below the drilling pile, the cutting ring preferably only removes a smaller part of the cross-section. At its upper end, the cutting ring is preferably mounted and sealed by means of a flange, preferably directly in the drive unit. This allows the axial forces required for the insertion process and generated by the feed device to be transferred to the cutting ring via the drilling pile and the drive unit. A gear ring is preferably applied to said flange of the cutting ring within the drive unit. The drive pinion of the motor/gear unit is also preferably positioned in this housing. Through holes are preferably provided in the circumference of the cutting ring in order to guide the conveying medium to the bottom. The cutting tools required for the insertion process are also preferably attached to the underside of the cutting ring. The soil below the cutting ring is preferably loosened using these cutting tools. For this purpose, the drive unit is preferably attached to the drilling pile in such a way that an activatable locking unit and/or a form-fitting connection is ensured.
A fourth aspect of the invention relates to a method for producing a foundation in the ground, wherein, in order to insert a drilling pile into the ground, a drilling unit is subjected to an axial force by means of at least one feed device via at least one fixing device, wherein a cutting ring located at the lower end of the drilling pile is rotated by means of a drive unit arranged on an inner or outer side of the drilling pile and creates an annular cut 8, wherein a drilling fluid is pumped into the excavation area of the cutting ring via at least one feed line and/or a high-pressure feed line, and wherein the drilling fluid is conveyed to the surface together with waste loosened by means of the cutting ring by means of a conveyor line.
The drilling pile is inserted into the ground by exerting axial forces on the drilling pile via a feed unit and a clamping area. These are primarily the pressing forces required for the insertion or drilling process. However, if, for example, the dead weight of the drilling pile already generates a vertical force that is higher than the necessary pressing force and the buoyancy of the entire unit, the feed device may also apply axial forces in the opposite direction (pulling forces). The feed device is also configured to receive and dissipate the torques that arise during the installation process via the clamping area. For this purpose, the feed device is anchored in a base platform.
At the same time as the feed forces are applied, the cutting ring is made to rotate in order to loosen the soil beneath the drilling pile. For this purpose, the cutting ring is driven by a motor/gear unit via a drive shaft. The direction of rotation may generally be clockwise or anti-clockwise or alternately in both directions.
Using a feed pump, drilling fluid is pumped to the cutting ring, where it mixes with the soil loosened by the cutting wheel and flows past the cutting ring through the feed lines on the inside or outside of the drilling pile to the surface. There, the drilling fluid may be disposed of with the loosened soil or be collected, treated and reused. The drilling fluid enters the excavation area from the opening of the feed line directly above the cutting ring. From there, it flows further along the underside of the cutting ring, where the soil in the annular cavity is machined and loosened by the cutting tools. The pumping process permanently generates a slight positive pressure in the annular cavity of the cutting ring, so that a collapse of the cavity can be prevented.
Due to the combination of mechanical and hydraulic loosening work of cutting tools and drilling fluid on the cutting ring, not only loose rock soils such as clay and sand but also hard soil types or individual soil obstacles such as stones or boulders can be handled in the manner described. The material flow may be improved by accelerating the soil loosening using a high-pressure feed line with high-pressure nozzles and preventing adhesions in the excavation area in cohesive soils. The drilling fluid including the loosened soil may be conveyed to the surface through the conveyor line using centrifugal conveyor or Venturi pumps or a combination thereof or using air lifting methods.
The sealing area between the rotating cutting ring and the drive unit prevents the conveyed material from penetrating the drive unit so that the drive pinion and the gear ring also arranged there do not come into contact with soil.
Once the drilling pile has reached its intended depth in the ground, the insertion process is complete, i.e. the rotation of the cutting ring is ended just as is the application of axial force (drilling pressing force) to the drilling pile. This allows the drilling unit to be pulled upwards using traction means on the circumference of the drive unit. The area of the cutting ring below the drilling pile is folded inwards and/or outwards to allow space for recovering the drilling unit. For this purpose, rotatable cutting ring parts are provided on the cutting ring, which are fixed during the sinking process and can be unlocked and swiveled in when the drive unit is recovered by shearing off shear bolts or hydraulic release. The feed device now holds the drilling pile in the position reached until the drilling pile is fixed in the ground.
For the fixing process, a fixing material is pumped through the conveyor line instead of the drilling fluid using the flushing pump. The fixing material may be, for example, a so-called Dämmer, which hardens after a certain dwell time. The fixing material is pumped by the feed pump through the conveyor line into the annular space until it reappears on the surface (or on the seabed). The annular space is then completely filled with fixing material or the drilling pile is completely surrounded by fixing material and is thus firmly embedded in the ground after the fixing material has hardened. The drilling pile may now be connected to a structure via the area protruding from the ground and be used as a foundation.
Finally, the feed device and the flushing pumps are separated from the drilling pile or the conveyor line and may be used for the next drilling process of a drilling pile. In order to reduce possible frictional forces on the outside and inside of the drilling pile, it is also possible to configure the feed device in such a way that it oscillates the drilling pile by small angles (e.g. 30°) to the left and right during the insertion process. The forces or torques required for this may also be transferred to the drilling pile via the clamping device.
It is also possible to provide so-called lubrication stations on the inside and/or outside of the drilling pile, as used in microtunneling or pipe driving. This can significantly reduce the friction between the soil and the drilling pile, making a particularly small and cost-effective feed device possible.
Under certain geological conditions (e.g. very few cohesive components in the soil matrix), the device according to the invention may be configured such that the annular space on the inside or outside of the drilling pile is reduced to a minimum. While this area would be lubricated by the small amount of drilling fluid that still enters there (and thus the friction be greatly reduced), the soil loosened by the cutting ring would be conveyed mainly through the conveyor line around the circumference of the drilling pile. The advantage of this configuration would be that the soil around the drilling pile would be stabilized and protected against accidental erosion by the drilling fluid.
The advantages of the present invention lie in particular in the aspects of ecology and economy (minimal noise emissions during construction, minimal soil replacement/excavation required), safety and risk (effective handling of ground obstacles, reduced execution risk for offshore areas due to short dwell times, weather), technology (optimal integration of the structure into the ground) and costs (high working speed due to only annular removal of the geology with short dwell times and reduction of the grouting material) as well as lower drive power of the units due to the ring cut instead of the full cut to insert the pile.
In an advantageous embodiment, the drilling unit includes at least one motor/gear unit attached to the drive unit.
As a result, the required torque can be introduced into the drive unit without losses or additional components.
In a further advantageous embodiment, the drilling unit includes a feed line and/or a high-pressure feed line which is attached to the drilling unit and/or can be attached to the drilling pile and is configured in such a way that drilling fluid can be introduced into an excavation area in order to be able to transport cut material removed by the cutting ring in the ground to a surface of the ground or a water surface. This embodiment enables the purposeful control of the positive pressure in the excavation area of the cutting ring.
In a further advantageous embodiment, the drilling unit and/or the drive unit includes a locking means by means of which the drilling unit and/or the drive unit can be detachably attached to the drilling pile in order to ensure multiple use of the drilling unit and thus a cost-effective solution.
In a further advantageous embodiment, the drilling unit includes a traction means, in particular a traction cable, configured such that the drilling unit and/or the drive unit can be recovered to the surface after the locking means has been released in order to ensure multiple use of the drilling unit and thus a cost-effective solution.
In a further advantageous embodiment, the drilling unit includes seals by means of which a bearing of the cutting ring is sealed from the outside in order to enable permanent use of the drive unit without massive wear.
In a further advantageous embodiment of the device, the drilling unit is arranged at one end of a drilling pile, in particular the end facing the ground, allowing for the purposeful application of load to the drilling unit/drive unit.
In a further advantageous embodiment of the device, the drive unit is arranged on an inner side of the drilling pile in order to allow for a minimal drilling cross-section of the ring cut.
In an advantageous embodiment of the cutting ring, the sub-segments are fixed to the cutting ring with retaining bolts and shear bolts, thus allowing for the drilling unit to be recovered efficiently and cost-effectively.
In a further advantageous embodiment of the cutting ring, a front side of the cutting ring facing away from a front side of the cutting ring provided with cutting tools may be stored in a bearing of the drive unit in order to enable a permanently safe and low-wear function of the drive unit.
In a further advantageous embodiment, the cutting ring is configured such that the outer diameter and/or inner diameter thereof can be reduced in order to recover the drilling unit and/or a drive unit of the drilling unit, in particular by shearing off the shear bolts and folding over the sub-segments around the retaining bolts. This configuration allows the cutting ring to be used multiple times with minimal effort for restoration and thus ensures economical use of the drilling unit.
In an advantageous embodiment of the method, in order to fix the drilling pile after the intended depth in the ground has been reached, a fixing material is pumped into the excavation area through the at least one conveyor line until the rising fixing material has filled the entire annular cut around the drilling pile and/or in a cavity of the drilling pile. This allows for the purposeful introduction of the fixing material to be controlled for embedding the drilling pile over the entire surface.
In a further advantageous embodiment of the method, after the drilling pile has been sunk, preferably before the annular cut is filled, the drilling unit is recovered to a surface of the ground or a water surface by means of a lifting device via traction means, wherein the inner and/or outer diameter of the drilling unit, in particular of the cutting ring, is changed, thus enabling the drilling unit to be recovered efficiently and cost-effectively.
In a further advantageous embodiment of the method, the cutting ring has sub-segments which are fixed to the cutting ring with retaining bolts and shear bolts while the sinking process takes place, wherein the shear bolts shear off when the drilling unit is recovered and the sub-segments fold away around the retaining bolts. This embodiment of the method allows the cutting ring to be recovered with minimal effort.
In a further advantageous embodiment of the method, the drive unit is arranged on the inside of a respective drilling pile during the creation of the cut in a cavity of the respective drilling pile and, after the drilling unit has been recovered, another drilling pile, the diameter of which is smaller than the diameter of the drilling pile, is inserted into the drilling pile in such a way that the drilling unit can be installed in the drilling pile in order to drill a particularly deep bore, a replacement bore and/or a drilling pile of very large diameter and/or weight. This embodiment is of great advantage, especially in difficult geologies, in order to increase safety when inserting the drilling pile.
The features and advantages described above in relation to the first aspect of the invention also apply to the other aspects of the invention and vice versa.
Further features and advantages are apparent from the following description of exemplary embodiments or embodiment with reference to the figures, the features shown there being exemplary in nature.
The drawings show at least partially schematically:
The drilling pile 1 consists of a steel pipe with a small wall thickness compared to the diameter. The length of the drilling pile 1 is shown in shortened form in the example. In practice, the length of the drilling pile must represent at least the penetration depth of the drilling pile in the ground plus the connection piece to the actual structure.
In the upper area of the drilling pile 1, a feed device 4 which controls the sinking and thus the load application via the fixing device 3 is shown. These components are arranged in such a way that they are above the ground 2 at all times during the insertion and fixing process of the drilling pile 1. The storage of this component on the base platform is not shown.
The motor/gear unit 5 generates a torque which is transmitted to a cutting ring 6. The drive unit 7 is fixed to the lower end of the drilling pile. The cutting surface of the cutting ring 6 forms an annular cut 8 in the ground 2 into which the drilling pile 1 is sunk.
The pressing force F for sinking and cutting the ground generates the pressing force for the cutting ring 6 using the dead weight of the device. The force F may assume a positive value (pressing force) or a negative value (pulling force). The cutting ring 6 is equipped with cutting tools 9 that produce the annular excavation of the ground 2. The arrangement is selected such that the excavation work can also be carried out in hard ground or rock.
The drive unit 7 can be lifted to the surface using the traction means 10 after the sinking process has been completed. The traction means 10 is attached to the locking means 12 of the drive unit by means of a tab 11. By pulling on the traction means 10 after previously releasing the locking means 12, the ring segment 6a of the cutting ring 6 is pressed against the drilling pile tip la until an inner shear bolt 14 fails and the inner and/or outer ring segments 6a and 28 fold down around the retaining bolt 15.
The conveyor line 16 inside the drilling pile 1 transports the drilling material and the conveyed material to the surface. The cleaned conveyed material is transported back into the excavation space 18 via the feed line 17. The feed line 17 is preferably attached to a traction means 10.
By rotating the motor/gear unit 5, the force is transferred to the drive pinion 21 and the teething in the gear ring 22 in the bearing 23 and the cutting ring 6 begins to rotate. The seals 24 seal the rotating part of the cutting ring 6 from the stationary housing of the drive unit 7. Through this rotation, the cutting tools 9 begin the excavation activity on the ground 2 until the final depth is reached.
The drilling fluid is conveyed into the excavation area 18 through the feed line 17 and transported to the surface by means of the feed/high-pressure feed line 17, 29, mixed with the drilling material, through the feed line 16.
The retaining bolts 15 and shear bolts 14 of the inner and outer ring segments 28, 6a are shown in the section of the cutting ring 6. As described, after completion of the sinking process, the remaining diameter of the cutting ring 6 may be reduced in order to recover the drive unit 7. After the drive unit 7 has been recovered, the fixing material described above may be introduced, for example through the feed line 16, in order to permanently anchor the drilling pile 1 in the annular cut 8.
As an alternative to shearing off the shear bolt 14, an activatable fixation of the ring segment 6a, 28 to the cutting ring 6 may be provided. For this purpose, a rotary feedthrough 27 is attached to the lower end of the drive unit 7, which can transmit hydraulic fluid, sensor data or electrical signals from the stationary to the rotating part of the drilling unit 13.
When recovering the drive unit 7, the shear bolts 14 are destroyed or retracted as described above and the outer and/or inner ring segments 6a and 28 may fold down on the fastening tabs 25 in order to reduce the diameter of the cutting ring 6 so that the entire drive unit 7 can be recovered to the surface.
The configuration of the ring segment 6a is preferably configured such that the drilling material is transported together with the conveyed material in the direction of the conveying line 16 on the side flanks 26 of said component. The rotation of the cutting ring may be performed clockwise and counterclockwise so that both side flanks 26 of the inner and outer segments of the ring segments 6a and 28 enable this material transport.
In the upper area of the drilling pile 1, a feed device 4 controlling the sinking and thus the load application via the fixing device 3 is shown. Said components are arranged in such a way that they are above the ground 2 at all times during the insertion and fixing process of the drilling pile 1. The support of this component on the base platform is not shown.
The motor/gear unit 5 of the drive unit 7, which is arranged outside the drilling pile 1, generates a torque which is transmitted to a cutting ring 6. The drive unit 7 is fixed to the lower end of the drilling pile. The cutting surface of the cutting ring 6 forms an annular cut 8 in the ground 2 into which the drilling pile 1 is sunk.
The pressing force F for sinking and cutting the ground generates the pressing force for the cutting ring 6 using the weight of the device. The force F may assume a positive value (pressing force) or a negative value (pulling force). The cutting ring 6 is equipped with cutting tools 9 which produce the annular excavation of the ground 2. The arrangement is selected such that the excavation work can also be carried out in hard ground or rock.
After completion of the sinking process, the drive unit 7 may be lifted to the surface by means of the traction means 10. The traction means 10 are attached to the locking means 12 of the drive unit by means of a tab 11. By pulling on the traction means 10 after previously releasing the locking means 12, the ring segment 6a of the cutting ring 6 is pressed against the drilling pile tip la until an inner shear bolt 14 fails and the inner and/or outer ring segments 6a and 28 fold down around the retaining bolt 15.
The conveyor line 16 inside the drilling pile 1 transports the drilling material and the conveyed material to the surface. The cleaned conveyed material is transported back into the excavation space 18 via the feed line 17. The feed line 17 is preferably attached to a traction means 10 outside the drilling pile.
It is to be noted that the embodiments are merely examples that are not intended to limit the scope of protection, the applications and the structure in any way. Rather, the preceding description provides the person skilled in the art with a guide for the implementation of at least one embodiment, wherein various changes, in particular with regard to the function and arrangement of the described components, can be made without departing from the scope of protection as apparent from the claims and combinations of features equivalent thereto.
| Number | Date | Country | Kind |
|---|---|---|---|
| 22159024.3 | Feb 2022 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2023/054055 | 2/17/2023 | WO |
