Drilling system for recovering virtually intact drill cores from loose to solid ground

Abstract

The apparatus is operated with a conventional rotary drive with a pile driver hammer. The torque and the blows of the drill head are transmitted to a drilling starting pipe (8) with a drill bit. Within the rotating starting pipe (8) there is a non-rotating sleeve (17). It is applied at the bottom to the inner side of the drill bit rotating beneath it. As a particular feature, the sleeve (17) is connected in terms of compressive and tensile force via a sleeve adapter (21) to axially successive parts that are rotatable with respect to one another and a pressurizing, flushing and recovering pipe DSB (19), connected to said parts, with the rotating drill head. The DSB (19) rotates together with the drill head and the drill pipe, and the sleeve adapter (21) connects to the non-rotating sleeve (17). With the DSB, first of all the sleeve (17) is pressurized from above, secondly flushing is effected, in that the flushing water for the bore is guided in the DSB (19) and is pressed outwardly out of the sleeve (17), and thirdly the recovery of the sleeve (17) is enabled, for an approximately intact drilling sample.

Description

Drilling system for retrieving virtually undisturbed drill cores from loose to solid ground

[0001] This drilling system relates to a method and a device for extracting core samples from particularly loose but also solid subsoil, whereby the core samples can be recovered and deposited almost undisturbed.

[0002] This means that a cylindrical core sample is extracted from the ground inside a hollow cylindrical sleeve, known as a core sampler or core catcher, and brought to the surface. Such core samples typically measure about one meter in length and 10 to 20 cm in diameter. However, they can also be considerably larger or smaller, depending on requirements and the dimensions of the drilling equipment. At the surface, the core sample is ejected from the hollow cylindrical sleeve and then lies horizontally, freely accessible, for example, on the inner surface of a half-cylinder or on a flat surface. Since such a soil sample partially disintegrates due to its material consistency when ejected from the sleeve, it is no longer completely undisturbed.However, the casing can also be lined internally with a liner made of, for example, rigid PVC or another suitable material, which fits snugly against its inner wall. This liner, along with the casing, is then pushed over the soil material during the drilling process. In this case, after the casing is retrieved, the liner is ejected, containing the unchanged core sample just as it was in the ground. The core can later be opened section by section, for example, with diametrically opposed cuts, so that the sample is then completely undisturbed. This applies when using a liner. One advantage is that, after retrieval from the casing, any volatile pollutants present in the drill core are trapped and preserved within the core. However, the use of liners is more complex and expensive than drilling without them.

[0003] Soil samples collected in this way provide information about soil composition and, in particular, about any pollutants that may have seeped into the soil over time. This allows for the creation of reliable damage registers and the implementation of appropriate measures for the remediation of such soils. For agriculture, in particular, it is valuable to gain knowledge about soil quality, the mineral composition of humus soils and their nutrient richness, or to identify any soil deficiencies. This information can then be used to determine which soils are suitable for which crops and how fertilization should be carried out, ultimately promoting ecologically sound and productive management of agricultural land.Such core drilling is also suitable for taking soil samples in old landfills, in soils suspected of being contaminated, and in unconsolidated rock formations, including fine sand layers, peat layers, and marine marl. The drilling method also works in soil layers located in groundwater.

[0004] The extraction of soil samples for geotechnical analysis from solid subsoil is a well-known and frequently used method. An internationally established standard penetration test (SPT) exists for this purpose, as defined in standard D1586 of the American Society for Testing and Materials (ASTM). For the test, a thick-walled sample tube with an outer diameter of 50.8 mm, an inner diameter of 35 mm, and a length of approximately 650 mm is used. This tube is driven into the ground at the bottom of a borehole by impacts from a slide hammer with a mass of 63.5 kg, which is dropped over a distance of 760 mm. The sample tube is driven 150 mm into the ground, and then the number of impacts required for the tube to penetrate 150 mm at a time, down to a depth of 450 mm, is recorded.The sum of the number of blows required for the second and third 6-inch penetration is referred to as the "standard penetration resistance" or "N-value", which is expressed in blows per foot. The number of beats per foot (bpf) is given. This value is fundamental for many different types of geotechnical calculations, such as bearing capacity and settlement estimates. In cases where 50 blows are insufficient to advance penetration through a 150 mm interval, the penetration is recorded after 50 blows. The number of beats provides an indication of the soil density and is used in many empirical geotechnical formulas.

[0005] While drilling in solid ground is well-established technology, drilling, and especially the extraction of core samples, from loose soil proves particularly challenging. This is because, in addition to the rotating drill bit, ramming is required – a hard impact on the drill head, which then transmits these impacts to the entire drill string, including the drill pipes, the core tube, and the attached drill bit. Consequently, all components are subjected to enormous mechanical and thermal stress, often resulting in a very short service life. For this reason, to date, there is no truly convincing drilling system that delivers reasonably acceptable core sample quality and, above all, offers a reasonable service life for the drilling system itself.

[0006] The extraction of cylindrical soil samples from loose subsoil is currently carried out using highly specialized drilling rigs. These rigs enclose a drill pipe with a drill bit attached to its lower end. The drilling process involves rotating the drill pipe, and thus the drill bit and the initial tube, while simultaneously driving the sample into the ground. Inside the initial tube, a sleeve is inserted with minimal play to act as a core catcher. This sleeve rests against a radially inward-projecting projection at the bottom of the drill bit.

[0007] Such a drilling method is described in EP 2 050 923. There, it is described as essential that the core catcher or sleeve inside the initial pipe must be held in place to prevent its rotation. A special fixing rod is proposed for this purpose, which runs continuously from top to bottom within the drill string and is rotationally fixed – i.e., without rotation – thus securing the sleeve against rotation. However, practical experience shows that a fixing rod is by no means necessary to secure the sleeve. The sleeve is held in place by the drilling rig, preventing it from rotating. This is because the core itself, which is inserted into the sleeve over the core during the lowering process, clamps the sleeve securely. This reliably prevents rotation. Therefore, the sleeve does not rotate during drilling; instead, it is pressed downwards axially, without rotation, along with the rotating movement of the initial pipe, over the drilled core and then lowered into the ground. Practical experience shows that the problem purported to be solved by EP 2 050 923 was essentially nonexistent. The core, growing into the lowering sleeve, will hardly rotate, or at most only very slightly, due to its connection with the ground. A locking rod to hold the sleeve and prevent its rotation is therefore unnecessary.It can even have a detrimental effect, namely when, under certain soil conditions, the sleeve twists by a few degrees in the direction of rotation of the drill bit despite a rotationally rigid fixing rod. While this does not affect the quality of the drill core, when using such a fixing rod, it means that the rod cannot absorb the resulting torsion and shears off. This leads to unplanned and lengthy drilling interruptions and time-consuming improvisational work to somehow retrieve the sleeve.

[0008] Normally, however, once a drilling section is reached, the drilling process stops, and the sleeve, along with the core sample, is pulled upwards out of the initial pipe. The core sample is then ejected horizontally from the sleeve, and the empty sleeve can be reinserted into the initial pipe. For deeper drilling, the initial pipe can be extended to deeper depths using the drill bit and section-by-section extensions. This is described in EP 2 050 923.

[0009] In the prior art, so-called cable core drilling methods are known, with which core samples can be readily retrieved from solid rock or solid subsoil. These methods utilize devices including a locking mechanism, resulting in a complex construction unsuitable for drilling in loose subsoil because the necessary ramming impacts would cause these core retrieval devices to break down very quickly. Furthermore, a sleeve or core catcher cannot be lowered downwards using cables. a drilled core sample will be pressed.

[0010] The difficulties of extracting such core samples from loose soil are manifold and are usually greatly underestimated. The drilling rig develops up to 28,000 Nm of torque, and the driving impacts cause enormous force surges, meaning those with very high peak forces and single-impact energies of up to 500 Nm, occurring at frequencies of, for example, 2400 rpm. -1 These applications place extreme demands on the design and its stability, demands that are difficult to determine purely mathematically. Many parts used in trials proved to be worn out and unusable after a short period of use. Reference is made here, for example, to the Sonnic rotary hammer, or more generally to all commercially available drill drives and rotary hammers, for which this is generally true.

[0011] Inappropriate drilling methods can also lead to contaminants from certain depths being carried downwards by the drill bit or core tube during the drilling process. In such cases, a recovered core sample can no longer be considered nearly undisturbed.

[0012] To date, no drilling rig is available that can be considered truly suitable for extracting virtually undisturbed soil samples, not only from solid subsoil but especially from loose subsoil, in the form of core samples. No known device functions reliably over extended periods and enables the efficient and straightforward extraction and retrieval of core samples, particularly from loose subsoil, allowing for the recovery of a large number of core samples per unit of time with minimal damage.

[0013] Against this background, the present invention aims to provide a drilling system, that is, a method and a device for taking virtually undisturbed soil samples from, in particular, loose subsoil, but equally also from solid subsoil, which drilling system is significantly superior to conventional methods in several respects. The actual drilling process should be faster, and any drilling interruptions should be reduced to minimal time windows. The device should have a significantly longer service life than Conventional drill strings and their components are offered. The boreholes are intended to provide virtually undisturbed soil samples and, depending on the material's composition, can be secured in such a way that, should the strings fall apart due to the material's consistency, the validity of the sample analysis is not affected or only minimally so.

[0014] This problem is solved by a method according to the features of claim 1 and with the device for carrying it out according to the features of claim 6.

[0015] The following description introduces this drilling system, that is, the device and the process it employs, and clearly explains the individual features and aspects of the process and the device. The special characteristics and function of the device and its components are explained comprehensively. It shows: Figure 1 A rotary hammer with drive and hammer for impact Rotating the drill head; Figure 2 The rotary hammer in a horizontal position, in a view from below; Figure 3 The rotary hammer with drill head in upright operating position; Figure 4 A drill head shown separately, with its external thread for screwing into a drill tube; Figure 5 The drill head according to Figure 4 in a longitudinal section, with central axial Bore for flushing and radial bore for venting; Figure 6 The assembled drilling system consisting of drill head, drill pipe, Initial pipe and attached drill bit; Figure 7 The composite drilling system from Figure 6 seen from a low angle; Figure 8 A drill pipe as an extension piece seen from a low angle; Figure 9 The drill pipe from Figure 8 as an extension piece seen from an oblique angle above; Figure 10 The drill bit in an enlarged view seen from a low angle; Figure 11 Assembled and from top to bottom: A pressure, flushing and Recovery pipe adapter (DSB adapter), followed by a pressure, flushing and recovery pipe DSB, and at the bottom of the pressure, flushing and recovery pipe DSB a sleeve or a core catcher; Figure 12 The DSB adapter for placing on top of the pressure, flushing and DSB recovery pipe; Figure 13 A DSB pressure, flushing and recovery pipe as an extension piece seen from a slant below; Figure 14 A sleeve adapter for the impact-resistant connection of the sleeve or the core catcher to the pressure, flushing and retrieval pipe, viewed from obliquely above to obliquely below; Figure 15 The sleeve adapter from Figure 14 for the impact-resistant connection of the sleeve or the core catcher to the pressure, flushing and recovery pipe, viewed from obliquely below to obliquely above; Figure 16 The individual parts of the sleeve adapter from Figures 14 and 15 in a linear exploded view; Figure 17 A sleeve or core catcher seen from a low angle; Figure 18 A sleeve or core catcher seen from a slightly oblique angle; Figure 19 A rolled-out spring retainer in the sleeve for the Retaining the drill core; Figure 20 Above the drill head, below the pressure, flushing and recovery pipe with the starting pipe at the bottom, in which the sleeve is inserted, before its removal from the starting pipe; Figure 21 The pressure, flushing and recovery pipe being pulled upwards to Removal of the sleeve or core catcher from the starting tube; Figure 22 The pressure, flushing and recovery pipe after the upward movement Removing the sleeve or core catcher from the starting tube; Figure 23 The sleeve adapter pulled out of the sleeve at the bottom Pressure, flushing and recovery pipe; Figure 24 shows an enlarged view of the lower part of the sleeve adapter, looking into the bore for the locking bolt and next to it the locking bolt; Figure 25 The pressure, flushing and recovery pipe with sleeve adapter at the Connecting an empty or emptied cartridge case; Figure 26 The pressure, flushing and recovery pipe with sleeve adapter and empty Sleeve before insertion into the initial tube; Figure 27 The pressure, flushing and recovery pipe with sleeve adapter and empty Sleeve inserted into the initial pipe when placing a drill pipe onto the initial pipe; Figure 28 The downward movement of a drill pipe over the pressure, flushing and Recovery pipe onto the starting pipe; Figure 29 Screwing a drill pipe onto the starting pipe; Figure 30 A drill pipe screwed onto the starting pipe; Figure 31 The DSB adapter at the top of the pressure, flushing and recovery pipe at the Placement on the upper end of the pressure, flushing and recovery pipe; Figure 32 The DSB adapter of the pressure, flushing and recovery pipe is fully attached; Figure 33 The drill head above the upper end of the pressure, flushing and recovery pipe and the uppermost drill pipe; Figure 34 Enlarged view of the lower threaded section of the drill head and the DSB adapter with the pressure, flushing and recovery pipe connected below inside the drill pipe; Figure 35 The drill head with drive flange during lowering over the upper End of the pressure, flushing and recovery pipe for screwing onto the drill pipe; Figure 36 Screwing the drill head with the drive flange onto the Drill pipe.

[0016] Figure 1 shows a rotary hammer with a drive and hammer for rotating the drill head, as is commonly found in commercially available rotary hammers. The output shaft 1 protrudes from the bottom, having a thread 3, and is rotated by a laterally arranged hydraulic drive 2. The rotary hammer incorporates an internal hammer mechanism that imparts impacts to the output shaft 1 from above. The rotational speeds of the drive vary from approximately 50 to 1000 rpm. Umin'1 The lower the rotational speed, the higher the applied torque at the output shaft 1, which at 50 rpm -1 Approximately 15 kNm is achieved. The driving impacts are generated at hydraulic pressures up to 200 bar and exhibit impact energies up to 500 Nm, at impact rates up to 2400 min⁻¹. -1 Figure 2 shows this rotary hammer in a bottom view with the output shaft 1 protruding from below, and Figure 3 shows it in its upright operating position, as the rotary hammer is used, with the drill head 5 connected to the output shaft 1 at the bottom, for which the thread 3 of the output shaft 1 has been screwed into the drill head. Figure 4 shows a drill head separately and enlarged, with its external thread for screwing into a drill pipe, and Figure 5 shows this drill head in a longitudinal section. The central axial bore 6 for flushing, the axial bore 37 with its inner wall visible from below, and a radial bore 7 for venting are clearly visible.

[0017] Starting with Figure 6, the drilling system according to the invention is presented and described. Here, the drilling system 4 is shown in its entirety from the outside. It consists very simply of, in principle, only eight parts, namely, visible from top to bottom from the outside, the following: 1. Drill head 5 2. One or more screwed-together drill pipe sections form the drill pipe 9. 3. Initial pipe 8 4. Drill bit 10 Inside the drill pipe 9 or the drill pipe sections and the initial pipe 8, and therefore not visible in Figure 6, are the following parts from top to bottom, as shown in Figure 11: 5. Pressure, flushing and recovery pipe adapter (DSB adapter) 18 6. One or more screwed-together pressure, flushing and recovery pipes (DSB) 19 7. Sleeve adapter 21 8. Sleeve 17

[0018] Figure 6 shows the assembled drilling system 4 with the drill head 5 for the drive at the top. It is screwed into an internal thread of the subsequent drill tube 9 and can then drive and rotate it clockwise (when viewed from above). The drill tube 9 is shown here with its lower external thread in a corresponding A suitable internal thread is screwed into the top of the initial pipe 8. These threads are relatively coarse, milled from the pipe material. The threads are preferably re-greased before each assembly, which is carried out using the rotating drill head 5. The drill pipe 9 can be extended with one or more drill pipe sections to penetrate deeper into the ground. The drill pipe sections are advantageously approximately 1 meter long. This makes them manageable and allows them to be carried by one person and stored as a stack at the drilling rig for insertion. The initial pipe 8 carries a drill bit 10 at its lower end. Figure 7 shows this assembled drilling system viewed from a low angle, while Figure 8 shows a single drill pipe 9 viewed from a low angle.At its lower end, a relatively coarse external thread 11 is formed, allowing it to be screwed into a corresponding internal thread 12 on the next drill tube 9, as shown in Figure 9, or into the lowest tube, i.e., the starting tube 8. Viewed from above, the hammer drill drive rotates clockwise during drilling, thus tightening these connecting threads 11 and 12. Of course, drilling in a counterclockwise direction is also possible; however, the threads used would then have to run in the opposite direction.

[0019] Figure 10 shows an enlarged view of the drill bit 10 from a low angle. Drill segments 13, reinforced with carbide pins, are brazed onto the underside of the drill bits, and lateral external removal elements 15 with inclined surfaces 14 ensure that the material is removed upwards. The volume of material located axially beneath the drill bit segments 13 of the drill bit 10, that is, directly beneath the rotating ring formed by the drill bit 10, is partly injected into the core, partly into the surrounding soil, and a portion is conveyed upwards as waste material on the outside of the drill bit 10, the initial pipe 8, and the drill pipe 9. In the lower part of the drill bit 10, an internal shoulder 16 is formed as a radially inwardly projecting projection, against which the sleeve, the core sample sleeve, or the core catcher abuts (the latter is not shown here). This sleeve is flush with this projection on the inside.As the drill bit 10 advances, the descending sleeve or core catcher encloses the exposed core, sealing it tightly. It is possible to use other commercially available drill bits, for example. For example, diamond crowns or crowns adorned in other ways.

[0020] Figure 11 shows, starting from the bottom, a sleeve 17 or core catcher. Above this, the sleeve adapter 21 can be seen, followed by the pressure, flushing, and retrieval pipe 19 with its upper pressure, flushing, and retrieval pipe adapter 18, which is subjected to the impacts of the ram hammer. In the example shown, this pressure, flushing, and retrieval pipe 19 rotates uniformly with the initial pipe 8 and any inserted drill pipe sections for the drill pipe 9 (Figure 6).

[0021] A particularly important and crucial element is the sleeve adapter 21 shown here, located between the pressure, flushing, and retrieval pipe 19 and the sleeve 17 or core catcher. While the pressure, flushing, and retrieval pipe 19 rotates and hammers, the descending sleeve 17 encloses the core sample growing into it during drilling without rotating. Only the strong, high-frequency ramming impacts from the pressure, flushing, and retrieval pipe 19 act on the sleeve 17, subjecting this sleeve adapter 21 to enormous peak forces. This adapter must therefore mediate between the rotation of the pressure, flushing, and retrieval pipe 19 and the non-rotating sleeve 17, simultaneously absorbing and withstanding enormous impacts at a high cadence and converting the rotation of the pressure, flushing, and retrieval pipe 19 into a rotation-free support on the sleeve 17.This cannot happen without sliding friction, and therefore it is clear that large amounts of frictional heat are generated. This heat must be thermally absorbed by the sleeve adapter 21, and at the same time, the sleeve adapter 21 must be adequately cooled to withstand this continuously generated frictional heat and dissipate it to the outside.

[0022] Figure 12 shows an enlarged view of the upper pressure, flushing, and recovery pipe adapter 18, or DSB adapter, of the pressure, flushing, and recovery pipe 19. Flushing water flows downwards through the interior of the pressure, flushing, and recovery pipe 19 via the axial bore with its inner wall 52 and is guided outwards within the sleeve adapter 21 to the outer surface of the initial pipe 8. A circumferential annular groove 54 is visible on the pressure, flushing, and recovery pipe adapter 18, into which an O-ring is inserted to seal against the inner wall of the axial bore 37 of the drill head 5.

[0023] Figure 13 shows a hollow pressure, flushing, and recovery pipe section (DSB) 53 as an optional extension pipe for the hollow pressure, flushing, and recovery pipe 19, which is simply screwed into the upper, corresponding internal thread of the pressure, flushing, and recovery pipe 19 connected below, using its lower external thread. The extension pipe 53 thus essentially corresponds to the actual pressure, flushing, and recovery pipe 19, which, in the example shown, has an internal thread at the top for extension.

[0024] The following section introduces the crucial and unique element of this drilling system: the sleeve adapter 21, which ensures the connection between the DSB 19 and the sleeve 17. Figure 14 shows this sleeve adapter 21 for the impact-resistant connection of the sleeve 17, or the core catcher, to the DSB 19 pressure, flushing, and retrieval pipe in a top-down oblique view. A threaded stub 35 protrudes from the top of the sleeve adapter 21, extending downwards into a base body 22 of the sleeve adapter. This base body 22 forms a plate or shoulder 44 at its upper end. The pressure, flushing, and retrieval pipe 19 is screwed onto this base body 22 via its lower internal thread, and thus rotates uniformly with the drill pipe 9 and the rotating pressure, flushing, and retrieval pipe 19. Below this is a sealing ring 36, which is preferably made of hard plastic rubber and can rotate with the base body 22.The rotation of the pressure, flushing, and retrieval pipe 19 is thus absorbed between the base body 22 and the stationary receiving ring 23, so that the stationary lower part 24 of the adapter 21 is connected to the sleeve 17 by a force-fit but rotationally fixed connection. A sliding sleeve 25, the purpose of which will become clear later, is visible above the visible part of the lower part 24. The sleeve 17, or the core catcher, is slid precisely onto this lower part 24 from below until its upper edge abuts the sliding sleeve 25 at the bottom. A pressure ring 33 made of hardened steel is attached to the bottom of the receiving ring 23 of the adapter. A rubber disc 27, projecting slightly radially beyond the lower part 24 of the base body 22, can also be seen at the bottom of the lower part 24. This disc seals the sleeve adapter 21 against the inner wall of the sleeve 17.

[0025] Figure 15 shows the sleeve adapter 21 in a view from a low angle. Here, from top to bottom, one can see first the threaded stub 35 for screwing the pressure, flushing, and retrieval pipe 19 onto it from above, then the shoulder 44 of the base body 22 of the sleeve adapter 21, followed by the hard rubber sealing ring 36, which rests on the receiving ring 23. Next comes the sliding sleeve 25, and below it, the pressure ring 33 made of hardened steel. The slightly radially projecting rubber disc 27 for sealing the sleeve adapter 21 against the inner wall of the sleeve 17 is clamped to the lower part 24 by a steel washer 29 and four axial screws 31. The diametrical bore 43 for the fixing bolt, which extends through this diametrical bore in the lower part 24, is also visible, as is a bore 38 for a locking bolt, as will become clear from the following figures.

[0026] The detailed construction of the sleeve adapter 21 is shown in Figure 16, which depicts this sleeve adapter 21 in an exploded view with the parts exploded along its central axis. Starting from the top, one first sees the base body 22 of the adapter 21, which is designed for rotation, followed by the sealing ring 36, the hard rubber plastic ring for sealing against the initial tube 8. This then rests on the receiving ring 23 shown below. This receiving ring 23 is stationary during operation, i.e., it does not rotate, and it transitions at the bottom into a tapered section with radial bores 41 all around, into which cylindrical pins 32 fit. These pins are shown further down in relation to the lower part 24, and their function will immediately become clear. Below the receiving ring 23, a circlip 26 is shown as a retaining ring, which, upon assembly, rests in the annular groove 45 on the base body 22.From below, the stationary lower part 24 of the sleeve adapter 21 is slid over the tapered section of the receiving ring 23. Subsequently, the cylindrical pins 32, shown around the circumference, are pressed from the outside into the radial bores 42 on the lower part 24 and into the corresponding radial bores 41 on the receiving ring 23, thus connecting these two parts 23 and 24 in a rotationally fixed manner. After inserting these cylindrical pins 32, the sliding sleeve 25 is slid over the tapered lower part of the receiving ring 23, covering and thus securing these cylindrical pins 32.

[0027] The retaining ring 26 is then inserted into the ring groove 45 at the lower end of the The base body 22 is inserted so that it is secured axially to the base body 22 by the receiving ring 23. The lower part 24 of the adapter 21 has a diametrically opposed bore 43 for receiving a locking bolt (not shown). At right angles to this diametrically opposed bore 43, there are two further radial bores 38 lying on a common axis, into which locking bolts 34 are inserted to secure the inserted locking bolt. These two locking bolts 34 each have a pressure-loaded ball 40 at their front, which engages in a longitudinal groove on the inserted locking bolt and, for example, snaps into a recess 56 at half the length of the groove, thus securing it. After being inserted into the bores 38, the locking bolts 34 are each secured by a circlip 39.The flushing water, which flows downwards from above through the hollow pressure, flushing, and recovery tube 19, flows outwards through the axially bored fixing bolt in bore 43, as will become clear. This flushing water first flows through the sleeve adapter 21 and then radially out of its lower part 24, namely on both sides through the fixing bolt in its axial bore to its end faces and thus outwards. The pressure ring 33 absorbs the axial forces acting on the sliding sleeve 25 and distributes them evenly onto the receiving ring 23, which is made of aluminum bronze. The rubber disc 27 and the slightly smaller steel disc 29 are clamped to the lower part 24 on four washers 28 and secured by means of the four screws 31 and their associated spring washers 30 shown in the illustration.

[0028] Figure 17 shows the sleeve 17, or core catcher, viewed from a low angle. On its inner side, the lower edge of the sleeve 17 is equipped with a number of spring steel elements 20 arranged around its circumference, which project upwards in an arc towards the central axis of the sleeve 17. When the sleeve 17, which is subjected to ramming blows from above in the same manner as the starting tube 8 and the drill bit 10, is placed over a core exposed by the drilling progress of the drill bit 10 and the starting tube 8, these spring steel elements 20 are pressed against the inner wall of the sleeve 17 by the core. The sleeve 17 is then moved further over the stationary core with a purely axial movement, without rotation, with the spring steel elements 20 thus pressed against its inner surface. However, when the sleeve 17 is pulled up with the pressure, flushing and retrieval pipe 19, these spring steel elements 20 act as barbs. When the drill core is pulled up, If the sleeve 17 is pulled upwards and does not develop sufficient adhesion force, these spring steel elements 20 engage radially into the core at the slightest slippage of the sleeve 17 on the drill core, curve towards the central axis of the sleeve 17, and form a collection basket for the drill core. This ensures that the core is securely held in the sleeve 17 and prevented from slipping downwards, thus reliably preventing core loss in the loose rock. A radial bore 46 for the flushing water coming from the sleeve adapter 21 is visible at the upper edge of the sleeve 17.

[0029] Figure 18 shows the sleeve 17, or core catcher, viewed from a slightly oblique angle above. Here, it can be seen that there are two diametrically aligned bores 46 located in the upper edge region of the sleeve 17. When the sleeve 17 is placed over the lower part 24 of the sleeve adapter 21, these two bores 46 align with the radial bores 43 in the lower part 24. This allows the flushing water flowing from the end faces of the locking bolt inserted there to escape from the interior of the adapter 21 and exit through these aligned bores 46 in the upper region of the sleeve 17. This flushing water performs several functions. First, it cools the sleeve adapter 21, which is heated due to the sliding friction between the rotating base body 22, the plastic hard rubber sliding ring 36 and the stationary receiving ring 23 and lower part 24, as well as due to the ramming impacts.Furthermore, it lubricates between the outer surface of the rotationally fixed sleeve 17 and the inner surface of the initial pipe 8 rotating around the sleeve, and finally, it conveys waste rock from below the drill bit 10 radially outwards and then upwards on the outer surface of the initial pipe 8. This continuously flushes the borehole and also lubricates and cools the external surface of the initial pipe 8. Depending on the conditions, however, it is also possible to drill dry.

[0030] Figure 19 shows an insert with spring steel elements 20, unrolled in the relaxed state, which here form a kind of comb. This comb is rolled lengthwise and then inserted downwards into the sleeve 17, where it rests on an inner shoulder 58, as can be seen in Figure 17.

[0031] This reveals and describes the individual components of the drilling system. How Does drilling and retrieving a core sample from loose subsoil now work with this drilling system? The entire process is explained using a sequence of images, for example, as shown in Figures 20 to 36.

[0032] Figure 20 shows, at the bottom, the exposed initial pipe 8 with the sleeve 17 inside and the hollow pressure, flushing, and retrieval pipe 19 screwed onto it by means of the sleeve adapter 21. Above this, the drill head 5 is shown, which is set in rotation by the hydraulic drill drive of the drill hammer 2 via a flange 47. Depending on the desired drilling depth, sections of drill pipe can be inserted between this drill head 5 and the lowest section, the initial pipe 8, as extension pipes for the drill pipe 9. The drill head 5 is screwed directly onto the initial pipe 8 at the beginning. Drilling then proceeds until the initial pipe 8 is almost embedded in the ground. The drill head 5 is then unscrewed from the initial pipe 8 by a counter-rotation.If the initial pipe 8, when buried in the ground, is exposed as shown here, i.e., the drill head 5 with the drive flange 47 is removed, the pressure, flushing, and retrieval pipe 19, with the sleeve 17 attached to its lower end, can be pulled axially upwards out of the initial pipe 8, as shown in Figure 21, where the sleeve adapter 21 is just emerging. In Figure 22, the adapter 21, along with the sleeve 17 (or core catcher) attached to the pressure, flushing, and retrieval pipe 19, has been completely pulled out of the initial pipe 8. Here, one end face of the locking bolt 48, which securely holds the sleeve 17 to the sleeve adapter 21, is visible. In this state, the sleeve 17 is pulled upwards out of the initial pipe 8 with the aid of the pressure, flushing, and retrieval pipe 19 until it finally reaches the surface.

[0033] Once the surface is reached, the locking bolt 48 is knocked, pulled, or pushed out of the bore 43 in the lower part 24 of the sleeve adapter 21, as shown in Figure 23. Only the empty diametric bore 43 in the lower part 24 of the sleeve adapter 21 is visible. Locking bolts 34 are inserted into two bores 38 perpendicular to the bore 43. These bolts have a ball 40 at their front, which is pressurized by a compression spring, as shown in Figure 16. The locking bolt 48 is driven against the resistance of these pressurized balls 40 at the front. the locking bolt 34 was knocked out of the diametrical bore 43, as can be seen from Figure 24.

[0034] Figure 24 shows an enlarged view of the lower part 24 of the sleeve adapter 21, looking into the diametrically opposed bore 43 for the locking bolt 48, which is shown separately next to it. However, in order to be inserted into the lower part 24 of the sleeve adapter 21, this bolt must first be rotated 45° about its longitudinal axis, as indicated by an arrow. On two opposite sides of this locking bolt 48, channel-like longitudinal grooves 50 are cut, the bottoms of which have a convex recess 56 halfway along the locking bolt 48. These spring-loaded balls 40 (Figure 16) of the locking bolts 34 fit into these recesses 56 and only when the fixing bolt 48 receives a sufficiently strong impact in the longitudinal direction is it able to overcome the locking mechanism by pushing back the spring-loaded balls 40 and can then be pushed or pulled out of the bore 43, while its longitudinal grooves 50 slide outwards past the balls 40.As can be seen here, a central transverse bore 49 is provided in the fixing bolt 48, which communicates with an axial bore 55. These bores 49 and 55 serve to guide the rinsing water, which enters the sleeve adapter 21 from above through the axial bore 51, through the transverse bore 49 into the fixing bolt 48, and is then guided outwards along the axial bore 55 from its end faces. One of the bores 46, into which the fixing bolt 48 previously engaged and held it, can still be seen on the sleeve 17 in Figure 25; the rinsing water exits through this bore.

[0035] After the sleeve 17, or core catcher, has been brought into a horizontal position on the surface and the contained core sample has been carefully pushed out of the sleeve 17 onto a trough-shaped core carrier using a piston, the core sample is now virtually undisturbed. The empty sleeve 17 can be immediately reinserted for the extraction of the next core sample, or a readily available empty sleeve 17 can be inserted. In one variant, a liner can be inserted into the sleeve 17, which then lines the inside of the sleeve 17 and into which a core sample grows. In this case, the retrieved core sample, along with the liner, is pushed out of the sleeve 17 and is then completely intact, like a sausage. Individual slices can be cut off in portions to... The structure of the drill core and how it changes along its entire length are to be examined. If, in the process, a sleeve 17 is brought to the surface along with the drill core, an empty sleeve 17 can be immediately connected to the sleeve adapter 21 after the sleeve 17 has been separated from the sleeve adapter 21, and this can be immediately lowered back into the initial pipe 8 in the borehole, thus allowing drilling to continue without interrupting the drilling operations due to the extraction of the drill core from the recovered sleeve 17.

[0036] Figure 25 shows how the sleeve adapter 21 is connected to an empty sleeve 17 by lowering it into the sleeve. When the bore 43 on the sleeve adapter 21 aligns with the bore 46 on the sleeve 17, the locking bolt 48 can be inserted, and the sleeve 17 is ready to be lowered into the initial pipe 8 along with the pressure, flushing, and retrieval pipe 19. This lowering process is illustrated in Figure 26. Once the sleeve 17 is fully inserted into the initial pipe 8, i.e., resting against the drill bit 10 at the bottom, the next step is shown in Figure 27. A drill pipe 9 is slipped over the pressure, flushing, and retrieval pipe 19 as an extension pipe and lowered onto the initial pipe 8, as shown in Figure 28, and then screwed onto the initial pipe 8, as shown in Figure 29. After the screws have been tightened, the situation is as shown in Figure 30.Finally, as shown in Figure 31, the pressure, flushing, and recovery pipe adapter 18 of the pressure, flushing, and recovery pipe 19 is first attached or screwed on, and then, from the position shown in Figure 32, the drill head 5 with the drive flange 47 is screwed on, as shown in Figure 33. Details of this are shown in Figures 34 to 36.

[0037] As can be seen from this description and the figures, the pressure, flushing, and retrieval pipe 19 lives up to its name. During drilling, it rotates uniformly with the drill pipe 9 or initial pipe 8, and the sleeve adapter 21 at its lower end provides the connection to the stationary sleeve 17 or core catcher. The hard ramming impacts on the pressure, flushing, and retrieval pipe 19 are reliably and directly transmitted by the sleeve adapter 21 to the sleeve 17 or core catcher. The core catcher is thus pressed downwards with the same pressure as the drill bit 10, ensuring the continuous lowering of the sleeve 17 over the exposed core. The pressure, flushing, and retrieval pipe 19 therefore primarily fulfills a pressure function. During drilling, flushing water can be pumped downwards through the pressure, flushing, and retrieval pipe 19 and is directed outwards through the sleeve adapter 21, that is, first axially through the pressure, flushing, and retrieval pipe 19, then axially through the sleeve adapter 21, and finally radially, that is, in the axial direction through the diametrically inserted fixing bolt 48 to its two end faces and then outwards through the bore 46 in the sleeve 17. The pressure, flushing, and retrieval pipe 19 therefore also has a flushing function. When it is necessary to retrieve the filled sleeve 17 with the drill core trapped inside, the sleeve 17 with the drill core contained within it is retrieved after the drill head 5 is loosened, using the pressure, flushing, and retrieval pipe 19. Therefore, the pressure, flushing, and retrieval pipe 19 also has a retrieval function. It integrally combines these three important functions.

[0038] In the embodiment described so far, the pressure, flushing, and retrieval pipe 19 rotates with the drill head 5 and the drill tube 9, and the sleeve adapter 21 mediates with respect to the rotationally fixed or non-rotating sleeve 17 by having two axially successive parts that are rotatable relative to each other. A sealing ring 36 made of hard rubber plastic is preferably arranged between the axially successive parts. If, in an alternative embodiment, a rotating disc body constructed similarly to this sleeve adapter—hereafter referred to as the drill head adapter—is screwed into the bore in the drill head 5 with its threaded stub at the top, the bore having an internal thread for this purpose, then the upper part of this rotating disc body or drill head adapter rotates with the drill head 5, while the lower part, which is rotatable relative to the upper part, remains stationary.It is connected to the now upper end of the rotary, flushing, and retrieval tube 19 in the same way as the previously described lower part of the sleeve adapter 21, using a locking bolt. This locking bolt, however, does not require an axial bore, but only a transverse bore to allow the flushing water to pass downwards. At the bottom, the pressure, flushing, and retrieval tube 19 is then screwed to a single lower part of a sleeve adapter 21. For this purpose, the lower part of the sleeve adapter 21 forms a threaded stub at its upper end, and the rotary, flushing, and retrieval tube 19 has a corresponding internal thread at its lower end. The connection of the lower part of the sleeve adapter 21 to the sleeve 17 is effected, as already described, via the locking bolt 48 with its axial bore 55. Flushing proceeds as before from the drill head 5 through the pressure, flushing, and retrieval tube 19 and the lower part of the sleeve adapter 21, and then... through the fixing bolt 48 to the outside. In this alternative design, the pressure, flushing, and retrieval pipe 19 also performs the three functions mentioned above: first, exerting pressure on the sleeve 17; second, flushing and thus cooling; and third, retrieving the sleeve 17 when it is full, that is, pulling it upwards to the surface. And despite the fact that the pressure, flushing, and retrieval pipe 19 remains stationary in this design, it can rotate if the sleeve 17 rotates a few degrees over a drill core during sinking. In this case, the drill head adapter, acting as a rotating disc body at the top with its two axially aligned and mutually rotatable parts, mediates with the rotating drill head 5.

[0039] With the inventive method for core drilling in loose to firm ground and for taking drill or soil samples from the same, as well as the inventive device for carrying out this method, almost undisturbed drill or soil samples can be taken, which enables optimal evaluation and analysis of their contents. Number list 1 Output shaft of the rotary hammer 2 hydraulic drilling drive of the drill hammer 3 threads on the output shaft 1 4 drilling system 5 drill head 6 axial bore on drill head 7 radial bore on drill head (venting) 8 Initial pipe 9 Drill pipe, extension for drill pipe 10 drill bits 11 External thread at the bottom of the drill pipe / extension pipe 9 12 internal threads at the top of the drill pipe / extension pipe 9 13 drill bit segments studded with carbide 14 Sloping surface on clearing elements 15 15 waste rock elements 16th paragraph, radial cantilever 17 Sleeve, core catcher 18 pressure, flushing and recovery pipe adapters 19 Pressure, flushing and recovery pipe 20 spring steel elements at the lower inner edge of the drill core catcher 17 21 Sleeve adapters between pressure, flushing and retrieval pipe and sleeve / core catcher 17 22 Base body top to sleeve adapter 21 23 Mounting ring for sleeve adapter 21 24 Lower part for sleeve adapter 21 25 Sliding sleeve to sleeve adapter 21 26 Retaining ring, preferably DIN 471-65 x 2.5 27 Rubber disc at the bottom for sleeve adapter 21 28 Washer for sleeve adapter 21 29 Steel disc at the bottom for sleeve adapter 21 30 spring washers, preferably DIN 128 - A8 31 Screw, preferably hexagon screw with thread up to the head ISO 4017 - M8 x 20 32. Cylindrical pin, preferably NW 8 x 25mm with internal thread M5 33 Pressure ring for sleeve adapter 21 34 locking bolts with pressure ball 40 35 Threaded stub at the top of the sleeve adapter 21 36 Upper sealing ring, preferably made of hard plastic rubber 37 Axial bore in the drill head 5 38 Hole for locking bolt 34 39 Seeger ring for locking bolt 34 40 pressure-loaded ball at the front of the locking bolt 34 41 radial bores all around the stationary mounting ring 23 of the sleeve adapter 21 42 radial bores all around the stationary lower part 24 of the sleeve adapter 21 43 Bore on the stationary lower part for fixing bolts 48 44 Shoulder at the top of the base body 22 of the sleeve adapter 21 45 Ring groove at the lower end of the base body 22 46 diametrical hole at the top of the sleeve 17 47 Drive flange on the drill head 5 48 fixing bolts in the lower part 24 of the sleeve adapter 21 49 Transverse bore in the fixing bolt 48 50 Longitudinal groove on the fixing bolt 48 51 Axial bore in the lower part 24 of the sleeve adapter 21 for the rinsing water 52 Inner wall of the axial bore in the pressure, flushing and recovery adapter 18 53 Pressure, flushing and recovery pipe section as extension pipe 54 Groove for O-ring on pressure, flushing and recovery pipe adapter 18 55 Axial bore in the fixing bolt 48 56 Recess halfway along the longitudinal groove 50

Claims

1. Method for core drilling in loose to solid ground and for taking samples from the same, in which an initial pipe (8) is drilled into the ground by means of a drilling system (4) with the initial pipe (8) and a drill bit (10) fastened thereto at a bottom end, and with a possible attachable drill pipe (9) consisting of one or more drill pipe sections, by rotation and superimposed ramming, wherein within the initial pipe (8), a sleeve (17) travels axially with the initial pipe (8), characterized in thata) the initial pipe (8) with the drill bit (10) arranged at the bottom end as well as the possible drill pipe (9) is drilled into the ground in a rotating and hammering manner by means of a drivable drill head (5) which can be subjected to hammering impacts, while the sleeve (17) is held in an interior of the initial pipe (8) without rotation as a result of a drill core growing relatively into the sleeve (17) and the sleeve is pressed down from above by a pressure, flushing and recovery pipe (19), so that the sleeve (17) moves downwardly in the axial direction with the initial pipe (8) while growing the drill core into an interior of the sleeve (17), wherein eitherthe pressure, flushing and recovery pipe (19) rotates along with the initial pipe (8) and the possible drill pipe (9) and pressurizes the nonrotating sleeve (17) via a sleeve adapter (21) with parts which can be rotated relative to one another, ora rotary disc body as a drill head adapter rotates at a top end of the pressure flushing and recovery pipe (19) and the rotary disc body is connected to the rotating drill head (5) and the non-rotating pressure, flushing and recovery pipe (19) pressurizes the non-rotating sleeve (17), b) after the sleeve (17) has been filled, the drill head (5) is lifted off the initial pipe (8), or lifted off the drill pipes (9) in case further drill pipes (9) have been connected to the initial drill pipe (8), by unscrewing any drill pipe (9) still above the bottom above the initial pipe (8), the pressure, flushing and recovery pipe (19) is exposed and is pulled out of the initial pipe (8)2021354880   07 Sep 2026together with the sleeve (17) and the sleeve (17) is detached from the pressure, flushing and recovery pipe (19).

2. Method according to claim 1, characterized in that after step b)c) an empty sleeve (17) is connected at the bottom to the pressure, flushing and recovery pipe (19) and, hanging on the pressure, flushing and recovery pipe (19), is lowered into the initial pipe (8) and, depending on the drilling depth, one or more sections of the pressure, flushing and recovery pipe (19) are inserted as extension pipes (53) and, correspondingly, one or more drill pipe sections for the drill pipe (9) are inserted and coupled to the drill head (5),d) drilling is continued until the sleeve (17) is filled, whereupon step b) is repeatedand wherein, in parallel or with a time delay to these processes, the drill cores are ejected from the recovered casings (17) in the horizontal position of the casings (17) mechanically, hydraulically or pneumatically into suitable horizontal tubular sections.

3. Method according to one of the preceding claims, characterized in that at the lower end of the sleeve (17), spring steel elements (20) initially directed into the interior of its lower mouth area towards the center are swung up by the drilling sample being turned over and growing into the sleeve (17) when the sleeve (17) is lowered, and which spring steel elements (20) retain the drilling core in the sleeve (17) when the sleeve (17) is pulled out.

4. Method according to one of the preceding claims, characterized in that no fixing rod is installed to retain the sleeve (17).

5. Method according to one of the preceding claims, characterized in that the initial pipe (8) and any drill pipe (9) and the pressure, flushing and recovery pipe (19) are connected and disconnected by screwing and unscrewing the drill head (5) mechanically driven by a rotary drive.2021354880   07 Sep 20266. Device for carrying out the method according to claim 1, having a rotary drive with a rotatable drilling head (5) which can be subjected to impacts from above by means of a pile driver and the torque of which can be transmitted to an initial pipe (8) with a drill bit (10) arranged at the end and to a possible drill pipe (9) consisting of one or more drill pipe sections connected to the initial pipe (8) at the top, characterized in that inside the initial pipe (8), a sleeve (17) or bore core catcher respectively free of rotation flushes, whereby the sleeve (17) by means of a sleeve adapter (21) having parts which can be rotated relative to one another, and a pressure, flushing and recovery pipe (19) connected thereto, is connected in a pressure-locking and traction-locking manner to the rotating drill head (5), whereby eitherthe pressure, flushing and recovery pipe (19) is connected to the drill head (5) in a co-rotating manner and the sleeve (17) is impactable by the pressure, flushing and recovery pipe (19) via the sleeve adapter (21) which is detachable from the sleeve (17), orthe pressure, flushing and recovery pipe (19) is connected to the drill head (5) in a non-rotating manner and the sleeve (17) is impactable by the pressure, flushing and recovery pipe (19) with pressure, while a rotary disc body is seated as a drill head adapter with mutually rotatable parts at the top of the pressure, flushing and recovery pipe (19) and is connected to the rotating drill head (5).

7. Device according to claim 6, characterized in that the sleeve (17) is seated with its lower end against a radially inwardly projecting projection (16) at the upper end of the drill bit (10) rotating along at the bottom of the initial pipe (8) in a rotation-free manner.

8. Device according to one of claims 6 to 7, characterized in that no fixing rod is installed for holding the sleeve (17).

9. Device according to one of claims 6 to 8, characterized in that the sleeve (17) has, in its lower mouth region, spring steel elements (20) projecting into the interior for securing the received drill core.2021354880   07 Sep 202610. Device according to one of claims 6 to 9, characterized in that the parts of the sleeve adapter (21) or of the rotary disk body which can be rotated relative to one another are axially consecutive as a drill head adapter, with an interposed sealing ring (36) of plastic hard rubber.

Images