EP1381756B2

EP1381756B2 - Method and device for drilling a hole and for securing an anchorage in a bore hole

Info

Publication number: EP1381756B2
Application number: EP02766568A
Authority: EP
Inventors: Josef Mocivnik
Original assignee: Alwag Tunnelausbau GmbH
Current assignee: Alwag Tunnelausbau GmbH
Priority date: 2001-04-26
Filing date: 2002-04-23
Publication date: 2010-03-24
Anticipated expiration: 2022-04-23
Also published as: HRP20030813A2; CZ20032893A3; EP1381756A1; WO2002088523A1; KR20040004603A; AT332436T; SI1381756T2; CN1503875A; KR100779340B1; US20040084217A1; SI1381756T1; CN100356035C; HU0303931A3; JP2004522019A; HK1066581A1; PL197261B1; US7080697B2; HU0303931A2; TW530113B; ES2262838T5

Description

The present invention relates to a method for drilling, in particular percussion or rotary impact drilling, a hole in soil or rock material and defining an anchor in the hole, wherein a borehole is formed by a drill bit mounted on a drill bit and at the same time a drill pipe in Distance is introduced and coupled to the drill bit cladding tube, wherein the cladding tube is introduced by a tensile stress on this coupling with the drill bit in the hole, as well as a device for drilling, in particular impact or rotary impact drilling, holes in soil or rock material and for producing an anchoring, wherein a drill bit mounted on a drill pipe forms a borehole and a tube surrounding the drill string and adjacent to the drill bit and thus coupled is provided, wherein the jacket tube by a tensile stress on this coupling with the drill bit in the borehole is insertable.
For example, the drill rod can be designed with additional ribs and grooves on its outer circumference, so that a correspondingly good anchoring effect can be achieved if the drill rod remains in the borehole and is subsequently backfilled. In connection with the production of a hole or borehole in soil or rock material and a subsequent definition of an anchorage or a lining in the borehole, it is for example from WO 98/21439 and the WO 98/58132 it is known to introduce a cladding tube into the wellbore during the drilling operation, such as impact or rotational impact drilling, whereupon after completion of the bore, if necessary, a portion of the drill crown is removed from the well together with the drill string while the cladding tube remains in the wellbore so that subsequently is formed by filling with a hardening mass anchor in the borehole. According to the training according to WO 98/58132 the drill pipe can be formed on its outer circumference with additional ribs and grooves, so that when the drill pipe remains in the borehole and a subsequent backfilling a correspondingly good anchor effect can be achieved.
From the WO 00/66873 From the WO 00/66873 there is provided an apparatus and method for forming a wellbore in soil or rock material, wherein a wellbore is produced by a drilling apparatus coupled to a separate drive via a drill string, and a friction bolt assembly into the body via a separate drive and independently of the introduction of the drill bit drilled hole is driven.
From the US-A 5,836,405 From the US-A 5,836,405 a handheld drilling apparatus has become known in which a drill string carrying a drill string is surrounded by a longitudinally slotted cladding or fastener at a distance, wherein both the drilling member and the cladding tube by exerting a shock load at the end facing away from the bore hole inside the hole be introduced.
and other references, embodiments are known in which the tubular anchorage to be introduced subsequently is held by appropriate holding elements at a diameter that is reduced compared to the final state, whereupon, after complete insertion into the borehole and removal of the holding devices, the pre-tensioned pipe, which usually has an in has substantially in the longitudinal direction extending slot, and thereby comes into contact with the borehole wall to achieve a desired anchoring effect or is pressed. The disadvantage of this known prior art is on the one hand the fact that the borehole has to be made in a first process step, whereupon, after removing the drilling tool and the drill rod, in a further process step the anchor device is introduced into the borehole, which may have a large length, and then subsequently by removing the corresponding holding device while expanding the outer diameter, a contact with the borehole wall is achieved. It is immediately evident that not only is a correspondingly increased expenditure of time required for the two separate working steps, but that a subsequent introduction of such an anchor device with a great length is possibly associated with difficulties. Furthermore, it can be assumed that removing the drilling device together with the drill rods and subsequently inserting the anchoring device can only be carried out in comparatively solid ground or rock, in which it must be ensured that not, for example, during the drilling process or after removing the drilling tool and before When the anchoring device is finally introduced, material breaks into the borehole, so that the borehole would be blocked, as a result of which the anchoring device can no longer be introduced. Alternatively, it is after making a well known to remove the drill with the drill pipe from the well, then an anchor or an anchor device is introduced into the well, for example, from the EP-B 0 241 451 , of the US-A 4,490,074 , of the DE-AS 21 05 888 , of the US-A 4,310,266 , of the EP-A-0 875 663 and further references are known in which the subsequently introduced, tubular anchorage is held by corresponding holding elements on a reduced compared to the final diameter, whereupon after complete insertion into the borehole and removing the holding devices, the prestressed tube, which usually has a in the has substantially slit extending in the longitudinal direction, widens and thereby comes into contact with the borehole wall to achieve a desired anchoring effect or is pressed. A disadvantage of this known prior art, on the one hand, the fact that the borehole must be prepared in a first process step, after which the drilling tool including the drill string in a further process step, the anchor device is introduced into the possibly a large length having borehole, then subsequently by removing the corresponding holding device by widening the outer diameter succeeds an investment in the borehole wall. It is immediately apparent that not only for the two separate steps, a correspondingly increased time is required, but that, where appropriate, a subsequent introduction of such an anchor device of great length is associated with difficulties. Furthermore, it can be assumed that a removal of the drilling device together with the drill pipe and a subsequent introduction of the anchoring device is feasible only in relatively solid soil or rock, which must be ensured that not, for example, during the drilling process or after removing the drill and before the final introduction of the anchoring device material breaks into the wellbore, so that the wellbore would be blocked, whereby an introduction of the anchor device is no longer possible.
The present invention therefore aims to provide a method and a device of the type mentioned above, wherein a simplified construction during the drilling process at least a provisional assurance is made possible and immediately after completion of a borehole anchoring to the inner wall of the well can be achieved ,
To solve these objects, the method according to the invention, starting from a method of the type mentioned above substantially characterized in that the cladding tube formed with a longitudinal slot is at least partially introduced substantially into engagement with the wellbore during drilling. Since the cladding tube formed with a longitudinal slot rests at least partially against the borehole wall during the production of the borehole, it becomes possible to provide an at least provisional securing during the boring process, it being ensured by providing the longitudinal slit that the cladding tube is sufficiently elastic or rigid is compliant to oppose, even with at least partial abutment against the borehole wall a not excessively large resistance to an introduction of the cladding tube, for example by a tensile or impact stress. In addition, it is ensured by the longitudinal slot having a cladding tube that immediately after the completion of the bore a corresponding anchorage by at least partial contact with the borehole wall can be achieved, so that to form such an anchoring time savings over known embodiments, wherein after completion of a hole the drill pipe has been removed and a separate anchor has been introduced into the borehole. In addition, the inventive method can be independent of the pierced Apply soil or rock material, since the cladding tube is introduced directly into the borehole during the introduction or formation of the borehole, so that even with loose rock, in which possibly a break-in at least after removal of the drilling tool and before the introduction of the anchorage are feared would have to fear any difficulties such as subsequently produced anchorages, since the introduced during drilling cladding always gets the free passage cross section of the well even with loose rock upright. After completion of the wellbore either the drilling tool can be at least partially removed with the drill string through the interior of the remaining casing in the wellbore or it can be to increase the anchor effect and the drill pipe together with the drill in the borehole, so that not only by the system Cladding tube to the borehole inner wall results in an anchoring effect, but also by the remaining drilling tool in the hole and the drill string anchoring effect can be increased. When introducing the cladding tube, which has a longitudinal slot, at least partially in contact with the borehole wall is further assumed that in a known introduction of a rinsing fluid in the region of the drill bit and thus carried out discharge of mined material also, in the region of the outer periphery the cladding tube a correspondingly liquid or viscous material layer is present, which gives a lubricating or lubricating effect when introducing the cladding tube. After completion of the bore and thus interruption of a further supply of a rinsing fluid, it is to be assumed that upon hardening of the material in the region of the outer circumference of the cladding tube, a corresponding increase in the friction between the outer circumference of the cladding tube and the borehole inner wall occurs, so that a correspondingly good anchoring effect of the adjacent to the borehole wall cladding can achieve.
In support of the anchoring effect of the at least partially already applied during insertion of the borehole inner wall cladding tube is proposed according to a preferred embodiment, that after completion of the borehole and removing the drill string an expandable element is introduced into the interior of the cladding tube and expanded. Such introduction of an expandable element enables the cladding tube to be reliably fixed on subsections, where appropriate, on the borehole inner wall, so that the anchoring effect can be increased.
In a particularly simple manner, an expandable element in the interior of the cladding tube can be defined in that the expandable element is widened by a impact stress, as corresponds to a further preferred embodiment of the method according to the invention. Such an expandable element not only provides a reliable abutment of the cladding tube at the borehole inner wall, but also counteracts a reduction of the clear cross section of the cladding tube, for example with a compressive stress by surrounding material or a tensile stress in the longitudinal direction of the anchor formed by the cladding tube otherwise, by providing the longitudinal slot, tensile stresses in the longitudinal direction of the cladding tube forming the anchorage could otherwise lead to a reduction in the armature cross section of the cladding tube, as a result of which the anchoring effect would be correspondingly reduced.
Depending on the surrounding material and thus also on the nature of the cladding tube, it is preferably proposed for an introduction of the cladding tube during the drilling process that the cladding tube is additionally introduced into the drilled hole by impact stress. It is according to the invention, the cladding tube, for example, coupled with the drill bit in a suitable manner and will be introduced by a tensile stress in the wellbore during the drilling process. In particular, with a larger material cross-section and thus higher strength having ducts, which are used to provide a more resistant anchorage, in addition, the cladding tube can be introduced by a Schlagbeanspruchung in the borehole simultaneously with the drilling process, not excessive forces on the drill bit for a take of the To introduce cladding tube.
For a proper introduction of the cladding tube during the drilling process is proposed in this context according to a further preferred embodiment, that after completion of the bore at least one defined by a predetermined breaking point connection along the slotted substantially longitudinally cladding tube is achieved.
A particularly simple release or separation of the predetermined breaking point is preferably carried out according to the invention in that the release or separation of the predetermined breaking point is effected by a slight retraction of at least the impact shoe and the cladding tube mounted thereon and an impact of the impact shoe. It can thus after completion of the bore by slight retraction of at least the beater and possibly the ring core and subsequent, the beater provided with festgehaltenem or at least partially frictionally mounted in the produced wellbore casing by expanding the inner diameter of the longitudinally slotted cladding tube by the For example, by providing matched support surfaces in the region of the front end of the cladding tube, a separation or release of the predetermined breaking point can be achieved by widening or spreading the front end of the cladding tube so that the overall outer diameter of the cladding tube is properly aligned expanded cladding on the finished borehole wall is achieved.
To further increase the anchoring effect, especially in loose rock or in cooperation with a projecting from the well end end optionally anchoring plate is proposed according to a further preferred embodiment that after completion of the well in a conventional manner, a filling of the interior of the cladding a hardening mass is made. The hardening material may leak out into the surrounding material, in particular in the front region and along the longitudinal slot of the expandable jacket tube, whereby the anchoring of the jacket tube is improved. By a leakage of the curing material and a subsequent bracing with an outer end of the cladding tube to be provided anchor plate can be beyond a fortification of possibly loosely layered soil or rock material can be achieved.
To solve the problems initially posed a device of the type mentioned above is substantially characterized in that the cladding tube has a longitudinal slot extending substantially in the longitudinal direction of the cladding tube. By providing a cladding tube formed with a longitudinal slot, it is ensured that the cladding tube can be introduced into the wellbore at least partially in contact with the borehole inner wall during the drilling operation, after which the drilling operation is terminated by the immediate, at least partial abutment of the cladding tube at the borehole inner wall a corresponding anchoring effect can be achieved.
In support of the anchoring effect is proposed according to a preferred embodiment that after completion of the borehole and removing the drill string an expandable element in the interior of the cladding tube can be introduced and expanded in abutment with the inner wall of the cladding tube. By such an expandable element, which is expandable in abutment against the inner wall of the cladding tube, a secure anchoring of the cladding tube is achieved in the borehole, wherein such an expandable element, for example, a reduction in cross-section of the cladding tube, in particular in a tensile stress on the anchoring formed by the cladding tube, counteracts and thus reliably maintains a desired anchor effect.
For a particularly favorable definition of the expandable element in the interior of the cladding tube is proposed according to a particularly preferred embodiment that the expandable element is formed by a sleeve which is expandable by introducing a particular conical element by a shock load, in particular when providing a plurality proposed by expandable elements inside the cladding tube and for a suitable positioning thereof according to a further preferred embodiment, that the cladding tube is provided on its inner wall with protrusions or protrusions for positioning the expandable element.
For a particularly simple introduction, it is preferably proposed that the cladding tube has at least one predetermined breaking point along its longitudinal slit running essentially in the longitudinal direction of the cladding tube. By inventively provided, at least one predetermined breaking point along the longitudinal slot of the cladding tube, the cladding tube can be easily introduced into the well during the drilling process, while after completion of the well, the at least one predetermined breaking point is solved or separated to the cladding in contact with the Drill hole inner wall to achieve the anchorage bring.
After completion of the bore, the at least one predetermined breaking point must be able to be released upon introduction of a corresponding force. In addition, however, the predetermined breaking point during the drilling process must ensure sufficient strength of the extending substantially over the entire length of the cladding longitudinal slot. For this purpose, it is proposed according to a further preferred embodiment that the at least one predetermined breaking point along the longitudinal slot of the cladding tube is formed by a weld for bridging the longitudinal slot. By appropriate positioning and training and optionally number of welds as a predetermined breaking point hiebei different requirements both in terms of resistance during the drilling process as well as for a separation or release of the predetermined breaking point after completion of the bore can be taken into account.
For a proper introduction of the cladding tube during the drilling process is also proposed that the cladding tube is set at the end facing the drill bit on a beater of the drill bit, as corresponds to a further preferred embodiment of the device according to the invention. In addition to such introduction of the cladding tube by a tensile stress by fixing the cladding tube to the drill bit or on the impact shoe can also be provided that on the protruding from the borehole end of the cladding tube a shock stress is applied, this particular for a greater strength having cladding tubes is possible.
In order to achieve a corresponding anchoring effect of the expandable after completion of the bore cladding tube is proposed according to a further preferred embodiment, that the cladding tube from a prestressed material, in particular metal, is formed. For the completion of the anchor or to increase the anchor effect in particular at partially loose layers of rock material moreover, it is preferably proposed according to the invention that, after completion of the borehole, an anchoring plate can be fixed to the casing tube at the end projecting from the soil or rock material.
For a proper removal of the mined rock is also proposed according to a further preferred embodiment that the cladding tube has in the region of the adjoining the drill bit end in a conventional manner at least one passage opening for introducing the degraded soil or rock material in the interior of the cladding so that the degraded material can be discharged from the bore in the space defined between the drill string and the cladding, in particular annular space.

Fig. 1 a schematic side view, partly in section, of a first embodiment of a device according to the invention for performing the method according to the invention;
Fig. 2 a schematic section in an enlarged view rotated along the line II-II of Fig. 1 ;
Fig. 3 in one too Fig. 1 a similar representation shows a modified embodiment of a device according to the invention for performing the method according to the invention;
Fig. 4 in a turn too Fig. 1 a similar illustration shows a comparative example of a device for carrying out the method;
Fig. 5 different stages during the implementation of the method according to the invention using a device according to the invention, wherein Figure 5a in one too Fig. 1 a similar illustration shows the process of producing a borehole with the method according to the invention, Figure 5b shows the removal of the drill string after completion of the borehole, Figure 5c shows the introduction of an expandable element into the interior of the jacket tube after completion of the borehole and removal of the drill string, and Fig. 5d Figure 3 shows the act of expanding the expandable element; and
Fig. 6 a schematic side view of a further modified embodiment of a device according to the invention for performing the method according to the invention.

The invention will be explained in more detail with reference to accompanying schematically illustrated in the drawings.

In this show:

Fig. 1 a schematic side view, partially in section, of a first embodiment of a device according to the invention for carrying out the method according to the invention;
Fig. 2 a schematic section in an enlarged view along the line II-II of Fig. 1 ;
Fig. 3 in one too Fig. 1 a similar representation of a modified embodiment of a device according to the invention for carrying out the method according to the invention;
Fig. 4 in a turn too Fig. 1 similar representation of a comparative example of an apparatus for performing the method;
Fig. 5 different stages during the implementation of the method according to the invention using a device according to the invention, wherein Figure 5a in one too Fig. 1 similar representation shows the process of producing a borehole with the method according to the invention, Figure 5b shows the removal of the drill pipe after completion of the well, Figure 5c shows the introduction of an expandable element into the interior of the cladding tube after completion of the borehole and removal of the drill string, and Fig. 5d shows the process of expanding the expandable element; other
Fig. 6 a schematic side view of another modified embodiment of a device according to the invention for carrying out the method according to the invention.

In Fig. 1 In Fig. 1 is generally denoted by 1 a drilling tool or a drill bit, which (s) with the interposition of a connector 2 and a schematically indicated by 3 beater with a running inside a cladding tube 4 drill string 5 is connected. The drill bit 1 is acted upon by the drill string 5 by a percussion or rotary impact drilling device arranged not shown in detail, outside the soil or rock material to be processed, whose surface is denoted by 6. The inner contour of a borehole formed by the drilling tool or the drill bit 1 is in Fig. 1 indicated schematically by 7.
It can also be seen that the sleeve 4 is made of a pretensioned material, in particular metal, the material in its relaxed state shown in solid lines outside the borehole having a larger outer circumference than in the state in the borehole shown by dashed, thin lines , the slot being labeled 8 '. The cladding tube 4 is thus introduced into the borehole under pretension, so that it is ensured that the cladding tube 4 is at least partially in contact with the borehole inner wall 7, in order to enable an at least provisional securing during the drilling process. How out Fig. 1 can be seen, the cladding tube 4 has a substantially longitudinally extending longitudinal slot 8, as well as from the illustration of Fig. 2 is clearly visible. From the illustration according to Fig. 2 It can further be seen that the sleeve 4 is made of a prestressed material, in particular metal, wherein the material has a larger outer circumference in its relaxed state outside the borehole shown in solid lines than in the condition shown by dashed, thin lines in the borehole wherein the slot is designated 8 '. Thus, the cladding tube 4 is biased into the borehole to assure that the cladding tube 4 is at least partially in contact with the borehole inner wall 7 so as to permit at least provisional securement already during the drilling operation.
It can also be seen that the drill rod 5 is provided with a central passage 9 through which a flushing fluid is introduced into the area of the drill bit 1, so that degraded material is at least partially in the area of the outer circumference of the cladding tube 4 between the cladding tube 4 and the inner wall 7 of the borehole is discharged, whereby a lubricating or sliding effect can be achieved by introducing the flushing fluid at the interface between the outer circumference of the cladding tube and the inner wall 7 of the borehole. Through this lubricating or sliding effect, the frictional resistance between the outer circumference of the cladding tube 4 and the inner wall of the borehole 7 is correspondingly reduced during the drilling process, while after completion of the borehole 7 and thus an interruption of the flushing agent supply in the area of the drill bit 1 by hardening, a frictional connection Connection between the cladding tube 4 and the inner wall 7 of the borehole can be achieved. Out Fig. 2 Furthermore, it can be seen that the drill pipe 5 is provided with a central passage 9, through which a flushing fluid is introduced into the region of the drill bit 1, so that mined material at least partially in the region of the outer circumference of the casing 4 between the casing 4 and the borehole inner wall. 7 is applied, which can be achieved by the introduction of the flushing fluid at the interface between the outer periphery of the cladding tube and the borehole inner wall 7, a lubricating effect. By this lubricating effect, the frictional resistance between the outer circumference of the cladding tube 4 and the borehole inner wall 7 during the drilling process is correspondingly reduced, while after completing the borehole 7 and thus interrupting the flushing agent supply in the region of the drill bit 1 by curing a frictional connection between the cladding tube 4 and the inner wall of the hole 7 can be achieved.
At the in Fig. 1 illustrated embodiment, the introduction of the cladding tube 4, which in the adjoining the drill bit 1 region 4 'has a conically tapered outer shape, by a tensile stress, which is introduced via the beater 3 on the cladding tube 4. At the in Fig. 1 illustrated embodiment, the introduction of the cladding tube 4, which in the adjoining the drill bit 1 region 4 'has a conically tapered outer shape, by a tensile stress, which is introduced via the beater 3 on the cladding tube 4. At the in Fig. 1 illustrated embodiment, the introduction of the cladding tube 4, which in the adjoining the drill bit 1 region 4 'has a conically tapered outer shape, by a tensile stress, which is introduced via the beater 3 on the cladding tube 4.
At 10 is in Fig. 1 At 10 is in Fig. 1 denotes a transition sleeve, which allows a definition of a drive device not shown for a percussion or rotary impact drilling.
At the in Fig. 3 shown, modified embodiment, in addition to the applied by the impact shoe 3 tensile stress, the cladding tube 4 in the region of the anchor head 6 via the transition sleeve 10 subjected to a shock stress, so that the cladding tube 4 is introduced under both a tensile and a impact stress in the interior of the hole again denoted by 7. At the in Fig. 3 shown, modified embodiment, in addition to the applied by the impact shoe 3 tensile stress, the cladding tube 4 in the region of the anchor head 6 via the transition sleeve 10 subjected to a shock stress, so that the cladding tube 4 is introduced under both a tensile and a impact stress in the interior of the hole again denoted by 7. At the in Fig. 3 shown, modified embodiment, in addition to the applied by the impact shoe 3 tensile stress, the cladding tube 4 in the region of the anchor head 6 via the transition sleeve 10 subjected to a shock stress, so that the cladding tube 4 is introduced under both a tensile and a impact stress in the interior of the hole again denoted by 7.
The cladding tube 4 in turn has a longitudinal slot 8 and is discontinued in partial areas of its outer circumference or formed with a reduced cross-section, wherein such stepped portions in Fig. 3 Denoted by 11. It can thus be achieved only a partial investment of the cladding tube 4, in particular during the Einbringvorgangs, which is favorable, for example, at an expected high frictional resistance between the outer circumference of the cladding tube 4 and the inner wall of the well 7 to achieve a proper drilling progress.
which is not covered by the invention, it can be seen that the cladding tube 4 is only introduced into the interior of the borehole 7 via an impact load on the anchor head 6 through the transition sleeve 10, while in this embodiment no traction due to a connection of the cladding tube 4 with the drill bit 1 is made. Such an introduction of a cladding tube 4 by means of impact stress is possible in particular in the case of a correspondingly more massive cladding tube or a cladding tube 4 which has a higher strength. In the embodiment according to Fig. 4 , which is not covered by the invention, it is seen that the cladding tube 4 is introduced only by a shock load on the anchor head 6 through the transition sleeve 10 into the interior of the borehole 7, while in this embodiment no Zugmitnahme by a compound of the cladding tube 4 with the drill bit 1 is made. Such introduction of a cladding tube 4 by means of impact stress is possible, in particular in the case of a correspondingly more solid cladding tube or a cladding tube 4, which has a higher strength.
At the in Fig. 5 At the in Fig. 5 shown, individual process steps is in Figure 5a the formation or production of the bore hole 7 is shown, wherein the cladding tube 4, for example, similar to the embodiment according to FIG Fig. 4 is introduced by an impact stress on the anchor head 6, while no connection between the cladding tube 4 and the drill head 1 is provided.
In Fig. 5 In each case an anchor plate 13 is indicated in the region of the projecting from the soil or rock material 12 end. In Fig. 5 In each case an anchor plate 13 is indicated in the region of the projecting from the soil or rock material 12 end. In Fig. 5 In each case an anchor plate 13 is indicated in the region of the projecting from the soil or rock material 12 end.
is shown, the drill rod 5 is removed from the borehole 7 according to the arrow 14, while the drill bit 1 remains in the borehole 7. After completion of the hole 7 is, as in Figure 5b is shown, the drill pipe 5 according to the arrow 14 removed from the borehole 7, while the drill bit 1 in the borehole 7 remains.
After removal of the drill string 4, an expandable element generally designated 15 is introduced into the interior of the cladding tube 4 in the interior of the cladding tube 4 in accordance with the arrow 16. The expandable element 15 consists of a sleeve 17, which is conically tapered and at least partially has a longitudinal slot 18, wherein in the interior of the sleeve 17, a conical element 19 can be introduced.
After insertion or insertion of the expandable, two-part element 15 into the interior of the cladding tube 4, for example in the region of stops or projections 20 for positioning the expandable element, a striking stress is exerted on the conical element 19 via the transition sleeve 10, so that the two-part, expandable element 15 is positioned at the desired position inside the cladding tube and fixed to the inner wall of the cladding tube 4.
This introduced, expandable element 15 ensures that a cross-sectional reduction of the cladding tube 4, for example, by a compressive stress by surrounding material or upon exerting a tensile stress in the direction of a pull or release movement of the anchor does not occur, so that the desired anchoring effect is reliably maintained , In a tensile stress on the anchor formed by the cladding tube 4 is in the event that the expandable element 15 is not provided, a reduction in cross-section through the longitudinal slot 8 of the cladding tube 4 possible, with such a reduction in cross-sectional area, the anchoring effect would be deteriorated.
Instead of providing positioning projections 20, the expandable element 15 can also be brought directly into contact with the drill bit 1 remaining in the borehole 7, as shown in FIG Fig. 5d is indicated. In addition, it can be provided that a plurality of expandable elements 15 is introduced into the interior of the cladding tube 4 in order to achieve a corresponding support, the anchoring effect of the cladding tube 4 at different locations. Such multiple, expandable elements 15 can be arranged by appropriate design in particular of the conical sleeve 17 and vote with corresponding positioning projections 20.
Alternatively or in addition to the introduction of the expandable elements 15 may be provided to fill the interior of the cladding tube 4 with a hardening mass after completion of the borehole 7 and optionally removing the drill string 5.
In a further modified embodiment, 1 denotes a drilling tool or a drill bit, which is connected to a drill rod 5 running inside a casing tube 4 with the interposition of a connecting piece 2 and a hammer shoe indicated schematically by 3, the drill bit 1 is acted upon via the drill rod 5 by an impact or rotary percussion drilling device, not shown, outside the soil or rock material to be processed, the surface of which is denoted by 6. The inner contour of a drill hole formed by the drilling tool or the drill bit 1 is shown in FIG Fig. 6 again denoted by 7. In Fig. 6 is in a further modified embodiment again denoted by 1 a drilling tool or a drill bit, which (s) is connected with the interposition of a connector 2 and a schematically indicated with 3 beater with a running inside a cladding tube 4 drill pipe 5, wherein the drill bit via the drill pipe 5 by a non-illustrated, outside of the soil or rock material to be processed, whose surface is denoted by 6, arranged impact or rotary impact drilling device is acted upon. The inner contour of a borehole formed by the drilling tool or the drill bit 1 is in Fig. 6 again denoted by 7.
As can be seen, the jacket tube 4 again has a longitudinal slot 8 running essentially in the longitudinal direction, at least one predetermined breaking point 29 being provided along the longitudinal extent of the longitudinal slot 8, this predetermined breaking point being formed by a weld 29, for example. The cladding tube 4 is fixed to the striking shoe 3 via an intermediate element or is carried along by the striking shoe 3 during the drilling process, so that the cladding tube 4 formed with the longitudinal slot 8 is introduced into the borehole 7 immediately during the drilling process. How out Fig. 6 can be seen, the cladding tube 4 in turn has a substantially longitudinally extending longitudinal slot 8, wherein at least one predetermined breaking point 29 along the longitudinal extension of the longitudinal slot 8 is provided, said predetermined breaking point is formed for example by a weld 29. The cladding tube 4 is here the beater 3 fixed via an intermediate element or is taken by the beater 3 during the drilling process, so that immediately during the drilling process with the longitudinal slot 8 trained cladding tube 4 is introduced into the borehole 7 .
For a removal of the material degraded by the drill bit 1, a passage opening 31 is provided in the front region of the jacket tube 4, wherein the passage opening 31 is formed to form an enlarged, clear passage cross section of the longitudinal slot 8. Through this passage opening 31 passes through the drilling tool 1 degraded material in the defined between the sheath 4 and the drill pipe 5 space or annulus and is applied to the end facing away from the drill bit 1. If necessary, for example symmetrically to the passage opening 31, a second passage opening in the cladding tube 4 may be provided on the radially opposite portion of the circumference.
After completion of the bore is carried out by loosening or separating the predetermined breaking point 29 defining weld a widening of the biased cladding tube 4, whereby the desired anchoring effect can be achieved.
After completion of the hole, the cladding tube 4 and at least the beater 3 and parts of the drill bit mounted thereon, for example, the ring bit with provision of a central drill bit and a radially surrounding ring bit, slightly withdrawn against the drilling or advancing direction 26, after which after this retraction again applying the impact shoe 3 via the drill pipe 5 in turn in the direction of the drilling operation 26, whereby the predetermined breaking point 29 is released.

Claims

A method for drilling, in particular impact drilling or rotary percussion drilling, a hole (7) in soil or rock material and fixing an anchorage in said hole, wherein a drill hole (7) is formed by means of a drill bit (1) mounted on a drill rod assembly (5) while simultaneously introducing a jacket tube (4) surrounding the drill rod assembly (5) in a spaced-apart manner, wherein the jacket tube (4) is introduced into the drill hole (7) by exerting a tensile stress via this coupling with the drill bit (1) characterized in that the jacket tube, which is formed with a longitudinal slot (8), is at least partially introduced in substantial abutment on the drill hole (7) during drilling.
A method according to claim 1, characterized in that an expandable element (15, 17, 19) is introduced into the interior of the jacket tube (4), and expanded, upon completion of the drill hole (7) and removal of the drill rod assembly (5).
A method according to claim 2, characterized in that the expandable element (15, 17, 19) is expanded by exerting an impact stress.
A method according to any one of claims 1, 2 or 3, characterized in that the jacket tube (4) is introduced into the drill hole (7) by exerting an impact stress.
A method according to any one of claims 1 to 4, characterized in that at least one connection provided along the substantially longitudinally slotted jacket tube (4) and defined by a predetermined breaking point (29) is separated upon completion of the bore (7).
A method according to claim 5, characterized in that the separation or breaking of the predetermined breaking point (29) is effected by a slight retraction of at least the impact shoe (3) and jacket tube (4) mounted thereon as well as an actuation of the impact shoe (3).
A method according to any one of claims 1 to 6, characterized in that a curing mass is filled into the interior of the jacket tube (4) in a manner known per se upon completion of the bore (7).
A device for drilling, in particular impact drilling or rotary percussion drilling, holes (7) in soil or rock material and producing an anchorage, wherein a drill bit (1) mounted on a drill rod assembly (5) makes a drill hole (7) and a jacket tube (4) surrounding the drill rod assembly (5) in a spaced-apart manner and following the drill bit (1) and being coupled therewith is provided, wherein the jacket tube (4) is introduced into the drill hole (7) by exerting a tensile stress via this coupling with the drill bit (1), characterized in that the jacket tube (4) comprises a longitudinal slot (8) substantially extending in the longitudinal direction of the jacket tube (4) .
A device according to claim 8, characterized in that an expandable element (15, 17, 19) is introducible into the interior of the jacket tube (4) and expandable in abutment on the inner wall of the jacket tube (4) upon completion of the drill hole (7) and removal of the drill rod assembly (5).
A device according to claim 9, characterized in that the expandable element (15) is comprised of a sleeve (17) which is expandable by an impact stress caused by the introduction of an especially conical element (19).
A device according to claim 9 or 19, characterized in that the jacket tube (4) on its inner wall is provided with elevations or projections (20) aimed to position the expandable element (15, 17, 19).
A device according to any one of claims 8 to 11, characterized in that the jacket tube (4) comprises at least one predetermined breaking point (29) along its longitudinal slot extending substantially in the longitudinal direction of the jacket tube (4).
A device according to claim 12, characterized in that the at least one predetermined breaking point (19) provided along the longitudinal slot (8) of the jacket tube (4) is formed by a weld bridging the longitudinal slot (8).
A device according to any one of claims 8 to 13, characterized in that the jacket tube (4), on its end facing the drill bit (1), is fixed to an impact shoe (3) of the drill bit (1).
A device according to any one of claims 8 to 14, characterized in that the jacket tube (4) is made of a prestressed material, in particular metal.
A device according to any one of claims 8 to 15, characterized in that at least upon completion of the drill hole (7) an anchoring plate (13) is fixable to the jacket tube (4) on its end projecting out of the soil or rock material.
A device according to any one of claims 8 to 16, characterized in that the jacket tube (4), in the region of its end following the drill bit (1), in a manner known per se comprises at least one passage opening aimed to introduce the excavated soil or rock material into the interior of the jacket tube (4).