Classifications

• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
  • E02D5/00—Bulkheads, piles, or other structural elements specially adapted to foundation engineering
  • E02D5/74—Means for anchoring structural elements or bulkheads
  • E02D5/76—Anchorings for bulkheads or sections thereof in as much as specially adapted therefor
• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B33/00—Sealing or packing boreholes or wells
  • E21B33/10—Sealing or packing boreholes or wells in the borehole
  • E21B33/12—Packers; Plugs
  • E21B33/128—Packers; Plugs with a member expanded radially by axial pressure

Definitions

• the invention relates to a borehole closure according to the preamble of claim 1.
• rock anchors in particular injection boreholes, in which, after the borehole has been created, a hardenable medium, for example a mortar suspension, is introduced into the borehole via the central longitudinal channel of the anchor rod, the anchor rod leaving the anchor rod via outlet bores in the area of the drill bit and - starting with the bottom of the borehole - fills the borehole.
• a hardenable medium for example a mortar suspension
• DE 37 17 024 C2 shows a borehole closure which consists of a flexible sleeve which is pushed from the air-side end over the anchor rod and into which a wedge body can be inserted which consists of a material which is harder relative to the sleeve and which is air-side the sleeve first protrudes.
• this borehole closure in a first step the sleeve and wedge body are first advanced over the air-side end of the anchor rod to the point at which the borehole closure is to be placed, with a tubular design then also being pushed over the anchor rod and with the wedge body cooperating setting device, which is provided with a special abutment, ' the wedge body is driven into the sleeve, so that it is subsequently expanded elastically and pressed against the borehole walls.
• the power transmission from the setting device to the wedge body obviously takes place intermittently, it being assumed that as a result of these impacts the flexible sleeve is stuck to the borehole walls and / or the outside of the anchor rods and does not evade the impacts in the direction of the borehole bottom.
• the handling and setting of such a known borehole closure can be difficult when the surrounding mountains are very low in cohesion, there is a considerable loosening or widening on the mouth side and the borehole closure at a comparatively great depth must be set.
• the sealing body is designed and arranged in such a way that it develops a sealing effect radially on the inside and outside, so that a seal is developed both against the borehole wall and against the outside of the injection pipe.
• the sealing body can be deformed in the manner yet to be explained, in order to achieve a firm and sealing contact with the sealing surfaces - on the other hand, in the undeformed state, it can easily be pushed over the injection pipe to the point at which the borehole closure is placed shall be.
• the borehole closure is designed as a circular-cylindrical base body, on the end faces of which pressure can be exerted for the purpose of pressing or developing a sealing effect, so that the sealing body, which consists of a highly elastic material that is deformable to a large extent, radially on the outside and inside under this pressure is deformed so that a sealing effect is developed both against the outer walls of the anchor rod and against the inner walls of the borehole.
• the force to be used for the targeted deformation of the sealing body is thus exerted exclusively on the End faces of an otherwise ring-cylindrical sealing body applied.
• a pressure device is assigned to the pressure plates to be used according to the invention, which is designed such that the state of deformation of the sealing body can be adjusted or fixed in order to ensure predetermined minimum contact forces in the area of the respective sealing surfaces.
• the features of claim 4 are directed to an advantageous embodiment of the pressure plates and the sealing body.
• the base body formed from these two components is rotationally symmetrical and the sealing body preferably consists of a rubber-elastic material, which gives it a high degree of deformability.
• the sealing body preferably consists of a comparatively soft rubber.
• the pressure plates designed as annular plates are made of a metallic material as force transmission elements, the connection between these annular plates on the one hand and the sealing body on the other hand being able to be effected by gluing, vulcanization or the like, so that this connection is in any case as liquid-tight can be seen.
• the features of claim 5 are directed to a possible design of the pressing device. This is then formed by tension rods, which are fixedly arranged on one circular ring plate and movable relative to the other circular ring plate, but are arranged such that they can be locked relative to the latter. On account of the thus adjustable displacement of the tension rods relative to the one annular ring plate and the resulting compression of the sealing body, this opens up the setting of defined elastic deformation states, which in turn correspond to sealing forces in the area of the interacting sealing surfaces. The prerequisite here is that the tension rods, which penetrate the sealing body spatially, are freely movable relative to the latter.
• claims 6 to 9 are directed to different configurations of the sealing body, which can in principle be formed as a one-piece tubular body or can also consist of two tubular bodies which are inserted coaxially into one another, in each case naturally a liquid-tight connection with the end circular plates is provided.
• the tension rods are guided within the annular space remaining between the tubular bodies, whereas in the first case the one-piece tubular body must be provided with slots, within which the tension rods are guided.
• the pressing device comprises a special setting device, which is in operative connection with the tension rods or can be brought in and serves to shift the annular plates relative to one another, the tension rods being opposite one Annular plate can be fixed or locked with this in order to fix a certain deformation state of the sealing body.
• the setting direction thus forms a system which is suitable for exerting a tensile force on the tension rods relative to the one annular plate.
• this condition can be met and this effect can also be developed in a relatively large depth of a borehole, for example 1 m to 1.5 m calculated from the mouth of the borehole
• the precise design of a setting device is basically of any type.
• the features of claim 12 are directed to a possible constructive configuration of the setting device, which hereafter consists of two tubes that can be moved relative to one another by means of a drive, the ends of the tension rods being fastened to the inner tube, whereas the outer tube, which is attached to one, Ring ring plate is supported, which forms the abutment for the displacement movement.
• These tubes can be made comparatively long.
• the drive of the setting device can in principle be any according to the features of claims 13 and 14.
• a clamping nut comes into consideration, which is supported on one end of the outer tube - however, a piston or cylinder unit which can be acted upon pneumatically or hydraulically can also be used as the drive.
• the link between the setting device and the ends of the tension rods is designed to be force-limited, so that when a predeterminable tensile force is exceeded, this Connection disconnects automatically.
• This can be done constructively in any way, for example by predetermined separation points, which are characterized by a cross-sectional weakening of force-transmitting elements, so that when a certain tensile force is exceeded, the yield point of the material is exceeded and thus a separating effect occurs.
• This can be achieved in the same way by bending and, in connection therewith, sliding off form-fitting connecting elements, etc.
• the coupling between the setting device and the tension rods is automatically released when a predetermined tensile force is exceeded.
• the setting of the borehole closures according to the invention always leads to defined and thus reproducible contact and thus sealing forces.
• the automatic loosening of the setting device also has the advantage that this setting device can be used in any further drill hole closures, the user not requiring any assembly work to loosen the connection. The result is an easy-to-use setting device that always leads to reproducible work results even with little care on the part of the user.
• Foaming process can be triggered by the pressing device and the deformation state at least attainable by the latter is designed such that this foaming process is triggered.
• the foaming process causes an increase in pressure within the recesses and - in connection therewith - a corresponding radial expansion of the sealing body, which results in a sealing contact with facing sides of the borehole wall on the one hand and the drilling or anchor rod on the other.
• the plastic to be foamed is preferably kept in closed capsules, tubes or other containers which are destroyed by the movement connected by the deformation by means of the pressing device, which directly affects the
• gases or a gas which are present in a liquid phase in the initial state and evaporate or expand by destroying the containers surrounding them, are also considered in principle, in particular in the case of closed recesses.
• the foaming process is formed by two substances which react with one another and which, in the initial state, are arranged in separate containers within the recesses of the sealing body, which containers are destroyed by axial compression of the sealing body, which compresses the substances own causes the foaming process reaction.
• claims 19 and 20 are directed to alternative designs of the sealing body. According to this, this can be provided with a plurality of recesses, preferably uniformly distributed in the circumferential direction, or with a single recess formed by an annular space. The latter version in particular ensures optimal radial pressure development due to the uniform radial expansion caused by the foaming or evaporation process.
• the recesses are particularly advantageously provided with radial passages on the inside and / or outside. This measure opens up an expansion of the foamable and hardenable plastic into zones outside the structure of the actual sealing body, a measure which is particularly advantageous in the case of very unstable and geometrically irregular borehole walls. In this way, in particular a reliable seal that seals even the smallest wall unevenness of the borehole is achieved. At the same time, even the smallest gaps between the sealing body on the one hand and the outside of the drill or anchor rod are sealed on the other.
• FIG. 1 shows a longitudinal section of a first embodiment of a borehole closure body according to the invention
• Fig. 2 is an end view of the closure body of Figure 1 according to the arrow II. 3 shows a longitudinal section of a further embodiment of a borehole closure body according to the invention;
• Fig. 4 is an enlarged view of the detail IV of Figure 3 in partial section.
• FIG. 5 shows a longitudinal section of a setting device according to the invention intended and designed to interact with the borehole closure
• FIG. 6 shows an illustration of the end region of a rock bolt on the borehole mouth side with a borehole closure attached.
• FIG. 7 shows another embodiment of a borehole closure according to the invention in axial section
• FIG. 8 shows a cross-sectional illustration of a borehole closure corresponding to a plane VIII-VIII of FIG. 7;
• FIG. 9 is an enlarged partial view of a detail IX of FIG. 7.
• the borehole closure 1 shown in FIGS. 1 and 2 consists essentially of two annular plates 2, 3, which are bent radially on the inside and outside by about 90, between which - viewed in the direction of the longitudinal axis 4 - a sealing body 5 extends, which follows will be described in more detail.
• the annular plates 2, 3 thus having a U-shaped profile in longitudinal section are arranged in such a way that their profiles are directed towards one another.
• the annular plates 2, 3 consist of a suitable metallic material and, together with the sealing body 5, form a hollow cylindrical 01 such a basic body enclosing a cylindrical space 6 that extends coaxially to the longitudinal axis 4.
• the sealing body consists of two tubular bodies which are coaxially nested, leaving an intermediate space 7
• connection of the sealing body with the annular plate 3 can in principle
• tension rods 14 Extending within the intermediate space 7 - offset in the circumferential direction by 90 from one another - are four tension rods 14, which are fixed with the annular plate 3 located underneath in a fixed, i.e. are suitable for a transmission 25 of tensile forces.
• the tension rods 14, which are made of a metallic material, can be welded to the circular ring plate 3, for example.
• the tie rods 14 are rectangular in cross-section, extend parallel to the longitudinal axis 4 and consequently the slots 15 are also rectangular.
• this geometry of the tension rods is not absolutely necessary, and in principle any other cross-sectional shapes can be used that are suitable for transmitting a sufficient tensile force.
• the tension rods 14 each have bores 16 at their upper ends, these bores — opposite one another laterally — being opposite symmetrically shaped notches 17. These notches 17, which result in cross-sectional weakenings defined in the area of the bores 16, result in a corresponding weakening of the tensile strength, the significance of which will be discussed in more detail below.
• the borehole closure 18 shown in FIG. 3 differs from that of FIGS. 1 and 2 only in that the sealing body shown here is designed as a one-piece tubular body 19 '.
• This tubular body 19 ' consists of a highly elastic, in particular rubber-elastic material, into which slots 20 are formed for receiving the tension rods 14, which, as in the previous exemplary embodiment, are fixedly attached to the circular plate 3 on the underside.
• the tension rods 14 are provided on one side with a sawtooth profile 23 , which is designed and designed for locking with the correspondingly configured edge 24 of the slot 15.
• the tension rod 14 in the direction of the edge 24 is under a certain elastic prestress, which enables the latching.
• FIG. 5 denotes a setting device suitable for mounting a borehole closure 1, 18, which essentially consists of two tubes which are plugged into one another coaxially while leaving an annular space 26, namely an outer tube 27 and an inner tube 28.
• Inner tube 28 is provided, at least on its upper end section in the drawing, with an external thread 29 which is in engagement with a clamping nut 30.
• the clamping nut 30 is in turn supported on the end face 31 of the outer tube 27.
• the external thread 29 can also extend over an arbitrarily long section thereof, starting from the upper end 32 of the inner tube.
• the inner tube 28 carries at its end section 33 opposite the end 32 a series of fastening devices, here four bolts 34, which extend radially and for cooperation, here for hanging in the bores 16 of the tension rods 14 of a borehole closure 1 , 18 are determined.
• a series of fastening devices here four bolts 34, which extend radially and for cooperation, here for hanging in the bores 16 of the tension rods 14 of a borehole closure 1 , 18 are determined.
• the pair of elements shown here bore-bolt is not absolutely necessary, so that any, comparable task, namely a tensile force transmission, releasable pair of elements can be used equally.
• the borehole closure 1, 18 is fastened to the inner tube 28 via these bolts 34, the latter extends coaxially to the longitudinal axis 4 of the borehole closure.
• the setting device 25 is dimensioned such that the outer tube 27 is supported on the end face of the circular ring plate 2.
• guide devices are also provided in the annular space 26 between the inner and outer tubes 27, 28, by means of which the inner tube 28 can be displaced relative to the outer tube 27 in the direction of arrow 35 or in the opposite direction thereof, but cannot be rotated with respect to the longitudinal axis 4.
• FIGS. 5 and 6 show a borehole 36, into which a rock anchor 37 is inserted, via the central, axially directed longitudinal bore 38 of which a hardenable medium is to be introduced into the borehole 36, for example a mortar suspension, with the Ring space 39 enclosing rock bolts 37 is to be closed at a suitable point in the region of the borehole mouth. It is assumed here that, depending on the found consistency of the borehole wall, this appears reasonable at a depth 40 - calculated approximately from the mouth of the borehole. In practice, this will be one
• Place of the borehole from which at least approximated to the borehole cross-section - seen over the further length of the borehole - has a constant cross-section, since a funnel-like widening of the borehole is always to be expected in the region of the borehole mouth, particularly in the case of very low-cohesion soil conditions .
• This can be a depth of up to 1.5 m.
• a borehole closure 18 To assemble a borehole closure 18, this is first hooked onto the bolts 34 of a setting device 25 with the bores 16 of its tension rods 14.
• the setting device consisting of inner tube 28, outer tube 27 and clamping nut 30, is then attached via the free end of the rock bolt 38 and pushed along it until the designated depth 40 is reached, the borehole walls of which appear suitable for attaching a borehole closure.
• the length of the setting device 25 is in any case designed such that the clamping nut 30 can be easily reached outside the borehole. For better actuation of the clamping nut 30, this can be provided with known manual actuating elements such as levers, handles or the like.
• the tension rods 14 are finally torn off and the notches 17 in the region of the bores 16 are accordingly dimensioned such that the remaining cross section available for a transmission of tensile force is sufficient to ensure a sufficient deformation of the sealing body and thus a sufficient contact force on the rock bolt 37 on the one hand and the borehole wall on the other hand.
• the user can immediately see that the assembly process of the borehole closure has ended, so that the setting device 25 can subsequently be stripped from the end of the rock bolt 37 protruding from the borehole 36 and for a new assembly process is available. Due to the sawtooth profile 23, the tension rods 14 are locked in their last clamping position, so that there is a secure fit of the borehole closure.
• a particularly low-cohesion state prevails in the area of the mouth and this state continues over a certain depth, starting from the mouth.
• the borehole closure 41 shown in FIGS. 7 and 8 has a globally hollow-cylindrical basic shape enclosing a cylindrical space 42, which is delimited at the end by circular ring plates 43, 44 made of a metallic material.
• the circular ring plates 43, 44 are bent radially on the inside and outside by about 90 and consequently have a U-shaped profile when viewed in axial section and these profiles are arranged facing one another in the context of the borehole closure.
• a sealing body 47 made of a rubber-elastic material, which with the facing inner sides of the Profiles of the annular plates 43, 44 glued or otherwise sealingly connected.
• the sealing body 47 has such a radial extent that the area radially delimited by the sections 45, 46 is completely filled.
• the sealing body 47 is otherwise smoothly formed radially on the inside and outside of the annular plates 43, 44.
• the sealing body 47 is provided with four continuous recesses 48 which extend parallel to its longitudinal axis in a central region of the radial thickness and which are approximately oval in cross section.
• metal rods 49 which are fixedly attached at one end to the inside of the circular plate 44, for example welded to it, and the other end of which extends through openings 50 in the opposite circular ring plate 43.
• the openings 50 and the sections of the tension rods 49 facing them have been given a special configuration, as shown in FIG. 9 in detail.
• the openings 50 have a design tapering in the direction of the arrow 51, and the tension rods 49 are provided with a sawtooth-like surface profile intended for locking with the upper edge 52 of the opening 50.
• each of the recesses 48 also contains two different substances 55 held in closed capsules, tubes or the like,
• the space 42 within the borehole closure is dimensioned such that the latter can be pushed axially over a rock anchor, a boring bar, an injection pipe or the like.
• the borehole closure according to the invention is mounted using an additional device, namely a setting device 25, which corresponds in structure and mode of operation to that according to FIG. 5.
• the setting device 25 can thus be coupled to the borehole closure in such a way that its inner tube 28 is by means of which is attached to this bolt 34 with the tie rods 49.
• the outer tube 27 is supported on the circular ring plate 43.
• the borehole closure is sealingly attached to the borehole wall on the one hand and to the rock anchor or injection anchor on the other hand, with the foaming process resulting in reliable, sealed filling of geometrically irregularly shaped borehole wall contours.
• this borehole closure achieves a particularly high pressure effect in the area of the required sealing surfaces, which is achieved on the one hand by the axial compression of the sealing body and on the other hand by the foaming process, both of which contribute to the greatest possible radial pressure development , both in the direction of the borehole wall and in the direction of the outside of the rock bolt.

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• Engineering & Computer Science (AREA)
• Mining & Mineral Resources (AREA)
• Life Sciences & Earth Sciences (AREA)
• Structural Engineering (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Geology (AREA)
• Geochemistry & Mineralogy (AREA)
• Fluid Mechanics (AREA)
• Physics & Mathematics (AREA)
• Environmental & Geological Engineering (AREA)
• Paleontology (AREA)
• Civil Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Piles And Underground Anchors (AREA)
• Dowels (AREA)
• Earth Drilling (AREA)

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Applications Claiming Priority (4)

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ID=25905128

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Cited By (3)

Citations (2)

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• 1991
  • 1991-07-02 DE DE19914121825 patent/DE4121825C2/de not_active Expired - Fee Related
  • 1991-12-21 DE DE19914142540 patent/DE4142540A1/de not_active Ceased
• 1992
  • 1992-05-21 JP JP4509212A patent/JPH07500387A/ja active Pending
  • 1992-05-21 AU AU16927/92A patent/AU1692792A/en not_active Abandoned
  • 1992-05-21 WO PCT/EP1992/001129 patent/WO1993001362A1/de active Search and Examination

Patent Citations (2)

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