DE10057041A1 - Anchoring device to be used in particular for brittle areas in mining or tunneling, assembled of permanently joined mantle and folded inner tube - Google Patents

Abstract

The device (1) is assembled of an outer pipe (10) provided with a narrow gap (11) alongside and accommodating a folded inner tube (12), unfolding when filled after positioning. A reinforcing sleeve (15) is attached to the upper end (14) of the outer pipe (10) and a second sleeve (17), surrounded by a flange (18, 24) and provided with an inlet (21) for the filling substance is positioned at the entrance (7) to the hole (3) prepared for the insertion of the anchor (1). The outer pipe (10) forms a unit with the unfolded inner pipe (12) in order to absorb the pulling forces as well as the shear forces acting on the device (1).

Description

The invention relates to a rock bolt with a longitudinally slotted casing tube and an anke that can be expanded via a pressed-in fluid and has an insertion fold gutter tube, which is closed at the deepest end of the borehole and on the outside Ren end is connectable to a pump unit, the outer end is bordered by a sleeve with a flange, which can be pressed against the mountains with a Dome plate is shaped accordingly.

Such rock anchors are used in so-called used mountain areas to avoid eruptions and instead put the mountain strata together to keep. Different designs of rock anchors are known, whereby one Depending on the area of application, drilling anchors are used, via which Ver strengthening material is pressed into the mountains. Such drill anchors are in the mountain but also in use in rock construction. Other types of anchors work with expansion parts, especially in the deepest borehole, in order to then relax by tightening the anchor rod to direct forces into the mountains and prevent them from opening up. Known are also so-called expansion anchors, in which a folded tube, the top and bottom is closed and which has a filling hole at the bottom, is filled with fluid so that the fold is raised and the pipe is thus against the borehole wall pressed. The filled-in fluid can then run out again, using a cap plate is ensured that the anchor is inserted accordingly under tension and thus also absorbs tensile forces in addition to shear forces. Especially around to be able to optimally absorb the shear forces or to absorb higher shear forces has been proposed in EP 540 601 B1, on the actual inflatable anchor to put on a longitudinally slotted jacket pipe. This slotted casing tube forms one separate unit, which when the anchor inner tube is inflated due to the longitudinal slide zes is pressed against the borehole wall. Through this second coat the so-called rigidity of the anchoring is significantly increased. Appropriate Trials have shown this. The resilience on train depends on this ten rock anchors from the coefficient of friction between the inner tube of the anchor  and the casing pipe and between the casing pipe and the mountains. Can not be avoided is that especially in damp mountains or when drilling small or by impairing the space between the mantle and anke a certain slip effect occurs, which then affects the effect of the rock anchor both with regard to the casing tube and especially the actual inflation tube or anchor inner tube severely impaired.

The invention is therefore based on the object, even for high tensile forces to create suitable, easy and safe to insert rock anchors.

The object is achieved according to the invention in that the slotted Jacket tube is designed as an outer tube and with the expandable anchor inside tube forms a structural unit transmitting tensile forces.

With the help of the solution according to the invention, the outer tube of the anchor and the anchor gutter tube to a unit that is suitable as in the prior art, high shear absorbing forces, but at the same time also very high tensile forces, because the anchor is now outside tube and anchor inner tube form a unit, so it is now only on the friction Coefficient arrives between the outer tube of the anchor and the mountains. This affects inflated anchor inner tube for the anchor outer tube at the same time as a stabilizer because it is a Springback or other deformation of the outer tube is prevented and ensure contributes to the fact that the outer wall of the outer anchor tube is always tight and high friction is pressed against the borehole wall.

After an expedient embodiment of the invention, it is provided that Anchor outer tube with the inner anchor tube at the outer end transmitting tensile forces connected is. According to the invention, the structural unit is thus manufactured by that the outer tube of the anchor is fixed to the inner tube of the anchor, specifically at the borehole mouth end. In theory, it is of course also possible to use the outer anchor tube and the anchor inner tube at the outer end, d. H. So at the end of the borehole mouth and also to connect the end facing the deepest hole. For the desired high tensile forces are sufficient for the connection at the outer end because  in this way it is ensured that it depends on the coefficient of friction between outer and inner tube does not arrive.

An embodiment of the invention is particularly expedient in which the anchor outer tube is formed as an extension of the sleeve while leaving a flange. Earlier it was pointed out that this sleeve with the flange is placed on the end of the anchor inner tube protruding from the borehole to ensure the introduction of the pressurized fluid and to achieve that this fluid also from the mouth of the borehole into the borehole or into the cavity, that the fold has reached. The anchor outer tube is now connected to the Sleeve connected, d. H. connected to it, thus transmitting the train forces is guaranteed in any case. When the mountains are deformed, the Frictional forces between the outer jacket of the outer anchor tube and the mountains be overcome before appropriate movements can occur. Thereby, that anchor outer tube and sleeve through the longitudinal bore in the calotte plate a safe transmission of the tensile forces is guaranteed.

A further embodiment of the invention provides that the outer tube and anchor Sleeve are formed as a continuous tube on which a ring serving as a flange put on flange and connected to the sleeve, preferably welded. anchor outer tube and sleeve form a unit, of course this unit on outer end is designed without a slot, i.e. as a completely closed tube, around here prevent deformation of the folded inner tube of the anchor and thus ensure it that the hydraulic fluid penetrates into the entire area of the inner tube of the anchor can. The flange is placed on this pipe afterwards and for example determined by welding, with other connecting means between Flange or ring flange and pipe are conceivable and possible.

The wall thickness of the combined anchor outer tube and the sleeve does not have to be be the same thickness throughout. Rather, the invention provides that the wall thickness the anchor outer tube in the borehole area the expected tensile and shear forces sufficient and in the sleeve area according to the pressure conditions of the inflowing fluid  is measured. It has already been pointed out that this sleeve has the task of keeping the corresponding flow channels open, through which the Fluid after passing the inlet bore up to the top of the folded anchor gutter pipe should flow and can flow. At the opposite end, i.e. H. in the The area of the deepest hole is also a sleeve designed as a reinforcing sleeve applied to prevent unfolding and the corresponding channels keep open.

Another way of optimized transmission of tensile forces is achieved in that the anchor outer tube connected to the calotte plate, preferably is wisely welded to it. Because the calotte plate is supported on the mountain surface is and on the other hand is supported on the flange of the sleeve, both parts, d. H. Outer tube and inner tube do not make different movements, so that it is also ensured in this way that only the friction between Outer surface or outer jacket of the outer anchor tube and inner wall of the borehole is decisive. The inevitable friction between the inner tube of the anchor and anchor outer tube, however, plays no role in this version. Both are usually charged together.

To make a connection, i.e. H. especially welding between domes plate and anchor outer tube to ensure an optimal connection is provided, that the outer end of the anchor outer tube of the elongated hole in the calotte plate adapted and guided through and connected to the calotte plate, is preferably welded. This gives the possibility of the anchor outer tube by an inner and an outer weld seam, so that the problems of Forehead welding does not occur. It is simply useful to do this, the anchor outer tube expand to ensure an all-round weld. In this now from Anchor outer tube formed "elongated hole" can then with the anchor inner tube the attached sleeve according to the course of the elongated tube the conditions adjust accordingly. While, in today's experience, actually only one A welded connection between the calotte plate and the outer tube of the anchor is conceivable imagine, however, that other connection technologies are also conceivable if one  for some reason cannot carry out a welding process or can want to.

With the help of the folded anchor inner tube, the anchor outer tube is to be expanded and pressed against the borehole wall. This expansion and pressing achieved one particularly optimal when the insert fold of the anchor inner tube with the Slot in the outer tube of the anchor is arranged correspondingly. Then it will Anchor outer tube spread apart early, with the unfolding anchor gutter pipe supports this process quickly and ensures that a full-surface ge all around plant against the inner wall of the borehole. It is also conceivable that Arrange the fold in another place. Even then there is a targeted upward movement width of the anchor outer tube ensured, but arises especially with the targeted Arrangement of the insert fold against the slot as quickly and as quickly as possible moderate expansion of the outer tube of the anchor.

It has been pointed out several times earlier that the highest possible Friction between the outer jacket of the anchor outer tube or the outer surface and the borehole wall is to be reached. This is mainly due to the bloating the anchor inner tube ensured, but can also be supported that the outer surface of the outer tube of the anchor with a friction-increasing coating is provided or roughened. This roughening should be the case that the insertion of the rock bolt into the borehole is not hindered and that on the other hand, there is no need to quasi ver the borehole wall shape or indent. Therefore one speaks of roughening or of a corresponding, friction-increasing coating would be conceivable, for example as the coating with an appropriate plastic or just the targeted Generate a rough exterior surface.

The anchor outer tube is extended by expanding the slot on the borehole dung pressed in through the folded inner tube of the anchor Fluid. This pressing can be specifically influenced by the slot in the Anchor outer tube as a continuous weak point or in sections as both  Vulnerability connecting cutting surfaces is formed. Through this especially The weak point formed is that the expansion occurs with a sudden expansion tear is connected, so that the anchor outer tube quasi against the borehole wall straps and then is already caught by the inner tube of the anchor so that a snapback is prevented. This snapping of the anchor outer tube to the borehole wall has the advantage that the borehole wall ver is evened, so that a continuous flat support or system is secure is provided.

The invention is characterized in particular in that a rock bolt is created, which can absorb high shear forces as well as high tensile forces. This is achieved above all by designing the casing tube as the outer tube of the anchor forms and forms a structural unit with the anchor inner tube. The train to be picked up Forces are thus significantly higher, advantageously through special training tion of the outer surface of the anchor outer tube also influences the tensile forces and can be increased. It is also advantageous that such a "unit" is the one lead into the borehole facilitates and ensures that after inserting the "Unit" the necessary forces can be safely introduced or applied NEN. It is also advantageous that with respect to the foldable anchor inner tube on be known techniques can be resorted to, but now as several times he believes both very high shear forces absorbed by such a rock anchor can be, as well as high tensile forces.

Further details and advantages of the subject matter of the invention result from the following description of the accompanying drawing, in which a preferred Embodiment with the necessary details and items shown is. Show it:

Fig. 1 a introduced into a wellbore rock bolt, partially in section,

Fig. 2 shows a cross section through an inserted into a wellbore rock bolt prior to expansion of the tubes,

Fig. 3 shows a section through a wellbore and an armature used after expansion,

Fig. 4 shows a further section, wherein the insertion is associated with the slot fold here,

Fig. 5 is a side view of a rock bolt before the Einschie ben into a borehole,

Fig. 6 shows the downhole end of the rock bolt with Runaway budding tube unit,

Fig. 7, the borehole end of the rock bolt with welded to the outer tube and anchor

Fig. 8 shows a section through the spherical cap with double welded anchor outer tube.

In the model shown in Fig. 1 rock anchor 1 is a double-tube anchor which is introduced into the rock 2 borehole 3 is inserted. The rock anchor 1 is in the not yet tensioned state, ie between the outer wall of the rock anchor 1 and the borehole wall 8 there remains a slot which only allows insertion into the borehole 3 . With the tensioning the rock anchor 1 in the bore hole 3 is to be prevented that become wider in the mountains 2 before handenen clefts 4, 5 and the mountains 2, characterized loosens. The rock bolt 1 is advanced into the deepest hole 6 and protrudes with its outer end 16 beyond the hole mouth 7 .

It can be seen from Fig. 1 that the actual rock anchor 1 consists of a man telrohr 9 and an anchor inner tube 12 . In particular, Fig. 2 shows that the tubular casing 9 surrounds the armature inner pipe 12. As will be explained further below, the casing tube 9 is formed here by an outer tube 10 , that is to say a tube which, together with the inner tube 12, can be fixed on the borehole side and brought together to form a unit.

The anchor outer tube 10 is equipped with a slot 11 running over a large part of the total length, so that when the anchor inner tube 12 expands, the anchor outer tube 10 bears against the borehole wall 8 .

In the inserted state, the anchor inner tube 12 is folded up, the pleat 13 being provided here in such a way that it is arranged exactly opposite the slot 11 . This can also be seen from FIG. 3, while according to FIG. 4 the insert fold 13 is positioned exactly on the opposite side, namely that with the slot 11 . Lter teres has the advantage that the pushing apart of the outer tube 10 and the application to the borehole wall 8 is accelerated and evened out.

Both Fig. 1 as well as Fig. 5 illustrate that are provided at both ends 14, 16 of the rock anchor 1 sleeves 17 and reinforcing sleeves 15. About this particular type of reinforcement in the end region should above all ensure that the necessary channels remain open when the liquid is pressed into the cavity of the anchor inner tube 12 , that is to say that no unfolding process is initiated so as to ensure that the liquid flows through.

The sleeve 17 at the outer end 16 has a bore 21 through which the pumped-up water flows from a pumping unit (not shown here) into the cavity of the anchor inner tube 12 and, on the other hand, a flange 18 with which the entire rock bolt 1 is then attached to the Dome plate 19 and thus supported on the borehole mouth 7 or the mountain 2 . The calotte plate 19 is slightly curved and has an elongated hole 20 in order to allow the rock anchor 1 to be inclined to a certain extent or to be movable, since the drilled hole 3 cannot always be arranged at right angles to the course of the mountain wall 22 .

1 can be seen in Fig. Primarily in that the sleeve passes into the armature outer tube 10 17. Both form a unit, with a round flange 24 then being applied to the outside of the sleeve 17 in order to enable support on the calotte plate 19 . In the well region 25 of the armature outer tube 10 may be indicated, be implemented special training for the outer surface 31 of the armature outer tube 10 as in FIG. 1. This is either a coating 32 or a roughening in order to specifically influence, ie to increase, the friction between the outer surface 31 and the borehole wall 8 . If now by pressing the fluid expanded in the armature inner tube 12 of this, it presses as in Fig. 3 and Fig. 4, the anchor outer tube 10 to the borehole wall 8 up close and ensures that the whole rock anchor 1 corresponding tensile forces and of course the shear forces on can take. In the sleeve region 26 , the wall of the outer anchor tube 10 or the sleeve 17 is either dimensioned the same or thicker, but in any case in such a way that the tasks described above can be performed, namely the securing of the corresponding channels between the walls the inner tube 12 to ensure the introduction of the pressure fluid.

Fig. 6 shows the sleeve region 26 , merging into the borehole region 25 GE according to the embodiment of FIG. 1, ie with the unitary embodiment of the outer tube 10 and sleeve 17th The anchor inner tube 12 , which is arranged within the slotted anchor outer tube 10 , is indicated. The dome plate 19 with the corresponding curvature 27 ensures a tight fit on the mountain wall 22 and with that the necessary tensile forces can be absorbed.

In the embodiment of FIG. 7, the armature outer tube 10 is connected to the dome plate 19 is connected and in accordance with Fig. 7 welded.

Fig. 8 shows then that the outer end is pulled through 28 of the armature outer tube 10 through the dome plate 19, so it can be an outer weld 29 and an inner weld joint 30 is attached. This makes it possible to absorb the corresponding tensile forces via the calotte plate 19 .

The anchor outer tube 10 has the long slot 11 already mentioned several times. This slot 11 is provided continuously according to FIG. 5, it also being conceivable to provide this slot 11 only over part of the length of the outer tube 10 of the anchor. It is also conceivable to design the slot 11 as a weak point, so that when the pressure fluid is pressed into the inner tube 12, the outer tube 10 is suddenly "torn open" and thus a targeted contact with the borehole wall 8 . In addition to the straight cutting surface 33 and 34 shown here on the slot 11 , it is also conceivable to provide other designs, the design shown here being the easiest to implement.

The present solution of the rock anchor 1 is characterized in particular by the fact that high shear forces can be absorbed via the design of the anchor outer tube 10 , ie both with respect to material and wall thickness. At the same time, this outer anchor tube 10 is then arranged or fixed such that it can absorb high tensile forces due to the adaptation to the borehole wall 8 . This creates a mountain anchor 1 that is optimally adaptable or adapted for use in mining and rock construction.

All of the above-mentioned features, including those that can only be taken from the drawings, alone and in combination are regarded as essential to the invention.

Claims (10)

1. rock anchor with longitudinally slotted casing tube ( 9 ) and an expandable via an injected fluid, an insertion fold ( 13 ) having an anchor inner tube ( 12 ), which is closed at the deepest hole ( 6 ) facing end ( 14 ) and at the outer end ( 16 ) with one Pump unit is designed to be connectable, the outer end ( 16 ) being bordered by a sleeve ( 17 ) with a flange ( 18 ) which is correspondingly shaped with a cap plate ( 19 ) which can be pressed onto the rock ( 2 ), characterized in that slotted jacket tube ( 9 ) is designed as an outer tube ( 10 ) and forms a structural unit that transmits tensile forces with the expandable inner tube ( 12 ). 2. Rock anchor according to claim 1, characterized in that the anchor outer tube ( 10 ) with the anchor inner tube ( 12 ) at the outer end ( 16 ) is connected to transmit tensile forces. 3. Rock anchor according to one of the preceding claims, characterized in that the anchor outer tube ( 10 ) is designed as an extension of the sleeve ( 17 ) while leaving a flange ( 18 ). 4. Rock anchor according to one of the preceding claims, characterized in that the outer anchor tube ( 10 ) and sleeve ( 17 ) are designed as a continuous tube on which a flange ( 18 ) serving as an annular flange ( 24 ) is placed and connected to the sleeve ( 17 ) , is preferably welded. 5. rock anchor according to one of the preceding claims, characterized in that the wall thickness of the anchor outer tube ( 10 ) in the borehole region ( 25 ) the expected tensile and shear forces sufficient and in the sleeve region ( 26 ) the pressure ratios of the inflowing fluid is dimensioned accordingly. 6. rock anchor according to one of the preceding claims, characterized in that the anchor outer tube ( 10 ) is connected to the calotte plate ( 19 ), preferably welded to it. 7. rock anchor according to claim 6, characterized in that the outer end ( 28 ) of the anchor outer tube ( 10 ) of the elongated hole ( 20 ) in the dome plate ( 19 ) adapted and guided through the dome plate ( 19 ) and connected to it, preferably welded , 8. rock anchor according to one of the preceding claims, characterized in that the insertion fold ( 13 ) of the anchor inner tube ( 12 ) with the slot ( 11 ) in the anchor outer tube ( 10 ) is arranged correspondingly. 9. rock anchor according to one of the preceding claims, characterized in that the outer surface ( 31 ) of the anchor outer tube ( 10 ) with a friction increase the coating ( 32 ) is provided or roughened. 10. rock anchor according to one of the preceding claims, characterized in that the slot ( 11 ) in the anchor outer tube ( 10 ) as a continuous weak point or in sections as both cutting surfaces ( 33 , 34 ) connecting weak point is formed.