CN217974351U - Self-drilling type prestressed anchor rod - Google Patents

Abstract

The application provides a from boring formula prestressed anchorage pole includes: the rod body is provided with a front end and a rear end which are opposite to each other along the length direction of the rod body; the drill bit is matched with the rod body through a first thread; the taper sleeve is matched with the rod body through second threads, and the turning directions of the second threads and the first threads are opposite; and the expansion pipe is matched with the taper sleeve to expand the rock body. The application provides a from boring formula prestressed anchorage pole can improve the efficiency of construction.

Description

Self-drilling type prestressed anchor rod

Technical Field

The application relates to the technical field of anchor bolt support, in particular to a self-drilling type prestressed anchor rod.

Background

A self-drilling anchor rod is an anchor rod in which an anchor rod body and a drill rod are combined into one body, and generally includes a rod body, a drill bit, and a nut. The full length of the rod body is provided with international standard external threads, the drill bit is installed at the top end of the rod body, and the nut is installed at the tail end of the rod body. When the anchor rod is installed, the hollow anchor rod body drives the drill bit to drill, after the drill hole is in place, the base plate and the nut are installed, then grouting is carried out, and the anchor rod is directly installed.

The self-drilling anchor rod construction technology is suitable for various complex geological conditions and construction site environments. The self-drilling anchor rod construction realizes integration of drilling, grouting and anchoring functions, has simple construction process, high construction efficiency and good anchoring effect, does not need to worry about hole collapse, and is widely applied to projects such as side slopes, dangerous rocks, deep foundation pit supporting, tunnel supporting and the like.

Although the self-drilling anchor rod directly drills through the anchor rod body as a drill rod, the problem of installation of the anchor rod which cannot be formed in a hole under the complex geological condition is solved, due to the fact that the timeliness of the underground engineering support on the anchor rod and the prestress application of the active support cannot be achieved structurally, the two requirements of loose and unstable rock strata on anchoring effect are urgently needed.

SUMMERY OF THE UTILITY MODEL

The application provides a self-drilling type prestressed anchor rod, which can improve the construction efficiency.

The application provides a from boring formula prestressed anchorage pole includes:

the rod body is provided with a front end and a rear end which are opposite to each other along the length direction of the rod body;

the drill bit is matched with the rod body through a first thread;

the taper sleeve is matched with the rod body through second threads, and the turning directions of the second threads and the first threads are opposite;

and the expansion pipe is matched with the taper sleeve to expand the rock body.

Several alternatives are provided below, but not as an additional limitation to the above general solution, but merely as a further addition or preference, each alternative may be combined individually for the above general solution or between several alternatives without technical or logical contradictions.

Optionally, the pitch of the first thread is 2 to 10 times that of the second thread.

Optionally, the first thread is arranged on the whole outer circumference of the rod body, and the second thread is arranged on a thread ridge of the first thread.

Optionally, the second thread is arranged at the front end of the rod body, and the length of the second thread is 10 mm-15 mm.

Optionally, the center of the rod body is provided with a grouting channel, and the drill bit is provided with a grouting hole communicated with the grouting channel.

Optionally, the periphery of the taper sleeve is provided with a backflow groove extending along the length direction of the rod body.

Optionally, the expansion pipe adopts an integrated structure and leaves a deformation absorption gap between the outer walls of the rod bodies, the expansion pipe is only provided with a deformation release groove which radially penetrates through the side wall, and the deformation release groove extends along the length direction of the rod body and is opened at the front end of the expansion pipe.

Optionally, the expansion pipe is further provided with a spalling belt with a relatively reduced wall thickness, the spalling belt extends along the length direction of the rod body in the circumferential direction of the expansion pipe, and the position of the spalling belt is right opposite to the position of the deformation release groove.

Optionally, the periphery of the expansion pipe is provided with a barb structure.

Optionally, the expansion pipe further comprises a limiting sleeve fixed outside the rod body in a sleeved mode, in an initial state, the front end of the taper sleeve abuts against and is limited by the drill bit, the front end of the expansion pipe is sleeved outside the taper sleeve, and the rear end of the expansion pipe abuts against and is limited by the limiting sleeve.

The application provides a from boring formula prestressed anchorage pole can improve the efficiency of construction.

Drawings

FIG. 1 is a schematic structural diagram of an embodiment of the present application;

FIG. 2 is an exploded view of FIG. 1;

FIG. 3 is an internal structural view of FIG. 1;

fig. 4 is an enlarged view of region a in fig. 3.

The reference numbers in the figures are as follows:

1. a rod body; 11. a first thread; 12. a second thread; 15. grouting a channel; 2. a drill bit; 21. grouting holes; 3. a taper sleeve; 31. a return chute; 4. an expansion pipe; 41. a deformation release groove; 422. a barb structure; 43. a spalling zone; 5. a position limiting sleeve; 6. a support plate; 7. a deformation absorbing gap; 8. a rod tail nut.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only some embodiments of the present application, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

It will be understood that when an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. When a component is referred to as being "disposed on" another component, it can be directly on the other component or intervening components may also be present.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the present application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Referring to fig. 1 to 4, in one embodiment, the self-drilling prestressed anchor includes a rod body 1, a drill bit 2, a taper sleeve 3, and an expansion pipe 4. The body of rod 1 has relative front end and rear end along self length direction, through the cooperation of first screw thread 11 between drill bit 2 and the body of rod 1, through the cooperation of second screw thread 12 between taper sleeve 3 and the body of rod 1, the second screw thread 12 is opposite with the direction of turning of first screw thread 11, and expansion pipe 4 cooperates with taper sleeve 3 to the tight rock mass of expanding.

Existing expanded tubular bolts are generally anchored by wedging a wedge into the expanded tube. The wedge of the present embodiment is designed to be a taper sleeve 3 with internal threads in order to maintain a threaded connection with the rod body 1, and the outer peripheral surface of the taper sleeve 3 is not strictly limited to a conical surface.

The shape of the expansion pipe 4 and the installation mode of the expansion pipe on the anchor rod in the embodiment can adopt the prior art, and is not taken as the improvement focus of the embodiment. For example, the expansion pipe 4 itself may adopt a split structure or an integrated structure, and the integrated structure may be designed into a single slot, two split, three split, etc., as long as expansion can be ensured. The installation mode of expansion pipe 4 on the stock can be with the rear end of expansion pipe 4 fixed in the body of rod 1, also can be with the front end of expansion pipe 4 connect in taper sleeve 3, has described multiple scheme among the prior art, and it is no longer repeated here, does not influence the cooperation that technical personnel in the field implemented taper sleeve 3 and expansion pipe 4. In short, reference is made to the prior art how to arrange the matching relationship between the expansion tube 4 and the rod body 1 or the taper sleeve 3 to realize the function of expanding the expansion tube 4 by moving the taper sleeve 3 backwards. The main improvement of this embodiment is how to drive the taper sleeve 3 backward.

The existing mode for driving the taper sleeve 3 to move backwards is that a screw and nut kinematic pair is formed by the rod body 1 and the nut by rotating the nut at the rear end of the rod body 1, so that the rod body 1 is promoted to move backwards towards the outside of the anchor hole along the axial direction, and the rod body 1 can also be directly pulled towards the outside of the anchor hole. This will make the exposed section overlength of the body of rod 1 rear end after the stock installation, need cut off unnecessary part, not only cause the waste of material, influence the efficiency of construction moreover.

In the method for driving the taper sleeve 3 to move backwards in the embodiment, the first thread 11 and the second thread 12 with opposite rotation directions are arranged on the rod body 1, and the first thread 11 and the second thread 12 may be partially overlapped or not overlapped in the length direction of the rod body 1. The thread matching of the drill bit 2, the taper sleeve 3 and the rod body 1 is equivalent to forming two sets of screw nut kinematic pairs of a common screw, and when the rod body 1 is rotated towards one direction, the drill bit 2 and the taper sleeve 3 are close to each other. When the rod body 1 is rotated in the other direction, the drill bit 2 and the taper sleeve 3 are far away from each other. One possible way of mounting the bolt will now be described, taking as an example the first thread 11 being a left-hand thread.

Under initial condition, the depth of the front end of the rod body 1 screwed into the drill bit 2 is not limited, the axial distance between the drill bit 2 and the taper sleeve 3 is not limited, and the drill bit can be tightly abutted and can also leave a distance.

When drilling, the drilling machine rotates the rear end of the rod body 1 anticlockwise, the drill bit 2 and the taper sleeve 3 are close to each other, namely, the drill bit 2 moves towards the rear relative to the rod body 1, and the taper sleeve 3 moves towards the front relative to the rod body 1. When the drill bit 2 abuts against the front end of the rod body 1, the axial movement is stopped, and the drill bit 2 starts to synchronously rotate along with the rod body 1 to form an anchor hole. After the drill bit 2 tightly abuts against the front end of the rod body 1, the taper sleeve 3 continuously moves forward and tightly abuts against the drill bit 2. Therefore, in the drilling process, the drill bit 2 finally serves as a limiting structure of the taper sleeve 3, and the taper sleeve 3 is prevented from excessively advancing and falling off.

When the anchor is fixed, the rear end of the clockwise rotation rod body 1, the drill bit 2 and the taper sleeve 3 are far away from each other, namely, the drill bit 2 moves towards the front relative to the rod body 1, and the taper sleeve 3 moves towards the rear relative to the rod body 1. In the backward moving process of the taper sleeve 3, the expansion pipe 4 is gradually expanded by the taper sleeve 3 and tightly propped against the inner wall of the anchor hole, so that the anchoring is realized.

After anchoring, the rear end of the rod body 1 is continuously rotated clockwise, and the rod body 1 is tensioned to generate prestress. For soft country rock, the backshifting distance of taper sleeve 3 will influence the size of prestressing force, and the backshifting distance of taper sleeve 3 does not rely on the axial displacement of the body of rod 1 again in this embodiment, so the stock of this application can not produce the exposed section of the body of rod 1 of overlength when providing abundant prestressing force.

In one embodiment, the pitch of the first thread 11 is 2 to 10 times that of the second thread 12. The first threads 11 are thicker threads, so that the construction efficiency is improved, and the interchangeability is better. The second thread 12 is a thinner thread, which can increase the transmission ratio of the torsion of the rod body 1 and the backward movement of the taper sleeve 3 and reduce the torsion on the rod body 1. Specifically, the pitch of the second thread 12 is 1mm to 2mm.

In one embodiment (not shown), the shaft includes a first section and a second section adjacent to each other, the first thread is disposed on the first section, and the second thread is disposed on the second section. The first segment has a first thread over its entire length and the second segment has a second thread over its entire length.

In order to reduce the processing cost of the anchor rod, in another embodiment, referring to fig. 2, the entire length of the outer circumference of the rod body 1 is provided with a first thread 11, and a second thread 12 is arranged on the thread ridge of the first thread 11. The general threaded rod in this embodiment make full use of stock field to on the basis of current threaded rod, only need further process out second screw 12 can, practiced thrift the processing cost when improving stock installation convenience.

Specifically, in one embodiment, the second thread 12 is disposed at the front end of the rod body 1. The second thread 12 is arranged at the end part of the rod body 1, so that the anchor rod can be conveniently assembled on site by workers, and the operation is more flexible. In theory, the second thread 12 can be arranged at both the front end of the rod body 1 and the rear end of the rod body 1. However, since the rear side of the taper sleeve 3 should reserve an installation space for the expansion pipe 4, if the second thread 12 is provided at the rear end of the rod body 1, the processing length of the second thread 12 is increased, and a longer assembly time is also required. Therefore, the second thread 12 is disposed at the front end of the rod body 1. On the other hand, in order to ensure that the anchor can generate enough prestress, the length of the second thread 12 cannot be too short, and in order to take account of the processing cost and the anchor performance, in one embodiment, the length of the second thread 12 is 10mm to 15mm, and the length of the second thread 12 refers to the span in the axial direction in the embodiment.

As known to those skilled in the art, a certain initial anchoring force needs to be generated between the expansion shell and the inner wall of the borehole before the anchor rod is anchored in order to fix the axial position of the expansion shell. If the initial anchor force is too small, when the rod body moves outwards of the drilled hole, the expansion shell can move backwards synchronously with the wedge, so that the taper sleeve cannot expand the expansion shell, and the construction efficiency is influenced.

In order to increase the initial anchoring force of the anchor rod, in an embodiment, referring to fig. 2 and 4, the expansion tube 4 is of an integral structure, and a deformation absorption gap 7 is left between the expansion tube 4 and the outer wall of the rod body 1, the expansion tube 4 is provided with only one deformation release groove 41 radially penetrating through the side wall, and the deformation release groove 41 extends along the length direction of the rod body and is open at the front end of the expansion tube 4.

In this embodiment, by providing the deformation releasing groove 41, the expansion pipe 4 can be deformed by contracting the deformation releasing groove 41 to obtain an elastic force, and the inner wall of the drilled hole is directly abutted by the elastic force of the expansion pipe 4 to form a primary anchoring force. Compared with the prior primary anchoring force obtained by the metal fin, the primary anchoring force obtained by the embodiment is greatly increased.

Referring to fig. 2, in one embodiment, the expansion tube 4 is further provided with a bursting tape 43 having a relatively reduced wall thickness, the bursting tape 43 extending along the length of the rod body 1. The bursting tape 43 of the embodiment does not penetrate through the wall of the expansion pipe 4 in the radial direction, so that the cross-sectional shape of the expansion pipe 4 is continuous instead of discontinuous like the prior split structure, and the arrangement ensures enough initial anchoring force on one hand and also ensures that the expansion pipe 4 is easy to expand on the other hand. In order to make the distribution of the anchoring force more uniform in the circumferential direction, in one embodiment, the location of the bursting tape 43 is directly opposite to the location of the strain relief groove 41 in the circumferential direction of the expansion pipe 4.

In one embodiment, the rod body 1 has a grouting passage 15 at the center thereof, and the drilling head 2 is provided with a grouting hole 21 communicating with the grouting passage 15. When drilling, water or air can be injected into the anchor hole or air can be discharged from the anchor hole through the grouting channel 15 and the grouting hole 21. Can also pour into anchoring agent such as cement mortar into towards anchor eye through slip casting passageway 15 and slip casting hole 21, be a whole with soft broken country rock cementing, promote the anchorability of tunnel leg.

Furthermore, the periphery of the taper sleeve 3 is provided with a backflow groove 31 extending along the length direction of the rod body 1, so that slurry can flow back conveniently, the periphery of the anchor rod can be filled with slurry, and the diffusion range of the slurry in rock stratum cracks is enlarged.

In one embodiment, at least two of the expansion zones 43 are circumferentially disposed, and each expansion zone 43 is circumferentially positioned in alignment with the return grooves 31 to reduce resistance to slurry backflow.

Referring to fig. 4, in one embodiment, the expansion tube 4 has a barb structure 422 on its outer circumference. Barb structure 422 has the stopping function, and during drilling, barb structure 422 is less with the frictional force of anchor eye inner wall, does not influence the stock and stretches into downtheholely. When the anchor is fixed, the friction force between the barb structure 422 and the inner wall of the anchor hole is large, so that the taper sleeve 3 can conveniently enter the expansion pipe 4.

Referring to fig. 1, in an embodiment, the self-drilling prestressed anchor rod of the present application further includes a limiting sleeve 5 fixed outside the rod body 1 in a sleeved manner, in an initial state, a front end of the conical sleeve 3 abuts against the drill bit 2 for limiting, a front end of the expansion pipe 4 is sleeved outside the conical sleeve 3, and a rear end of the expansion pipe 4 abuts against the limiting sleeve 5 for limiting.

Specifically, in one embodiment (not shown), the rod body includes a first rod body and a second rod body, the first rod body and the second rod body are respectively butted against two ends of a limiting sleeve, and the limiting sleeve also serves as an anchor rod connecting sleeve. During assembly, the first rod body and the second rod body are firstly in threaded fit with the limiting sleeve, and then are hooped by a tool to stop rotation.

In one embodiment, the self-drilling prestressed anchor of the present application further comprises a support plate 6 and a shank nut 8. The layer board 6 cup joints in the rear end of the body of rod 1, and the pole tail nut 8 and the body of rod 1 screw-thread fit and butt layer board 6's rear side.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features. When technical features in different embodiments are represented in the same drawing, it can be seen that the drawing also discloses a combination of the embodiments concerned.

The above-mentioned embodiments only express several implementation modes of the present application, and the description thereof is specific and detailed, but not construed as limiting the scope of the claims. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims (10)

1. Self-drilling prestressed anchor rod, its characterized in that includes:

the rod body is provided with a front end and a rear end which are opposite to each other along the length direction of the rod body;

the drill bit is matched with the rod body through a first thread;

the taper sleeve is matched with the rod body through second threads, and the turning directions of the second threads and the first threads are opposite;

and the expansion pipe is matched with the taper sleeve to expand the rock mass.

2. The self-drilling prestressed anchor of claim 1, wherein the pitch of said first thread is 2-10 times that of said second thread.

3. A self-drilling prestressed anchor according to claim 1, wherein said shank is provided with said first thread along its entire length of its outer circumference, and said second thread is provided on the thread ridge of said first thread.

4. A self-drilling prestressed anchor bolt according to claim 3, wherein said second thread is formed at the front end of said shank and has a length of 10-15 mm.

5. A self-drilling, pre-stressed anchor according to claim 1, wherein said shank is provided with a grouting passage at the center thereof, and said drill is provided with a grouting hole communicating with said grouting passage.

6. The self-drilling prestressed anchor rod as claimed in claim 1, wherein the taper sleeve is provided at its outer periphery with a return groove extending in the longitudinal direction of the rod body.

7. The self-drilling prestressed anchor bolt of claim 3, wherein said expansion pipe is an integral structure and has a deformation absorption gap with the outer wall of said bolt body, said expansion pipe is provided with only one deformation release groove radially penetrating the side wall, said deformation release groove extends along the length direction of said bolt body and opens at the front end of said expansion pipe.

8. The self-drilling prestressed anchor rod as claimed in claim 7, wherein said expansion pipe is further provided with a bursting area with a relatively reduced wall thickness, said bursting area extends along the length direction of said rod body, and the position of said bursting area is opposite to the position of said deformation releasing groove in the circumferential direction of said expansion pipe.

9. The self-drilling prestressed anchor of claim 7, wherein said expansion pipe has a barbed configuration on its outer circumference.

10. The self-drilling prestressed anchor rod of claim 7, further comprising a limiting sleeve fixed outside the rod body in a sleeved manner, wherein in an initial state, the front end of the taper sleeve abuts against the drill bit for limiting, the front end of the expansion pipe is sleeved outside the taper sleeve, and the rear end of the expansion pipe abuts against the limiting sleeve for limiting.

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