Multi-stage yielding adjustable large-deformation anchor rod and method

Abstract

The multistage yielding adjustable large-deformation anchor rod comprises a rod body, a pressure bearing cylinder and a protective cover, the rod body comprises a section A, a section B and a section C, one end of the section B is connected with the section A, the other end of the section B is connected with the pressure bearing cylinder and the section C, the section C is connected with the pressure bearing cylinder through an adjusting assembly, and one end of the section C is connected with the protective cover. According to the multi-stage yielding adjustable large-deformation anchor rod, the pressure bearing section adopts the multi-step sleeve and bears the specified nut pressure value in sequence, the pressure bearing section of the rod body is provided with the multiple sections of threads, the nut is subjected to shear failure within the set force value range by utilizing the material strength difference of the rod body and the nut and setting the failure coefficient of the threads, and therefore the stress of the anchor rod is reduced. Therefore, displacement and yielding of the anchor rod are achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of pressure-yielding anchor rods, and in particular relates to a multi-stage pressure-yielding adjustable large deformation anchor rod and a method. Background Art

[0002] With the development of geotechnical anchoring technology, anchor rods have become a form of support that can effectively improve the strength of geotechnical bodies and are widely used in the field of underground engineering support. Traditional anchor rods are usually made of fully threaded fine-rolled steel bars, and the grouting method adopts through-section grouting. Due to the influence of natural factors such as large deformation of rock formations and earthquakes, the elongation of anchor rods is low, resulting in insufficient extension length and failure to adapt to large deformation environments and breakage.

[0003] In order to adapt to the situation of large deformation of rock formations and prevent the anchor body from being damaged, a series of constant resistance large deformation anchors have been developed at home and abroad. According to the working principle, they can be divided into two types: material type and structural type. Material type large deformation anchors need to use materials with large elongation, and have high requirements on material performance and strength. This type of anchor is often more expensive.

[0004] Patent CN202520346U provides a variable diameter round steel structure, which adapts to rock deformation by large displacement of the cold drawn rod body. This anchor rod may not be able to adapt to the instantaneous release of surrounding rock strain energy, and there are certain safety hazards.

[0005] Most structural large deformation anchors adopt the shell expansion principle. Patent CN103603685B provides an extendable energy-absorbing anchor, which provides a large deformation capacity for the anchor, but the wedge-shaped platform has problems such as wear during the sliding process. And the wedge-shaped platform does not have the function of being manually adjustable or replaceable in the later stage.

[0006] Patent CN114542144B provides a multi-stage pressure-yielding constant resistance large deformation anchor rod, which is provided with multi-stage sleeve sections, and the resistance generated by the wedge-shaped head squeezing the sleeve increases step by step to control the deformation of the surrounding rock.

[0007] The existing large deformation anchor technology is a permanently embedded anchor. The structure that resists deformation is the effective stroke. The anchor head cannot be maintained or replaced, or the stroke or deformation resistance cannot be adjusted during the monitoring process. Summary of the invention

[0008] In order to solve the above technical problems, the present invention provides a multi-stage pressure-yielding adjustable large deformation anchor rod and method, which can solve the requirement of the rod structure to adapt to the large deformation of the rock formation on the extension of the anchor rod, and provide a disassembly and replacement plan for the maintenance and multiple use of the anchor rod after pressure-yielding, which solves the problem of breakage of traditional anchor rods under conditions of large impact deformation, and the problem of one-time use due to the inability to maintain it in the later stage due to the limitations of the existing anchor rod structure.

[0009] The present invention is achieved through the following technical solutions.

[0010] The present invention provides a multi-stage pressure-yielding adjustable large deformation anchor rod, comprising a rod body, a pressure-bearing cylinder and a protective cover, wherein the rod body comprises section A, section B and section C, one end of section B is connected to section A, the other end of section B is connected to the pressure-bearing cylinder and section C, section C is connected to the pressure-bearing cylinder via an adjusting component, and one end of section C is connected to the protective cover.

[0011] Preferably, an isolation tube A is provided on the section B, and a sensor is provided on the isolation tube A.

[0012] Preferably, the outer surface of section A is provided with threads, which are directly bonded to concrete to form an inner anchoring section.

[0013] Preferably, the gap between the B section and the isolation tube A is filled with anti-corrosion material.

[0014] Preferably, the C section is arranged in a conical shape, a thread is arranged on the C section, and the C section is threadedly connected to the adjustment component.

[0015] Preferably, the adjustment assembly comprises nut A, nut B and nut C, and the nut A, nut B and nut C are arranged on the C section.

[0016] Preferably, a load-bearing adjustment section A, a load-bearing adjustment section B and a load-bearing adjustment section C are provided on the pressure-bearing cylinder, and nuts A, B and C are respectively provided in the load-bearing adjustment section A, the load-bearing adjustment section B and the load-bearing adjustment section C.

[0017] Preferably, a sealing piece is provided at the location where the rod body penetrates the pressure-bearing cylinder, and the protective cover is filled with anti-corrosion material.

[0018] Preferably, the effective thread segments of the nut A and C can bear a load value F1>F pm , where F pm is the ultimate breaking force of the rod body, and the effective threaded section of the nut B and C can bear the load value F2 = n1F pm , where F2<F pm , the effective thread section load-bearing value of nut C and C section is F3=n2F pm , where F3<F pm Or F3≤F2.

[0019] A maintenance method for a multi-stage pressure-adjustable large deformation anchor rod comprises the following steps: after removing the protective cover, taking out the failed nut and installing a single replacement nut, lengthening the rod body by using the connecting nut and the connecting screw, and tensioning the bearing rod body tension by a jack, at this time adjusting the distance between the normally working load-bearing nut and the corresponding bearing surface in the direction of the protective cover, rotating the new replacement nut until it contacts the corresponding bearing surface and reinstalling the protective cover, and completing the maintenance work after removing the equipment and tooling used for maintenance.

[0020] The beneficial effects of the present invention are:

[0021] 1. The present invention provides a multi-stage pressure-yielding adjustable large deformation anchor rod. The pressure-bearing section adopts a multi-step sleeve and bears the specified nut pressure value in sequence. The pressure-bearing section of the rod body is provided with multiple sections of threads. The strength difference between the rod body and the nut material and the setting of the thread failure coefficient are utilized to make the nut fail in shear within the set force value range, thereby realizing the displacement of the anchor rod and pressure relief.

[0022] 2. Different nuts of the adjustment assembly of the present invention can be set with different thread failure coefficients, and the thread failure coefficient of each level of nuts increases with the F value direction, thereby gradually increasing the bearing capacity of the pressure section. Or, by setting the same thread failure coefficient, the anchor rod can achieve constant resistance sliding.

[0023] 3. According to the rock formation conditions, when installing the anchor rod, the L value of the nuts at each level of the adjustment component from the bearing surface can be set, so as to adjust the pressure displacement value of the rod body.

[0024] 4. The present invention provides a disassembly and replacement solution for maintenance and multiple use of the anchor rod after compression based on the structure. When the anchor rod actively shears the failed nut to cope with the large deformation of the rock formation, the failed nut can be replaced, or the distance L between the remaining non-failed nuts and the bearing surface can be adjusted again.

[0025] 5. The rod body of the present invention is provided with a free section, and the free section is isolated from the concrete, which can effectively improve the elongation of the rod body in the working state.

[0026] 6. The present invention is provided with a safety-level load-bearing, that is, when the rock and soil body is extremely deformed and exceeds the design force value of the rod body, the safety nut can provide a certain safety precaution and rely on the monitoring of the sensor to prevent or reduce the risk of landslide. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the structure of the present invention;

[0028] Figure 2 It is a schematic diagram of the maintenance structure of the present invention;

[0029] Figure 3 It is a schematic diagram of the structure of segment C of the present invention;

[0030] Figure 4 It is a schematic diagram of the structure of the present invention;

[0031] In the figure: 1-rod body, 101-section A, 102-section B, 103-section C, 2-isolation tube A, 3-sensor, 4-sealing piece, 5-nut A, 6-pressure cylinder, 601-bearing adjustment section A, 602-bearing adjustment section B, 603-bearing adjustment section C, 604-bearing surface A, 605-bearing surface B, 606-bearing surface C, 7-nut B, 8-nut C, 801-replacement nut, 10-protective cover, 11-connecting nut, 12-jack, 13-connecting screw, 201-pressure cylinder, 202-nut D, 203-nut E, 204-nut F, 205-isolation tube B, 206-rod body B, 207-pressure plate, 208-fastening nut. DETAILED DESCRIPTION

[0032] The technical solution of the present invention is further described below, but the scope of protection claimed is not limited to the description.

[0033] Embodiment 1:

[0034] like Figures 1 to 3 As shown, a multi-stage pressure-adjustable large deformation anchor bolt comprises a rod body 1, a pressure-bearing cylinder 6 and a protective cover 10. The rod body 1 comprises a section A 101, a section B 102 and a section C 103. One end of the section B 102 is connected to the section A 101, and the other end of the section B 102 is connected to the pressure-bearing cylinder 6 and the section C 103. The section C 103 is connected to the pressure-bearing cylinder 6 through an adjustment component, and one end of the section C 103 is connected to the protective cover 10 through a threaded section D. The section A 101 is a bonding section, the section B 102 is a free section, and the section C 103 is a pressure-bearing section. The material strength of the rod body 1 is greater than the material strength of the adjustment component.

[0035] An isolation tube A2 is arranged on the B section 102. The outer contour of the B section 102 is smooth. The rod body of this section is not in contact with or bonded to the external concrete and can extend freely. A sensor 3 is arranged on the isolation tube A2.

[0036] 1. The outer surface of the A section 101 is provided with threads. The threads increase the contact area between the outer wall of the A section 101 and the concrete, change the original smooth surface of the rod body, and improve the bonding performance. The external threads can bear a certain force value, and a certain thread section can increase the bearing capacity of the inner anchoring section of the anchor rod, and can effectively reduce the length of the inner anchoring section compared to the smooth rod body.

[0037] The gap between the B section 102 and the isolation tube A2 is filled with an anti-corrosion material, which is anti-corrosion oil.

[0038] The C segment 103 is configured in a conical shape, and a thread is configured on the C segment 103. The diameters of the thread segment A, the thread segment B, the thread segment C, and the thread segment D decrease in sequence, and the C segment 103 is threadedly connected to the adjustment component.

[0039] The adjustment assembly includes nut A5, nut B7 and nut C8, which are arranged on section C 103 from left to right, wherein section C 103 is connected to nut A5 through thread section A, connected to nut B7 through thread section B, and connected to nut C8 through thread section C. The number of nuts can be set according to actual conditions. Nut A5 is a safety nut, which provides certain safety precautions.

[0040] The pressure-bearing cylinder 6 is provided with a load-bearing adjustment section A601, a load-bearing adjustment section B602 and a load-bearing adjustment section C603. The number of load-bearing adjustment sections can be set according to actual needs. Nuts A5, B7 and C8 are respectively arranged in the load-bearing adjustment sections A601, B602 and C603. When the load-bearing adjustment sections are working, the tension of the rod body 1 is converted into pressure through the nut end surface of the adjustment assembly to give load to the pressure-bearing cylinder 6.

[0041] Working principle of the pressure section: Nut C8 contacts the load-bearing adjustment section C603, converting the tension of the rod body 1 into the pressure of the load-bearing adjustment section C603 through the thread; the nut B7 knob is turned to the position L2 from the load-bearing adjustment section B602, and the nut A5 knob is turned to the position L1 from the load-bearing adjustment section A601, L1>L2. When the rock formation deforms greatly so that F≥n2F pm When the thread of nut C8 fails due to shear, the rod moves L2 in the direction of F. At this time, nut B7 contacts the load adjustment section B602 and starts to work. When the subsequent rock formation deformation makes F≥n1F pm When the thread of nut B7 fails due to shearing, the rod moves in the direction of F. At this time, the safety nut abuts against the load-bearing adjustment section A601 and starts to work.

[0042] L1 and L2 are the adjustable travels of the rod body 1. n1 can be equal to n2, that is, the force value reaches n1F when the anchor rod is working. pm When n1>n2, the anchor rod can achieve constant resistance sliding; or n1>n2, that is, the anchor rod can achieve graded variable resistance sliding.

[0043] A plugging member 4 is provided at the location where the rod body 1 penetrates the pressure-bearing cylinder 6 , and an anti-corrosion material is filled in the protective cover 10 , and the anti-corrosion material is anti-corrosion oil.

[0044] The effective threaded section of the nut A5 and the C section 103 can bear a load value F1>F pm , where F pm is the ultimate breaking force of the rod body 1, and the effective threaded section of the nut B7 and the C section 103 can bear a load value of F2 = n1F pm , where F2<F pm The effective threaded section of nut C8 and C section 103 can bear the load F3 = n2F pm , where F3<F pm Or F3≤F2.

[0045] A maintenance method for a multi-stage pressure-adjustable large deformation anchor bolt comprises the following steps: after removing the protective cover 10, the failed nut is taken out and a single replacement nut is installed, the rod body 1 is extended by using the connecting nut 11 and the connecting screw 13, and the tensile force of the bearing rod body 1 is tensioned by the jack 12, at this time, the distance between the normally working load-bearing nut and the corresponding bearing surface is adjusted in the direction of the protective cover 10, the new replacement nut 801 is rotated to contact the corresponding bearing surface and the protective cover 10 is reinstalled, and the equipment and tooling used for maintenance are removed, and the maintenance work is completed.

[0046] When the anchor rod actively shears the failed nut in response to large deformation of the rock formation, the failed nut can be replaced, or the distance L between the remaining unfailed nuts and the bearing surface can be adjusted to achieve the effect of multiple uses of the anchor rod. Take the failure of nut C8 as an example. At this time, nut A7 is working and L2=0. After removing the protective cover 10, take out the failed nut C8 and install a single replacement nut. Use the connecting nut 11 and the connecting screw 13 to extend the rod body 1, and use the jack 12 to tension the tension of the bearing rod body 1. At this time, the distance L2 from the nut A7 to the bearing surface B605 can be adjusted outward. Screw the replacement nut 801 until it contacts the bearing surface C606. Replacing multi-stage nuts can refer to similar methods.

[0047] Embodiment 2:

[0048] Anchor structure Figure 4 As shown, the anchor rod body is divided into a pressure-bearing section, a free section and an external bearing section. The anchor rod pressure-bearing section is set in a stable rock formation, and a plurality of groups of bearing adjustment sections are arranged in the pressure-bearing tube 201. Nuts D202, E203 and F204 are arranged in order in the bearing adjustment section. By utilizing the strength difference between the rod body B206 and the nut material and by setting the thread failure coefficient, the nut fails in shearing under the set force value range. The principle is the same as that of Example 1, so as to achieve the displacement of the anchor rod and yield pressure, and convert it to the next level of nut bearing pressure. An isolation tube B205 is arranged on the free section of the rod body B206, and the external bearing section of the rod body B206 is fixed by setting a pressure plate 207 and a tightening nut 208. This embodiment needs to calculate the distance L between the nut and the bearing adjustment section in advance, and design the yield pressure level and the thread failure coefficient according to the engineering conditions.

[0049] 1. Both Example 1 and Example 2 are pressure-yielding constant resistance large deformation anchor rods, which have pressure-yielding capabilities and are used in the same scenarios. However, Example 1 can be maintained later, and the pressure-yielding value of the anchor rod can be appropriately adjusted according to the later state of the rock and soil.

[0050] 2. The difference between Example 1 and Example 2 lies in the relative movement direction of the anchor rod body during the pressure release process. When the rod body of Example 1 releases pressure, the rod body 1 moves toward the inside of the rock and soil body relative to the pressure-bearing cylinder 6 along the F direction; when the rod body of Example 2 releases pressure, the rod body B206 moves toward the outside of the rock and soil body in the direction of the protective cover relative to the pressure-bearing cylinder 201.

Claims

1. A multi-stage pressure-adjustable large deformation anchor bolt, characterized in that: The invention comprises a rod body (1), a pressure-bearing cylinder (6) and a protective cover (10); the rod body (1) comprises an A section (101), a B section (102) and a C section (103); one end of the B section (102) is connected to the A section (101); the other end of the B section (102) is connected to the pressure-bearing cylinder (6) and the C section (103); the C section (103) is connected to the pressure-bearing cylinder (6) via an adjusting component; one end of the C section (103) is connected to the protective cover (10).

2. A multi-stage pressure-adjustable large deformation anchor rod as claimed in claim 1, characterized in that: An isolation tube A (2) is disposed on the B section (102), and a sensor (3) is disposed on the isolation tube A (2).

3. The multi-stage pressure-adjustable large deformation anchor rod according to claim 1, characterized in that: The outer surface of the A section (101) is provided with threads.

4. The multi-stage pressure-adjustable large deformation anchor rod according to claim 1, characterized in that: The gap between the B section (102) and the isolation tube A (2) is filled with anti-corrosion material.

5. The multi-stage pressure-adjustable large deformation anchor rod according to claim 1, characterized in that: The C section (103) is arranged in a conical shape, a thread is arranged on the C section (103), and the C section (103) is threadedly connected to the adjustment component.

6. The multi-stage pressure-adjustable large deformation anchor rod according to claim 1, characterized in that: The adjustment assembly comprises a nut A (5), a nut B (7) and a nut C (8), wherein the nut A (5), the nut B (7) and the nut C (8) are arranged on the C section (103).

7. The multi-stage pressure-adjustable large deformation anchor rod according to claim 1, characterized in that: The pressure-bearing cylinder (6) is provided with a load-bearing adjustment section A (601), a load-bearing adjustment section B (602) and a load-bearing adjustment section C (603), and the load-bearing adjustment section A (601), the load-bearing adjustment section B (602) and the load-bearing adjustment section C (603) are respectively provided with a nut A (5), a nut B (7) and a nut C (8).

8. The multi-stage pressure-adjustable large deformation anchor rod according to claim 1, characterized in that: A sealing member (4) is provided at the point where the rod body (1) on the pressure-bearing cylinder (6) passes through, and an anti-corrosion material is filled in the protective cover (10).

9. The multi-stage pressure-adjustable large deformation anchor rod according to claim 6, characterized in that: The effective threaded section of the nut A (5) and the C section (103) can bear a load value F1>F pm , where F pm is the ultimate breaking force of the rod body (1), and the effective threaded section of the nut B (7) and the C section (103) can bear a load value of F2 = n1F pm , where F2<F pm The effective threaded section of nut C (8) and section C (103) can bear a load of F3 = n2Fpm, where F3 < F pm Or F3≤F2.

10. A maintenance method for a multi-stage pressure-adjustable large deformation anchor bolt as claimed in any one of claims 1 to 9, characterized in that: The following steps are involved: After removing the protective cover (10), the failed nut is taken out and a single replacement nut is installed. The rod body (1) is extended by using the connecting nut (11) and the connecting screw (13), and the tension of the bearing rod body (1) is tensioned by the jack (12). At this time, the distance between the nut that normally bears the load and the corresponding bearing surface is adjusted in the direction of the protective cover (10), and the new replacement nut (801) is rotated until it contacts the corresponding bearing surface and the protective cover (10) is reinstalled. After removing the equipment and tooling used for maintenance, the maintenance work is completed.

Images