Shear-resistant variable-resistance yielding anchor rod capable of measuring pre-tightening force and use method of shear-resistant variable-resistance yielding anchor rod

Abstract

The invention belongs to the technical field of underground engineering supporting, and particularly discloses a shear-resistant variable-resistance yielding anchor rod capable of measuring pretightening force and a using method thereof.The shear-resistant variable-resistance yielding anchor rod is provided with an anchor rod body, the anchor rod body comprises a head section, a middle standard section and a tail section which are sequentially connected, the head section comprises a head end rod body, the head end rod body is provided with a piston head, and the piston head is sleeved with a sleeve; the sleeve and the piston head form a piston structure. A piston cylinder structure is arranged on the middle standard section and is used for adapting to shear deformation caused by dislocation and slippage deformation of a rock stratum. The tail section comprises a first rod body and a second rod body, the tail end of the second rod body is arranged in the first rod body in a penetrating mode along the rod length of the first rod body, connected with the elastic piece and capable of sliding in the rod length direction of the first rod body, and the tail end of the second rod body is provided with an outer extension and capable of feeding back deformation of the elastic piece. The problem that a common anchor rod cannot meet the requirement for large deformation of surrounding rock is solved, the problem that an existing anchor rod is prone to being cut off under transverse displacement of a rock stratum is solved, and meanwhile the pretightening force can be measured.

Description

Technical Field

[0001] The invention belongs to the technical field of underground engineering support, and particularly relates to a shear-resistant variable resistance pressure-yielding anchor rod capable of measuring preload force and a use method thereof. Background Art

[0002] As the depth of mineral mining increases, the engineering geological conditions faced by mining become more complex, and the surrounding rock structure of deep tunnels becomes more complex. Due to the prominent contradiction between the high ground stress in the deep surrounding rock and the low strength of the surrounding rock mass, the influence of engineering actions and environmental conditions during excavation, and the mining stress formed during the mining of mineral resources, the surrounding rock of deep tunnels is prone to large deformation damage and anchor shear fracture failure, which poses a huge challenge to mine safety production and is an urgent problem to be solved in deep mineral resource mining.

[0003] Anchor rods are a main support form widely and efficiently used in the field of underground engineering support. At present, in order to solve the problem of supporting large deformation of deep high-stress surrounding rock, the project requires that the anchor rod can not only provide stable support force, but also produce large elongation deformation to meet the requirements of large deformation of broken surrounding rock. In order to solve the above problems, the compression support technology is usually used to make the anchor rod produce large tensile deformation without being broken. However, it is found in actual engineering that many anchor rods are sheared off because they cannot withstand large shear stress, which leads to failure of anchor rod support, which can lead to very serious consequences. At the same time, with the more and more widespread application of preload, the size of the preload and whether it reaches the designed size during installation have an important influence on the strength of the anchor rod. Therefore, it is becoming more and more important to know the size of the preload, which will help to determine whether the anchor rod has reached the required preload.

[0004] Therefore, there is a need for an anchor rod that can not only measure whether the preload force of the anchor rod has reached the predetermined requirement, but also produce considerable elongation deformation to meet the requirements of large deformation of the surrounding rock, and can automatically adjust the complete deformation of the rod body to meet the requirements of lateral deformation of the surrounding rock, and can also automatically adjust the bending deformation of the rod to adapt to the lateral deformation and dislocation of the surrounding rock. That is, an anchor rod that integrates preload force measurement, automatic adjustment, deformation pressure relief and resistance to lateral deformation to solve existing engineering and technical problems. Summary of the invention

[0005] In view of the above-mentioned problems, the purpose of the present invention is to provide a shear-resistant variable resistance yielding anchor rod capable of measuring preload and a method of using the same, which can measure the preload of the shear-resistant variable resistance yielding anchor rod, automatically adjust the bending deformation of the rod body, and provide a corresponding support force that increases with the deformation, thereby generating a larger elongation deformation to meet the requirements of large deformation of the surrounding rock.

[0006] The technical solution of the present invention is: a shear resistance variable resistance pressure release anchor rod capable of measuring preload, comprising an anchor rod body, the anchor rod body comprising a head section, a middle standard section and a tail section connected in sequence, the head section comprising a head end rod body, the head end of the head end rod body is provided with a piston head, a sleeve is provided outside the piston head, the sleeve and the piston head constitute a piston structure, and the piston structure is used for variable resistance pressure release; The middle standard section has a piston-cylinder structure, which is used to adapt to the shear deformation caused by the slip deformation of the rock formation; The tail section includes: a first rod body, an elastic member is arranged inside, and a through groove is arranged on the side wall along the rod length direction of the first rod body; a preload tray is sleeved on the first rod body, and the preload tray is used to apply a preload force to the first rod body; a second rod body, the tail end of which is arranged in the first rod body along the rod length of the first rod body and is connected to the elastic member, and can slide along the rod length direction of the first rod body; an extension is arranged at the tail end of the second rod body, one end of the extension passes through the through groove and forms an extension gap with the preload tray, the width of the extension gap changes with the sliding of the second rod body, and the width of the extension gap is used to feedback the deformation of the elastic member.

[0007] Furthermore, the intermediate standard section includes: There are N first connecting rod bodies, N ≥ 1, and the first ends of the first connecting rod bodies are all provided with first pistons; There are N+1 second connecting rod bodies, and the tail ends of the second connecting rod bodies are all provided with piston cylinders; the second connecting rod bodies are connected to the first connecting rod bodies end to end in sequence, and the first piston is slidably arranged in the piston cylinder corresponding to its position.

[0008] Furthermore, the tail end of the first connecting rod body is fixed to the head end of the adjacent second connecting rod body by bolts and nuts, and the head end of the second connecting rod body is fixed to the tail end of the head end rod body.

[0009] Furthermore, a second piston having the same structure as the first piston is arranged at the end of the second rod body, and the second piston is slidably arranged in a piston cylinder on the second connecting rod body at the tail end of the middle standard section.

[0010] Furthermore, a limiting disc is provided at the tail end of the second connecting rod body, and the limiting disc is located at the port of the piston cylinder for limiting.

[0011] Furthermore, a plurality of metal rings are arranged inside the sleeve, the outer rings of the metal rings are fixed at intervals on the inner wall of the sleeve, and the inner rings are used to block the piston head. When the pulling force applied to the piston head is greater than the damage threshold of the metal rings, the metal rings will be destroyed and then the piston head will move.

[0012] Furthermore, the preload tray comprises: The disc body is movably arranged on the first rod body and contacts the side wall of the anchor hole near the first end of the first rod body; The fastener is fixed on the first rod body and is located on one side of the disc body close to the tail end of the first rod body. It is used to limit the disc body. The actual fixed position of the fastener on the first rod body is adjusted to adjust the preload force.

[0013] Furthermore, a preload monitoring module is also included, and the preload monitoring module includes: A micro laser distance measuring device, used for emitting laser and receiving laser, is arranged at any one of the tail end of the first rod body or the tail end of the second rod body; A reflector is arranged opposite to the micro laser ranging device and is disposed at another location of the tail end of the first rod body or the tail end of the second rod body, and is used to reflect the laser emitted by the micro laser ranging device to the micro laser ranging device; The reader is connected to the micro laser distance measuring device and is used to display the actual distance measured by the micro laser distance measuring device. The actual distance is used to feedback the specific deformation amount of the elastic member, thereby realizing the measurement of the preload force.

[0014] Furthermore, the method for using the shear resistance variable resistance yielding anchor rod comprises: An anchor hole is drilled at the determined position of the surrounding rock, and the anchor rod body is assembled and placed in the anchor hole for grouting. After the slurry is solidified, the preload tray is passed through the first rod body and the preload force is applied, and the applied preload force is fed back through the extended gap; when the surrounding rock undergoes a large deformation, the head end rod body will undergo relative displacement under the pulling of the anchor rod body, and the piston structure provides resistance to prevent the head end rod body from moving; when the rock strata in the surrounding rock undergo shear deformation, shear force will be applied to the anchor rod body, and the shear force generated by the anchor rod body will be reduced by the piston cylinder structure.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The present invention can generate large shear deformation through the piston cylinder structure to meet the lateral movement of the rock formation, and can generate large telescopic deformation through the piston structure to meet the requirements of large deformation of the surrounding rock, and use the width of the overhanging gap to feedback the deformation of the elastic member to measure the preload force. The relative movement between the piston head and the sleeve is used to achieve the pressure-releasing effect in which the resistance increases with the deformation of the anchor rod body.

[0016] The invention integrates multiple functions in one, solves the problem that ordinary anchor rods cannot meet the large deformation of surrounding rocks, solves the problem that existing anchor rods are easily sheared under the lateral displacement of rock formations, and can measure the size of preload force at the same time. The invention has a simple structure and stable functions, which can greatly improve the support efficiency, and the deformation and pressure-relieving function of the anchor rod can effectively reduce the occurrence of accidents and ensure the life safety of workers. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1is a structural cross-sectional view of embodiment 1 of the present invention; Figure 2 It is a cross-sectional view of the head section rod body and the sleeve of the present invention; Figure 3 is a cross-sectional view of a second connecting rod body of the present invention; Figure 4 It is a structural schematic diagram of the limiting disc of the present invention; Figure 5 It is a structural cross-sectional view of embodiment 2 of the present invention.

[0018] Among them, 1-head section, 10-piston head, 2-middle standard section, 21-first connecting rod body, 210-first piston, 22-second connecting rod body, 220-piston cylinder, 23-limiting disc, 3-tail section, 31-first rod body, 310-elastic part, 32-second rod body, 320-extension, 3200-second piston, 4-sleeve, 40-metal ring, 5-preload tray, 51-disc body, 52-fastener, 6-preload monitoring module, 61-laser ranging device, 62-reflector, 63-reading instrument. DETAILED DESCRIPTION

[0019] Combine the following Figures 1 to 5 , the specific implementation methods of the present invention are described in detail. In the description of the present invention, it should be understood that the terms "center", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0020] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features; in the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0021] It should be noted that the circuit connections involved in the present invention all adopt conventional circuit connection methods and do not involve any innovation.

[0022] Example 1 like Figure 1 The shear-resistant variable resistance pressure-yielding anchor rod with measurable preload force shown has an anchor rod body, which includes a head section 1, a middle standard section 2 and a tail section 3 connected in sequence. The cross-sections of the head section 1, the middle standard section 2 and the tail section 3 of the anchor rod body are all circular structures.

[0023] The head section 1 includes a head end rod body, a piston head 10 is provided at the head end of the head end rod body, a sleeve 4 is provided outside the piston head 10, the sleeve 4 and the piston head 10 form a piston structure, and the piston structure is used for variable resistance and pressure relief. Among them, an expansion rubber plug is provided at the opening of the sleeve 4, and the expansion rubber plug is in close contact with the outer wall of the head end rod body to ensure the air tightness of the piston structure and ensure the existence of pressure to relieve pressure. It should be noted that: when the piston head 10 moves inside the sleeve 4, the gas in the piston structure is compressed, causing the air pressure to gradually increase, thereby achieving variable resistance and pressure relief.

[0024] The middle standard section 2 is provided with a piston-cylinder structure, which is used to adapt to shear deformation caused by slip deformation of rock formations.

[0025] The tail section 3 includes a first rod body 31 and a second rod body 32. An elastic member 310 is arranged inside the first rod body 31, and a through slot is arranged on the side wall along the rod length direction of the first rod body 31; a preload tray 5 is sleeved on the first rod body 31, and the preload tray 5 is used to apply preload force to the first rod body 31; the tail end of the second rod body 32 is arranged inside the first rod body 31 along the rod length of the first rod body 31 and is connected to the elastic member 310, and can slide along the rod length direction of the first rod body 31; an extension 320 is arranged at the tail end of the second rod body 32, and one end of the extension 320 passes through the through slot and forms an extension gap with the preload tray 5, and the width of the extension gap changes with the sliding of the second rod body 32, and the width of the extension gap is used to feedback the deformation of the elastic member 310. Among them, the elastic member 310 of this embodiment adopts a commercially available spring with a large elastic coefficient.

[0026] Preferably, the intermediate standard section 2 includes a first connecting rod body 21 and a second connecting rod body 22, wherein there are N first connecting rod bodies 21, N≥1, and the head end of each first connecting rod body 21 is provided with a first piston 210. There are N+1 second connecting rod bodies 22, and the tail end of each second connecting rod body 22 is provided with a piston cylinder 220; the second connecting rod body 22 is connected to the first connecting rod body 21 head to tail in sequence, and the first piston 210 is slidably arranged in the piston cylinder 220 corresponding to its position.

[0027] The first connecting rod body 21 and the second connecting rod body 22 can be produced in a standardized manner, and the length of the intermediate standard section 2 can be adjusted by selecting different numbers of the first connecting rod body 21 and the second connecting rod body 22. Shear deformation occurs by torsion bending between the first connectable rod body 21 and the second connectable rod body 22, thereby adapting to the slip deformation of the rock formation.

[0028] Preferably, the tail end of the first connecting rod body 21 is fixed to the head end of the adjacent second connecting rod body 22 by bolts and nuts, and the head end of the second connecting rod body 22 is fixed to the tail end of the head end rod body. Among them, the bolts are high-strength bolts and the nuts are high-strength nuts.

[0029] Preferably, a second piston 3200 having the same structure as the first piston 210 is provided at the end of the second rod body 32 , and the second piston 3200 is slidably disposed in the piston cylinder 220 on the second connecting rod body 22 at the tail end of the middle standard section 2 .

[0030] Preferably, Figure 3 , Figure 4 As shown, a limiting disc 23 is provided at the tail end of the second connecting rod body 22, and the limiting disc 23 is located at the port of the piston cylinder 220 for limiting.

[0031] Preferably, Figure 2 As shown, a plurality of metal rings 40 are arranged inside the sleeve 4, and the outer rings of the metal rings 40 are fixed at intervals on the inner wall of the sleeve 4, and the inner rings are used to block the piston head 10. When the pulling force on the piston head 10 is greater than the damage threshold of the metal ring 40, the metal ring 40 will be destroyed and then moved. In actual use, since the metal ring 40 blocks the piston head 10, the piston head 10 needs a certain force to destroy the metal ring 40, so this structure is used together with the piston structure to achieve a gradually increasing pressure release effect. It should be noted that the damage threshold of the metal ring 40 is affected by factors such as its own material, thickness and the shape of the annular structure, and can be selectively used according to actual needs in actual use.

[0032] Preferably, the preload tray 5 includes a tray body 51 and a fastener 52. The tray body 51 is movably arranged on the first rod body 31, and contacts the side wall of the anchor hole near the head end of the first rod body 31. The fastener 52 is fixed on the first rod body 31, and is located on the side of the tray body 51 near the tail end of the first rod body 31, and is used to limit the tray body 51. The actual fixed position of the fastener 52 on the first rod body 31 is adjusted to adjust the preload. Among them, the adjustment fastener 52 adopts an anti-slip nut, and a thread is provided on the outer side wall of the first rod body 31. The preload is applied to the first rod body 31 by tightening the anti-slip nut.

[0033] It should be noted that: the tail end of the head end rod body of this embodiment is also provided with a grouting plug, the size of which matches the aperture of the anchor hole, thereby having a good effect of preventing the slurry from flowing back. At the same time, there is also a grouting conduit with one end extending into the inner side of the grouting plug, and the other end of the grouting conduit extends upward out of the disc body 51. A rubber pad is provided inside the piston cylinder structure, and the rubber pad is located at the opening of the piston cylinder 220. When the anchor rod body is subjected to shear force, the rubber pad can ensure that the first connectable rod body 21 and the second connectable rod body 22 can be twisted along the force direction to prevent damage.

[0034] Preferably, the method for using the shear resistance variable resistance pressure-yielding anchor rod of this embodiment includes: An anchor hole is drilled at the position determined by the surrounding rock, the anchor rod body is assembled, and the stop plug is arranged close to the tail end of the head end rod body. Then the anchor rod body is placed in the anchor hole, and cement slurry is injected into the gap between the sleeve 4 and the anchor hole through the grouting pipe. The cement slurry forms a cement slurry condensate in the area formed by the stop plug, the sleeve 4 and the inner wall of the anchor hole.

[0035] After the slurry is solidified, the preload tray 5 is inserted into the first rod body 31 , and the preload is applied to the first rod body 31 by tightening the anti-slip nut, and the applied preload is fed back through the overhanging gap.

[0036] When the surrounding rock undergoes large deformation, the head end of the rod will undergo relative displacement under the pulling of the anchor rod body. At this time, the piston structure provides resistance to prevent the head end of the rod from moving. When the rock strata in the surrounding rock undergo shear deformation, shear force will be applied to the anchor rod body, and the shear force generated by the anchor rod body will be reduced by the piston cylinder structure.

[0037] When the surrounding rock 1 undergoes a large deformation, the head end rod body will undergo a relative displacement under the pulling of the anchor rod body. At this time, the air pressure inside the piston structure and the metal ring 40 jointly provide resistance to the piston head 10 to prevent the head end rod body from continuing to move. In addition, because the metal ring 40 is squeezed by the piston head 10 and is damaged, the head end rod body and the sleeve 4 are mutually displaced, thereby achieving the pressure relief effect as the deformation increases to meet the requirements of large deformation of the surrounding rock.

[0038] When the rock formation in the surrounding rock undergoes shear deformation, shear force will be applied to the anchor rod body. The rubber pad can ensure that the first connectable rod body 21 and the second connectable rod body 22 can be twisted along the force direction to prevent damage. In addition, the second connectable rod body 22 and the first connectable rod body 21, and the second connectable rod body 22 and the head end rod body are fixed by bolts and nuts. The bolt and nut connection can ensure that the relative displacement of each rod is bent under the action of force, and can be rotated, bent and twisted, so it will not be sheared when any tangential deformation occurs, and the self-adjusting type can meet the requirements of the tangential deformation of the surrounding rock. It should be noted that if the rubber pad is not added, the rods will be in direct contact when the piston structure is stretched to the maximum. If twisting occurs at this time, the limit disc 23 may be damaged under the action of friction.

[0039] Example 2 The difference from Example 1 is that: preferably, Figure 5As shown, the preload monitoring module 6 is also included, and the preload monitoring module 6 includes a micro laser distance measuring device 61, a reflector 62 and a reader 63. The micro laser distance measuring device 61 is used to emit and receive lasers, and is arranged at any one of the tail ends of the first rod body 31 or the tail ends of the second rod body 32. The reflector 62 is distributed relative to the micro laser distance measuring device 61, and is arranged at another place of the tail end of the first rod body 31 or the tail end of the second rod body 32. The reflector 62 is used to transmit the laser emitted by the micro laser distance measuring device 61 to the micro laser distance measuring device 61. The reader 63 is connected to the micro laser distance measuring device 61, and is used to display the actual distance measured by the micro laser distance measuring device 61. The actual distance is used to feedback the specific deformation amount of the elastic member 310, thereby realizing the measurement of the preload.

[0040] Since the embodiment 1 uses the extension gap formed between the exposed end of the extension 320 and the tension tray 5 to feedback the deformation of the elastic member 310 to achieve the measurement of the preload force, this method has a large error on the one hand, and on the other hand, further measurement of the extension gap is required to know the deformation of the elastic member 310. Therefore, the present embodiment directly adds a preload monitoring module 6, which can directly provide more accurate and direct feedback on the specific deformation of the elastic member 310.

[0041] The specific models of the above electronic components are not specially specified, and ordinary products available on the market can be selected as long as they can meet the use requirements of the present invention.

[0042] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and does not limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention are included in the protection scope of the present invention.

Claims

1. A shear-resistant variable resistance pressure-yielding anchor capable of measuring preload, comprising an anchor body, the anchor body comprising a head section (1), a middle standard section (2) and a tail section (3) connected in sequence, characterized in that: The head section (1) comprises a head end rod body, a piston head (10) is arranged at the head end of the head end rod body, a sleeve (4) is sleeved on the outside of the piston head (10), the sleeve (4) and the piston head (10) form a piston structure, and the piston structure is used for variable resistance pressure relief; The middle standard section (2) has a piston-cylinder structure, which is used to adapt to shear deformation caused by slip deformation of the rock formation; The tail section (3) comprises: a first rod body (31) having an elastic member (310) disposed therein and a through slot disposed on a side wall along the length direction of the first rod body (31); a preload tray (5) sleeved on the first rod body (31), the preload tray (5) being used to apply a preload force to the first rod body (31); a second rod body (32), the tail end of which is disposed inside the first rod body (31) along the length of the first rod body (31) and connected to the elastic member (310), and capable of sliding along the length direction of the first rod body (31); an extension (320) being disposed at the tail end of the second rod body (32), one end of the extension (320) passing through the through slot and forming an extension gap with the preload tray (5), the width of the extension gap changing with the sliding of the second rod body (32), the width of the extension gap being used to provide feedback on the deformation amount of the elastic member (310).

2. A shear resistance variable resistance pressure-yielding anchor capable of measuring preload force as claimed in claim 1, characterized in that: The intermediate standard section (2) includes: There are N first connecting rod bodies (21), where N≥1, and the first ends of the first connecting rod bodies (21) are all provided with first pistons (210); There are N+1 second connecting rod bodies (22), and the tail ends of the second connecting rod bodies (22) are all provided with piston cylinders (220); the second connecting rod bodies (22) are connected to the first connecting rod bodies (21) end to end in sequence, and the first piston (210) is slidably arranged in the piston cylinder (220) corresponding to its position.

3. A shear resistance variable resistance pressure-yielding anchor capable of measuring preload force as claimed in claim 2, characterized in that: The tail end of the first connecting rod body (21) is fixed to the head end of the adjacent second connecting rod body (22) by means of bolts and nuts, and the head end of the second connecting rod body (22) is fixed to the tail end of the head end rod body.

4. A shear resistance variable resistance pressure-yielding anchor capable of measuring preload force as claimed in claim 2, characterized in that: A second piston (3200) having the same structure as the first piston (210) is provided at the end of the second rod body (32), and the second piston (3200) is slidably disposed in a piston cylinder (220) on the second connecting rod body (22) at the tail end of the middle standard section (2).

5. A shear resistance variable resistance pressure-yielding anchor capable of measuring preload force as claimed in claim 2, characterized in that: A limiting disc (23) is provided at the tail end of the second connecting rod body (22), and the limiting disc (23) is located at the port of the piston cylinder (220) and is used for limiting.

6. A shear resistance variable resistance pressure-yielding anchor capable of measuring preload force as claimed in claim 1, characterized in that: A plurality of metal rings (40) are arranged inside the sleeve (4); outer rings of the metal rings (40) are fixed at intervals on the inner wall of the sleeve (4); the inner rings are used to block the piston head (10); when the pulling force applied to the piston head (10) is greater than a damage threshold of the metal rings (40), the metal rings (40) are damaged and the piston head (10) moves.

7. The shear resistance variable resistance pressure-yielding anchor rod capable of measuring preload force as claimed in claim 1, characterized in that: The preload tray (5) comprises: The disc body (51) is movably disposed on the first rod body (31) and is in contact with the side wall of the anchor hole at a side close to the head end of the first rod body (31); The fastener (52) is fixed on the first rod (31) and is located on a side of the disc (51) close to the rear end of the first rod (31), and is used to limit the disc (51). The actual fixed position of the fastener (52) on the first rod (31) is adjusted to adjust the preload force.

8. The shear resistance variable resistance pressure-yielding anchor rod capable of measuring preload force as claimed in claim 1, characterized in that: It also includes a preload monitoring module (6), which includes: A micro laser distance measuring device (61), used for emitting laser light and receiving laser light, is arranged at any one of the tail end of the first rod body (31) or the tail end of the second rod body (32); A reflector (62) is arranged opposite to the micro laser distance measuring device (61) and is disposed at the tail end of the first rod body (31) or at another location of the tail end of the second rod body (32). The reflector (62) is used to reflect laser light emitted by the micro laser distance measuring device (61) to the micro laser distance measuring device (61); The reader (63) is connected to the micro laser distance measuring device (61) and is used to display the actual distance measured by the micro laser distance measuring device (61). The actual distance is used to feedback the specific deformation amount of the elastic member (310), thereby realizing the measurement of the preload force.

9. The method for using the shear resistance variable resistance pressure relief anchor rod according to any one of claims 1 to 8, characterized in that: include: An anchor hole is drilled at a determined position of the surrounding rock, and the anchor rod body is assembled and placed in the anchor hole for grouting. After the grout is solidified, the preload tray (5) is inserted into the first rod body (31) and a preload force is applied, and the applied preload force is fed back through the extended gap. When the surrounding rock undergoes a large deformation, the head end of the rod body will undergo relative displacement under the pulling of the anchor rod body, and the piston structure will provide resistance to prevent the head end of the rod body from moving. When the rock formation in the surrounding rock undergoes shear deformation, a shear force will be applied to the anchor rod body, and the shear force generated by the anchor rod body will be reduced by the piston cylinder structure.

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