A graded pressure relief construction method for injection-anchor-spray coordinated support

Abstract

This invention relates to the field of pressure-relief anchor technology and discloses a graded pressure-relief construction method for injection-anchor-spraying coordinated support, comprising: drilling pre-grouting holes in the surrounding rock for pre-reinforcement before TBM excavation; performing initial spraying reinforcement on the surrounding rock after the TBM excavation is completed; drilling holes in the surrounding rock to install graded pressure-relief control anchors, each anchor comprising a rod body, an outer ring, a pressure-relief sleeve, and an inner ring; during the deformation of the surrounding rock, when the surrounding rock pressure exceeds the frictional force of the first-stage pressure-relief friction fit, the rod body drives the inner ring to move between the inner cavity of the pressure-relief sleeve; when the surrounding rock pressure exceeds the frictional force of the second-stage pressure-relief friction fit, the rod body drives the front end of the pressure-relief sleeve to move between the outer ring and the second-stage pressure-relief sleeve; after completing the installation and support procedures of the graded pressure-relief control anchors, spraying reinforcement is performed again at the tail of the TBM. The advantages of this invention are: it can improve the characteristics of the surrounding rock, release the deformation performance of the surrounding rock, and effectively solve the problem of tunnel stability.

Description

Technical Field

[0001] This invention belongs to the field of tunnel construction technology, specifically relating to a graded pressure relief construction method for injection-anchor-spray coordinated support. Background Art

[0002] Shotcrete and rock bolt support, a commonly used support method in tunnel construction, has been widely applied and achieved great success. However, as construction moves westward and deeper, it faces challenges such as poor stability, difficulty in support, and the gradual shift of the loosened zone to deeper parts of the surrounding rock, including expansive surrounding rock, water-softened surrounding rock, and sedimentary rocks with well-developed bedding and obvious stratification effects. Traditional shotcrete and rock bolt support methods are no longer applicable, and there is an urgent need to study a new construction method. By studying the support force and yield amount corresponding to the deformation of the surrounding rock at different stages after excavation due to factors such as expansion deformation, fragmentation deformation, and elastic deformation at different depths of the tunnel, targeted solutions can be proposed. This has important theoretical value and engineering significance for improving the design of tunnel support structures and engineering construction. Summary of the Invention

[0003] The purpose of this invention is to address the shortcomings of the prior art by providing a graded pressure relief construction method for injection-anchor-spray coordinated support. This construction method uses a combination of injection, anchoring, and spraying to reinforce the surrounding rock. By varying the frictional forces between the pressure relief sleeve and the inner ring, as well as between the inner and outer rings, a first-level and a second-level pressure relief frictional fit is formed. This achieves a "control-relief-control-relief" effect on the surrounding rock, thereby releasing deformation, reducing pressure, and improving the stress distribution of the surrounding rock.

[0004] The inner ring and the inner cavity of the pressure relief sleeve form a first-level pressure relief friction fit; the front end of the pressure relief sleeve and the outer ring form a second-level pressure relief friction fit.

[0005] The objective of this invention is achieved through the following technical solutions:

[0006] A graded pressure relief construction method for injection-anchor-spray coordinated support includes the following steps:

[0007] S1: Drill pre-grouting holes in the surrounding rock before the TBM excavation to carry out pre-reinforcement;

[0008] S2: After the TBM excavates the surrounding rock, it performs initial shotcrete reinforcement on the surrounding rock; then, it drills holes in the surrounding rock to install graded pressure relief control anchor bolts, which include a rod body, an outer ring, a pressure relief sleeve, and an inner ring.

[0009] S3: In the initial state, the rear end of the rod body presses the inner ring against the rear port of the inner cavity of the pressure-relief sleeve through a nut; the front end of the pressure-relief sleeve extends into the borehole and presses the outer ring against the surrounding rock outside the borehole; a first-level pressure-relief friction fit is formed between the inner ring and the inner cavity of the pressure-relief sleeve; a second-level pressure-relief friction fit is formed between the front end of the pressure-relief sleeve and the outer ring; wherein, the frictional force of the second-level pressure-relief friction fit is greater than the frictional force of the first-level pressure-relief friction fit;

[0010] During the deformation of the surrounding rock, when the surrounding rock pressure is greater than the friction force of the first-stage pressure relief friction fit, the rod body drives the inner ring and the inner cavity of the pressure relief sleeve to undergo a first-stage pressure relief movement until the inner ring moves to the end of the inner cylinder of the pressure relief sleeve and stops.

[0011] When the surrounding rock pressure is greater than the friction force of the secondary pressure relief friction fit, the rod body drives the front end of the pressure relief sleeve to move in a secondary pressure relief movement with the outer ring and move into the borehole until the limiting ring protruding from the rear end of the pressure relief sleeve abuts against the outer ring and stops moving.

[0012] S4: After completing the installation and support process of the graded pressure relief control anchor bolts, reinforce the TBM tail with grout again.

[0013] The main body of the pressure relief sleeve is a cylindrical cylinder. The front end of the cylinder is provided with a tapered end, and the rear end of the cylinder is provided with a radially protruding limiting ring. A through hole is opened at the center of the tapered end for the rod to pass through, and the diameter of the through hole is the same as the outer diameter of the rod.

[0014] In step S2, the drilling is divided into two steps. The first step is to drill a hole according to the diameter of the rod body. The second step is to enlarge the hole based on the outer diameter of the pressure relief sleeve. The depth of the enlargement is the length of the pressure relief sleeve.

[0015] The outer ring includes a fixed pressure relief ring, a ring platform, adjustable pressure relief components, a slide groove, a guide ring, and a drive assembly. The ring platform is disposed along the annular outer edge of the front end face of the fixed pressure relief ring, and the inner ring wall of the fixed pressure relief ring is a longitudinally variable diameter section that fits the tapered end. Four sets of adjustable pressure relief components are arranged circumferentially, each comprising an adjustable pressure relief arc segment, a connecting rod, and a guide contact head. The rod body of the connecting rod is assembled in the slide groove to allow the connecting rod to slide radially. The guide is provided with two ends of the connecting rod connected to the adjustable pressure relief arc segment and the guide contact head, respectively. The inner arc surface of the adjustable pressure relief arc segment is in contact with the tapered end. The guide contact head is in sliding contact with the inner ring of the guide ring. The inner ring of the guide ring is provided with four sets of guide diameter changing segments, each set of guide diameter changing segments corresponding to one guide contact head. The guide diameter changing segments include a small inner diameter segment, a transition segment, and a large inner diameter segment arranged in sequence. The guide ring is driven to rotate by the driving assembly.

[0016] The outer wall surface of the guide ring is provided with a ring of external teeth, the front end surface of the fixed pressure relief ring is provided with an annular guide groove, and the rear end surface of the guide ring is provided with a convex rail. The convex rail on the guide ring is correspondingly matched and installed in the annular guide groove to form a rotational guide support for the rotation of the guide ring. The drive assembly includes a hydraulic telescopic rod and a rack fixedly installed on the hydraulic telescopic rod body. The rack meshes with the external teeth on the guide ring to drive the guide ring to rotate.

[0017] The rod body has a pressure sensor for monitoring surrounding rock pressure. The pressure sensor is connected to the controller of the hydraulic telescopic rod for control. Based on the surrounding rock pressure data monitored by the pressure sensor, the controller controls whether the drive assembly drives the guide ring to rotate. In the initial state, the transition section on the guide ring contacts the guide contact head. When it is necessary to increase the friction between the outer ring and the pressure relief sleeve, the guide ring is rotated so that the small inner diameter section contacts the guide contact head and presses the adjustable pressure relief arc section against the conical end. When it is necessary to reduce the friction between the outer ring and the pressure relief sleeve, the guide ring is rotated so that the large inner diameter section contacts the guide contact head to release the pressure of the adjustable pressure relief arc section on the conical end.

[0018] The fixed pressure relief ring and the ring platform together form the equipment installation groove space. The thickness of the adjustable pressure relief component, the slide groove, the guide ring, and the drive assembly is all less than the height of the ring platform.

[0019] The advantages of this invention are:

[0020] (1) Compared with the traditional anchor-mesh-spray support construction, this injection-anchor-spray coordinated support graded pressure relief construction method can improve the characteristics of the surrounding rock, release the deformation performance of the surrounding rock, effectively solve the tunnel stability problem, ensure the safety of the tunnel structure, and shorten the construction period.

[0021] (2) The graded pressure control anchor fully utilizes the graded failure characteristics of the surrounding rock to maximize the self-stabilizing ability of the surrounding rock, without the need for repeated maintenance, thus saving support materials;

[0022] (3) The outer ring that performs secondary pressure relief friction with the pressure relief sleeve is equipped with an adjustable pressure relief component on the basis of the fixed pressure relief ring. It can flexibly adjust the pressure relief amount based on the surrounding rock pressure to meet the requirements of different deformation amounts on site. Attached Figure Description

[0023] Figure 1 This is a side view of the graded pressure relief control anchor bolt in the surrounding rock in this invention;

[0024] Figure 2 This is a side view of the graded pressure relief control anchor bolt moving in the surrounding rock in the present invention.

[0025] Figure 3 This is a side view of the graded pressure relief control anchor bolt moving in two stages on the surrounding rock in this invention;

[0026] Figure 4 This is a detailed view of the outer ring structure of the graded pressure relief control anchor bolt in this invention;

[0027] Figure 5 For the present invention Figure 4 AA diagram in the image;

[0028] Figure 6 This is a detailed partial structural diagram of the adjustable pressure member within the outer ring of the present invention, where the conical end is not pressed tightly.

[0029] Figure 7 For the present invention Figure 6 The diagram of BB in the image.

[0030] like Figure 1-7 The markings in the diagram are as follows:

[0031] 1. Surrounding rock; 2. Rod body; 3. Inner ring; 4. Pressure relief sleeve; 5. Outer ring; 6. Nut;

[0032] Conical end 41, cylindrical body 42, limiting ring 43;

[0033] Fixed pressure relief ring 51, adjustable pressure relief component 52, adjustable pressure relief arc segment 52a, connecting rod 52b, guide contact head 52c, slide groove 53, guide ring 54, small inner diameter segment 54a, transition segment 54b, large inner diameter segment 54c, external meshing tooth 55, ring platform 56, telescopic drive rod 57, straight rack 58, annular guide groove 59. Detailed Implementation

[0034] The features and other related features of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments, so as to facilitate understanding by those skilled in the art:

[0035] Example: Figure 1-7 As shown, this embodiment specifically relates to a graded pressure relief construction method for injection-anchor-spray coordinated support, including the following steps:

[0036] (S1) Pre-grouting holes are drilled in the surrounding rock 1 before the TBM excavation to reinforce it in advance, improve its mechanical properties, give full play to its self-stabilizing effect, and enhance its self-stability. It should be noted that tunnel excavation can also be achieved by shield tunneling; this embodiment uses TBM excavation as an example for explanation.

[0037] The specific method of advance grouting is as follows: First, according to the advance forecast information, use an advance drilling rig to drill through the hole in the TBM cutterhead to make advance drilling, and then connect the grouting pump to carry out advance grouting. In order to improve the grouting effect, the cement mortar is replaced with ultrafine cement-water glass dual liquid grout to ensure the injection range and grouting pressure, which reduces the water flow into the surrounding rock 1 to a certain extent, improves the physical and mechanical properties of the surrounding rock in the soft rock tunnel, such as compressive strength, tensile strength, shear strength, etc., and helps to achieve uniform bearing. According to the loosening range of the surrounding rock 1, the grouting hole is 300-400mm deeper than the loosening range of the surrounding rock 1.

[0038] (S2) After the TBM excavates the surrounding rock 1, the surrounding rock 1 is prone to weathering and expansion when exposed to water. The surrounding rock 1 is reinforced with initial shotcrete to prevent weathering and moisture absorption.

[0039] After the initial shotcrete reinforcement of the surrounding rock 1 is completed, a hole is drilled in the surrounding rock 1 based on the diameter of the rod body 2. On this basis, the rear end of the first hole is enlarged according to the outer diameter of the cylinder 42 of the pressure relief sleeve 4. The depth of the enlarged hole is the length of the pressure relief sleeve 4, so that the pressure relief sleeve 4 can extend into the enlarged hole part during the subsequent graded pressure relief process. After the hole enlargement is completed, the graded pressure relief control anchor rod is installed. The graded pressure relief control anchor rod includes the rod body 2, the outer ring 5, the pressure relief sleeve 4, and the inner ring 3.

[0040] The main body of the pressure sleeve 4 is a cylindrical cylinder 42. The front end of the cylinder 42 is provided with a tapered end 41, and the rear end of the cylinder 42 is provided with a radially protruding limiting ring 43. A through hole for the rod 2 to pass through is opened in the center of the tapered end 41. The diameter of the through hole is the same as the outer diameter of the rod 2. The outer diameter of the tapered end 41 gradually narrows and decreases in the longitudinal direction (towards the depth of the surrounding rock 1).

[0041] The outer ring 5 includes a fixed pressure relief ring 51, a ring platform 56, an adjustable pressure relief component 52, a slide groove 53, a guide ring 54, and a drive assembly. The ring platform 56 is set along the annular outer edge of the front end face of the fixed pressure relief ring 51. The two together enclose a groove space for the installation and arrangement of various components. The thickness of each of the aforementioned components is less than the height of the ring platform 56. During installation, the fixed pressure relief ring 51 and the ring platform 56 are fastened to the surrounding rock 1, thereby preventing the components in the groove space from being squeezed and damaged.

[0042] The inner wall of the fixed pressure ring 51 is a longitudinally variable diameter section that fits the tapered end 41; such as Figure 4 , 5 As shown in Figures 6 and 7, four sets of adjustable pressure-relieving components 52 are arranged circumferentially. Each adjustable pressure-relieving component 52 includes an adjustable pressure-relieving arc segment 52a, a connecting rod 52b, and a guide contact head 52c. The rod body of the connecting rod 52b is assembled in the slide groove 53 to guide the connecting rod 52b in the radial direction. The two ends of the connecting rod 52b are respectively connected to the adjustable pressure-relieving arc segment 52a and the guide contact head. The inner arc surface of the adjustable pressure-relieving arc segment 52a can fit against the conical end 41. The guide contact head 52c slides in contact with the inner ring of the guide ring 54. The inner ring of the guide ring 54 is provided with four sets of guide diameter-changing segments. Each set of guide diameter-changing segments corresponds to a guide contact head 52c. The guide diameter-changing segments include a small inner diameter segment 54a, a transition segment 54b, and a large inner diameter segment 54c arranged in sequence. The rotation of the guide ring 54 is driven by a drive assembly.

[0043] A ring of external teeth 55 is provided on the outer wall surface of the guide ring 54, an annular guide groove 59 is provided on the front end surface of the fixed pressure ring 51, and a convex rail is provided on the rear end surface of the guide ring 54. The convex rail on the guide ring 54 is correspondingly matched and installed in the annular guide groove 59 to form a rotational guide support for the rotation of the guide ring 54. The drive assembly includes a hydraulic telescopic rod 57 and a rack 58 fixedly installed on the body of the hydraulic telescopic rod 57. The rack 58 meshes with the external teeth 55 on the guide ring 54 to drive the guide ring 54 to rotate.

[0044] (S3) In the initial state, the rear end of the rod 2 presses the inner ring 3 against the rear end of the inner cavity of the pressure-relieving sleeve 4 through the nut 6; the front end of the pressure-relieving sleeve 4 extends into the borehole and presses the outer ring 5 against the surrounding rock 1 outside the borehole; the inner ring 3 and the inner cavity of the pressure-relieving sleeve 4 form a first-level pressure-relieving friction fit; the front end of the pressure-relieving sleeve 4 and the outer ring 5 form a second-level pressure-relieving friction fit; wherein, the friction force of the second-level pressure-relieving friction fit is greater than that of the first-level pressure-relieving friction fit. It should be noted that, in order to ensure sufficient friction force, the inner ring 3 and the inner cavity of the pressure-relieving sleeve 4 adopt an interference fit, and the outer ring 5 and the pressure-relieving sleeve 4 also adopt an interference fit. When relative sliding occurs between the pressure-relieving sleeve 4 and the outer ring 5, the pressure-relieving sleeve 4 will cause radial compression to the inner ring of the fixed pressure-relieving ring 51 of the outer ring 5.

[0045] During the deformation of the surrounding rock 1, when the surrounding rock pressure gradually exceeds the frictional force of the first-stage pressure relief friction fit (i.e., the frictional force between the inner ring 3 and the pressure relief sleeve 4), the rod 2 drives the inner ring 3 and the inner cavity of the pressure relief sleeve 4 to undergo a first-stage pressure relief movement. As the inner ring 3 moves into the surrounding rock 1, the deformation energy of the surrounding rock is gradually released during the movement, and the rate of increase of the surrounding rock pressure slows down. When the surrounding rock pressure is equal to the working resistance of the rod 2, the pressure relief movement stops, and the pressure relief process ends. When the surrounding rock pressure is greater than the frictional force of the first-stage pressure relief friction fit, the first-stage pressure relief process continues until the inner ring 3 moves to the end of the inner cylinder of the pressure relief sleeve 4 and stops.

[0046] If the surrounding rock deformation continues after the first-stage pressure relief, the surrounding rock pressure will continue to increase. If the surrounding rock pressure has not yet increased to the friction force of the second-stage pressure relief friction fit, the rod 2 will deform to release the surrounding rock deformation energy. When the surrounding rock pressure increases to a level greater than the friction force of the second-stage pressure relief friction fit, relative sliding occurs between the outer ring 5 and the pressure relief sleeve 4, initiating the second-stage pressure relief process. The rod 2 drives the conical end 41 of the pressure relief sleeve 4 to move deeper into the surrounding rock 1 and enter the reaming section of the borehole. As the pressure relief process continues, the surrounding rock deformation energy is released, and the increase in surrounding rock pressure slows down. When the magnitude equals the working resistance of the second-stage pressure relief (the friction force of the second-stage pressure relief friction fit), the pressure relief process stops, the surrounding rock pressure and support resistance reach equilibrium, and the surrounding rock deformation is controlled during the staged pressure relief process. Finally, the movement stops when the convex limiting ring 43 at the rear end of the pressure relief sleeve 4 abuts against the outer ring 5.

[0047] It should be noted that the rod body 2 has a pressure sensor (not shown in the figure) for monitoring the surrounding rock pressure. The pressure sensor is connected to the controller of the hydraulic telescopic rod 57 for control. Based on the surrounding rock pressure data monitored by the pressure sensor, the drive assembly is controlled to drive the guide ring 54 to rotate. That is, during the secondary pressure relief, if the surrounding rock pressure is less than the secondary pressure relief working resistance, the rod body 2 will deform to release the deformation energy of the surrounding rock. If the rod body 2 continues to deform, it will be an unsafe process. Therefore, the secondary pressure relief working resistance between the outer ring 5 and the pressure relief sleeve 4 needs to be adjusted by the adjustable pressure relief component 52. The specific explanation is as follows:

[0048] In the initial state, the transition section 54b on the guide ring 54 is brought into contact with the guide contact head 52c. When it is necessary to increase the friction between the outer ring 5 and the pressure relief sleeve 4, the guide ring 54 is rotated so that the small inner diameter section 54a is brought into contact with the guide contact head 52c and the adjustable pressure relief arc section 52a is pressed onto the conical end 41. Under the guidance of the slide groove 55, the adjustable pressure relief arc section 52a is pressed onto the conical end 41, thereby increasing the secondary pressure relief working resistance. When it is necessary to reduce the friction between the outer ring 5 and the pressure relief sleeve 4, the guide ring 54 is rotated so that the large inner diameter section 54c is brought into contact with the guide contact head 52c to release the pressure of the adjustable pressure relief arc section 52a on the conical end 41. When the conical end 41 is pulled into the depth of the surrounding rock, the adjustable pressure relief arc section 52a will not obstruct the conical end 41.

[0049] (S4) After completing the installation and support of the graded pressure control anchor bolts, in order to prevent air and moisture from reducing the physical and mechanical properties of the surrounding rock, and at the same time improve the stress of the surrounding rock and reduce stress concentration points, the TBM tail is reinforced again with shotcrete.

[0050] The advantages of this embodiment are:

[0051] (1) Compared with the traditional anchor-mesh-spray support construction, this injection-anchor-spray coordinated support graded pressure relief construction method can improve the characteristics of the surrounding rock, release the deformation performance of the surrounding rock, effectively solve the tunnel stability problem, ensure the safety of the tunnel structure, and shorten the construction period.

[0052] (2) The graded pressure control anchor fully utilizes the graded failure characteristics of the surrounding rock to maximize the self-stabilizing ability of the surrounding rock, without the need for repeated maintenance, thus saving support materials;

[0053] (3) The outer ring that performs secondary pressure relief friction with the pressure relief sleeve is equipped with an adjustable pressure relief component on the basis of the fixed pressure relief ring. It can flexibly adjust the pressure relief amount based on the surrounding rock pressure to meet the requirements of different deformation amounts on site.

Claims

1. A graded pressure relief construction method for injection-anchor-spray coordinated support, characterized in that... The construction method includes the following steps: S1: Drill pre-grouting holes in the surrounding rock before the TBM excavation to carry out pre-reinforcement; S2: After the TBM excavates the surrounding rock, it performs initial shotcrete reinforcement on the surrounding rock; then, it drills holes in the surrounding rock to install graded pressure relief control anchor bolts, which include a rod body, an outer ring, a pressure relief sleeve, and an inner ring. S3: In the initial state, the rear end of the rod body presses the inner ring against the rear port of the inner cavity of the pressure-relief sleeve through a nut; the front end of the pressure-relief sleeve extends into the borehole and presses the outer ring against the surrounding rock outside the borehole; a first-level pressure-relief friction fit is formed between the inner ring and the inner cavity of the pressure-relief sleeve; a second-level pressure-relief friction fit is formed between the front end of the pressure-relief sleeve and the outer ring; wherein, the frictional force of the second-level pressure-relief friction fit is greater than the frictional force of the first-level pressure-relief friction fit; During the deformation of the surrounding rock, when the surrounding rock pressure is greater than the friction force of the first-stage pressure relief friction fit, the rod body drives the inner ring and the inner cavity of the pressure relief sleeve to undergo a first-stage pressure relief movement until the inner ring moves to the end of the inner cylinder of the pressure relief sleeve and stops. When the surrounding rock pressure is greater than the friction force of the secondary pressure relief friction fit, the rod body drives the front end of the pressure relief sleeve to move in a secondary pressure relief movement with the outer ring and move into the borehole until the limiting ring protruding from the rear end of the pressure relief sleeve abuts against the outer ring and stops moving. S4: After completing the installation and support process of the graded pressure relief control anchor bolts, reinforce the tail of the TBM with grout again; The main body of the pressure relief sleeve is a cylindrical cylinder. The front end of the cylinder is provided with a tapered end, and the rear end of the cylinder is provided with a radially protruding limiting ring. A through hole is opened at the center of the tapered end for the rod to pass through, and the diameter of the through hole is the same as the outer diameter of the rod. The outer ring includes a fixed pressure relief ring, a ring platform, adjustable pressure relief components, a slide groove, a guide ring, and a drive assembly. The ring platform is disposed along the annular outer edge of the front end face of the fixed pressure relief ring, and the inner ring wall of the fixed pressure relief ring is a longitudinally variable diameter section that fits the tapered end. Four sets of adjustable pressure relief components are arranged circumferentially, each comprising an adjustable pressure relief arc segment, a connecting rod, and a guide contact head. The rod body of the connecting rod is assembled in the slide groove to allow the connecting rod to slide radially. The guide is provided with two ends of the connecting rod connected to the adjustable pressure relief arc segment and the guide contact head, respectively. The inner arc surface of the adjustable pressure relief arc segment is in contact with the tapered end. The guide contact head is in sliding contact with the inner ring of the guide ring. The inner ring of the guide ring is provided with four sets of guide diameter changing segments, each set of guide diameter changing segments corresponding to one guide contact head. The guide diameter changing segments include a small inner diameter segment, a transition segment, and a large inner diameter segment arranged in sequence. The guide ring is driven to rotate by the driving assembly.

2. The graded pressure relief construction method for injection-anchor-spray coordinated support according to claim 1, characterized in that... In step S2, the drilling is divided into two steps. The first step is to drill a hole according to the diameter of the rod body. The second step is to enlarge the hole based on the outer diameter of the pressure relief sleeve. The depth of the enlargement is the length of the pressure relief sleeve.

3. The graded pressure relief construction method for injection-anchor-spray coordinated support according to claim 1, characterized in that... The outer wall surface of the guide ring is provided with a ring of external teeth, the front end surface of the fixed pressure relief ring is provided with an annular guide groove, and the rear end surface of the guide ring is provided with a convex rail. The convex rail on the guide ring is correspondingly matched and installed in the annular guide groove to form a rotational guide support for the rotation of the guide ring. The drive assembly includes a hydraulic telescopic rod and a rack fixedly installed on the hydraulic telescopic rod body. The rack meshes with the external teeth on the guide ring to drive the guide ring to rotate.

4. The graded pressure relief construction method for injection-anchor-spray coordinated support according to claim 3, characterized in that... The graded pressure relief control anchor has a pressure sensor on its rod body to monitor the surrounding rock pressure. The pressure sensor is connected to the controller of the hydraulic telescopic rod for control. Based on the surrounding rock pressure data monitored by the pressure sensor, the controller controls whether the drive assembly drives the guide ring to rotate. In the initial state, the transition section on the guide ring is brought into contact with the guide contact head; When it is necessary to increase the friction between the outer ring and the pressure relief sleeve, rotate the guide ring to make the small inner diameter section contact the guide contact head and press the adjustable pressure relief arc section against the tapered end; when it is necessary to reduce the friction between the outer ring and the pressure relief sleeve, rotate the guide ring to make the large inner diameter section contact the guide contact head to release the pressure of the adjustable pressure relief arc section on the tapered end.

5. The graded pressure relief construction method for injection-anchor-spray coordinated support according to claim 3, characterized in that... The fixed pressure relief ring and the ring platform together form the equipment installation groove space. The thickness of the adjustable pressure relief component, the slide groove, the guide ring, and the drive assembly is all less than the height of the ring platform.

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