Method for reinforcing rock burst roadway

Abstract

The invention provides a method for reinforcing a rock burst roadway. The rock burst roadway reinforcing method comprises the steps that S1, a roadway surrounding rock integrity index lambda x at the position x in a roadway is obtained; s2, whether reinforcement or pressure relief is needed at the position x is judged according to the roadway surrounding rock integrity index lambdax, and if pressure relief is needed at the position x, pressure relief is conducted at the position x in a blasting mode; and if the position x needs to be reinforced, spraying, anchor cable supplementary driving and grouting are sequentially conducted on the position x. The problem that in the prior art, the reinforcing effect of the rock burst roadway cannot meet the reinforcing requirement of a user is effectively solved.

Description

Technical Field

[0001] The invention relates to the technical field of coal mine rock burst tunnel support, and in particular to a rock burst tunnel reinforcement method. Background Art

[0002] At present, after the rock burst tunnel is excavated, the coal and rock mass are subjected to multiple vibration shocks due to the continuous release of energy in the tunnel and the coal and rock mass around the mining area, and its internal damage gradually accumulates, and even a large number of cracks are generated, which is very prone to plastic deformation. Specifically, as an important passage for workers and coal transportation, the deformation and damage of coal mine tunnels must be controlled within a safe range. If the rock burst tunnel is deformed and damaged, effective measures must be taken to strengthen it to prevent the overall failure of the support system under the influence of large energy events and cause safety accidents.

[0003] In the prior art, most reinforcement methods for rock burst tunnels still rely on experience and qualitative measures, which lack specificity and thus affect the reinforcement effect. Summary of the invention

[0004] The main purpose of the present invention is to provide a method for reinforcing a rock burst tunnel to solve the problem that the reinforcement effect of the rock burst tunnel in the prior art cannot meet the reinforcement needs of users.

[0005] In order to achieve the above-mentioned object, the present invention provides a rock burst tunnel reinforcement method, comprising: step S1: obtaining the tunnel surrounding rock integrity index λ at position x in the tunnel x ; Step S2: According to the tunnel surrounding rock integrity index λ x Determine whether the x position needs to be reinforced or depressurized. If the x position needs to be depressurized, blasting is used to depressurize the position. If the x position needs to be reinforced, spraying, anchoring and grouting are performed in sequence at the x position.

[0006] Furthermore, the tunnel surrounding rock integrity index λ at the position x in the tunnel is obtained x The method comprises: Step S11: taking out a coal block of a preset size in the tunnel and obtaining the longitudinal wave velocity v of the coal block p ; Step S12: Obtain the acoustic wave velocity of the coal body at the x position within the range of 2.5L to 3.5L in the tunnel Step S13: According to the formula: Determine the tunnel surrounding rock integrity index λ x ; Where L is the length of the anchor cable.

[0007] Furthermore, according to the tunnel surrounding rock integrity index λ x The method for determining whether reinforcement or pressure relief is required at the x position includes: if: Then the x position needs to be reinforced; if it satisfies: Then pressure relief is required at position x.

[0008] Further, the method of relieving the pressure at the location by blasting includes: Step S21: Determine the formula according to the formula: Determine the radius R of the crushing circle 1 , according to the formula: Determine the radius of the crack circle R 2 ; where ρ 0 is the density of the explosive, D is the detonation velocity of the explosive in the coal, n is the pressure increase coefficient on the blast hole wall after the explosive explodes, K is the radial uncoupling coefficient, that is, the ratio of the blast hole radius to the charge radius, η is the insulation coefficient, l c is the axial uncoupling coefficient, B is the insulation coefficient, α is the load propagation attenuation index, β is the stress wave propagation attenuation index, R b is the blasthole radius, σ cd is the uniaxial dynamic compressive strength of rock, σ td is the uniaxial dynamic tensile strength of the rock; Step S22; according to the formula: R 3 =2R 2 Determine the spacing of the pressure relief holes.

[0009] Furthermore, the method for spraying at the x position includes: spraying a plastic material with a thickness of 4 to 6 mm, a tensile strength greater than 2 MPa, a bonding strength greater than 1 MPa, an elongation at break greater than 30% and a curing time less than or equal to 60 s at the x position of the lane.

[0010] Furthermore, the method for supplementing the anchor cable at the x position includes: step S23: installing an anchor cable with a nominal diameter of 20 to 25 mm, a breaking load greater than 460 kN, a maximum force total elongation greater than 4%, and a sealing pressure greater than 20 MPa at the x position; step S24: installing an impact-resistant anchor assembly outside the anchor cable, the impact-resistant anchor assembly including: a tray, the anchor cable is passed through the tray; an anchor ring, located on one side of the tray, the inner hole of the anchor ring is a tapered hole; the inner diameter of the tapered hole gradually increases from the tray to the anchor ring; a plurality of clips, the plurality of clips are arranged around the anchor cable, at least a portion of each clip extends into the tapered hole; a plurality of anti-backward anchor assemblies, the plurality of anti-backward anchor assemblies are arranged one-to-one with the plurality of clips, and each anti-backward anchor assembly is arranged between the corresponding clip and the tapered hole.

[0011] Furthermore, each clip has a first recess, and the anchor ring has a second recess arranged on the hole wall of the tapered hole; each anti-retraction anchor assembly includes: a sleeve, which is arranged in the second recess, and the sleeve has a through hole; an elastic structure, which is arranged in the sleeve, and the first end of the elastic structure abuts against the inner surface of the sleeve; and a ejector pin, the first end of the ejector pin extends out of the sleeve after passing through the through hole, and the second end of the ejector pin abuts against the second end of the elastic structure.

[0012] Further, the method for grouting at the position x includes: according to the tunnel surrounding rock integrity index λ x Select grouting material, if 0.4<λ x <0.65, then use micron-nano composite grouting material, the slurry water seepage rate of micron-nano composite grouting material is less than 4%, the density is 1.45-1.55kg / m3, the setting time is 2-20min, the stone rate is 100% and the 2h setting strength is 8-12MPa; if λ x <0.4, nano-modified composite single-liquid grouting material is used. The particle size D95 of the nano-modified composite single-liquid grouting material is less than 15μm, the initial setting time is 1.2-1.8h, the final setting time is 8-10h, the compressive strength at 28d is greater than or equal to 50MPa, the flexural strength at 28d is greater than or equal to 6MPa, the bonding strength with the coal body at 28d is greater than or equal to 3MPa, and the maximum reaction temperature is less than 25℃.

[0013] Furthermore, after the reinforcement at the x position is completed, the rock burst tunnel reinforcement method also includes: Step S3: installing a comprehensive mine pressure monitoring station every 50m at the x position to monitor the working resistance of the anchor cable, roof separation, and tunnel surface displacement.

[0014] Furthermore, during the monitoring process of the comprehensive mine pressure monitoring station, the method for reinforcing the impact ground pressure tunnel also includes: if the working resistance of the anchor cable exceeds 80% of its breaking period; or, the deep base point reading of the roof separation exceeds 100mm or the shallow base point reading exceeds 75mm, and the reading change exceeds 20mm / day; or, the tunnel surface displacement exceeds 100mm, then the x position is reinforced.

[0015] Using the technical solution of the present invention, the rock burst tunnel reinforcement method includes: first obtaining the tunnel surrounding rock integrity index λ at the position x in the tunnel x , and then according to the tunnel surrounding rock integrity index λ xDetermine whether the x position needs to be reinforced or decompressed. If the x position needs to be decompressed, decompress it by blasting; if the x position needs to be reinforced, spray, add anchor cables, and grout at the x position in turn. In this way, the rock burst tunnel reinforcement method in this application is generally based on the support principle of "deep unloading and shallow support". The acoustic wave test is used to determine the broken area and intact area of ​​the tunnel surrounding rock, and the pressure is relieved in the deep coal body structure intact area to release the elastic energy inside the coal rock body, reduce the far-field stress concentration and impact load, and improve the stress state of the tunnel; in the shallow broken area, a thin spraying surface is carried out to seal the surrounding rock, and high-elongation grouting anchor cables are added for grouting reinforcement to improve the integrity and impact deformation resistance of the surrounding rock, thereby solving the problem that the reinforcement effect of the rock burst tunnel in the prior art cannot meet the user's reinforcement needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0017] Figure 1 A schematic diagram of the sonic wave test of the coal body side according to an embodiment of the rock burst tunnel reinforcement method of the present invention is shown;

[0018] Figure 2 Shows Figure 1 Schematic diagram of the coal blasting decompression damage radius of the rock burst tunnel reinforcement method;

[0019] Figure 3 Shows Figure 1 A half-section diagram of the anti-impact anchor assembly and anchor cable after assembly in the rock burst tunnel reinforcement method;

[0020] Figure 4 Shows Figure 1 A cross-sectional view of the anti-retraction anchor assembly of the rock burst tunnel reinforcement method in a tensioned state;

[0021] Figure 5 Shows Figure 1 A cross-sectional view of the anti-retraction anchor assembly of the rock burst tunnel reinforcement method when it is in a locked state.

[0022] The above drawings include the following reference numerals:

[0023] 10. Tray; 20. Anchor cable; 30. Anchor ring; 31. Conical hole; 32. Second recess; 40. Clip; 41. First recess; 50. Anti-retraction anchor assembly; 51. Sleeve; 52. Elastic structure; 53. Ejector pin; 60. Self-aligning ball pad. DETAILED DESCRIPTION

[0024] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0025] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meanings as commonly understood by ordinary technicians in the technical field to which this application belongs.

[0026] In the present invention, unless otherwise specified, the directional words used, such as "up" and "down", usually refer to the directions shown in the drawings, or to the vertical, perpendicular or gravity directions; similarly, for ease of understanding and description, "left" and "right" usually refer to the left and right shown in the drawings; "inside" and "outside" refer to the inside and outside relative to the outline of each component itself, but the above directional words are not used to limit the present invention.

[0027] In order to solve the problem that the reinforcement effect of the rock burst tunnel in the prior art cannot meet the reinforcement needs of users, the present application provides a rock burst tunnel reinforcement method.

[0028] like Figures 1 to 5 As shown in the figure, the reinforcement methods for rock burst tunnels include:

[0029] Step S1: Obtain the tunnel surrounding rock integrity index λ at position x in the tunnel x ;

[0030] Step S2: According to the tunnel surrounding rock integrity index λ x Determine whether the x position needs to be reinforced or depressurized. If the x position needs to be depressurized, blasting is used to depressurize the position. If the x position needs to be reinforced, spraying, anchoring and grouting are performed in sequence at the x position.

[0031] The technical solution of the present embodiment is applied. The reinforcement method for the rock burst tunnel in the present embodiment is generally based on the support principle of "deep unloading and shallow support". The ultrasonic test is used to determine the broken area and the intact area of ​​the tunnel surrounding rock, and the pressure is relieved in the deep coal body structure intact area to release the elastic energy inside the coal rock body, reduce far-field stress concentration and impact load, and improve the stress state of the tunnel; a thin spraying surface is performed to seal the surrounding rock in the shallow broken area, and high-elongation grouting anchor cables are added for grouting reinforcement to improve the integrity of the surrounding rock and its resistance to impact deformation, thereby solving the problem that the reinforcement effect of the rock burst tunnel in the prior art cannot meet the reinforcement needs of users.

[0032] In this embodiment, the tunnel surrounding rock integrity index λ at the position x in the tunnel is obtained. x The methods include:

[0033] Step S11: Take out coal blocks of preset size in the tunnel and obtain the longitudinal wave velocity v of the coal blocks p ;

[0034] Step S12: Obtain the acoustic wave velocity of the coal body at the x position within the range of 2.5L to 3.5L in the tunnel

[0035] Step S13: According to the formula: Determine the tunnel surrounding rock integrity index λ x ; Where L is the length of the anchor cable.

[0036] Specifically, the acoustic wave test method is combined with the length of the anchor cable to quantitatively divide the range of "reinforcement" and "pressure relief" of the tunnel surrounding rock. A complete 150mm×150mm coal block is taken from the reinforced tunnel and cut and polished in the laboratory. The coal block is then tested by ultrasonic wave to determine that the longitudinal wave velocity of the coal block is v p The acoustic wave velocity of coal bodies at different positions within 3L of the tunnel surrounding rock was tested by acoustic part. According to formula (1), the tunnel surrounding rock integrity index λ at the position x from the tunnel surface is determined x .

[0037] In this embodiment, according to the tunnel surrounding rock integrity index λ x Methods for determining whether reinforcement or pressure relief is required at the x position include:

[0038] If satisfied: Then the x position needs to be reinforced;

[0039] If satisfied: Then pressure relief is required at position x.

[0040] Specifically, according to the above judgment criteria, the scope of "reinforcement" and "pressure relief" of surrounding rock is quantitatively divided.

[0041] In this embodiment, the method of relieving the pressure at the location by blasting includes:

[0042] Step S21: Determine the formula according to the formula: Determine the radius R of the crushing circle 1 , according to the formula: Determine the radius of the crack circle R 2 ; where ρ 0 is the density of the explosive, D is the detonation velocity of the explosive in the coal, n is the pressure increase coefficient on the blast hole wall after the explosive explodes, K is the radial uncoupling coefficient, that is, the ratio of the blast hole radius to the charge radius, η is the insulation coefficient, l cis the axial uncoupling coefficient, B is the insulation coefficient, α is the load propagation attenuation index, β is the stress wave propagation attenuation index, R b is the blasthole radius, σ cd is the uniaxial dynamic compressive strength of rock, σ td is the uniaxial dynamic tensile strength of rock;

[0043] Step S22: According to the formula: R 3 =2R 2 Determine the spacing of the pressure relief holes.

[0044] Specifically, under the action of blasting, a crushing circle and a fracture circle will be formed with the blasthole as the center. The crushing circle is mainly formed by the compression and shearing of the coal body due to the impact of blasting, while the fracture circle is formed by the tensile effect of the coal body. The fracture circle is far beyond the range of the crushing circle, so the blasting pressure relief range usually only considers the size of the fracture circle. Limited by the conditions for obtaining explosives in the mine, coal mines generally use uncoupled charging for pressure relief. Among them, the spacing between the pressure relief holes is taken as the radius R of the fracture circle 2 The length of the charging interval is determined by the "pressure relief" range in step S2, and the sealing length is 1 / 3 of the blasting hole depth.

[0045] In this embodiment, the method for spraying at the x position includes: spraying a plastic material with a thickness of 4 to 6 mm, a tensile strength greater than 2 MPa, a bonding strength greater than 1 MPa, an elongation at break greater than 30% and a curing time less than or equal to 60 s at the x position of the lane.

[0046] Specifically, the thin sprayed surface can not only prevent the weathering of the surrounding rock and the rusting of the metal support, but also because the above-mentioned material has good plastic characteristics, in the impact ground pressure tunnel, when frequent energy events occur, the air side of the tunnel surrounding rock is constrained and energy-absorbing by the plastic sprayed material, which greatly improves the stress state of the shallow surrounding rock when subjected to dynamic loads and inhibits the expansion of cracks in the shallow surrounding rock of the tunnel.

[0047] In this embodiment, the method for adding anchor cables at position x includes:

[0048] Step S23: installing an anchor cable 20 with a nominal diameter of 20-25 mm, a breaking load greater than 460 kN, a maximum force total elongation greater than 4%, and a sealing pressure greater than 20 MPa at position x;

[0049] Step S24: Install the impact-resistant anchor assembly outside the anchor cable 20. Figure 3As shown, the impact-resistant anchor assembly includes a pallet 10, an anchor ring 30, a plurality of clips 40, and a plurality of anti-retraction anchor assemblies 50. The anchor cable 20 is inserted into the pallet 10, the anchor ring 30 is located on one side of the pallet 10, and the inner hole of the anchor ring 30 is a tapered hole 31; along the direction from the pallet 10 to the anchor ring 30, the inner diameter of the tapered hole 31 gradually increases. The plurality of clips 40 are arranged around the anchor cable 20, and at least part of each clip 40 extends into the tapered hole 31. The plurality of anti-retraction anchor assemblies 50 are arranged one by one with the plurality of clips 40, and each anti-retraction anchor assembly 50 is arranged between the corresponding clip 40 and the tapered hole 31.

[0050] Specifically, after normal anchoring and prestressing, high-pressure grouting is performed using a hollow tube. Compared with conventional grouting anchor cables, the method of adding anchor cables makes the tunnel more capable of bearing and can apply high prestress and high pressure resistance. The sealing pressure is increased by more than 5 times, greatly improving the grouting effect.

[0051] In this embodiment, the tray 10 is an arched support plate of 300×300×16mm, the ball socket opening is designed as an inverted trapezoid, and the impact-resistant anchor assembly also includes a self-aligning ball pad 60, which is embedded in the ball socket opening, and its mechanical properties match the strength of the anchor cable, with a thickness of not less than 16mm, a height of not less than 60mm, and a bearing capacity not less than the breaking load of the entire steel strand. Among them, the self-aligning ball pad 60 is formed by hot plate stamping, with blunt corners and a bearing capacity greater than 500KN.

[0052] In this embodiment, there are three clips 40 , and the three clips 40 are arranged at intervals around the anchor cable 20 .

[0053] like Figure 4 and Figure 5 As shown, each clip 40 has a first recess 41, and the anchor ring 30 has a second recess 32 arranged on the hole wall of the tapered hole 31. Each anti-retraction anchor assembly 50 includes a sleeve 51, an elastic structure 52 and an ejector pin 53. The sleeve 51 is arranged in the second recess 32, the sleeve 51 has a through hole, the elastic structure 52 is arranged in the sleeve 51, and the first end of the elastic structure 52 abuts against the inner surface of the sleeve 51. The first end of the ejector pin 53 passes through the through hole and extends out of the sleeve 51, and the second end of the ejector pin 53 abuts against the second end of the elastic structure 52.

[0054] Optionally, the elastic structure 52 is a spring.

[0055] Specifically, the ejector pin 53 is lifted by the spring and contacts the clip 40. During the tensioning process, as the clip 40 gradually enters the interior of the anchor ring 30, the ejector pin 53 enters the first recess 41 after reaching the preset preload force, so that the clip 40 and the anchor ring 30 are fixed together, thereby preventing the anchor cable 20 from being unanchored when subjected to dynamic loads, thereby causing the support system to fail.

[0056] In this embodiment, the method for grouting at the position x includes: according to the tunnel surrounding rock integrity index λ x Select grouting material, if 0.4<λ x <0.65, then use micron-nano composite grouting material, the slurry water seepage rate of micron-nano composite grouting material is less than 4%, the density is 1.45-1.55kg / m3, the setting time is 2-20min, the stone rate is 100% and the 2h setting strength is 8-12MPa; if λ x <0.4, nano-modified composite single-liquid grouting material is used. The particle size D95 of the nano-modified composite single-liquid grouting material is less than 15μm, the initial setting time is 1.2-1.8h, the final setting time is 8-10h, the compressive strength at 28d is greater than or equal to 50MPa, the flexural strength at 28d is greater than or equal to 6MPa, the bonding strength with the coal body at 28d is greater than or equal to 3MPa, and the maximum reaction temperature is less than 25℃.

[0057] Specifically, the slurry penetrates, diffuses, and fills the tunnel surrounding rock, solidifies and hardens after a certain period of time, thereby improving the integrity and strength of the tunnel surrounding rock, improving the anchoring force and prestress transfer effect of the support structure, thereby improving the self-bearing capacity of the tunnel surrounding rock and the bearing capacity and support effect of the support structure, and effectively controlling the deformation and damage of the tunnel under strong mining stress.

[0058] In this embodiment, after the reinforcement at the x position is completed, the rock burst tunnel reinforcement method further includes: step S3: installing a comprehensive mine pressure monitoring station every 50m at the x position to monitor the working resistance of the anchor cable, roof separation, and tunnel surface displacement. In this way, by arranging a comprehensive mine pressure monitoring station in the tunnel reinforcement area, the working resistance of the anchor cable, roof separation, and tunnel surface displacement are monitored, and dynamic feedback is performed and corresponding measures are taken according to the mine pressure monitoring data.

[0059] In this embodiment, during the monitoring process of the mine pressure monitoring comprehensive measuring station, the rock burst tunnel reinforcement method also includes: if the working resistance of the anchor cable exceeds 80% of its breaking period; or, the top plate separation deep base point reading exceeds 100mm or the shallow base point reading exceeds 75mm, and the reading change exceeds 20mm / day; or, the tunnel surface displacement exceeds 100mm, then the x position is reinforced.

[0060] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0061] The rock burst tunnel reinforcement method includes: first obtaining the tunnel surrounding rock integrity index λ at the x position in the tunnel x , and then according to the tunnel surrounding rock integrity index λ xDetermine whether the x position needs to be reinforced or decompressed. If the x position needs to be decompressed, decompress it by blasting; if the x position needs to be reinforced, spray, add anchor cables, and grout at the x position in turn. In this way, the rock burst tunnel reinforcement method in this application is generally based on the support principle of "deep unloading and shallow support". The acoustic wave test is used to determine the broken area and intact area of ​​the tunnel surrounding rock, and the pressure is relieved in the deep coal body structure intact area to release the elastic energy inside the coal rock body, reduce the far-field stress concentration and impact load, and improve the stress state of the tunnel; in the shallow broken area, a thin spraying surface is carried out to seal the surrounding rock, and high-elongation grouting anchor cables are added for grouting reinforcement to improve the integrity and impact deformation resistance of the surrounding rock, thereby solving the problem that the reinforcement effect of the rock burst tunnel in the prior art cannot meet the user's reinforcement needs.

[0062] Obviously, the above-described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0063] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0064] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein.

[0065] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for reinforcing a rock burst tunnel, characterized in that: include: Step S1: Obtain the tunnel surrounding rock integrity index λ at position x in the tunnel x ; Step S2: According to the tunnel surrounding rock integrity index λ x Determine whether the x position needs to be reinforced or depressurized. If the x position needs to be depressurized, blasting is used to depressurize the position. If the x position needs to be reinforced, spraying, anchoring and grouting are performed in sequence at the x position.

2. The rock burst tunnel reinforcement method according to claim 1, characterized in that: Get the tunnel surrounding rock integrity index λ at position x in the tunnel x The methods include: Step S11: Take out a coal block of a preset size in the tunnel and obtain the longitudinal wave velocity v of the coal block. p ; Step S12: Obtain the acoustic wave velocity of the coal body at the x position within the range of 2.5L to 3.5L in the tunnel Step S13: According to the formula: Determine the tunnel surrounding rock integrity index λ x ; Where L is the length of the anchor cable.

3. The rock burst tunnel reinforcement method according to claim 1, characterized in that: According to the tunnel surrounding rock integrity index λ x Methods for determining whether reinforcement or pressure relief is required at the x position include: If satisfied: Then the x position needs to be reinforced; If satisfied: Then pressure relief is required at position x.

4. The rock burst tunnel reinforcement method according to claim 1, characterized in that: Methods for depressurizing the area by blasting include: Step S21: Determine the formula according to the formula: Determine the radius of the crushing circle R1 according to the formula: Determine the radius of the crack circle R2; Where ρ0 is the density of the explosive, D is the detonation velocity of the explosive in the coal, n is the pressure increase coefficient on the blast hole wall after the explosive explodes, K is the radial uncoupling coefficient, that is, the ratio of the blast hole radius to the charge radius, η is the insulation coefficient, l c is the axial uncoupling coefficient, B is the insulation coefficient, α is the load propagation attenuation index, β is the stress wave propagation attenuation index, R b is the blasthole radius, σ cd is the uniaxial dynamic compressive strength of rock, σ td is the uniaxial dynamic tensile strength of rock; Step S22: Determine the spacing of the pressure relief holes according to the formula: R3=2R2.

5. The rock burst tunnel reinforcement method according to claim 1, characterized in that: Methods for spraying at the x position include: At the x position of the lane, a plastic material with a thickness of 4 to 6 mm, a tensile strength greater than 2 MPa, a bonding strength greater than 1 MPa, an elongation at break greater than 30% and a curing time less than or equal to 60 s is sprayed.

6. The rock burst tunnel reinforcement method according to claim 1, characterized in that: The methods for adding anchor cables at the x position include: Step S23: installing an anchor cable (20) having a nominal diameter of 20-25 mm, a breaking load greater than 460 kN, a maximum force total elongation greater than 4%, and a sealing pressure greater than 20 MPa at position x; Step S24: installing an impact-resistant anchor assembly outside the anchor cable (20), wherein the impact-resistant anchor assembly comprises: A pallet (10), wherein the anchor cable (20) is inserted into the pallet (10); An anchor ring (30) is located on one side of the tray (10), and the inner hole of the anchor ring (30) is a tapered hole (31); along the direction from the tray (10) to the anchor ring (30), the inner diameter of the tapered hole (31) gradually increases; A plurality of clips (40), wherein the plurality of clips (40) are arranged around the anchor cable (20), and at least a portion of each clip (40) extends into the tapered hole (31); A plurality of anti-retraction anchor assemblies (50) are arranged in one-to-one correspondence with the plurality of clips (40), and each anti-retraction anchor assembly (50) is arranged between the corresponding clip (40) and the tapered hole (31).

7. The rock burst tunnel reinforcement method according to claim 6, characterized in that: Each of the clips (40) has a first recess (41), and the anchor ring (30) has a second recess (32) arranged on the hole wall of the tapered hole (31); Each of the anti-retraction anchor assemblies (50) comprises: A sleeve (51) is disposed in the second recess (32), and the sleeve (51) has a through hole; An elastic structure (52) is arranged in the sleeve (51), and a first end of the elastic structure (52) abuts against an inner surface of the sleeve (51); An ejector pin (53), wherein a first end of the ejector pin (53) passes through the through hole and then extends out of the sleeve (51), and a second end of the ejector pin (53) abuts against a second end of the elastic structure (52).

8. The rock burst tunnel reinforcement method according to claim 1, characterized in that: Methods for grouting at the x position include: According to the tunnel surrounding rock integrity index λ x Select grouting material, if 0.4<λ x <0.65, a micron-nano composite grouting material is used, wherein the slurry water seepage rate of the micron-nano composite grouting material is less than 4% and the density is 1.45~1.55kg / m 3 , the setting time is 2 to 20 minutes, the stone rate is 100% and the setting strength after 2 hours is 8 to 12 MPa; if λ x <0.4, a nano-modified composite single-liquid grouting material is used, and the particle size D of the nano-modified composite single-liquid grouting material is 95 Less than 15μm, initial setting time of 1.2-1.8h, final setting time of 8-10h, compressive strength at 28d greater than or equal to 50MPa, flexural strength at 28d greater than or equal to 6MPa, bonding strength with coal body at 28d greater than or equal to 3MPa and maximum reaction temperature less than 25℃.

9. The rock burst tunnel reinforcement method according to claim 1, characterized in that: After the reinforcement at the x position is completed, the rock burst tunnel reinforcement method further includes: Step S3: Install a comprehensive mine pressure monitoring station at the x position every 50 m to monitor the working resistance of the anchor cable, roof separation, and tunnel surface displacement.

10. The rock burst tunnel reinforcement method according to claim 9, characterized in that: During the monitoring process of the comprehensive mine pressure monitoring station, the rock burst tunnel reinforcement method further includes: If the working resistance of the anchor cable exceeds 80% of its breaking period; or the top plate separation depth base point reading exceeds 100mm or the shallow base point reading exceeds 75mm, and the reading change exceeds 20mm / day; or the tunnel surface displacement exceeds 100mm, the x position shall be reinforced.

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