A method and system for artificial hole making and pressure relief of a large roadway in a panel and anchor injection collaborative support

Abstract

The application discloses a disc area large roadway artificial cavity pressure relief and anchor injection collaborative support method and system. It includes: laying a test section, measuring the in-situ ground stress, surrounding rock mechanical parameters, surrounding rock loose and broken range and roadway section size, and establishing a support calculation model according to the measurement results; installing a one-time pressure relief support component on the roadway roof, two sides and bottom corner to form an initial load; using the support calculation model to determine the depth, spacing, section size and shape of the artificial cavity pressure relief structure, and constructing the cavity structure in the deep part of the two sides of the coal body to shift the high stress peak to the deep part of the coal body; after deformation stabilization, constructing a secondary anchor injection support component and injecting slurry to form an anchor injection reinforcement ring; monitoring the roadway convergence, roof separation and support component stress throughout the process, and determining the correction parameters of the subsequent construction section according to the monitoring results. The application can realize the collaborative control of pressure relief and energy release first and anchor injection reinforcement later under the premise of ensuring the overall stability of the disc area large roadway surrounding rock.

Description

Technical Field

[0001] This application relates to the field of coal mine roadway support technology, specifically to a method and system for coordinated support of artificial cavity creation and anchor injection in the main roadway of a panel. Background Technology

[0002] As coal mining depth increases, the main roadways in the mining panel are often in an environment of high-level tectonic stress, mining-induced stress, and softening of the surrounding rock. After the roadway is excavated, high stress concentrations easily form at the roadway sides and shoulder corners, leading to frequent problems such as roof delamination, sidewall bulging, bottom corner shearing, and excessive stress on support components, resulting in continuous shrinkage of the roadway cross-section and repeated repairs.

[0003] Existing high-strength rigid supports typically focus on improving the resistance of anchor bolts, anchor cables, or scaffolding, making it difficult to actively change the stress concentration location around the roadway. Although simple pressure relief measures can release some energy, if the pressure relief location, spacing, and scale lack mechanical parameter constraints, it can easily lead to the weakened zone connecting with the shallow fractured zone of the roadway, thereby reducing the overall stability of the coal pillar or sidewall. Simple grouting reinforcement may be torn or sheared while the surrounding rock is still in the rapid deformation stage.

[0004] Therefore, a method and system for coordinated support of artificial cavity creation and anchor injection in the main roadway of the panel area is needed. Summary of the Invention

[0005] This application aims to solve the technical problems of large deformation of surrounding rock, failure of support components, and unclear connection between pressure relief and support in the main roadway of a high-stress panel area, and provides a method and system for coordinated support of artificial cavity creation for pressure relief and anchor injection in the main roadway of a panel area.

[0006] To achieve the above objectives, this application adopts the following technical solution: In a first aspect, this application provides a method for coordinated support of artificial cavity creation and anchoring in the main roadway of a panel, comprising the following steps: S1. Set up test sections, measure the original rock stress, surrounding rock mechanical parameters, surrounding rock loosening and fracture range and tunnel cross-sectional dimensions, obtain the measurement results, and establish a support calculation model based on the measurement results; S2, using the original rock stress, the surrounding rock mechanical parameters and the surrounding rock loosening and fracture range from the measurement results, after the roadway is excavated or repaired, a primary pressure relief support component is installed on the roadway roof, two sides and bottom corners. The primary pressure relief support component provides constant resistance or increased resistance bearing within the preset pressure relief displacement range to form the initial bearing. S3, after the initial bearing is formed, the support calculation model is used to determine the burial depth, spacing, cross-sectional size and shape of the artificial cavity pressure relief structure, and the artificial cavity pressure relief structure is constructed in the deep part of the coal body on both sides of the roadway to transfer the high stress peak to the deep part of the coal body; S4. After the roadway convergence rate and the stress change of the primary pressure support component meet the deformation stability criterion, the secondary anchoring support component is constructed and grout is injected into the surrounding rock fissures. The secondary anchoring support component, the grout solidified body and the surrounding rock form an anchoring reinforcement ring. S5. During the entire construction process from S2 to S4, monitor the roadway convergence, roof delamination, and stress on the support components, obtain the monitoring results, and determine the correction parameters of the artificial cavity pressure relief structure, the primary pressure relief support component, or the secondary anchoring support component for the subsequent construction section based on the monitoring results.

[0007] Further, in S1, the original rock stress includes vertical stress, maximum horizontal principal stress, minimum horizontal principal stress, and the direction of maximum horizontal principal stress; the surrounding rock mechanical parameters include uniaxial compressive strength, elastic modulus, Poisson's ratio, cohesion, internal friction angle, and tensile strength of the coal body, roof, and floor strata; the range of loosening and fracturing of the surrounding rock is determined by at least one of the following methods: borehole inspection, drill cuttings volume test, sonic testing, or surrounding rock fracture observation.

[0008] Furthermore, in S2, the primary pressure relief support component includes at least two of the following: pressure relief anchor bolts, pressure relief anchor cables, steel strips, metal mesh, pallets, and surface spraying layers. The pressure relief displacement of the primary pressure relief support component is 50mm to 200mm, and the anchoring end of the primary pressure relief support component is located outside the loosening and fracturing range of the surrounding rock.

[0009] Further, in S3, the artificial cavity-forming pressure relief structure is a cylindrical hole, an elliptical hole, a square groove hole, or a slot extending along the direction of the roadway; assuming the roadway width is W, the bottom depth of the artificial cavity-forming pressure relief structure is 1.5W to 2.0W, the spacing between adjacent artificial cavity-forming pressure relief structures along the direction of the roadway is 3W to 5W, the diameter of the cylindrical hole is 0.3m to 1.2m, and the width of the square groove hole or the slot is 0.3m to 1.0m.

[0010] Furthermore, in S3, the support calculation model uses the following constraints to determine the burial depth, spacing, cross-sectional dimensions, and shape of the artificial cavity pressure relief structure: the maximum principal stress peak value in the shallow part of the roadway sidewall decreases after cavity creation, the stress peak value position moves to the deeper part of the coal body, the plastic zone of the roadway surrounding rock does not connect with the plastic zone around the artificial cavity pressure relief structure, and the coal pillar stability coefficient is not less than 1.2.

[0011] Furthermore, in S3, the artificial cavity-forming pressure relief structure is formed by drilling and enlarging, mechanical grooving, hydraulic cutting, water jet enlarging, or a combination of the above methods; after the cavity is formed, the loose coal and rock on the borehole wall are cleaned, and the cavity or groove forming the weakened area is retained.

[0012] Furthermore, in S4, the deformation stability criterion is that the daily convergence of the roadway is not greater than 2 mm / d for at least 3 consecutive days, or the axial force change rate of the first-time pressure relief support component is not greater than 10% for at least 3 consecutive days, or both of the above conditions are met simultaneously.

[0013] Furthermore, in S4, the secondary anchoring support component includes at least one of grouting anchor rods, grouting anchor cables, side reinforcement anchor cables, and bottom corner anchor rods; the grout is cement-based grout, mining inorganic grouting material, polyurethane chemical grout, or silicate chemical grout, and the grouting pressure is 1 MPa to 3 MPa.

[0014] Furthermore, in S5, when any of the following situations occur in the monitoring results: the daily convergence of the roadway is greater than 5 mm / d, the roof delamination is greater than 20 mm, or the axial force of the anchor bolt or anchor cable reaches more than 80% of the design bearing capacity, at least one of the following measures shall be taken for the subsequent construction section: reducing the spacing of the artificial cavity pressure relief structure, increasing the cross-sectional size of the artificial cavity pressure relief structure, increasing the density of the primary pressure relief support component, advancing the construction time of the secondary anchoring support component, or increasing the grouting pressure, and the correction parameters shall be determined based on the measures taken.

[0015] Secondly, this application also provides a combined support system for artificial cavity creation and anchoring in main roadways of a panel, comprising: The measurement unit is used to be set up at the test section to collect data on the original rock stress, surrounding rock mechanical parameters, surrounding rock loosening and fracture range, and tunnel cross-sectional dimensions, and to establish a support calculation model based on the collected data. A primary pressure relief support unit is installed on the roof, sides and bottom corners of the roadway to provide constant or increased resistance bearing within a preset pressure relief displacement range, forming the initial bearing. The artificial cavity pressure relief structure is set deep in the coal body on both sides of the roadway. The burial depth, spacing, cross-sectional size and shape of the artificial cavity pressure relief structure are determined by the support calculation model. The artificial cavity pressure relief structure and the primary pressure relief support unit are arranged in a staggered layer in space. The secondary anchoring support unit is installed in the shallow surrounding rock of the roadway. The secondary anchoring support unit is constructed after the roadway convergence rate and the stress change of the primary pressure relief support unit meet the deformation stability criterion. The secondary anchoring support unit is connected to the grout solidified body in the surrounding rock fissures through grouting slurry to form an anchoring reinforcement ring. The monitoring unit is installed in the roadway and on the primary pressure relief support unit and the secondary anchoring support unit. It is used to collect roadway convergence data, roof delamination data and support unit stress data, and to determine the correction parameters of the artificial cavity pressure relief structure, the primary pressure relief support unit or the secondary anchoring support unit for subsequent construction sections based on the collected monitoring data.

[0016] Compared with the prior art, this application has the following beneficial effects: This application provides a method for coordinated support of artificial cavity creation and anchoring in the main roadway of a panel. Through systematic measurement in step S1, the original rock stress and surrounding rock mechanical parameters are directly used to determine the parameters for primary cavity creation and secondary anchoring support, achieving quantitative support design. Through primary cavity creation support in step S2, a controlled bearing structure is formed in the shallow surrounding rock, allowing the surrounding rock to release some deformation energy under controlled conditions. Through step S3, artificial cavity creation and pressure relief structures are set up deep within the coal seam on both sides, transferring high stress peaks to deeper coal seams away from the roadway outline. Through step S4, secondary anchoring support is implemented after the surrounding rock deformation stabilizes, forming an anchoring reinforcement ring. Through full-process monitoring and feedback in step S5, correction parameters are determined. The coordinated operation of these steps overcomes the shortcomings of existing technologies, such as the lack of quantitative basis for support design, the disconnect between cavity creation and anchoring reinforcement, and the lack of a dynamic feedback mechanism, achieving full-process coordinated control of the surrounding rock in the main roadway of a panel.

[0017] This application limits the use of at least two combinations of yield anchor bolts, yield anchor cables, steel strips, metal mesh, pallets, and surface spraying in a single yield support, and controls the yield displacement to be 50mm to 200mm. At the same time, the anchoring end is set outside the loosening and fracture range of the surrounding rock. This allows the shallow surrounding rock to release deformation energy under controlled conditions while ensuring that the anchoring force is effectively transferred to the stable surrounding rock. This avoids the problem of rigid support breaking and failing due to its inability to adapt to the deformation of the surrounding rock, and improves the adaptability of the support structure in the early deformation stage of the surrounding rock.

[0018] This application limits the bottom depth of the artificial cavity-forming pressure relief structure to 1.5W to 2.0W and the spacing to 3W to 5W. It uses mechanical constraints such as a decrease in peak stress after cavity formation, a shift in the peak stress position to deeper areas, non-connection of the plastic zone, and a coal pillar stability coefficient of not less than 1.2 to determine the cavity-forming parameters. This provides a quantitative mechanical basis for the pressure relief location and scale, avoiding the risk of connection between the pressure-relieved weakened zone and the shallow fractured zone of the roadway, thus ensuring the overall stability of the coal pillar. Simultaneously, by limiting the grouting pressure of the secondary anchoring support to 1MPa to 3MPa, and taking adjustment measures when the daily convergence exceeds 5mm / d, the roof delamination exceeds 20mm, or the anchor cable axial force reaches more than 80% of the design bearing capacity, the grouting consolidation body can effectively cement the fractures after the surrounding rock stabilizes, avoiding the problem of continuous deformation and damage to early grouting. Furthermore, by monitoring threshold trigger parameters for correction, this method can adapt to geological conditions changing along the roadway direction. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a flowchart of a method for coordinated support of artificial cavity creation and anchoring in a main roadway of a panel area, provided in an embodiment of this application. Figure 2 This is a schematic diagram of the artificial hole arrangement provided in the embodiments of this application; Figure 3 This is a schematic diagram of the anchoring support structure provided in the embodiments of this application.

[0021] In the picture, 1-Road slab of the tunnel, 2-Road slab of the tunnel, 3-Primary pressure relief support components of the tunnel, 4-Overlying rock strata of the tunnel, 5-Artificial cavity-making pressure relief structure, 6-Secondary anchoring support components. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0023] See Figure 1 This application provides a method for coordinated support of artificial cavity creation and anchoring in the main roadway of a panel, comprising the following steps: S1. Set up test sections, measure the original rock stress, surrounding rock mechanical parameters, surrounding rock loosening and fracture range and tunnel cross-sectional dimensions, obtain the measurement results, and establish a support calculation model based on the measurement results; In a more specific embodiment provided in this application, the in-situ rock stress is determined using a stress relief method or a hydraulic fracturing method. The in-situ rock stress includes vertical stress, maximum horizontal principal stress, minimum horizontal principal stress, and the direction of the maximum horizontal principal stress.

[0024] Coal and rock samples were collected from the roof, floor, and sidewalls of the roadway for indoor mechanical testing. The mechanical parameters of the surrounding rock included the uniaxial compressive strength, elastic modulus, Poisson's ratio, cohesion, internal friction angle, and tensile strength of the coal body, roof, and floor strata.

[0025] Specifically, at least one of the following methods is used to determine the extent of loosening and fracturing of the surrounding rock: borehole inspection, drill cuttings testing, sonic testing, or observation of surrounding rock fractures.

[0026] Based on the above measurement results, a support calculation model was established that includes the roadway outline, coal and rock stratification, and coal bodies on both sides.

[0027] S2, using the original rock stress, the surrounding rock mechanical parameters and the surrounding rock loosening and fracture range from the measurement results, after the roadway is excavated or repaired, a primary pressure relief support component is installed on the roadway roof, two sides and bottom corners. The primary pressure relief support component provides constant resistance or increased resistance bearing within the preset pressure relief displacement range to form the initial bearing. Specifically, after the tunnel is excavated or widened, a pressure relief support component should be installed in a timely manner.

[0028] In a more specific embodiment provided in this application, the primary pressure relief support component includes at least two of the following: pressure relief anchor bolts, pressure relief anchor cables, steel strips, metal mesh, pallets, and surface spraying layers.

[0029] The pressure relief displacement of the primary pressure relief support component is 50mm to 200mm, which causes the surrounding rock to undergo controlled deformation under the constraint of shallow support and releases part of the deformation energy.

[0030] The anchoring end of the primary pressure-bearing support component is located outside the loosening and fracturing range of the surrounding rock determined by S1. By forming a controlled bearing structure in the shallow surrounding rock of the roadway, the roadway has the necessary profile stability before artificial cavity construction, and allows the surrounding rock to release some deformation energy under controlled conditions, effectively avoiding unrestrained failure.

[0031] S3, after the initial bearing is formed, the support calculation model is used to determine the burial depth, spacing, cross-sectional size and shape of the artificial cavity pressure relief structure, and the artificial cavity pressure relief structure is constructed in the deep part of the coal body on both sides of the roadway to transfer the high stress peak to the deep part of the coal body; Numerical simulation analysis was conducted using the support calculation model established by S1, and the burial depth, spacing, cross-sectional dimensions, and shape of the artificial cavity pressure relief structure were determined under the following four constraints: The four constraints are: the peak value of the maximum principal stress in the shallow part of the roadway sidewall decreases after the cavity is created; the position of the stress peak moves to the deeper part of the coal body; the plastic zone of the roadway surrounding rock does not connect with the plastic zone around the artificial cavity pressure relief structure; and the coal pillar stability coefficient is not less than 1.2.

[0032] Under the premise of satisfying the above four constraints, the following parameters of the artificial cavity decompression structure are determined: With the tunnel width as W, the bottom depth of the artificial cavity pressure relief structure is 1.5W to 2.0W; The spacing between adjacent artificial cavity-forming and pressure-relieving structures along the tunnel direction is 3W to 5W; The artificial cavity decompression structure is a cylindrical hole, an elliptical hole, a square groove hole, or a slot extending along the tunnel direction. The diameter of the cylindrical hole is 0.3m to 1.2m, and the width of the square groove hole or the slot hole is 0.3m to 1.0m.

[0033] Artificial cavity decompression structures are constructed deep within the coal seam on both sides of the roadway. Specific methods include: drilling and enlarging, mechanical grooving, hydraulic cutting, water jet enlargement, or a combination of the above methods.

[0034] After the cavity is created, the loose coal and rock on the borehole wall are cleaned up, and the cavity or groove that forms the weakened area is preserved.

[0035] The artificial cavity-forming pressure relief structure is located deep within the coal seam on both sides, and is spatially staggered with the primary pressure relief support component described in S2.

[0036] This step involves creating artificial cavity-forming pressure relief structures deep within the coal seam on both sides of the roadway. This weakens the deep coal seam, altering the stress transmission path and causing high stress peaks to move away from the roadway outline, thereby reducing the stress on shallow support components. Using mechanical constraints (reduced stress peaks, non-connected plastic zones, and a coal pillar stability coefficient ≥1.2) as the design basis avoids the problem of existing pressure relief technologies failing to provide mechanical constraints, which can lead to connections between the weakened zone and the shallow fractured zone.

[0037] S4. After the roadway convergence rate and the stress change of the primary pressure support component meet the deformation stability criterion, the secondary anchoring support component is constructed and grout is injected into the surrounding rock fissures. The secondary anchoring support component, the grout solidified body and the surrounding rock form an anchoring reinforcement ring. In a more specific embodiment provided in this application, the deformation stability criterion is one or a combination of the following conditions: The daily convergence of the roadway for no less than 3 consecutive days shall not exceed 2 mm / d; the axial force change rate of the primary pressure relief support component for no less than 3 consecutive days shall not exceed 10%.

[0038] The secondary anchoring support components include at least one of grouting anchor bolts, grouting anchor cables, side reinforcement anchor cables, and bottom corner anchor bolts.

[0039] In a more specific embodiment provided in this application, the grout may be at least one of the following materials: cement-based grout, mining inorganic grouting material, polyurethane chemical grout, or silicate chemical grout; the grouting pressure is 1 MPa to 3 MPa.

[0040] The secondary anchoring support components are installed in the shallow surrounding rock of the roadway and are arranged in a staggered manner with the artificial cavity-making and pressure-relieving structure in space.

[0041] This step involves anchoring reinforcement after the surrounding rock deformation has stabilized. By filling the cracks with grout, cementing and breaking the surrounding rock, and increasing the coupling between the anchor bolt or anchor cable and the surrounding rock, an anchoring reinforcement ring is formed around the tunnel outline, effectively avoiding the risk of early grouting being continuously deformed, cracked, or sheared.

[0042] S5. During the entire construction process from S2 to S4, monitor the roadway convergence, roof delamination, and stress on the support components, obtain the monitoring results, and determine the correction parameters of the artificial cavity pressure relief structure, the primary pressure relief support component, or the secondary anchoring support component for the subsequent construction section based on the monitoring results.

[0043] In a more specific embodiment provided in this application, the following are monitored throughout the construction process: tunnel convergence, roof delamination, and axial force of anchor bolts or anchor cables.

[0044] When any of the following situations occur in the monitoring results: The daily convergence of the tunnel is greater than 5 mm / d; The delamination of the top slab is greater than 20mm; The axial force of the anchor bolt or anchor cable reaches more than 80% of the design bearing capacity. At least one of the following adjustment measures shall be taken for subsequent construction sections: Reduce the spacing of the artificial cavity-forming pressure relief structure; Increase the cross-sectional dimensions of the artificial cavity-forming pressure relief structure; Increase the density of the primary pressure relief support components; The construction time of the secondary anchoring support components was brought forward; Increase grouting pressure.

[0045] The correction parameters are determined based on the measures taken.

[0046] This step, through dynamic monitoring and parameter feedback throughout the construction process, enables the method to adapt to changing geological conditions along the tunnel direction and achieve iterative optimization of parameters between different geological sections.

[0047] See Figure 2 and Figure 3 This embodiment provides a combined support system of artificial cavity creation and anchoring in the main roadway of a panel area, the system comprising: The measurement unit is used to be set up at the test section to collect data on the original rock stress, surrounding rock mechanical parameters, surrounding rock loosening and fracture range, and tunnel cross-sectional dimensions, and to establish a support calculation model based on the collected data.

[0048] A primary pressure relief support unit is installed on the roof, sidewalls, and bottom corners of the roadway to provide constant or increased resistance bearing capacity within a preset pressure relief displacement range, forming the initial bearing capacity. In the primary pressure relief support unit, the primary pressure relief support components include at least two of the following: pressure relief anchor bolts, pressure relief anchor cables, steel strips, metal mesh, pallets, and surface spraying layers. The pressure relief displacement of the primary pressure relief support unit is 50mm to 200mm, and the anchoring end of the primary pressure relief support unit is located outside the loosened and fractured range of the surrounding rock.

[0049] Artificial cavity pressure relief structures 5 are installed deep within the coal seam on both sides of the roadway. The burial depth, spacing, cross-sectional dimensions, and shape of the artificial cavity pressure relief structures 5 are determined by the support calculation model. The artificial cavity pressure relief structures 5 and the primary pressure relief support unit are arranged in a staggered spatial arrangement. With the roadway width W, the bottom depth of the holes in the artificial cavity pressure relief structures is 1.5W to 2.0W, and the spacing between adjacent artificial cavity pressure relief structures along the roadway direction is 3W to 5W. The artificial cavity pressure relief structures 5 are cylindrical holes, elliptical holes, square groove holes, or slots extending along the roadway direction. The diameter of the cylindrical holes is 0.3m to 1.2m, and the width of the square groove holes or slots is 0.3m to 1.0m.

[0050] A secondary anchoring support unit is installed in the shallow surrounding rock of the roadway. The secondary anchoring support unit is constructed after the roadway convergence rate and the stress change of the primary pressure relief support unit meet the deformation stability criterion. The secondary anchoring support unit is connected to the grout consolidation body in the surrounding rock fissures through grouting grout, forming an anchoring reinforcement ring. The secondary anchoring support unit includes at least one of grouting anchor bolts, grouting anchor cables, side reinforcement anchor cables, and bottom corner anchor bolts; the grout is cement-based grout, mining inorganic grouting material, polyurethane chemical grout, or silicate chemical grout, and the grouting pressure is 1 MPa to 3 MPa.

[0051] The monitoring unit is installed in the roadway and on the primary pressure relief support unit and the secondary anchoring support unit. It is used to collect roadway convergence data, roof delamination data and support unit stress data, and to determine the correction parameters of the artificial cavity pressure relief structure 5, the primary pressure relief support unit or the secondary anchoring support unit in the subsequent construction section based on the collected monitoring data.

[0052] Reference Figure 3 The primary pressure relief support unit, the artificial cavity pressure relief structure 5, and the secondary anchoring support unit are arranged sequentially from the shallow to the deep part of the roadway.

[0053] In another embodiment of this application, reference is made to... Figures 1 to 3Before constructing the main roadway in the deep panel of a coal mine, the S1 procedure was first implemented. Test sections were selected along the roadway direction to determine the in-situ rock stress and surrounding rock mechanical parameters. The loosening and fracture range of the sidewalls and roof was determined by drilling inspection. Based on the test results, the anchorage layer, pressure relief displacement, and spacing of the primary pressure relief support component 3 were determined, and a support calculation model was established.

[0054] When executing S2, the primary pressure relief support component 3 is promptly deployed after the roadway excavation. The primary pressure relief support component 3 is deployed in the roadway roof 1, two sidewalls, and bottom corner areas. Its shallow restraint effect can control the initial spalling, roof delamination, and bottom corner shear. At the same time, the pressure relief anchor bolts or pressure relief anchor cables provide a certain pressure relief displacement through the pressure relief structure, allowing the surrounding rock to release some energy under the support state without unrestrained failure.

[0055] Reference Figure 2 When executing S3, artificial cavity-forming pressure relief structures 5 are arranged deep within the coal seam on both sides of the roadway. These structures are not located near the roadway outline, but rather outside the anchorage bearing area of ​​the primary pressure relief support component 3, maintaining a distance between them and the shallow surrounding rock of the roadway. After cavity creation, high stress concentration areas in the overlying strata 4 and the coal seam on both sides of the roadway shift to the outside of the artificial cavity-forming pressure relief structure 5 or deeper, thereby reducing the concentrated stress on the roadway roof 1, roadway floor 2, and nearby support components on both sides.

[0056] In one embodiment, the roadway width W is 5m, the artificial cavity pressure relief structure 5 adopts cylindrical holes with a bottom depth of 7.5m to 10m, a spacing of 15m to 25m along the roadway direction, and a hole diameter of 0.5m to 0.8m. If the coal body is relatively soft or the mining impact is strong, the spacing or hole diameter can be appropriately reduced or increased, provided that the support calculation model meets the requirement that the coal pillar stability coefficient is not less than 1.2 and the plastic zone is not connected.

[0057] Reference Figure 3 Once the monitoring results show that the roadway convergence rate has stabilized, S4 is executed. The secondary anchoring support component 6 passes through the fractured surrounding rock from the shallow part of the roadway and enters the relatively intact surrounding rock. After grouting, the grout fills the cracks in the surrounding rock and forms a solidified body. This solidified body, together with the secondary anchoring support component 6, reinforces the shallow surrounding rock of the roadway. Together with the deep artificial cavity decompression structure 5 on both sides, it forms a synergistic structure of "shallow support, deep decompression, and reinforcement after stabilization".

[0058] During S5, roadway convergence, roof delamination, and stress on support components are recorded throughout the construction process. If monitoring results indicate that the surrounding rock is still in a rapid deformation phase, the secondary anchoring support is postponed or the density of the first pressure relief support is increased. If the shallow stress in the roadway sidewalls remains high after artificial cavity creation, or the axial force of the support components approaches the design bearing capacity, the cavity spacing is reduced or the cavity cross-section is increased for subsequent construction sections. If grout diffusion is insufficient, the grouting pressure is appropriately increased or the grout type is adjusted. Through the above feedback, each construction section can achieve effective pressure relief and reinforcement while ensuring the overall stability of the coal seam.

[0059] The embodiments described above are merely preferred embodiments of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various improvements and substitutions without departing from the technical principles of this application, and these improvements and substitutions should also be considered within the scope of protection of this application. Therefore, the scope of protection of this patent application should be determined by the scope of the claims.

Claims

1. A method for coordinated support of artificial cavity creation and anchoring in main roadways of a panel area, characterized in that, Includes the following steps: S1. Set up test sections, measure the original rock stress, surrounding rock mechanical parameters, surrounding rock loosening and fracture range and tunnel cross-sectional dimensions, obtain the measurement results, and establish a support calculation model based on the measurement results; S2, using the original rock stress, the surrounding rock mechanical parameters and the surrounding rock loosening and fracture range from the measurement results, after the roadway is excavated or repaired, a primary pressure relief support component is installed on the roadway roof, two sides and bottom corners. The primary pressure relief support component provides constant resistance or increased resistance bearing within the preset pressure relief displacement range to form the initial bearing. S3, after the initial bearing is formed, the support calculation model is used to determine the burial depth, spacing, cross-sectional size and shape of the artificial cavity pressure relief structure, and the artificial cavity pressure relief structure is constructed in the deep part of the coal body on both sides of the roadway to transfer the high stress peak to the deep part of the coal body; S4. After the roadway convergence rate and the stress change of the primary pressure support component meet the deformation stability criterion, the secondary anchoring support component is constructed and grout is injected into the surrounding rock fissures. The secondary anchoring support component, the grout solidified body and the surrounding rock form an anchoring reinforcement ring. S5. During the entire construction process from S2 to S4, monitor the roadway convergence, roof delamination, and stress on the support components, obtain the monitoring results, and determine the correction parameters of the artificial cavity pressure relief structure, the primary pressure relief support component, or the secondary anchoring support component for the subsequent construction section based on the monitoring results.

2. The method for coordinated support of artificial cavity creation and anchoring in a main roadway of a panel area according to claim 1, characterized in that, In S1, the original rock stress includes vertical stress, maximum horizontal principal stress, minimum horizontal principal stress, and the direction of maximum horizontal principal stress; the surrounding rock mechanical parameters include uniaxial compressive strength, elastic modulus, Poisson's ratio, cohesion, internal friction angle, and tensile strength of the coal body, roof, and floor strata; the range of loosening and fracturing of the surrounding rock is determined by at least one of the following methods: borehole inspection, drill cuttings volume test, sonic testing, or surrounding rock fracture observation.

3. The method for coordinated support of artificial cavity creation and anchoring in a main roadway of a panel area according to claim 1, characterized in that, In S2, the primary pressure relief support component includes at least two of the following: pressure relief anchor bolt, pressure relief anchor cable, steel strip, metal mesh, pallet, and surface spray layer. The pressure relief displacement of the primary pressure relief support component is 50mm to 200mm, and the anchoring end of the primary pressure relief support component is located outside the loosening and fracturing range of the surrounding rock.

4. The method for coordinated support of artificial cavity creation and anchoring in a main roadway of a panel area according to claim 1, characterized in that, In S3, the artificial cavity-forming pressure relief structure is a cylindrical hole, an elliptical hole, a square groove hole, or a slot extending along the direction of the roadway; assuming the roadway width is W, the bottom depth of the artificial cavity-forming pressure relief structure is 1.5W to 2.0W, the spacing between adjacent artificial cavity-forming pressure relief structures along the direction of the roadway is 3W to 5W, the diameter of the cylindrical hole is 0.3m to 1.2m, and the width of the square groove hole or the slot is 0.3m to 1.0m.

5. The method for coordinated support of artificial cavity creation and anchoring in a main roadway of a panel area according to claim 1, characterized in that, In S3, the support calculation model uses the following constraints to determine the burial depth, spacing, cross-sectional dimensions, and shape of the artificial cavity pressure relief structure: the maximum principal stress peak value in the shallow part of the roadway sidewall decreases after cavity creation, the stress peak value position moves to the deeper part of the coal body, the plastic zone of the roadway surrounding rock does not connect with the plastic zone around the artificial cavity pressure relief structure, and the coal pillar stability coefficient is not less than 1.

2.

6. The method for coordinated support of artificial cavity creation and anchoring in a main roadway of a panel area according to claim 1, characterized in that, In S3, the artificial cavity-forming pressure relief structure is formed by drilling and enlarging, mechanical grooving, hydraulic cutting, water jet enlargement, or a combination of the above methods; after the cavity is formed, the loose coal and rock on the borehole wall are cleaned, and the cavity or groove forming the weakened area is retained.

7. The method for coordinated support of artificial cavity creation and anchoring in a main roadway of a panel area according to claim 1, characterized in that, In S4, the deformation stability criterion is that the daily convergence of the roadway is not greater than 2 mm / d for at least 3 consecutive days, or the axial force change rate of the first-time pressure relief support component is not greater than 10% for at least 3 consecutive days, or both of the above conditions are met simultaneously.

8. The method for coordinated support of artificial cavity creation and anchoring in a main roadway of a panel area according to claim 1, characterized in that, In S4, the secondary anchoring support component includes at least one of grouting anchor rods, grouting anchor cables, side reinforcement anchor cables, and bottom corner anchor rods; the grout is cement-based grout, mining inorganic grouting material, polyurethane chemical grout, or silicate chemical grout, and the grouting pressure is 1MPa to 3MPa.

9. The method for coordinated support of artificial cavity creation and anchoring in a main roadway of a panel area according to claim 1, characterized in that, In S5, when any of the following situations occur in the monitoring results: the daily convergence of the roadway is greater than 5 mm / d, the roof delamination is greater than 20 mm, or the axial force of the anchor bolt or anchor cable reaches more than 80% of the design bearing capacity, at least one of the following measures shall be taken for the subsequent construction section: reducing the spacing of the artificial cavity pressure relief structure, increasing the cross-sectional size of the artificial cavity pressure relief structure, increasing the density of the primary pressure relief support component, advancing the construction time of the secondary anchoring support component, or increasing the grouting pressure, and the correction parameters shall be determined based on the measures taken.

10. A system for coordinated support of artificial cavity creation and anchoring in a main roadway of a panel, characterized in that, include: The measurement unit is used to be set up at the test section to collect data on the original rock stress, surrounding rock mechanical parameters, surrounding rock loosening and fracture range, and tunnel cross-sectional dimensions, and to establish a support calculation model based on the collected data. A primary pressure relief support unit is installed on the roof, sides and bottom corners of the roadway to provide constant or increased resistance bearing within a preset pressure relief displacement range, forming the initial bearing. The artificial cavity pressure relief structure is set deep in the coal body on both sides of the roadway. The burial depth, spacing, cross-sectional size and shape of the artificial cavity pressure relief structure are determined by the support calculation model. The artificial cavity pressure relief structure and the primary pressure relief support unit are arranged in a staggered layer in space. The secondary anchoring support unit is installed in the shallow surrounding rock of the roadway. The secondary anchoring support unit is constructed after the roadway convergence rate and the stress change of the primary pressure relief support unit meet the deformation stability criterion. The secondary anchoring support unit is connected to the grout solidified body in the surrounding rock fissures through grouting slurry to form an anchoring reinforcement ring. The monitoring unit is installed in the roadway and on the primary pressure relief support unit and the secondary anchoring support unit. It is used to collect roadway convergence data, roof delamination data and support unit stress data, and to determine the correction parameters of the artificial cavity pressure relief structure, the primary pressure relief support unit or the secondary anchoring support unit for subsequent construction sections based on the collected monitoring data.

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