Rock burst prevention and control method for deep rock engineering

Abstract

The invention relates to the technical field of underground engineering safety, in particular to a rockburst prevention and control method for deep rock engineering, and the method comprises the steps: S1, collecting initial information; and S2, rock burst risk and position initial evaluation. And S3, excavation and energy reduction. And S4, re-evaluating the rockburst risk. And S5, releasing energy of the high-energy risk grade rockburst. And S6, energy absorption optimization design of the supporting system is carried out. Through a six-step systematic design process in the whole process, the change of rockburst prevention and control from experience judgment to quantification, process and systematization is realized; according to the method, key parameters needing to be collected and engineering measures needing to be taken in all stages are defined, and a quantitative calculation method for the rockburst grade, the energy grade and the supporting energy absorption capacity is provided.

Description

Technical Field

[0001] This invention relates to the field of underground engineering safety technology, and in particular to a method for preventing rockbursts in deep rock engineering. Background Technology

[0002] Rockbursts are a typical dynamic hazard in deep rock engineering, usually triggered by the rapid release of high energy within underground rock masses. They manifest as sudden fracturing, spalling, ejection, or even explosion of the rock mass. The destructive process is violent, characterized by its suddenness, immense destructive force, and wide-ranging impact, seriously threatening the lives of engineering personnel and the stability of engineering structures. In environments with extremely high geostress, rockbursts occur frequently and are of a high severity, becoming a key challenge restricting safe construction in deep rock engineering.

[0003] Currently, rockburst prevention and control mainly relies on field experience, analogies to similar projects, and simplified static analysis. Typically, appropriate surface support methods, such as shotcrete, steel mesh, and anchor bolt combinations, are selected based on the predicted rockburst level. However, current rockburst prevention and control methods struggle to accurately reflect complex stress fields and dynamic energy release processes. They lack response mechanisms and quantitative design for the entire process of tunnel selection, excavation, and subsequent support, resulting in significant limitations. Furthermore, existing support system designs are still primarily based on experience-based selection, making it difficult to quantitatively assess and optimize their energy absorption performance, leading to unreliable prevention and control effects under extreme geological conditions. Summary of the Invention

[0004] In view of the above-mentioned shortcomings and deficiencies of the existing technology, the present invention provides a rockburst prevention and control method for deep rock engineering, which solves the technical problems that the current rockburst prevention and control methods are unable to accurately reflect the complex stress field and dynamic energy release process, lack response mechanisms and quantitative design for the entire process of tunnel selection, tunnel excavation and subsequent support, and have obvious limitations.

[0005] To achieve the above objectives, the main technical solutions adopted by the present invention include: This invention provides a method for preventing rockbursts in deep rock engineering, comprising the following steps: S1. Initial Information Acquisition: Obtain rock mass engineering geological information and stress field data to preliminarily determine the tunnel excavation area. Based on the rock mass engineering geological information obtained in S1, establish a three-dimensional numerical model and combine it with stress field data to invert the geostress field of the excavation area, and obtain the magnitude and direction distribution of the principal stress in the excavation area. S2. Initial assessment of rockburst risk and location: In the three-dimensional model of S1, a tunnel excavation simulation project is carried out. The location and level of rockburst in the simulated tunnel are obtained through numerical evaluation and microseismic monitoring as the rockburst risk information of the simulated tunnel. S3. Excavation Energy Reduction: Based on the ground stress field in S1 and the rockburst risk information in S2, adjust the excavation parameters in the actual excavation process accordingly to reduce the stress concentration effect caused by tunnel excavation during the excavation process. S4. Rockburst Risk Reassessment: After the S3 excavation, the overall energy of the surrounding rock is reduced. Through numerical simulation and microseismic monitoring, the location and level of rockburst in the surrounding rock formed after excavation are reassessed to provide data support for subsequent energy release and absorption. S5. Energy release of high-energy risk level rockburst: The rockburst risk level of the surrounding rock is determined based on the location and level information obtained from the reassessment of rockburst risk level in S4. If the rockburst risk level of the surrounding rock assessed in S4 reaches a strong or higher level, the energy of the surrounding rock at a strong or higher level will be released and directionally transferred to reduce the rockburst risk. If the S4 assessment result does not reach the level of strong or above, skip S5 and proceed directly to S6; S6. Energy absorption of the support system: Based on the location and level information obtained from the reassessment of rockburst risk level in S4, the control parameters and requirements are obtained, and the appropriate energy absorption control parameters of the support system can be selectively optimized.

[0006] Optionally, S1 includes the following steps: S11. Obtain geological structure information, lithological distribution information and surrounding rock grade information of the excavation area through geological exploration, drilling sampling and core analysis as rock mass engineering geological information; S12. Obtain the magnitude and direction of the principal stress at typical control points as geostress field data. S13. Based on the rock mass engineering geological information obtained in S11, establish a three-dimensional numerical model, and combine it with the geostress field data measured in S12 to invert the geostress field of the excavation area and obtain the magnitude and direction distribution of the principal stress in the excavation area.

[0007] Optionally, step S2 includes the following steps: S21. Based on the three-dimensional numerical model established by S11 and the excavation direction around the tunnel, engineering excavation simulation was carried out to obtain numerical evaluation results and preliminarily determine the main stress concentration areas and potential rockburst risk areas. S22. Based on the numerical evaluation results in S21, microseismic monitoring sensors are deployed at the locations of the main stress concentration areas and potential rockburst risk areas on site to monitor the surrounding rock of the tunnel in real time and compare it with the numerical evaluation results in S21 to further assess the potential rockburst level and possible location.

[0008] Optionally, the excavation parameters are: For TBM tunnels, the excavation route is adjusted, the excavation rate is reduced, and the tunneling parameters are optimized.

[0009] For drill-and-blast tunnels, the excavation cross-section shape is changed, the excavation sequence is adjusted, and the excavation rate is reduced.

[0010] Optionally, in S4, the main stress concentration areas and potential rockburst risk areas of the tunnel after S3 excavation are obtained through numerical simulation and on-site microseismic monitoring data as rockburst risk information, and the rockburst level and location are reassessed to ensure the safety of the surrounding rock.

[0011] Optionally, S5 includes the following steps: S51. For TBM tunnels, in high-energy rockburst risk areas, prestress is unloaded by constructing stress relief holes, combined with microwave stress relief.

[0012] S52. For drill-and-blast tunnels, microwave stress relief holes are set in high-energy rockburst risk areas, and microwave irradiation is used to release energy. The pilot tunnel is also optimized according to the stress distribution characteristics of the surrounding rock.

[0013] Optionally, the inclusion of the potential maximum damage depth Rock wall displacement calculation Quantitative load generated by rockburst Quantitative energy generated by rockburst ; S6 includes the following steps: S61, Potential Maximum Damage Depth The calculation is performed using the formula shown below: ; ; ; ; ; in, The potential depth of damage; This represents the maximum shear stress in the rock. The uniaxial compressive strength of the rock; For rock mass and geological correction factors; Control parameters related to the excavation shape; The geological strength index can be determined based on S1; and These are the maximum and minimum principal stresses; This refers to the tunnel cross-sectional height. This refers to the width of the tunnel cross-section; The weight of the rock mass; The S-wave velocity in the rock mass; The peak velocity of the particles obtained from microseismic monitoring; The elastic modulus of the rock mass; The Poisson's ratio of the rock mass; For design parameters, the value generally ranges from 0.2 to 0.3 depending on the design purpose; R is the distance from the seismic source. , The value range is 0.53–1.14; The magnitude of the earthquake was obtained from microseismic monitoring. S62, Rock Wall Displacement Calculation The calculation formula is as follows: ; Where BF is the rock mass fragmentation coefficient; S63: Quantitative load generated by rockburst The calculation is as follows: ; in, The mass of the ejected rock block; The ejection speed; This represents the change in peak particle velocity before and after the rockburst. This represents the change in time before and after the rock eruption. This is the magnification factor; S64, Quantitative Energy Generated by Rockbursts The calculation is as follows: ; in, The rock fragments were ejected. The ejection velocity is taken as twice the peak velocity of the mass source center; It represents the distance from which the rock fragments are ejected; q = 1, 0, and -1 represent the rock fragments ejected from the top plate, side wall, and bottom plate, respectively. This is the acceleration due to gravity.

[0014] Optionally, step S6 further includes the following step: S65. Based on the actual project and local earthquake magnitude Rock wall displacement calculation Quantitative load generated by rockburst Quantitative energy generated by rockburst Multiple indicators are considered, and a suitable support system is selected.

[0015] Optionally, the support system includes the maximum allowable displacement of the support system. Support system bearing capacity Maximum energy absorption of the support system and the load safety factor of the support system Displacement safety factor Energy safety factor : The maximum permissible displacement of the support system The calculation is as follows: ; in, This represents the maximum allowable displacement of the surface support; This refers to the ultimate deformation value of the support material inside the rock mass; different support systems under different rockburst conditions. and It can be obtained through indoor experiments; The bearing capacity of the support system A conservative design can utilize the surface support system with maximum load-bearing capacity. The value of the bearing capacity of different support systems can be obtained from indoor experiments. The support system absorbs the maximum energy. The calculation is as follows: ; ; ; ; ; in, Energy absorbed by the deformation of the anchor bolt and tray; Energy absorbed by the surface support; The energy absorbed to reinforce the fractured and deformed rock mass; The energy absorbed by the strain of the support material inside the rock mass; , and The contribution coefficients of each support unit to energy absorption are 1, and the sum of the three is 1. Among them, the displacement safety factor of the support system Load safety factor Energy safety factor The calculation formula is as follows: ; ; .

[0016] Optionally, S65 further includes determining the rationality of the support system, the determination method being as follows: S66 ; in, The allowable safety factor can be determined based on factors such as the nature of the project, the type and level of rockburst, and the location of the rockburst. S67: If the requirements are met according to the calculation results of S651, the final result is determined; otherwise, return to S65 and reselect the support system for optimization design until the requirements are met.

[0017] The beneficial effects of this invention are as follows: This invention provides a rockburst prevention and control method for deep rock engineering, specifically a rockburst prevention and control method based on an "energy reduction-energy release-energy absorption" mechanism. It constructs a "six-step" systematic design process covering the entire rockburst occurrence process, realizing the transformation of rockburst prevention and control from experience-based judgment to quantitative, process-oriented, and systematic approaches. This invention clarifies the key parameters to be collected and the engineering measures to be taken at each stage, proposes quantitative calculation methods for rockburst level, energy level, and support energy absorption capacity, and constructs a three-dimensional safety factor evaluation system for displacement, load, and energy. This provides a quantifiable, executable, and iterative scientific path for rockburst prevention and control design in deep rock engineering. Through full-process rockburst risk assessment and energy absorption prevention and control parameter calculation, it effectively avoids the problems of reliance on experience and unstable design results in existing technologies, thus improving the scientific rigor and reliability of rockburst prevention and control in deep rock engineering. Attached Figure Description

[0018] Figure 1 This is a flowchart of the steps of a rockburst prevention and control method for deep rock engineering provided by the present invention; Figure 2 This is a schematic diagram of the specific structure of S6 in a rockburst prevention and control method for deep rock engineering provided by the present invention; Figure 3 The impact factor provided by this invention Semi-quantization calculation method; Figure 4 This invention provides , and Calculation method; Figure 5 This invention provides Semi-quantization calculation method; Figure 6 This invention provides a process for calculating the three major safety factors and evaluating the overall support scheme. Detailed Implementation

[0019] To better explain and facilitate understanding of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0020] See the image below. Figures 1-6 As shown, the present invention proposes a rockburst prevention method for deep rock engineering, comprising the following steps: S1. Initial Information Acquisition: Obtain rock mass engineering geological information and stress field data to preliminarily determine the tunnel excavation area. Based on the rock mass engineering geological information obtained in S1, establish a three-dimensional numerical model and combine it with stress field data to invert the geostress field of the excavation area, and obtain the magnitude and direction distribution of the principal stress in the excavation area.

[0021] S2. Initial assessment of rockburst risk and location: In the three-dimensional model of S1, a tunnel excavation simulation project is carried out. The location and level of rockburst in the simulated tunnel are obtained through numerical evaluation and microseismic monitoring as the rockburst risk information of the simulated tunnel.

[0022] S3. Excavation Energy Reduction: Based on the ground stress field in S1 and the rockburst risk information in S2, the excavation parameters in the actual excavation process are adjusted accordingly to reduce the stress concentration effect caused by tunnel excavation.

[0023] S4. Rockburst Risk Reassessment: After the S3 excavation, the overall energy of the surrounding rock is reduced. Through numerical simulation and microseismic monitoring, the location and level of rockburst in the surrounding rock formed after excavation are reassessed to provide data support for subsequent energy release and absorption.

[0024] S5. Energy release of high-energy risk level rockburst: The rockburst risk level of the surrounding rock is determined based on the location and level information obtained from the reassessment of rockburst risk level in S4. If the rockburst risk level of the surrounding rock assessed in S4 reaches a strong or higher level, the energy of the surrounding rock at a strong or higher level will be released and directionally transferred to reduce the rockburst risk. If the S4 assessment result does not reach the level of "strong" or above, skip S5 and proceed directly to S6.

[0025] S6. Energy absorption of the support system: Based on the location and level information obtained from the reassessment of rockburst risk level in S4, the control parameters and requirements are obtained, and the appropriate energy absorption control parameters of the support system can be selectively optimized.

[0026] Here, the energy-absorbing support design of the support system is presented. Based on the rockburst risk reassessment results of S4, and considering the rockburst level and location, the energy absorption and control parameters of the support system are given. A load safety factor for the support system is introduced. Displacement safety factor Energy safety factor The indicators are used to quantitatively evaluate and optimize the effectiveness of the support system from three dimensions: bearing capacity, deformation coordination, and energy absorption.

[0027] Specifically, such as Figure 6As shown, based on the geological and rockburst information obtained from S1 to S4, the maximum destructive depth of the rockburst can be assessed. Combined with on-site conditions, the rockburst damage area can be further clarified, thereby quantifying the bearing capacity, deformation displacement, and absorbed energy required for prevention and control.

[0028] Furthermore, a preliminary support system can be selected, and its adaptability can be evaluated from three aspects: displacement control, load bearing capacity, and energy absorption. If the support effect does not meet the requirements, the support system should be redesigned until the control objectives are met, achieving the optimal energy reduction, optimal energy release, and optimal energy absorption control methods.

[0029] This embodiment provides a rockburst prevention and control method for deep rock engineering, specifically a rockburst prevention and control method based on the "energy reduction-energy release-energy absorption" mechanism. It constructs a six-step systematic design process covering the entire rockburst occurrence process, realizing the transformation of rockburst prevention and control from experience-based judgment to quantitative, process-oriented, and systematic approaches. This invention clarifies the key parameters to be collected and the engineering measures to be taken at each stage, proposes quantitative calculation methods for rockburst level, energy level, and support energy absorption capacity, and constructs a three-dimensional safety factor evaluation system for displacement, load, and energy. This provides a quantifiable, executable, and iterative scientific path for rockburst prevention and control design in deep rock engineering. Through full-process rockburst risk assessment and calculation, it effectively avoids the problems of reliance on experience in rockburst prevention and control decisions and unstable design results in existing technologies, improving the scientific rigor and reliability of rockburst prevention and control in deep rock engineering.

[0030] Further, S1 includes the following steps: S11. Obtain geological structure information, lithological distribution information and surrounding rock grade information of the excavation area through geological exploration, drilling sampling and core analysis as rock mass engineering geological information.

[0031] S12. Obtain the magnitude and direction of the principal stress at typical control points as geostress field data.

[0032] S13. Based on the rock mass engineering geological information obtained in S11, establish a three-dimensional numerical model and, combined with the geostress field data measured in S12, invert the geostress field of the excavation area to obtain the magnitude and direction distribution of the principal stresses in the excavation area. Specifically, clarify the principal stresses. , and Size, orientation, and distribution.

[0033] Furthermore, S2 involves a preliminary assessment of the main rockburst occurrence risk and location, issuing a rockburst risk assessment report, identifying possible rockburst types, and obtaining parameters such as the rockburst location and rockburst level for multiple rockburst events. S2 includes the following steps: Based on the three-dimensional numerical model established by S11 and the excavation direction around the tunnel, engineering excavation simulation was carried out to obtain numerical evaluation results and preliminarily determine the main stress concentration areas and potential rockburst risk areas.

[0034] S22. Based on the numerical assessment results in S21, deploy microseismic monitoring sensors at the locations of major stress concentration areas and potential rockburst risk zones on site to monitor the surrounding rock of the tunnel in real time and compare the results with the numerical assessment results in S21 to further assess the potential rockburst level and possible location. Conduct microseismic monitoring and early warning work. Statistically record the number of microseismic events, rock mass fracturing events, microseismic energy release from rock mass fracturing events, and the location of rock mass fracturing events to obtain the potential location of rockbursts and the local earthquake magnitude. It should be noted that the operation of the microseismic monitoring sensor is existing technology, and will not be elaborated upon here.

[0035] Furthermore, the excavation parameters are: For TBM tunnels, measures such as adjusting the excavation route, reducing the excavation rate, and optimizing tunneling parameters can reduce the formation of stress concentration zones and lower the risk of rockbursts. Furthermore, based on on-site construction conditions, the risk of rockbursts can be further reduced by controlling the cutterhead speed and propulsion force, reducing the propulsion rate (daily advance), and controlling the disturbance range of the excavation face.

[0036] For drill-and-blast tunnels, by changing the shape of the excavation cross section, adjusting the excavation sequence, and reducing the excavation rate, stress concentration can be effectively reduced, energy accumulation in the surrounding rock can be controlled, and the risk of rockburst can be lowered.

[0037] Specifically, the traditional horseshoe-shaped cross-section can be adjusted to a circular cross-section to enhance the stability of the surrounding rock. Depending on the site conditions, the central or upper guide tunnel can be excavated first to alleviate stress concentration at the working face. Controlling the cycle advance length reduces the disturbance range of a single excavation, lowering the energy release intensity. Pre-splitting blasting technology can be used to cut off high-stress paths and release localized energy in advance.

[0038] Furthermore, the feasibility of the above optimization scheme can be analyzed based on the three-dimensional numerical model established in S21.

[0039] Furthermore, in S4, through numerical simulation and the acquisition of microseismic monitoring data from the site, the main stress concentration areas and potential rockburst risk areas of the tunnel after S3 excavation are obtained as rockburst risk information, and the rockburst level and location are reassessed to ensure the safety of the surrounding rock.

[0040] Further, S5 includes the following steps: S51. For TBM tunnels, in high-energy rockburst risk areas, prestressing is unloaded by constructing stress relief holes. Based on this, microwave stress relief technology can be combined to further improve the efficiency and depth of local energy release.

[0041] Specifically, based on the results of the previous analysis (S1 and S2), the location (such as the working face, arch, sidewalls, etc.) and arrangement parameters (number, depth, angle, spacing) of the stress relief holes are determined.

[0042] Furthermore, microwave irradiation technology (it should be noted that this is an existing technology and will not be elaborated upon here) can be combined to improve the efficiency and depth of local energy release. Microwave irradiation design parameters include irradiation area, irradiation duration, and event frequency, with priority given to covering areas of high stress concentration to enhance stress relief.

[0043] S52. For drill-and-blast tunnels, microwave stress relief holes are installed in high-energy rockburst risk areas. Microwave irradiation is also used for energy release, and the pilot tunnel is optimized based on the stress distribution characteristics of the surrounding rock. Simultaneously, the pilot tunnel design is optimized based on the stress distribution characteristics of the surrounding rock to actively unload stress in local high-stress areas. Specifically, based on the results of previous analyses (S1 and S2), stress relief holes are preferentially deployed in high-stress concentration areas such as the tunnel face, arch shoulders, arch crown, and sidewalls, specifying their number, depth, arrangement angle, and spacing to form local unloading zones.

[0044] Furthermore, a microwave emitting device is inserted into the hole to carry out directional microwave irradiation. The irradiation time, irradiation power, irradiation frequency and irradiation area are adjusted according to the actual needs on site. Priority should be given to covering the intersection of structural surfaces and brittle rock strata.

[0045] Furthermore, the control parameters include the potential maximum depth of damage. Rock wall displacement calculation Quantitative load generated by rockburst Quantitative energy generated by rockburst ; S6 includes the following steps: S61, Potential Maximum Damage Depth The calculation is performed using the formula shown below: ; ; ; ; ; in, The potential depth of damage; This represents the maximum shear stress in the rock. The uniaxial compressive strength of the rock; For rock mass and geological correction factors; Control parameters related to the excavation shape; The geological strength index can be determined based on S1; and These are the maximum and minimum principal stresses; This refers to the tunnel cross-sectional height. This refers to the width of the tunnel cross-section; The weight of the rock mass; The S-wave velocity in the rock mass; The peak velocity of the particles obtained from microseismic monitoring; The elastic modulus of the rock mass; The Poisson's ratio of the rock mass; For design parameters, the value generally ranges from 0.2 to 0.3 depending on the design purpose; R is the distance from the seismic source. , The value range is 0.53–1.14; The magnitude of the local earthquake was obtained from microseismic monitoring.

[0046] The value can be determined according to Figure 3 Confirmed. Figure 3 As shown, based on the geological survey results obtained in step S1, the main structural planes and their spatial relationships near the excavation area can be identified. Here, θ is the dip angle of the structural plane. The angle between the structural plane orientation and the tunnel axis. For example, when the evaluation location is outside the fault influence range shown in the numerical simulation results, and the dip angle θ of the structural surface is less than 30° and the angle between the strike and the tunnel axis is... When the angle is greater than 60°, it can be taken as follows: =1. For different structural conditions and rockburst risk areas, the criteria in the figure can be adjusted. This value increases the potential maximum damage depth. The calculation accuracy.

[0047] Specifically, The value can be determined according to Figure 5 Confirmed. Figure 5 As shown, based on the geological structural features, dominant structural plane combination characteristics, and geological structural occurrence obtained in S1, the integrity level of the rock mass is determined. When the structural plane condition score... When the value is 16, and the rock mass in the excavation area is monolithic with no obvious joints or extremely large joint spacing, and the tunnel is in a low-disturbance state, it can be taken as follows: =95.

[0048] Furthermore, structural surface conditional scores The calculation formula is as follows: ; in, For the surface roughness of the joint, The degree of alteration of the joint surface, This refers to the degree of fill of the structural surfaces. Specific values ​​for each parameter can be found in [reference needed]. Figure 5 . Figure 5 The document provides standard grading criteria for structural plane survey data acquired through S1, facilitating the quantitative evaluation of rock mass structural characteristics. In other words, the calculation using this formula enables the overall... To achieve more accurate calculations of potential damage depth, it is possible to locate support systems more precisely, thereby improving the precision of prevention and control.

[0049] S62, Rock Wall Displacement Calculation The calculation formula is as follows: ; Wherein, BF is the rock mass fragmentation coefficient.

[0050] S63: Quantitative load generated by rockburst The calculation is as follows: ; in, The mass of the ejected rock block; The ejection speed; This represents the change in peak particle velocity before and after the rockburst. This represents the change in time before and after the rock eruption. This is the magnification factor; S64, Quantitative Energy Generated by Rockbursts The calculation is as follows: ; in, The rock fragments were ejected. The ejection velocity is taken as twice the peak velocity of the mass source center; It represents the distance from which the rock fragments are ejected; q = 1, 0, and -1 represent the rock fragments ejected from the top plate, side wall, and bottom plate, respectively. This is the acceleration due to gravity.

[0051] Furthermore, S6 also includes the following steps: S65. Based on the actual project and local earthquake magnitude Rock wall displacement calculation Quantitative load generated by rockburst Quantitative energy generated by rockburst Multiple indicators are considered, and a suitable support system is selected.

[0052] Specifically, referring to this embodiment, if <0 (minor rockburst), it is recommended to use anchor bolts and energy-absorbing nets for support; if 0 ≤ For rockbursts ≤1.5 (moderate), it is recommended to use anchors plus energy-absorbing nets and shotcrete layers for support; if 1.5 ≤ ≤2.5 (severe rockburst), it is recommended to use anchor bolts, energy-absorbing nets, shotcrete, steel arches, and reinforcing bars for support; if For rockbursts of ≥2.5 (extremely strong), it is recommended to use anchor bolts, energy-absorbing nets, shotcrete layers, steel arch frames, and steel reinforcement bars for support.

[0053] Furthermore, the parameters of the on-site support system components should be initially configured based on the rockburst level and surrounding rock conditions, specifically including: Anchor bolts: Consider length, diameter, anchoring method (full bonding / end anchoring), and type (e.g., deformable anchor bolts, telescopic anchor bolts). Energy-absorbing mesh: Select the appropriate energy absorption capacity level, wire diameter, and weaving density based on the controlled energy level; Shotcrete coating: Specify the thickness (e.g., 6–12 cm), strength grade (C20–C40), and whether fiber reinforcement is added; Steel arch frame: Select the model (I18~U36), cross-sectional shape, and layout spacing according to the support spacing and surrounding rock stability; Reinforcing bar strips: The diameter (φ16~φ25), length, layout method and density are selected according to the deformation energy absorption requirements.

[0054] Furthermore, the parameters of the on-site support system components should be initially configured based on the rockburst level and surrounding rock conditions, specifically including: Anchor bolts: Consider length, diameter, anchoring method (full bonding / end anchoring), and type (e.g., deformable anchor bolts, telescopic anchor bolts).

[0055] Energy-absorbing mesh: Select the appropriate energy absorption capacity level, wire diameter, and weaving density based on the controlled energy level.

[0056] For sprayed concrete: specify the thickness (e.g., 6–12 cm), strength grade (C20–C40), and whether fiber reinforcement is added.

[0057] Steel arch frame: Select the model (I18~U36), cross-sectional shape, and layout spacing according to the support spacing and surrounding rock stability.

[0058] Reinforcing bar strips: The diameter (φ16~φ25), length, layout method and density are selected according to the deformation energy absorption requirements.

[0059] Furthermore, the support system includes the maximum allowable displacement of the support body. Support system bearing capacity Maximum energy absorption of the support system and the load safety factor of the support system Displacement safety factor Energy safety factor : The maximum permissible displacement of the support system The calculation is as follows: ; in, This represents the maximum allowable displacement of the surface support; This refers to the ultimate deformation value of the support material inside the rock mass; different support systems under different rockburst conditions. and It can be obtained through indoor experiments.

[0060] The bearing capacity of the support system A conservative design can utilize the surface support system with maximum load-bearing capacity. The value of the bearing capacity of different support systems can be obtained from indoor experiments. The support system absorbs the maximum energy. The calculation is as follows: ; ; ; ; ; in, Energy absorbed by the deformation of the anchor bolt and tray; Energy absorbed by the surface support; The energy absorbed to reinforce the fractured and deformed rock mass; The energy absorbed by the strain of the support material inside the rock mass; , and The contribution coefficients of each support unit to energy absorption are given, and the sum of the three is 1. Considering the conservative nature of the support design, The value can be taken as 0. The contribution coefficients of each component in different types of support systems can be tested using a test device for evaluating the energy absorption performance of shotcrete-anchor-mesh support systems. It should be noted that the energy absorption test of the support system can be completed using existing specialized test equipment and methods, which will not be elaborated upon here.

[0061] Among them, the displacement safety factor of the support system Load safety factor Energy safety factor The calculation formula is as follows: ; ; .

[0062] Furthermore, S65 also includes determining the rationality of the support system, the determination method being as follows: S66 ; in, The allowable safety factor can be determined based on factors such as the nature of the project, the type and level of rockburst, and the location of the rockburst.

[0063] Specifically, taking this embodiment as a reference, when the rockburst type is a fracture rockburst, chain rockburst, or time-delay rockburst, or when the rockburst occurs in the main tunnel, the allowable safety factor should be 1.8 to 2.0. In other cases, the allowable safety factor should be 1.5 to 1.8.

[0064] S67: If the requirements are met based on the calculation results of S651, the final energy absorption and control parameters are determined; otherwise, return to S65 and reselect the support system for optimization design until the requirements are met.

[0065] In the description of this invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0066] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0067] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first and second features are in direct contact, or that they are in indirect contact through an intermediate medium. Furthermore, "above," "over," or "on top" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," or "beneath" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0068] In the description of this specification, the terms "one embodiment," "some embodiments," "embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0069] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make modifications, alterations, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for preventing rockbursts in deep rock engineering, characterized in that: Includes the following steps: S1. Initial Information Acquisition: Obtain rock mass engineering geological information and stress field data to preliminarily determine the tunnel excavation area. Based on the rock mass engineering geological information obtained in S1, establish a three-dimensional numerical model and combine it with stress field data to invert the geostress field of the excavation area, and obtain the magnitude and direction distribution of the principal stress in the excavation area. S2. Initial assessment of rockburst risk and location: In the three-dimensional model of S1, a tunnel excavation simulation project is carried out, and the location and level information of rockburst in the simulated tunnel are obtained through numerical evaluation and microseismic monitoring. S3. Excavation Energy Reduction: Based on the ground stress field in S1 and the rockburst risk information in S2, adjust the excavation parameters in the actual excavation process accordingly to reduce the stress concentration caused by tunnel excavation during the excavation process. S4. Rockburst Risk Reassessment: After the S3 excavation, the overall energy of the surrounding rock is reduced. Through numerical simulation and microseismic monitoring, the location and level of rockburst in the surrounding rock formed after excavation are reassessed to provide data support for subsequent energy release and absorption. S5. Energy release of high-energy risk level rockburst: The rockburst risk level of the surrounding rock is determined based on the location and level information obtained from the reassessment of rockburst risk level in S4. If the rockburst risk level of the surrounding rock assessed in S4 reaches a strong or higher level, the energy of the surrounding rock at a strong or higher level will be released and directionally transferred to reduce the rockburst risk. If the S4 assessment result does not reach the level of strong or above, skip S5 and proceed directly to S6; S6. Energy absorption of the support system: Based on the location and level information obtained from the reassessment of rockburst risk level in S4, the control parameters and requirements are obtained, and the appropriate energy absorption control parameters of the support system can be selectively optimized.

2. The rockburst prevention method for deep rock engineering as described in claim 1, characterized in that: S1 includes the following steps: S11. Obtain geological structure information, lithological distribution information and surrounding rock grade information of the excavation area through geological exploration, drilling sampling and core analysis as rock mass engineering geological information; S12. Obtain the magnitude and principal stress direction of the geostress at typical control points as geostress field data; S13. Based on the rock mass engineering geological information obtained in S11, establish a three-dimensional numerical model, and combine it with the geostress field data measured in S12 to invert the geostress field of the excavation area and obtain the magnitude and direction distribution of the principal stress in the excavation area.

3. The rockburst prevention method for deep rock engineering as described in claim 2, characterized in that: S2 includes the following steps: S21. Based on the three-dimensional numerical model established by S11 and the excavation direction around the tunnel, engineering excavation simulation was carried out to obtain numerical evaluation results and preliminarily determine the main stress concentration areas and potential rockburst risk areas. S22. Based on the numerical evaluation results in S21, microseismic monitoring sensors are deployed at the locations of the main stress concentration areas and potential rockburst risk areas on site to monitor the surrounding rock of the tunnel in real time and compare it with the numerical evaluation results in S21 to further assess the potential rockburst level and possible location.

4. The rockburst prevention method for deep rock engineering as described in claim 1, characterized in that: The excavation parameters are: For TBM tunnels, the excavation route is adjusted, the excavation rate is reduced, and the tunneling parameters are optimized. For drill-and-blast tunnels, the excavation cross-section shape is changed, the excavation sequence is adjusted, and the excavation rate is reduced.

5. The rockburst prevention method for deep rock engineering as described in claim 4, characterized in that: In S4, numerical simulation and on-site microseismic monitoring data are used to obtain the main stress concentration areas and potential rockburst risk areas of the tunnel after S3 excavation as rockburst risk information, and the rockburst level and location are reassessed to ensure the safety of the surrounding rock.

6. The rockburst prevention method for deep rock engineering as described in claim 5, characterized in that: S5 includes the following steps: S51. For TBM tunnels, in high-energy rockburst risk areas, prestress is unloaded by constructing stress relief holes, combined with microwave stress relief. S52. For drill-and-blast tunnels, microwave stress relief holes are set in high-energy rockburst risk areas, and microwave irradiation is used to release energy. The pilot tunnel is also optimized according to the stress distribution characteristics of the surrounding rock.

7. The rockburst prevention method for deep rock engineering as described in claim 6, characterized in that: The control parameters include the potential maximum damage depth. Rock wall displacement calculation Quantitative load generated by rockburst Quantitative energy generated by rockburst ; S6 includes the following steps: S61, Potential Maximum Damage Depth The calculation is performed using the formula shown below: ； ； ； ； ； in, The potential depth of damage; This represents the maximum shear stress in the rock. The uniaxial compressive strength of the rock; For rock mass and geological correction factors; Control parameters related to the excavation shape; The geological strength index can be determined based on S1; and These are the maximum and minimum principal stresses; This refers to the tunnel cross-sectional height. This refers to the width of the tunnel cross-section; The weight of the rock mass; The S-wave velocity in the rock mass; The peak velocity of the particles obtained from microseismic monitoring; The elastic modulus of the rock mass; The Poisson's ratio of the rock mass; For design parameters, the value is generally taken in the range of 0.2-0.3 depending on the design purpose; R is the distance from the earthquake source; , The value range is 0.53–1.14; The magnitude of the earthquake was obtained from microseismic monitoring. S62, Rock Wall Displacement Calculation The calculation formula is as follows: ； Where BF is the rock mass fragmentation coefficient; S63: Quantitative load generated by rockburst The calculation is as follows: ； in, The mass of the ejected rock block; The ejection speed; This represents the change in peak particle velocity before and after the rockburst. This represents the change in time before and after the rock eruption. This is the magnification factor; S64, Quantitative Energy Generated by Rockbursts The calculation is as follows: ； in, The rock fragments were ejected. The ejection velocity is taken as twice the peak velocity of the mass source center; It represents the distance from which the rock fragments are ejected; q = 1, 0, and -1 represent the rock fragments ejected from the top plate, side wall, and bottom plate, respectively. This is the acceleration due to gravity.

8. The rockburst prevention method for deep rock engineering as described in claim 7, characterized in that: S6 further includes the following steps: S65. Based on the actual project and local earthquake magnitude Rock wall displacement calculation Quantitative load generated by rockburst Quantitative energy generated by rockburst Multiple indicators are considered, and a suitable support system is selected.

9. The rockburst prevention method for deep rock engineering as described in claim 8, characterized in that: The energy absorption and control parameters corresponding to the support system include the maximum permissible displacement of the support system. Support system bearing capacity Maximum energy absorption of the support system and the load safety factor of the support system Displacement safety factor Energy safety factor : The maximum permissible displacement of the support system The calculation is as follows: ； in, This represents the maximum allowable displacement of the surface support. This refers to the ultimate deformation value of the support material inside the rock mass; different support systems under different rockburst conditions. and It can be obtained through indoor experiments; The bearing capacity of the support system A conservative design can utilize the surface support system with maximum load-bearing capacity. The value of the bearing capacity of different support systems can be obtained from indoor experiments. The support system absorbs the maximum energy. The calculation is as follows: ； ； ； ； ； in, Energy absorbed by the deformation of the anchor bolt and tray; Energy absorbed by the surface support; The energy absorbed to reinforce the fractured and deformed rock mass; The energy absorbed by the strain of the support material inside the rock mass; , and The contribution coefficients of each support unit to energy absorption are 1, and the sum of the three is 1. Among them, the displacement safety factor of the support system Load safety factor Energy safety factor The calculation formula is as follows: ； ； 。 10. The rockburst prevention method for deep rock engineering as described in claim 9, characterized in that: S65 further includes determining the rationality of the support system, and the determination method is as follows: S66、 ； in, The allowable safety factor can be determined based on factors such as the nature of the project, the type and level of rockburst, and the location of the rockburst. S67: If the requirements are met based on the calculation results of S651, the final energy absorption and control parameters are determined; otherwise, return to S65 and reselect the support system for optimization design until the requirements are met.

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