Comprehensive monitoring and handling method for destruction region after extremely strong time-delayed rockburst occurs

Abstract

A comprehensive monitoring and handling method for a destruction region after an extremely strong time-delayed rockburst occurs, which method relates to the technical field of deep-underground hard-rock tunnel engineering. By means of providing micro-seismic monitoring systems in a destruction region of an extremely strong time-delayed rockburst, carrying out a crustal stress test (1), an acoustic wave test and borehole imaging (2), and blasting vibration monitoring of the surface and interior of surrounding rock, and performing long-term disturbance stress monitoring on the destruction region of the extremely strong time-delayed rockburst. Therefore, with regard to the aftermath of an extremely strong time-delayed rockburst, the monitoring efficiency is improved, and a rational and effective support system is established, thereby ensuring later-stage safety.

Description

A comprehensive monitoring and treatment method for post-catastrophic damage areas caused by time-delayed extremely strong rock bursts Technical Field

[0001] This invention relates to the field of deep-buried hard rock tunnel engineering technology, and in particular to a comprehensive monitoring and treatment method for the damage area after a time-delayed extremely strong rock burst. Background Technology

[0002] As transportation tunnels, water conservancy and hydropower projects, and metal mines continue to expand into deeper areas, they inevitably traverse numerous deeply buried areas with high ground stress, leading to frequent rockburst disasters. Among these, time-delayed rockbursts refer to rockbursts that occur after the stress has readjusted to equilibrium due to the unloading effect of tunnel excavation, and are subsequently subjected to external disturbances.

[0003] Time-delayed rockbursts typically lag behind the excavation face by a certain time and spatially by a certain distance, increasing the difficulty of predicting rockburst disasters and seriously affecting construction progress, threatening the safety of on-site personnel and equipment. After a time-delayed extremely strong rockburst occurs, it may recur. How to achieve comprehensive monitoring and treatment of the damaged area has become a focus of attention in the engineering and academic communities. Currently, support systems for time-delayed extremely strong rockburst damaged areas generally use anchor bolts, steel mesh, and sprayed concrete. However, the monitoring system for time-delayed extremely strong rockburst damaged areas is incomplete, and corresponding support treatment methods are not adopted. The selection of support methods lacks reliable basis, exhibiting a certain degree of randomness and subjectivity, resulting in casualties, equipment damage, and project delays. How to establish a monitoring system for time-delayed extremely strong rockburst damaged areas, take effective support measures to reduce the risk of subsequent time-delayed rockburst disasters in the damaged area, and improve tunnel construction safety is a problem that needs to be solved in tunnel engineering construction.

[0004] Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a comprehensive monitoring and treatment method for the damaged area after a time-delayed extremely strong rockburst. This method improves monitoring efficiency, enhances the support concept for the damaged area, and improves the safety of support methods after a time-delayed extremely strong rockburst, establishing a more rational and effective support system to ensure subsequent safety.

[0006] A comprehensive monitoring and treatment method for post-disaster damage areas caused by time-delayed extremely strong rock bursts, specifically including the following steps:

[0007] Step 1: After the occurrence of time-delayed extremely strong rockburst, high-pressure water is sprayed into the area damaged by the time-delayed extremely strong rockburst to release pressure by softening the surrounding rock on the surface of the rockburst damaged area. After the rockburst phenomenon disappears, that is, after the stress release sound in the rockburst damaged area disappears and no more rockburst fragments appear, a 5cm thick layer of CF30 high-performance steel fiber concrete is sprayed into the damaged area.

[0008] Step 2: Erect I16 steel arch support at the location of the time-delayed extremely strong rockburst damage area. To ensure the overall rigidity of the steel frame support, Φ42 locking anchor rods are used to connect the steel frame with Φ25 U-shaped steel bars. Welding is used at the connection points between the Φ42 locking anchor rods and the I16 steel arch frame, the contact points between the I16 steel arch frame and the Φ25 U-shaped steel bars, and the connection points between the Φ25 U-shaped steel bars and the Φ42 locking anchor rods. Ensure that the weld length at the contact point between the Φ25 U-shaped steel bars and the I16 steel arch frame is not less than 10cm.

[0009] Step 3: Deploy microseismic sensors at 50 meters before and 100 meters after the time-delayed extremely strong rockburst damage area, respectively. The first section is closer to the time-delayed extremely strong rockburst damage area than the second section. The microseismic sensors deployed at the first and second sections in front of the time-delayed extremely strong rockburst damage area are connected to one microseismic monitoring system, while the microseismic sensors deployed at the first and second sections behind the time-delayed extremely strong rockburst damage area are connected to another microseismic monitoring system.

[0010] The microseismic monitoring system includes a preamplifier, a signal acquisition and processing system, and a recording and display system. The preamplifier receives the detection signals from the microseismic sensors, transmits them to the signal acquisition and processing system, and displays and stores them on the recording and display system. Through the deployed microseismic sensors, it acquires seismic wave information emitted when the rock mass undergoes microfractures. After processing by the signal acquisition system, it determines the magnitude, location, time, number, and energy release information of the microseismic event.

[0011] Step 4: Based on the microseismic event data acquired by the microseismic sensors received by the microseismic monitoring system, the spatial distribution characteristics of microseismic events in the area of ​​time-delayed extremely strong rockburst damage and the aggregation of microseismic events in the area of ​​time-delayed extremely strong rockburst damage are obtained by locating the microseismic events.

[0012] Step 5: If there are many concentrated microseismic events in the area of ​​time-delayed extremely strong rockburst damage, and the microseismic activity is strong, then there is still a potential risk of rockburst in the damaged area. After the initial spraying of CF30 high-performance steel fiber concrete in the area of ​​time-delayed extremely strong rockburst damage, the system anchor support should be replaced with energy-absorbing anchor support. The row spacing and column spacing of the energy-absorbing anchor should be 1-1.5m, the length should be greater than the maximum depth of the crater area, and the diameter should be 25mm. The steel mesh support should be replaced with energy-absorbing steel mesh support. The mesh spacing of the energy dissipation protection net is 25cm×25cm, the overlap length of the net is not less than 1 grid, and it should be arranged close to the initial sprayed concrete layer.

[0013] If there are few and scattered microseismic events in the area where time-delayed extremely strong rockburst damage occurs, and the microseismic activity is weak, then conventional support is adopted, namely, systematic anchor bolt support and steel mesh support, and drilling is carried out at a diameter of 1.5 times the maximum damage location of the time-delayed extremely strong rockburst.

[0014] Step 6: Re-spray 15cm thick CF30 high-performance steel fiber reinforced concrete in the area of ​​time-delayed extremely strong rockburst damage;

[0015] Step 7: Using the stress relief method, conduct three-dimensional geostress measurements at a borehole location 1.5 times the tunnel diameter in the area of ​​maximum damage caused by the time-delayed extremely strong rockburst. If the area of ​​damage caused by the time-delayed extremely strong rockburst is a high-stress area, i.e., the ratio of the uniaxial saturated compressive strength of the rock to the maximum initial geostress perpendicular to the tunnel axis is greater than 7, then stress relief holes should be arranged at the tunnel arch foot, sidewalls, arch shoulders, and arch crown in the area of ​​damage caused by the time-delayed extremely strong rockburst. The row and column spacing of the stress relief holes should be 1-1.5m, the length should be greater than the maximum depth of the crater area, and the diameter should be 50mm. If the area of ​​damage caused by the time-delayed extremely strong rockburst is a general geostress area, i.e., the ratio of the uniaxial saturated compressive strength of the rock to the maximum initial geostress perpendicular to the tunnel axis is less than or equal to 7, then stress relief holes are not required.

[0016] Step 8: Conduct acoustic testing and borehole photography at the location of the geostress testing borehole to identify and measure the geological characteristics of the time-delayed extremely strong rockburst damage area. Check and record the integrity of the rock mass and the development of fractures inside the borehole in the time-delayed extremely strong rockburst damage area. If the rock mass fractures are developed inside the time-delayed extremely strong rockburst damage area, i.e., the number of structural surface groups is greater than or equal to 3 groups and the average spacing is less than 1.0m, then add two rows of advanced grouting small pipe supports to the time-delayed extremely strong rockburst damage surface. The spacing of the advanced grouting small pipes is 0.5-1m, the length is greater than the maximum depth of the crater area, and the diameter is 42mm. If the rock mass fractures are not developed inside the time-delayed extremely strong rockburst damage area, i.e., the number of structural surface groups is less than or equal to 2 groups and the average spacing is greater than 1.0m, then it is not necessary to arrange advanced grouting small pipe supports.

[0017] Step 9: Conduct blasting vibration monitoring on the surface and inside of the surrounding rock in the time-delayed extremely strong rockburst damage area. This is achieved by drilling several holes from the tunnel wall into the surrounding rock within the area, fixing triaxial vibration sensors at different radial depths in each hole, and collecting and storing the blasting vibration velocity and acceleration measured by each sensor. If the blasting vibration velocity in the time-delayed extremely strong rockburst damage area is greater than 25 cm / s, analyze the blasting parameters and reduce the amount of explosive in each segment to avoid vibration superposition. If the vibration velocity in the time-delayed extremely strong rockburst damage area is less than or equal to 25 cm / s, no adjustment of the blasting parameters is required.

[0018] Step 10: During the erection of the steel arch frame, the over-excavated part of the blast pit of the time-delayed extremely strong rock burst is backfilled and compacted with CF30 high-performance steel fiber concrete, and then shotcrete is sprayed until the sprayed layer completely covers the steel frame and the surface is flat to ensure the stability of the steel frame.

[0019] Step 11: Test the disturbance stress of the tunnel wall rock mass in the time-delayed extremely strong rockburst failure area. Select three measurement points in different directions and measure the strain change ε ​​in the strain gauge directions of the three measurement points P1, P2, and P3 in the time-delayed extremely strong rockburst failure area. z ε θ ε 45° The Poisson's ratio and elastic modulus of the rock in the measurement area were determined, and the disturbance stress components σ at measurement points P1, P2, and P3 were calculated using Hooke's law of elasticity. θ σ z τ Zθ If abnormal stress concentration occurs, timely measures should be taken to pre-drill pressure relief, control blasting, and strengthen support to prevent rock bursts from happening again.

[0020] The disturbance stress component σ θ σ z τ zθ The formula is as follows:

[0021] In the formula, ε z ε θ ε 45° To measure the strain difference before and after stress relief in the direction of the strain gauge, σ θ σ z τ zθ Let E be the disturbance stress component after tunnel excavation, E be the elastic modulus, and μ be Poisson's ratio.

[0022] The beneficial effects of adopting the above technical solution are as follows:

[0023] This invention provides a comprehensive monitoring and treatment method for the damaged area after a time-delayed extremely strong rockburst. It involves conducting microseismic monitoring, stress testing, borehole imaging and acoustic testing, monitoring of surface and internal rock fracture vibrations, and monitoring of disturbance stress in the rockburst-damaged area. Based on the monitoring results, corresponding prevention and control methods are provided. The method employs targeted treatment of the time-delayed extremely strong rockburst-damaged area through methods such as initial spraying of 5cm thick CF30 high-performance steel fiber reinforced concrete, I16 steel arch support, energy-absorbing anchors and energy-absorbing steel mesh, subsequent spraying of 15cm thick CF30 high-performance steel fiber reinforced concrete, stress relief holes, pre-grouting small guide pipes, and controlled blasting to avoid vibration superposition. This ensures the subsequent safety of the risk area after a rockburst and reduces the damage and losses caused by time-delayed rockburst disasters. The technical solution of this invention effectively solves the subsequent damage of time-delayed rockbursts by targeted monitoring and corresponding support of the rockburst-damaged area, reduces the losses caused by rockbursts, and ensures construction safety. Attached Figure Description

[0024] Figure 1 is a flowchart of the integrated monitoring of the time-delay type extremely strong rockburst damage area in an embodiment of the present invention;

[0025] Figure 2 is a flowchart of the time-delay type extremely strong rockburst damage area support system in an embodiment of the present invention;

[0026] Figure 3 is a schematic diagram of the steel arch frame connection in the time-delay type extremely strong rockburst damage area in an embodiment of the present invention;

[0027] Figure 4 is a schematic diagram of the microseismic monitoring system in an embodiment of the present invention;

[0028] Figure 5 is a schematic diagram of the integrated monitoring plan of the time-delay type extremely strong rockburst damage area in an embodiment of the present invention;

[0029] Figure 6 is a schematic diagram of the comprehensive monitoring profile of the time-delay type extremely strong rockburst damage area in an embodiment of the present invention;

[0030] Figure 7 is a cross-sectional view of the support system for the time-delay type extremely strong rockburst damage area in an embodiment of the present invention. Detailed Implementation

[0031] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of the invention.

[0032] A comprehensive monitoring and treatment method for post-crash damage areas caused by time-delayed extremely strong rock eruptions is disclosed. Figure 1 is a schematic flowchart of the comprehensive monitoring system for post-crash damage areas caused by time-delayed extremely strong rock eruptions in this embodiment. Based on the comprehensive monitoring results of the post-crash damage areas caused by time-delayed extremely strong rock eruptions, corresponding support measures are taken, as shown in Figure 2. The specific steps include:

[0033] Step 1: After the occurrence of time-delayed extremely strong rockburst, high-pressure water is sprayed into the area damaged by the time-delayed extremely strong rockburst to release pressure by softening the surrounding rock on the surface of the rockburst damaged area. After the rockburst phenomenon disappears, that is, after the stress release sound in the rockburst damaged area disappears and no more rockburst fragments appear, a 5cm thick layer of CF30 high-performance steel fiber concrete is sprayed into the damaged area.

[0034] Step 2: Erect I16 steel arch support at the location of the time-delayed extremely strong rockburst damage area. To ensure the overall rigidity of the steel frame support, Φ42 anchor bolts are used to connect the steel frame with Φ25 U-shaped steel bars. The connection points between the Φ42 anchor bolts and the I16 steel arch, the contact points between the I16 steel arch and the Φ25 U-shaped steel bars, and the connection points between the Φ25 U-shaped steel bars and the Φ42 anchor bolts are welded, ensuring that the weld length at the contact point between the Φ25 U-shaped steel bars and the I16 steel arch is not less than 10cm. At the same time, it is required that the steel arch is in close contact with the initial shotcrete. The specific connection method between the steel arch, the anchor bolts, and the U-shaped steel bars is shown in Figure 3.

[0035] Step 3: Deploy microseismic sensors at 50 meters before and 100 meters after the time-delayed extremely strong rockburst damage area, respectively. The first section is closer to the time-delayed extremely strong rockburst damage area than the second section. The microseismic sensors deployed at the first and second sections in front of the time-delayed extremely strong rockburst damage area are connected to one microseismic monitoring system, while the microseismic sensors deployed at the first and second sections behind the time-delayed extremely strong rockburst damage area are connected to another microseismic monitoring system.

[0036] The microseismic monitoring system, as shown in Figure 4, includes a preamplifier, a signal acquisition and processing system, and a recording and display system. The preamplifier receives the detection signals from the microseismic sensors, transmits them to the signal acquisition and processing system, and displays and stores them on the recording and display system. Through the arranged microseismic sensors, the system acquires seismic wave information emitted when the rock mass undergoes microfractures. After processing by the signal acquisition system, the system determines the magnitude, location, time, number, and energy release information of the microseismic event.

[0037] Step 4: Based on the microseismic event data acquired by the microseismic sensors received by the microseismic monitoring system, the spatial distribution characteristics of microseismic events in the area of ​​time-delayed extremely strong rockburst damage and the aggregation of microseismic events in the area of ​​time-delayed extremely strong rockburst damage are obtained by locating the microseismic events.

[0038] Step 5: If there are many concentrated microseismic events in the area of ​​time-delayed extremely strong rockburst damage, and the microseismic activity is strong, then there is still a potential risk of rockburst in the damaged area. After the initial spraying of CF30 high-performance steel fiber concrete in the area of ​​time-delayed extremely strong rockburst damage, the system anchor support should be replaced with energy-absorbing anchor support. The row spacing and column spacing of the energy-absorbing anchor should be 1-1.5m, the length should be greater than the maximum depth of the crater area, and the diameter should be 25mm. The steel mesh support should be replaced with energy-absorbing steel mesh support. The mesh spacing of the energy dissipation protection net is 25cm×25cm, the overlap length of the net is not less than 1 grid, and it should be arranged close to the initial sprayed concrete layer.

[0039] If there are few and scattered microseismic events in the area where time-delayed extremely strong rockburst damage occurs, and the microseismic activity is weak, then conventional support is adopted, namely, systematic anchor bolt support and steel mesh support, and drilling is carried out at a diameter of 1.5 times the maximum damage location of the time-delayed extremely strong rockburst.

[0040] Step 6: Re-spray 15cm thick CF30 high-performance steel fiber reinforced concrete in the area of ​​time-delayed extremely strong rockburst damage;

[0041] Step 7: Using the stress relief method, conduct three-dimensional geostress measurements at a borehole location 1.5 times the tunnel diameter in the area of ​​maximum damage caused by a time-delayed extremely strong rockburst. If the area of ​​damage caused by a time-delayed extremely strong rockburst is a high-stress area, i.e., the ratio of the uniaxial saturated compressive strength of the rock to the maximum initial geostress perpendicular to the tunnel axis is greater than 7, rockbursts occur during the excavation of hard rock, the tunnel wall rock mass shows peeling and spalling, many new cracks, and poor tunnel formation, while the rock core of soft rock shows cake-like phenomena, displacement of the tunnel wall rock mass occurs during the excavation process, the duration is long, and the tunnel formation is poor, then stress relief holes should be arranged at the tunnel arch foot, sidewalls, arch shoulders, and arch crown in the area of ​​damage caused by the time-delayed extremely strong rockburst. The row and column spacing of the stress relief holes should be 1-1.5m, the length should be greater than the maximum depth of the crater area, and the diameter should be 50mm. If the area of ​​damage caused by a time-delayed extremely strong rockburst is a general geostress area, i.e., the ratio of the uniaxial saturated compressive strength of the rock to the maximum initial geostress perpendicular to the tunnel axis is less than or equal to 7, then stress relief holes are not required, as shown in Figures 5 and 6.

[0042] Step 8: Conduct acoustic testing and borehole photography at the location of the geostress testing borehole to identify and measure the geological characteristics of the time-delayed extremely strong rockburst damage area. Check and record the integrity of the rock mass and the development of fractures inside the borehole in the time-delayed extremely strong rockburst damage area. If the rock mass fractures are well-developed inside the time-delayed extremely strong rockburst damage area, i.e., the number of structural plane groups is greater than or equal to 3 groups and the average spacing is less than 1.0m, then add two rows of advanced grouting pipes for support on the time-delayed extremely strong rockburst damage surface. The spacing of the advanced grouting pipes is 0.5-1m, the length is greater than the maximum depth of the crater area, and the diameter is 42mm. The function of the first row of pipes is to stop water and prevent grouting, and the function of the second row of pipes is to grout and consolidate the surrounding rock near the damage surface. If the rock mass fractures are not well-developed inside the time-delayed extremely strong rockburst damage area, i.e., the number of structural plane groups is less than or equal to 2 groups and the average spacing is greater than 1.0m, then it is not necessary to arrange advanced grouting pipes for support.

[0043] Step 9: Conduct blasting vibration monitoring on the surface and inside of the surrounding rock in the time-delayed extremely strong rockburst damage area. This is achieved by drilling several holes from the tunnel wall into the surrounding rock within the area, fixing triaxial vibration sensors at different radial depths in each hole, and collecting and storing the blasting vibration velocity and acceleration measured by each sensor. If the blasting vibration velocity in the time-delayed extremely strong rockburst damage area is greater than 25 cm / s, analyze the blasting parameters and reduce the amount of explosive in each segment to avoid vibration superposition. If the vibration velocity in the time-delayed extremely strong rockburst damage area is less than or equal to 25 cm / s, no adjustment of the blasting parameters is required.

[0044] Step 10: During the erection of the steel arch frame, the over-excavated part of the blast pit of the time-delayed extremely strong rock burst is backfilled and compacted with CF30 high-performance steel fiber concrete. Then, spray concrete until the sprayed layer completely covers the steel frame and the surface is flat to ensure the stability of the steel frame, as shown in Figure 7.

[0045] Step 11: Test the disturbance stress of the tunnel wall rock mass in the time-delayed extremely strong rockburst failure area. Select three measurement points in different directions and measure the strain change ε ​​in the strain gauge directions of the three measurement points P1, P2, and P3 in the time-delayed extremely strong rockburst failure area. z ε θ ε 45° The Poisson's ratio and elastic modulus of the rock in the measurement area were determined, and the disturbance stress components σ at measurement points P1, P2, and P3 were calculated using Hooke's law of elasticity. θ σ z σ zθ If abnormal stress concentration occurs, timely measures should be taken to pre-drill pressure relief, control blasting, and strengthen support to prevent rock bursts from happening again.

[0046] The disturbance stress component σ θ σ z τ zθ The formula is as follows:

[0047] In the formula, ε z ε θ ε 45° To measure the strain difference before and after stress relief in the direction of the strain gauge, σ θ σ z τ zθ Let E be the disturbance stress component after tunnel excavation, E be the elastic modulus, and μ be Poisson's ratio.

[0048] The above description is merely a preferred embodiment of this disclosure and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in the embodiments of this disclosure is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the above-described inventive concept. For example, technical solutions formed by substituting the above-described features with (but not limited to) technical features with similar functions disclosed in the embodiments of this disclosure.

Claims

1. A comprehensive monitoring and treatment method for post-disaster damage areas caused by time-delayed extremely strong rock bursts, characterized in that, Includes the following steps: Step 1: After the occurrence of time-delayed extremely strong rockburst, high-pressure water is sprayed into the area damaged by the time-delayed extremely strong rockburst to release pressure by softening the surrounding rock on the surface of the rockburst damaged area. After the rockburst phenomenon disappears, that is, after the stress release sound in the rockburst damaged area disappears and no more rockburst fragments appear, a 5cm thick layer of CF30 high-performance steel fiber concrete is sprayed into the damaged area. Step 2: Erect I16 steel arch support at the location of the time-delayed extremely strong rockburst damage area. To ensure the overall rigidity of the steel frame support, Φ42 locking anchor rods are used to connect the steel frame with Φ25 U-shaped steel bars. Welding is used at the connection points between the Φ42 locking anchor rods and the I16 steel arch frame, the contact points between the I16 steel arch frame and the Φ25 U-shaped steel bars, and the connection points between the Φ25 U-shaped steel bars and the Φ42 locking anchor rods. Ensure that the weld length at the contact point between the Φ25 U-shaped steel bars and the I16 steel arch frame is not less than 10cm. Step 3: Deploy microseismic sensors at 50 meters before and 100 meters after the time-delayed extremely strong rockburst damage area, respectively. Connect the microseismic sensors deployed at the first and second sections in front of the time-delayed extremely strong rockburst damage area to one microseismic monitoring system, and connect the microseismic sensors deployed at the first and second sections behind the time-delayed extremely strong rockburst damage area to another microseismic monitoring system. Step 4: Based on the microseismic event data acquired by the microseismic sensors received by the microseismic monitoring system, the spatial distribution characteristics of microseismic events in the area of ​​time-delayed extremely strong rockburst damage and the aggregation of microseismic events in the area of ​​time-delayed extremely strong rockburst damage are obtained by locating the microseismic events. Step 5: If there are many and concentrated microseismic events in the area of ​​time-delayed extremely strong rockburst damage, and the microseismic activity is strong, then there is still a potential risk of rockburst in the damaged area. After the initial spraying of CF30 high-performance steel fiber concrete in the area of ​​time-delayed extremely strong rockburst damage, the system anchor bolt support is replaced with energy-absorbing anchor bolt support, and the steel mesh support is replaced with energy-absorbing steel mesh support. If there are few and scattered microseismic events in the area where time-delayed extremely strong rockburst damage occurs, and the microseismic activity is weak, then conventional support shall be adopted. Step 6: Re-spray 15cm thick CF30 high-performance steel fiber reinforced concrete in the area of ​​time-delayed extremely strong rockburst damage; Step 7: Using the stress relief method, three-dimensional geostress measurements were conducted at the location of a borehole with a diameter of 1.5 times the maximum damage area of ​​the time-delayed extremely strong rockburst. Step 8: Conduct acoustic testing and borehole photography at the location of the geostress test borehole to identify and measure the geological characteristics of the time-delayed extremely strong rockburst damage area, and check and record the integrity of the rock mass inside the borehole and the development of fractures in the time-delayed extremely strong rockburst damage area. Step 9: Conduct blasting vibration monitoring on the surface and inside of the surrounding rock in the time-delayed extremely strong rockburst damage area. Several boreholes are drilled from the tunnel wall into the surrounding rock within the time-delayed extremely strong rockburst damage area. Triaxial vibration sensors are fixed at different radial depths in each borehole. The blasting vibration velocity and acceleration measured by each triaxial vibration sensor at its location are collected and stored. When the blasting vibration velocity in the time-delayed extremely strong rockburst damage area exceeds 25 cm / s, the blasting parameters are analyzed to reduce the impact of each blast. Adjust the amount of explosive in each section to avoid vibration superposition; when the vibration velocity in the area damaged by a time-delay type extremely strong rockburst is less than or equal to 25cm / s, there is no need to adjust the blasting parameters. Step 10: During the erection of the steel arch frame, the over-excavated part of the blast pit of the time-delayed extremely strong rock burst is backfilled and compacted with CF30 high-performance steel fiber concrete, and then shotcrete is sprayed until the sprayed layer completely covers the steel frame and the surface is flat to ensure the stability of the steel frame. Step 11: Test the disturbance stress of the tunnel wall rock mass in the time-delayed extremely strong rockburst failure area. Select three measurement points in different directions and measure the strain difference ε in the strain gauge directions of the three measurement points P1, P2, and P3 in the time-delayed extremely strong rockburst failure area. z ε θ ε 45° The Poisson's ratio and elastic modulus of the rock in the measurement area were determined, and the disturbance stress components σ at measurement points P1, P2, and P3 were calculated using Hooke's law of elasticity. θ σ z τ zθ If abnormal stress concentration occurs, timely measures should be taken to pre-drill pressure relief, control blasting, and strengthen support to prevent rock bursts from happening again.

2. The method for comprehensive monitoring and treatment of post-disaster damage areas caused by time-delayed extremely strong rock bursts according to claim 1, characterized in that, In step 3, the first cross section is closer to the time-delay type extremely strong rockburst damage area than the second cross section.

3. The method for comprehensive monitoring and treatment of post-disaster damage areas caused by time-delayed extremely strong rock bursts according to claim 1, characterized in that, The microseismic monitoring system described in step 3 includes a preamplifier, a signal acquisition and processing system, and a recording and display system. The preamplifier receives the detection signals from the microseismic sensors, transmits them to the signal acquisition and processing system, and displays and stores them on the recording and display system. Through the deployed microseismic sensors, it acquires seismic wave information emitted when the rock mass undergoes microfractures. After processing by the signal acquisition system, it determines the magnitude, location, time, number, and energy release information of the microseismic event.

4. The method for comprehensive monitoring and treatment of post-disaster damage areas caused by time-delayed extremely strong rock bursts according to claim 1, characterized in that, In the energy-absorbing anchor support described in step 5, the row spacing and column spacing of the energy-absorbing anchor are 1-1.5m, the length is greater than the maximum depth of the crater area, and the diameter is 25mm; in the energy-absorbing steel mesh support, the mesh spacing of the energy-dissipating protective mesh is 25cm×25cm, the overlap length of the mesh is not less than 1 mesh, and it is arranged close to the initial shotcrete layer.

5. The method for comprehensive monitoring and treatment of post-disaster damage areas caused by time-delayed extremely strong rock bursts according to claim 1, characterized in that, The conventional support described in step 5 involves using system anchor bolt support and steel mesh support, and drilling a hole with a diameter 1.5 times that of the tunnel at the location of the maximum damage from a time-delayed extremely strong rockburst.

6. The method for comprehensive monitoring and treatment of post-disaster damage areas caused by time-delayed extremely strong rock bursts according to claim 1, characterized in that, The three-dimensional geostress measurement described in step 7 is as follows: If the time-delayed extremely strong rockburst damage area belongs to a high geostress area, that is, the ratio of the uniaxial saturated compressive strength of the rock to the maximum initial geostress in the direction perpendicular to the tunnel axis is greater than 7, then stress relief holes are arranged at the tunnel arch foot, sidewall, arch shoulder, and arch crown in the time-delayed extremely strong rockburst damage area. The row spacing and column spacing of the stress relief holes are 1-1.5m, the length is greater than the maximum depth of the crater area, and the diameter is 50mm. If the time-delayed extremely strong rockburst damage area belongs to a general geostress area, that is, the ratio of the uniaxial saturated compressive strength of the rock to the maximum initial geostress in the direction perpendicular to the tunnel axis is less than or equal to 7, then stress relief holes do not need to be arranged.

7. The method for comprehensive monitoring and treatment of post-disaster damage areas caused by time-delayed extremely strong rock bursts according to claim 1, characterized in that, Step 8, which involves checking and recording the integrity of the rock mass and the development of fractures inside the borehole in the time-delayed extremely strong rockburst damage area, specifically involves the following: If fractures are developed in the rock mass inside the time-delayed extremely strong rockburst damage area, i.e., the number of structural face groups is greater than or equal to 3 groups and the average spacing is less than 1.0m, then two rows of advanced grouting small guide pipes are added to the time-delayed extremely strong rockburst damage surface. The spacing between the advanced grouting small guide pipes is 0.5-1m, the length is greater than the maximum depth of the crater area, and the diameter is 42mm. If fractures are not developed in the rock mass inside the time-delayed extremely strong rockburst damage area, i.e., the number of structural face groups is less than or equal to 2 groups and the average spacing is greater than 1.0m, then advanced grouting small guide pipe support is not required.

8. The method for comprehensive monitoring and treatment of post-disaster damage areas caused by time-delayed extremely strong rock bursts according to claim 1, characterized in that, The disturbance stress component σ mentioned in step 11 θ σ z τ zθ The formula is as follows: In the formula, ε z ε θ ε 45° To measure the strain difference before and after stress relief in the direction of the strain gauge, σ θ σ z τ zθ Here, E represents the disturbance stress component at the measurement point after tunnel excavation, μ represents the elastic modulus, and E represents Poisson's ratio.

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