Construction method and system for quantitative early-warning rockburst grade of micro-seismic parameters of double-track tunnel

Abstract

The invention belongs to the field of high-burial-depth underground space safety early warning and protection, and discloses a construction method and system for judging and distinguishing double-track tunnel micro-seismic parameter quantitative early warning rockburst grades, and the method comprises the steps: designing a micro-seismic monitoring system sensor arrangement method; wave velocity setting; judging the reliability of the monitoring effect of the same monitoring system on the double-track tunnel; comparing geological revelation conditions of the tunnel faces in the similar mileage sections of the double-track tunnel; determining rockburst grade classification and quantitative judgment criteria; distinguishing and establishing quantitative criteria of high-precision rockburst of each grade of the double-track tunnel; judging whether to distinguish and establish a rockburst early warning judgment standard; unifying tunnel early warning discrimination standard establishment methods; the reliability of the method is judged according to the occurrence condition of subsequent rockburst, and meanwhile the threshold value is perfected. According to the invention, two sections can be monitored at the same time through a set of microseismic monitoring system, so that half of manpower, material and financial investment is saved. The blank of establishing a quantitative criterion method for distinguishing micro-seismic monitoring and early-warning rockburst of the double-track tunnel under similar geological conditions in the same work area is filled, and the method has high practical value.

Description

Technical Field

[0001] The present invention belongs to the field of safety early warning and protection of deep underground space, and in particular to a construction method and system for judging and distinguishing the quantitative early warning rockburst level of microseismic parameters of double-line tunnels. Background Art

[0002] With the deepening of infrastructure construction, especially in the western region with complex geological conditions, rock burst has become a serious challenge in tunnel excavation. Although microseismic monitoring technology has achieved remarkable results in rock burst early warning, it still faces many challenges in double-line tunnel application.

[0003] First, geological differences mean that different microseismic parameters need to be considered in early warning for dual-track tunnels. Even under similar geological conditions, microseismic activities in different tunnels vary significantly, making it difficult to apply a unified early warning model.

[0004] Secondly, the microseismic activity before a rockburst is complex and changeable, including changes in time, space and intensity. Accurately identifying and quantifying these characteristics is the key to predicting a rockburst. The suddenness, hysteresis and continuity of a rockburst make early warning complicated.

[0005] Thirdly, the early warning model needs to adapt to different geological conditions and microseismic activity characteristics and have the ability to be updated and adjusted in real time. At the same time, the continuous recording and analysis of field data is crucial to determine the level and probability of rockburst.

[0006] In addition, the setting of warning thresholds is also extremely challenging. It needs to be determined based on a large amount of field data and analysis results, and needs to be updated regularly. Different warning thresholds need to be set for different levels of rock burst.

[0007] Finally, the implementation of microseismic monitoring technology in deep underground environments faces technical challenges such as equipment deployment, data transmission, and data analysis. It is necessary to ensure the stability of the monitoring equipment and the accuracy of data processing.

[0008] In summary, the method and establishment process of quantitative early warning of rockburst level by microseismic parameters in double-line tunnels need to consider multiple aspects. In the future, through continuous research and practice, we hope to gradually improve the accuracy and reliability of early warning and provide strong guarantee for safe tunnel construction. Summary of the invention

[0009] In view of the problems existing in the prior art, the present invention provides a construction method and system for judging and distinguishing the quantitative early warning rockburst level of microseismic parameters of double-line tunnels.

[0010] The present invention is implemented as follows: a method for determining and distinguishing the quantitative early warning rockburst level of microseismic parameters of a double-line tunnel, the method comprising:

[0011] S1: Design of sensor layout method for microseismic monitoring system;

[0012] S2: wave speed setting;

[0013] S3: Determine the reliability of the same monitoring system for monitoring double-track tunnels;

[0014] S4: Comparison of geological exposure of the tunnel faces in similar mileage sections of double-track tunnels;

[0015] S5: Determine the rockburst classification and quantitative judgment criteria;

[0016] S6: Differentiate and establish quantitative criteria for high-precision rockburst of various grades in double-track tunnels;

[0017] S7: Method for determining whether to distinguish and establish rockburst warning criteria;

[0018] S8: A method for establishing a unified tunnel warning identification standard;

[0019] S9: The reliability of this method is determined by subsequent rockburst occurrences, and the threshold is improved.

[0020] Further, the S1 specifically includes:

[0021] According to the on-site construction process and safety design, the double-track tunnel is divided into a leading tunnel and a trailing tunnel, that is, one tunnel is excavated quickly and is the leading tunnel, and the other tunnel is excavated slowly and is the trailing tunnel. At present, the construction conditions in different projects of double-track tunnels are different. Since there is no fixed arrangement method for sensor arrangement, it is necessary to first establish a sensor arrangement method suitable for the tunnel. However, through uninterrupted experiments and attempts at different construction sites, the sensor arrangement method designed here can basically meet the monitoring requirements of all double-track tunnels. The specific plan is as follows:

[0022] Six sensors are used, all arranged in the pilot tunnel; the sensors are distributed in four sections, the first section is 50 to 80 meters away from the pilot tunnel face, and each section is about 30 meters apart. The range can be appropriately increased or decreased according to actual conditions; four sensors are installed on the side close to the rear tunnel, and two sensors are installed on the side away from the rear tunnel. The sensors on both sides are installed with staggered elevations, and try not to be located in a straight line at the same elevation. The sensors on the same side are also arranged in this regular pattern.

[0023] Further, the S2 specifically includes:

[0024] (1) Find a known earthquake source point in each tunnel of the double-track tunnel as test point 1 and record it as (X1, Y1, Z1); in the drilling and blasting construction tunnel, the blasting point can be used as the earthquake source point, in the TBM construction tunnel, a fixed blasting point can be used as the test point, or a known rock burst point can be used as the test point;

[0025] (2) Taking the known sensor coordinates as test point 2;

[0026] (3) The monitoring system records the time it takes for the sound waves generated at each test point to reach each sensor. With the known source point of each sensor as the center, the product of wave velocity and time is used as the radius to locate the test point 1' (X2, Y2, Z2) in space. The error can be obtained by calculating the spatial distance between test points 1 and 1'.

[0027] (4) Calculate the error values ​​at different wave speeds in the two tunnels and form a trend graph;

[0028] (5) Determine the wave velocity at the bottom of the trend graph as the wave velocity with the smallest error;

[0029] Further, the S3 specifically includes:

[0030] Microseismic energy is one of the main parameters for early warning of rock bursts based on microseismic monitoring, and can verify the difference in the microseismic monitoring capabilities of the monitoring microseismic system for double-track tunnels; to ensure a single variable, it is necessary to ensure that the release capacity of the source point itself is consistent; the amount of explosives and the quality of explosives required for face blasting are consistent, so the energy generated by the blasting events in the left and right tunnels can be selected as the test point; and due to the effect of explosive release in different mileage sections, the energy released by each blasting or received by the monitoring system is different, and all blasting events within a range of events can be selected and the average value and standard deviation can be selected for comparison. In TBM construction tunnels, quantitative fixed-point blasting tests, or multi-point and multi-volume blasting tests, can be used to test the reliability of the monitoring equipment through distance attenuation intervals or charge attenuation gradients;

[0031] If the comparison results do not exceed one order of magnitude and the difference does not exceed 20%, it indicates that the microseismic parameter values ​​in the double-line tunnel collected by the same system are reliable.

[0032] Further, the S4 specifically includes:

[0033] By comparing and recording the differences in geological conditions, the differences in microseismic activity during the rockburst incubation process can be reflected. It is necessary to continuously record the geological exposure of the adjacent faces of the leading tunnel and the trailing tunnel over a period of time, and compare the geological differences of the exposed faces. The recorded content includes the number and occurrence of joints, fissures and structural surfaces, groundwater, rock types and other data, and compare the exposure conditions at the same mileage. According to the degree of difference, the difference level is divided into three levels: high, medium and low. This is used as the basis for judging whether the double-line tunnel is distinguished and establishing a method for quantitative early warning of rockburst levels of microseismic parameters of microseismic double-line tunnels.

[0034] Further, the S5 specifically includes:

[0035] At present, there are differences in the classification of rockburst in different projects. However, according to statistics from many engineering projects, the most commonly classified rockburst levels are generally: no rockburst, slight rockburst, moderate rockburst, strong rockburst, and extremely strong rockburst;

[0036] In addition, it is necessary to stipulate the quantitative standards for each rockburst level. Most of the on-site construction is done by qualitative sound, the size of falling blocks, combined with quantitative blast pit depth, ejection speed and other methods to make a quick judgment. Because qualitative judgment is greatly affected by personal experience, and the ejection speed cannot be accurately recorded, the blast pit depth is often used as the most quantitative standard on site. For example, no damage is called no rockburst, blast pit depth <0.5m is a slight rockburst, blast pit depth 0.5m~1.5m is a moderate rockburst, blast pit depth 1.5m~3m is a strong rockburst, and blast pit depth >3m is a strong rockburst.

[0037] The above specific quantitative judgment standards are examples of the combination of multiple projects. The specific quantitative criteria for the blast pit depth level need to be determined jointly by multiple units on site.

[0038] Further, the S6 specifically includes:

[0039] During the rock mass excavation process, rock micro-fractures, i.e. microseismic events, will inevitably occur. Each microseismic event represents a micro-fracture. The number of microseismic events and microseismic energy represent the degree of rock degradation and can express the severity of the rock burst that may occur. The changes in the frequency and energy of microseismic events can be expressed as the activity of microseismic activity. The more active the microseismic activity is, the greater the level and probability of rock burst that may occur.

[0040] When a rockburst occurs, microfractures will inevitably occur, but the presence of microfractures does not necessarily mean that a rockburst will occur; therefore, before a rockburst occurs, the number and energy of microseismic events in the double-line tunnel can be recorded respectively, and then the no-rockburst threshold can be determined based on the number and energy records of microseismic events. After that, the changes in microseismic activity of each level of rockburst are selected to determine the rockburst threshold of each level. The specific method is as follows:

[0041] (1) Determine the quantitative threshold of rockburst-free level for double-track tunnels

[0042] Before the rock burst occurs, the changes in the microseismic activity of the two lines are continuously recorded, and the maximum energy and the maximum number of microseismic events are recorded every day in units of days. 0 is used as the quantitative lower limit of no rock burst, and the maximum energy and number of each double-line tunnel before the rock burst occurs are used as the upper limit of the quantitative threshold of no rock burst level;

[0043] (2) Determine the quantitative thresholds for rockburst levels from mild to severe in double-track tunnels

[0044] Select the number and energy data of three minor rockbursts in one of the tunnels (the number can be selected according to the actual situation on site. If the number of rockbursts is large, it can be appropriately increased. Three times is the minimum number for quickly determining the quantification level). Take the highest number and highest energy of microseismic events in the three minor rockbursts as the threshold of high probability of minor rockbursts; take the average number of cumulative microseismic events and cumulative energy of microseismic events in the three minor rockbursts as the threshold of medium probability of minor rockbursts; take the lowest number and average energy of microseismic events in the three minor rockbursts as the threshold of low probability of minor rockbursts; if the quantitative threshold of the minor rockburst is lower than the quantitative standard of the previous level, that is, the quantitative standard of no rockburst of the corresponding tunnel in (1), then the quantitative threshold of the previous level and the exceeded threshold of the current level are exchanged, and the probability level exchange is analogous;

[0045] In the same way, determine the high, medium and low probability thresholds of minor to severe rockburst in another tunnel;

[0046] (3) Determine the quantitative threshold of extremely strong rockburst level in double-line tunnels

[0047] The energy upper limit of strong rock burst is taken as the lower limit threshold of extremely strong rock burst, and there is no upper limit. The quantity threshold is taken as the lowest number of microseismic events of extremely strong rock burst, and there is no upper limit.

[0048] The high, medium and low probability thresholds of each rockburst level in the two tunnels are determined in the same way.

[0049] Further, the S7 specifically includes:

[0050] (1) First, calibrate and record using energy as the main criterion;

[0051] 1) Method for judging the rock burst level:

[0052] When judging the level of no rock burst, the lower limit of energy is 0 and is not considered; the difference between the upper and lower limits of the no rock burst energy threshold is compared. If the difference in the upper limit energy is less than 20% of any tunnel, it is recorded as 0; if the difference in the upper limit energy is more than 20% of any tunnel, it is recorded as 1;

[0053] 2) Method for judging the level of minor rockburst to severe rockburst

[0054] When judging the level from slight rockburst to severe rockburst, the upper and lower limits need to be compared by difference respectively, which is the same as the method of judging the level without rockburst. If the energy difference between the upper or lower limit is less than 20% of any tunnel, it is recorded as 0. If the upper or lower limit exceeds 20% of any tunnel, it is recorded as 1. Each level is recorded in this way.

[0055] 3) Method for determining the level of extremely strong rockburst

[0056] When judging the level of extremely strong rockburst, the upper limit of energy is infinite and is not considered. The difference between the lower limits of the extremely strong rockburst energy threshold is compared. If the difference in the lower limit energy is less than 20% of any tunnel, it is recorded as 0. If the difference in the number exceeds 20% of any tunnel, it is recorded as 1.

[0057] (2) Then, the quantity is used as the main criterion for calibration and recording, and the recording method is the same as the energy calibration recording method (1) above;

[0058] (3) The above recorded values ​​are accumulated. If the final accumulated value is greater than 3, it is necessary to establish early warning judgment standards for double-track tunnels respectively. If the final accumulated value is less than or equal to 3, a unified tunnel early warning judgment standard is established.

[0059] Further, the S8 specifically includes:

[0060] Add the cross discrimination method and the principle of taking the higher rather than the lower, and unify them on the basis of the threshold of the double-line tunnel;

[0061] (1) Unified quantitative thresholds for rockburst-free levels

[0062] The lower limit of no rock burst still starts at 0, and the upper limit is the minimum value and energy of the threshold of any tunnel in the double-track tunnel without rock burst;

[0063] (2) Unify the quantitative thresholds of rockburst levels from minor to severe

[0064] The upper limit of low-level rock burst is used as the lower limit of the adjacent high-level rock burst. When the lower limits are unified, the lower limit threshold is also established by the number and energy minimum value of the lower limit of any double-track tunnel. The medium-risk area is established by the average value of each level of rock burst in the double-track tunnel, and the high-risk upper limit is established by the minimum value of the maximum number of any double-track tunnel. In this way, the upper and lower limits of rock bursts of various levels can be unified.

[0065] (3) Unified quantification threshold of extremely strong rockburst level

[0066] The lower limit of extremely severe rockburst is the same as the upper limit of high risk of strong rockburst, with the same energy and quantity, and no upper limit.

[0067] Another object of the present invention is to provide a system for implementing the method for constructing a method for determining and distinguishing the quantitative early warning rockburst level of microseismic parameters of a double-line tunnel, and the system comprises:

[0068] Arrangement design and wave speed setting module, used for sensor arrangement design and wave speed setting of microseismic monitoring system;

[0069] Reliability determination module, used to determine the reliability of the same monitoring system for double-track tunnel monitoring;

[0070] The exposure comparison module is used to compare the geological exposure of the tunnel face in similar mileage sections of double-track tunnels;

[0071] A judgment criteria determination module is used to determine the rockburst grade classification and quantitative judgment criteria;

[0072] The criterion establishment module is used to distinguish and establish high-precision quantitative criteria for rock bursts of various levels in double-line tunnels;

[0073] A standard establishment module is used to determine whether to distinguish and establish a rockburst warning discrimination standard;

[0074] Method unification module, used to unify the tunnel warning judgment standard establishment method;

[0075] The threshold improvement module is used to judge the reliability of the method through subsequent rock burst occurrences and to improve the threshold value.

[0076] In combination with the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solutions to be protected by the present invention are as follows:

[0077] First, in view of the technical problems existing in the above-mentioned prior art, some creative technical effects are brought about after solving the problems. The specific description is as follows:

[0078] 1. According to the positioning principle, if the on-site sensors want to achieve positioning, the number must reach 4. Due to the complexity of on-site construction, it is very easy to cause the sensors to be damaged and stop working. Here, 6 sensors are selected to ensure the minimum safety reserve for continuous monitoring. In order to ensure a larger safety reserve on site, many on-site plans will increase the number of sensors. All layout plans can arrange extra sensors at will on the basis of this 6-sensor plan. Therefore, this number setting plan can meet the requirements of all tunnels in terms of quantity.

[0079] 2. Due to the safety requirements of the site, the distance between the leading tunnel and the trailing tunnel is generally not too close, at least 20 to 30 meters. Considering the rapid construction on site, the distance between the leading tunnel and the trailing tunnel is generally not too far, basically maintained within 150 meters. On-site rock bursts generally occur at the tunnel face or its vicinity, and the effective monitoring range of the sensor is generally within 200 meters. All 6 sensors are arranged in the leading tunnel, which can basically realize the high-risk rock burst area of ​​the leading tunnel and the trailing tunnel. In terms of monitoring range requirements, this can basically meet the monitoring requirements of all high-risk rock burst areas of double-track tunnels.

[0080] 3. Four sensors are installed on the side close to the rear tunnel and two sensors are installed on the side away from the rear tunnel. This is to meet the monitoring requirements of the rear tunnel as much as possible while meeting the normal monitoring requirements of the lead tunnel.

[0081] 4. The elevations of sensors on the same side and different sides are not in the same straight line, and the distance between different sections is 30 meters. This is to ensure that the subsequent waveform positioning is not affected by the sensor layout and causes positioning deviation

[0082] 5. The sensors at the section position can be attached to the surface of the tunnel rock mass, or installed deep in the rock mass after drilling a hole in the rock mass. The distance between the first section and each section can be appropriately adjusted to meet the construction requirements or installation requirements of the currently monitored tunnel. The flexibility of this method can be suitable for different double-line tunnel microseismic monitoring tasks.

[0083] 6. Affected by the inhomogeneity of the rock mass, the sound waves generated by rock fracture will experience different degrees of attenuation when transmitted to the sensor. There is a difference in the propagation wave speed of the two tunnels. Therefore, finding the wave speed with the smallest error in the two tunnels and setting it can minimize the error without affecting the difference in microseismic data of the tunnels on both sides.

[0084] 7. Using the number "3" as the standard for determining whether to establish an early warning can ensure that each level of rock burst can be accurately determined and avoid the tediousness of distinguishing on-site work.

[0085] 8. The addition of the cross-discrimination method and the principle of taking the higher rather than the lower is to ensure a certain safety reserve during on-site warnings, and to ensure on-site safety more conservatively while minimizing false alarms.

[0086] The present invention can monitor two sections simultaneously through a set of microseismic monitoring systems, saving half of the human, material and financial resources. At the same time, this method fills the gap in establishing a quantitative judgment method for distinguishing and distinguishing microseismic monitoring and early warning rock bursts in double-line tunnels under similar geological conditions in the same work area, and has strong practical value. In addition, the same system can realize a systematic comparison of microseismic activities in double-line tunnels, which is helpful for further accurate and in-depth research on double-line tunnels, and can help improve the accuracy of microseismic monitoring and early warning of double-line rock bursts.

[0087] Second, in the industrial application of tunnel construction, rockburst is one of the main factors leading to safety accidents and project delays. Existing technologies have many problems in rockburst early warning, such as unreasonable sensor layout, inaccurate wave velocity parameter setting, poor reliability of monitoring system, unclear rockburst grade classification standards, etc. These problems seriously affect the accuracy and timeliness of rockburst early warning in practical applications, and increase construction risks and costs.

[0088] The present invention solves the problems of unreasonable sensor layout and inaccurate wave velocity parameter setting by designing a reasonable sensor layout scheme for the microseismic monitoring system and accurately setting the wave velocity parameters. In industrial applications, this optimization ensures the accuracy and coverage of monitoring data, allowing microseismic signals to be captured and analyzed more comprehensively and accurately, thereby improving the reliability of the monitoring system and the accuracy of the data.

[0089] The present invention uses advanced algorithms and mathematical models to conduct in-depth analysis and processing of the collected microseismic data. By establishing rockburst classification and quantitative judgment criteria, and applying high-precision quantitative criteria, the rockburst risk in different areas of the tunnel is accurately assessed. This process solves the problem of unclear rockburst classification standards, making rockburst warning more scientific and efficient in industrial applications.

[0090] The present invention achieves high-precision early warning of tunnel rockburst risk by optimizing sensor layout, wave velocity parameter setting, and applying advanced algorithms and mathematical models. In industrial applications, unified early warning discrimination criteria and threshold adjustment based on feedback from actual rockburst occurrences greatly improve the reliability and practicality of early warning. It significantly reduces safety accidents caused by rockbursts during construction, reduces construction risks and costs, provides strong technical support for tunnel construction safety management, and promotes the advancement and application of related industrial technologies.

[0091] Third, the expected benefits and commercial value of the technical solution of the present invention after transformation are:

[0092] The present invention can monitor two sections simultaneously through a set of microseismic monitoring systems, saving half of the human, material and financial resources. At the same time, this method fills the gap in establishing a quantitative judgment method for distinguishing and distinguishing microseismic monitoring and early warning rock bursts in double-line tunnels under similar geological conditions in the same work area, and has strong practical value. In addition, the same system can realize a systematic comparison of microseismic activities in double-line tunnels, which is helpful for further accurate and in-depth research on double-line tunnels, and can help improve the accuracy of microseismic monitoring and early warning of double-line rock bursts. BRIEF DESCRIPTION OF THE DRAWINGS

[0093] Figure 1 It is a flow chart of a construction method for judging and distinguishing the quantitative early warning rockburst level of microseismic parameters of a double-line tunnel provided by an embodiment of the present invention;

[0094] Figure 2 is a sensor distribution location diagram provided by an embodiment of the present invention;

[0095] Figure 3 It is a diagram showing error calculation under different wave speeds in a tunnel provided by an embodiment of the present invention;

[0096] Figure 4 This is a comparison diagram of blasting radiation energy of a double-line tunnel provided by an embodiment of the present invention;

[0097] Figure 5 It is a flow chart of a method for judging and distinguishing and establishing quantitative standards for early warning of a double-line tunnel provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0098] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0099] Industrial Application Example 1: Urban Subway Tunnel Construction

[0100] During the construction of a subway tunnel in a certain city, the tunnel passed through multiple complex geological areas, including hard rock, soft soil and fault zones, with a high risk of rock burst. The construction party hoped to use a high-precision microseismic monitoring system to provide real-time warning of tunnel rock burst risks, thereby ensuring construction safety.

[0101] 1. Sensor arrangement (S1):

[0102] According to the specific geological conditions and construction progress of the tunnel, microseismic sensors are arranged in different areas to ensure coverage of the entire tunnel.

[0103] Sensor spacing and density are adjusted according to geological conditions to ensure data accuracy and comprehensiveness.

[0104] 2. Wave speed setting (S2):

[0105] At the beginning of construction, on-site wave velocity tests are carried out to obtain wave velocity data of different geological layers and set them in the monitoring system.

[0106] The wave velocity parameters are updated regularly to adapt to the changes in geological conditions during the construction process.

[0107] 3. Monitoring system reliability assessment (S3):

[0108] Compare and analyze microseismic data from different monitoring points to ensure the stability and reliability of the monitoring system in each geological area.

[0109] 4. Comparison of geological exposure (S4):

[0110] During the tunnel excavation process, the geological exposure of the face is compared regularly and the monitoring strategy is adjusted.

[0111] 5. Rockburst classification and quantitative judgment criteria (S5):

[0112] Based on the frequency, energy and source location of microseismic events, rock burst grade classification standards are formulated, and the quantitative judgment criteria are updated in real time.

[0113] 6. Establish high-precision quantitative criteria (S6):

[0114] In different geological areas, high-precision quantitative criteria for rockburst levels are established and applied based on microseismic data and geological conditions.

[0115] 7. Warning judgment criteria (S7, S8):

[0116] Based on geological and construction conditions, formulate and unify tunnel early warning identification standards.

[0117] 8. Verify and improve thresholds (S9):

[0118] The reliability of the early warning method is verified through actual rockburst occurrence situations, and the early warning threshold is adjusted in a timely manner.

[0119] Through the above method, the construction party successfully predicted and prevented multiple rock burst incidents during the construction of the subway tunnel, significantly improving construction safety and reducing construction risks and costs.

[0120] Industrial Application Example 2: Highway Tunnel Construction

[0121] During the construction of a highway tunnel in a mountainous area, the tunnel needs to pass through multiple fault zones and water-rich areas, and the risk of rock burst is extremely high. The project team hopes to achieve real-time early warning and risk control of rock burst through an accurate microseismic monitoring system.

[0122] 1. Sensor arrangement (S1):

[0123] A high density of microseismic sensors are arranged in the tunnel to cover all critical areas, including fault zones and water-rich areas.

[0124] 2. Wave speed setting (S2):

[0125] The wave velocity parameters for different areas are set using geological survey data and on-site wave velocity test results.

[0126] 3. Monitoring system reliability assessment (S3):

[0127] Continuously monitor the microseismic data of each monitoring point in the double-line tunnel to ensure the stability and reliability of the system.

[0128] 4. Comparison of geological exposure (S4):

[0129] Regularly compare the geological exposure of the heading face during tunnel excavation and adjust the monitoring plan in a timely manner.

[0130] 5. Rockburst classification and quantitative judgment criteria (S5):

[0131] Based on the monitoring data, rockburst grade classification standards and quantitative judgment criteria are formulated and updated in real time.

[0132] 6. Establish high-precision quantitative criteria (S6):

[0133] In each geological area, high-precision quantitative criteria for rockburst grade are established based on microseismic data and geological conditions.

[0134] 7. Warning judgment criteria (S7, S8):

[0135] Establish unified tunnel early warning identification standards and apply them in actual construction.

[0136] 8. Verify and improve thresholds (S9):

[0137] Through feedback from actual rockburst events, early warning methods and thresholds are verified and optimized.

[0138] The application of this invention in highway tunnel construction has successfully predicted and prevented multiple rock burst events, improved construction safety, and significantly reduced construction risks and costs. At the same time, the successful application of this method provides new technical support for tunnel construction safety management. Industrial Application Example 1: Urban Subway Tunnel Construction

[0139] During the construction of a subway tunnel in a certain city, the tunnel passed through multiple complex geological areas, including hard rock, soft soil and fault zones, with a high risk of rock burst. The construction party hoped to use a high-precision microseismic monitoring system to provide real-time warning of tunnel rock burst risks, thereby ensuring construction safety.

[0140] 1. Sensor arrangement (S1):

[0141] According to the specific geological conditions and construction progress of the tunnel, microseismic sensors are arranged in different areas to ensure coverage of the entire tunnel.

[0142] Sensor spacing and density are adjusted according to geological conditions to ensure data accuracy and comprehensiveness.

[0143] 2. Wave speed setting (S2):

[0144] At the beginning of construction, on-site wave velocity tests are carried out to obtain wave velocity data of different geological layers and set them in the monitoring system.

[0145] The wave velocity parameters are updated regularly to adapt to the changes in geological conditions during the construction process.

[0146] 3. Monitoring system reliability assessment (S3):

[0147] Compare and analyze microseismic data from different monitoring points to ensure the stability and reliability of the monitoring system in each geological area.

[0148] 4. Comparison of geological exposure (S4):

[0149] During the tunnel excavation process, the geological exposure of the face is compared regularly and the monitoring strategy is adjusted.

[0150] 5. Rockburst classification and quantitative judgment criteria (S5):

[0151] Based on the frequency, energy and source location of microseismic events, rock burst grade classification standards are formulated, and the quantitative judgment criteria are updated in real time.

[0152] 6. Establish high-precision quantitative criteria (S6):

[0153] In different geological areas, high-precision quantitative criteria for rockburst levels are established and applied based on microseismic data and geological conditions.

[0154] 7. Warning judgment criteria (S7, S8):

[0155] Based on geological and construction conditions, formulate and unify tunnel early warning identification standards.

[0156] 8. Verify and improve thresholds (S9):

[0157] The reliability of the early warning method is verified through actual rockburst occurrence situations, and the early warning threshold is adjusted in a timely manner.

[0158] Through the above method, the construction party successfully predicted and prevented multiple rock burst incidents during the construction of the subway tunnel, significantly improving construction safety and reducing construction risks and costs.

[0159] Industrial Application Example 2: Highway Tunnel Construction

[0160] During the construction of a highway tunnel in a mountainous area, the tunnel needs to pass through multiple fault zones and water-rich areas, and the risk of rock burst is extremely high. The project team hopes to achieve real-time early warning and risk control of rock burst through an accurate microseismic monitoring system.

[0161] 1. Sensor arrangement (S1):

[0162] A high density of microseismic sensors are arranged in the tunnel to cover all critical areas, including fault zones and water-rich areas.

[0163] 2. Wave speed setting (S2):

[0164] The wave velocity parameters for different areas are set using geological survey data and on-site wave velocity test results.

[0165] 3. Monitoring system reliability assessment (S3):

[0166] Continuously monitor the microseismic data of each monitoring point in the double-line tunnel to ensure the stability and reliability of the system.

[0167] 4. Comparison of geological exposure (S4):

[0168] Regularly compare the geological exposure of the heading face during tunnel excavation and adjust the monitoring plan in a timely manner.

[0169] 5. Rockburst classification and quantitative judgment criteria (S5):

[0170] Based on the monitoring data, rockburst grade classification standards and quantitative judgment criteria are formulated and updated in real time.

[0171] 6. Establish high-precision quantitative criteria (S6):

[0172] In each geological area, high-precision quantitative criteria for rockburst grade are established based on microseismic data and geological conditions.

[0173] 7. Warning judgment criteria (S7, S8):

[0174] Establish unified tunnel early warning identification standards and apply them in actual construction.

[0175] 8. Verify and improve thresholds (S9):

[0176] Through feedback from actual rockburst events, early warning methods and thresholds are verified and optimized.

[0177] The application of this invention in highway tunnel construction has successfully predicted and prevented multiple rock burst events, improved construction safety, and significantly reduced construction risks and costs. At the same time, the successful application of this method provides new technical support for tunnel construction safety management.

[0178] like Figure 1 As shown, an embodiment of the present invention provides a method for determining and distinguishing the quantitative early warning rockburst level of microseismic parameters of a double-line tunnel, the method comprising:

[0179] S1: Design of sensor layout method for microseismic monitoring system;

[0180] S2: wave speed setting;

[0181] S3: Determine the reliability of the same monitoring system for monitoring double-track tunnels;

[0182] S4: Comparison of geological exposure of the tunnel faces in similar mileage sections of double-track tunnels;

[0183] S5: Determine the rockburst classification and quantitative judgment criteria;

[0184] S6: Differentiate and establish quantitative criteria for high-precision rockburst of various grades in double-track tunnels;

[0185] S7: Method for determining whether to distinguish and establish rockburst warning criteria;

[0186] S8: A method for establishing a unified tunnel warning identification standard;

[0187] S9: The reliability of this method is determined by subsequent rockburst occurrences, and the threshold is improved.

[0188] This method realizes early warning and identification of rock burst level in double-line tunnels through a series of steps. The specific steps and working principles are as follows:

[0189] #S1: Design of sensor layout method for microseismic monitoring system

[0190] - Working principle: Microseismic sensors are placed in the tunnel to monitor microseismic activities in real time. The placement method needs to be determined according to the specific geological conditions, construction progress and monitoring needs of the tunnel to ensure the accuracy and coverage of the monitoring data.

[0191] #S2: Wave speed setting

[0192] - Working principle: According to the on-site geological conditions and experimental data, the wave velocity parameters of the monitoring area are set. Wave velocity is a key parameter for microseismic event location and energy calculation. Accurately setting the wave velocity helps improve the accuracy of microseismic event location.

[0193] #S3: Determine the reliability of the same monitoring system for dual-track tunnel monitoring

[0194] - Working principle: By comparing and analyzing the microseismic data of different monitoring points in the double-line tunnel, the monitoring effect of the same monitoring system in different tunnel sections is evaluated to ensure its reliability and consistency.

[0195] #S4: Comparison of geological exposure of the tunnel face in similar mileage sections of double-track tunnels

[0196] - Working principle: Compare and analyze the geological exposure of the tunnel faces in similar mileage sections of double-track tunnels to understand the impact of different geological conditions on microseismic activities. This helps to accurately predict rock burst risks under different geological conditions.

[0197] #S5: Determine rockburst classification and quantitative judgment criteria

[0198] - Working principle: According to microseismic monitoring data and geological conditions, the rockburst classification standard is formulated and the judgment criteria are quantified. For example, the rockburst grade is divided according to the frequency, energy, source location and other parameters of the microseismic event.

[0199] #S6: Distinguishing and establishing quantitative criteria for high-precision rockburst of different grades in double-line tunnels

[0200] - Working principle: In different areas of the double-track tunnel, high-precision quantitative rockburst level criteria are established based on microseismic data and geological conditions. These criteria need to be able to reflect the risk level of rockburst in different areas.

[0201] #S7: Method for determining whether to establish rockburst warning criteria

[0202] - Working principle: Evaluate whether it is necessary to establish rockburst warning standards under different geological and construction conditions. If necessary, further refine the warning discrimination standards.

[0203] #S8: Unified tunnel warning identification standard establishment method

[0204] - Working principle: Under the premise of ensuring reliability and accuracy, a unified standard for rock burst warning is formulated to ensure that consistent warning standards are used throughout the double-track tunnel.

[0205] #S9: Determine the reliability of this method through subsequent rock bursts and improve the threshold

[0206] - Working principle: During the actual construction process, based on the actual occurrence of rock burst, the reliability of the early warning method and judgment criteria is verified and improved, and the early warning threshold is adjusted and optimized in a timely manner.

[0207] This method is designed through reasonable sensor layout, setting accurate wave velocity parameters, evaluating the reliability of the monitoring system, analyzing geological exposure, determining rockburst classification and quantitative criteria, distinguishing and unifying early warning standards, and optimizing through feedback from actual rockburst occurrences, ultimately achieving accurate early warning and identification of rockburst levels in double-track tunnels. This series of steps are closely linked to ensure the scientificity and practicality of the early warning method.

[0208] The S1 specifically includes:

[0209] According to the on-site construction process and safety design, the double-track tunnel is divided into a leading tunnel and a trailing tunnel, that is, one tunnel is excavated quickly and is the leading tunnel, and the other tunnel is excavated slowly and is the trailing tunnel. At present, the construction conditions in different projects of double-track tunnels are different. Since there is no fixed arrangement method for sensor arrangement, it is necessary to first establish a sensor arrangement method suitable for the tunnel. However, through uninterrupted experiments and attempts at different construction sites, the sensor arrangement method designed here can basically meet the monitoring requirements of all double-track tunnels. The specific plan is as follows:

[0210] Six sensors are used, all arranged in the pilot tunnel; the sensors are distributed in four sections, the first section is 50 to 80 meters away from the pilot tunnel face, and each section is about 30 meters apart. The range can be appropriately increased or decreased according to actual conditions; four sensors are installed on the side close to the rear tunnel, and two sensors are installed on the side away from the rear tunnel. The sensors on both sides are installed with staggered elevations, and try not to be located in a straight line at the same elevation. The sensors on the same side are also arranged in this regular pattern.

[0211] Here, we take the case where the difference between the leading tunnel and the trailing tunnel is 150 meters as an example. Figure 2As shown in the figure, sensors I to VI are placed on sections a to d when they are laid. Sensors I and II are located on the right side walls of sections a and c, sensors III and V are located on the left spandrels of sections a and c, and sensors IV and VI are located on the left side walls of sections b and d. Section a is about 50m away from the tunnel face, and about 30m between sections a and d. Relative to the right tunnel, the sensor arrangement is a subsequent sensor arrangement, and relative to the left tunnel, the sensor arrangement is a side wall star sensor arrangement. At this time, the system can simultaneously capture microseismic signals from the left and right tunnels. When the tunnel face of the pilot tunnel advances about 30m forward, or the lining follow-up distance behind the pilot tunnel is less than 10m from sensor VI, the sensor in section d is moved forward to the front of section a, and the sensor in section c is moved forward in the next cycle, and so on, to ensure the continuity of microseismic monitoring.

[0212] The S2 specifically includes:

[0213] (1) Find a known earthquake source point in each tunnel of the double-track tunnel as test point 1 and record it as (X1, Y1, Z1); in the drilling and blasting construction tunnel, the blasting point can be used as the earthquake source point, in the TBM construction tunnel, a fixed blasting point can be used as the test point, or a known rock burst point can be used as the test point;

[0214] (2) Taking the known sensor coordinates as test point 2;

[0215] (3) The monitoring system records the time it takes for the sound waves generated at each test point to reach each sensor. With the known source point of each sensor as the center, the product of wave velocity and time is used as the radius to locate the test point 1' (X2, Y2, Z2) in space. The error can be obtained by calculating the spatial distance between test points 1 and 1'.

[0216] (4) Calculate the error values ​​at different wave speeds in the two tunnels and form a trend graph;

[0217] (5) Determine the wave velocity at the bottom of the trend graph as the wave velocity with the smallest error;

[0218] Figure 3 This is the error calculation display diagram of a tunnel. It can be seen from the figure that when the P-wave speed is 6100m / s, the error of the left tunnel is the smallest, which is 5.71m. When the P-wave speed is 5900m / s, the error of the right tunnel is the smallest, which is 5.04m. The error of the left tunnel is 6.00m. At this time, the average error of the left and right tunnels is also the smallest, which is 5.52m. Therefore, the P-wave speed is set to 5900m / s.

[0219] The S3 specifically includes:

[0220] Microseismic energy is one of the main parameters for early warning of rock bursts based on microseismic monitoring, and can verify the difference in the microseismic monitoring capabilities of the monitoring microseismic system for double-track tunnels; to ensure a single variable, it is necessary to ensure that the release capacity of the source point itself is consistent; the amount of explosives and the quality of explosives required for face blasting are consistent, so the energy generated by the blasting events in the left and right tunnels can be selected as the test point; and due to the effect of explosive release in different mileage sections, the energy released by each blasting or received by the monitoring system is different, and all blasting events within a range of events can be selected and the average value and standard deviation can be selected for comparison. In TBM construction tunnels, quantitative fixed-point blasting tests, or multi-point and multi-volume blasting tests, can be used to test the reliability of the monitoring equipment through distance attenuation intervals or charge attenuation gradients;

[0221] If the comparison results do not exceed one order of magnitude and the difference does not exceed 20%, it indicates that the microseismic parameter values ​​in the double-line tunnel collected by the same system are reliable.

[0222] The reliability test was conducted by taking the actual blasting in the tunnel as an example during the construction using the drilling and blasting method. Figure 4 This is an energy comparison chart of a double-track tunnel during three months of actual monitoring of a tunnel. It can be seen from the figure that the blasting radiation energy error and standard deviation of the leading tunnel and the trailing tunnel meet the monitoring requirements.

[0223] The S4 specifically includes:

[0224] By comparing and recording the differences in geological conditions, the differences in microseismic activity during the rockburst incubation process can be reflected. It is necessary to continuously record the geological exposure of the adjacent faces of the leading tunnel and the trailing tunnel over a period of time, and compare the geological differences of the exposed faces. The recorded content includes the number and occurrence of joints, fissures and structural surfaces, groundwater, rock types and other data, and compare the exposure conditions at the same mileage. According to the degree of difference, the difference level is divided into three levels: high, medium and low. This is used as the basis for judging whether the double-line tunnel is distinguished and establishing a method for quantitative early warning of rockburst levels of microseismic parameters of microseismic double-line tunnels.

[0225] The S5 specifically includes:

[0226] At present, there are differences in the classification of rockburst in different projects. However, according to statistics from many engineering projects, the most commonly classified rockburst levels are generally: no rockburst, slight rockburst, moderate rockburst, strong rockburst, and extremely strong rockburst;

[0227] In addition, it is necessary to stipulate the quantitative standards for each rockburst level. Most of the on-site construction is done by qualitative sound, the size of falling blocks, combined with quantitative blast pit depth, ejection speed and other methods to make a quick judgment. Because qualitative judgment is greatly affected by personal experience, and the ejection speed cannot be accurately recorded, the blast pit depth is often used as the most quantitative standard on site. For example, no damage is called no rockburst, blast pit depth <0.5m is a slight rockburst, blast pit depth 0.5m~1.5m is a moderate rockburst, blast pit depth 1.5m~3m is a strong rockburst, and blast pit depth >3m is a strong rockburst.

[0228] The above specific quantitative judgment standards are examples of the combination of multiple projects. The specific quantitative criteria for the blast pit depth level need to be determined jointly by multiple units on site.

[0229] The S6 specifically includes:

[0230] During the rock mass excavation process, rock micro-fractures, i.e. microseismic events, will inevitably occur. Each microseismic event represents a micro-fracture. The number of microseismic events and microseismic energy represent the degree of rock degradation and can express the severity of the rock burst that may occur. The changes in the frequency and energy of microseismic events can be expressed as the activity of microseismic activity. The more active the microseismic activity is, the greater the level and probability of rock burst that may occur.

[0231] When a rockburst occurs, microfractures will inevitably occur, but the presence of microfractures does not necessarily mean that a rockburst will occur; therefore, before a rockburst occurs, the number and energy of microseismic events in the double-line tunnel can be recorded respectively, and then the no-rockburst threshold can be determined based on the number and energy records of microseismic events. After that, the changes in microseismic activity of each level of rockburst are selected to determine the rockburst threshold of each level. The specific method is as follows:

[0232] (1) Determine the quantitative threshold of rockburst-free level for double-track tunnels

[0233] Before the rock burst occurs, the changes in the microseismic activity of the two lines are continuously recorded, and the maximum energy and the maximum number of microseismic events are recorded every day in units of days. 0 is used as the quantitative lower limit of no rock burst, and the maximum energy and number of each double-line tunnel before the rock burst occurs are used as the upper limit of the quantitative threshold of no rock burst level;

[0234] (2) Determine the quantitative thresholds for rockburst levels from mild to severe in double-track tunnels

[0235] Select the number and energy data of three minor rockbursts in one of the tunnels (the number can be selected according to the actual situation on site. If the number of rockbursts is large, it can be appropriately increased. Three times is the minimum number for quickly determining the quantification level). Take the highest number and highest energy of microseismic events in the three minor rockbursts as the threshold of high probability of minor rockbursts; take the average number of cumulative microseismic events and cumulative energy of microseismic events in the three minor rockbursts as the threshold of medium probability of minor rockbursts; take the lowest number and average energy of microseismic events in the three minor rockbursts as the threshold of low probability of minor rockbursts; if the quantitative threshold of the minor rockburst is lower than the quantitative standard of the previous level, that is, the quantitative standard of no rockburst of the corresponding tunnel in (1), then the quantitative threshold of the previous level and the exceeded threshold of the current level are exchanged, and the probability level exchange is analogous;

[0236] In the same way, determine the high, medium and low probability thresholds of minor to severe rockburst in another tunnel;

[0237] (3) Determine the quantitative threshold of extremely strong rockburst level in double-line tunnels

[0238] The energy upper limit of strong rock burst is taken as the lower limit threshold of extremely strong rock burst, and there is no upper limit. The quantity threshold is taken as the lowest number of microseismic events of extremely strong rock burst, and there is no upper limit.

[0239] The high, medium and low probability thresholds of each rockburst level in the two tunnels are determined in the same way.

[0240] The S7 specifically includes:

[0241] (1) First, calibrate and record using energy as the main criterion;

[0242] 1) Method for judging the rock burst level:

[0243] When judging the level of no rock burst, the lower limit of energy is 0 and is not considered; the difference between the upper and lower limits of the no rock burst energy threshold is compared. If the difference in the upper limit energy is less than 20% of any tunnel, it is recorded as 0; if the difference in the upper limit energy is more than 20% of any tunnel, it is recorded as 1;

[0244] 2) Method for judging the level of minor rockburst to severe rockburst

[0245] When judging the level from slight rockburst to severe rockburst, the upper and lower limits need to be compared by difference respectively, which is the same as the method of judging the level without rockburst. If the energy difference between the upper or lower limit is less than 20% of any tunnel, it is recorded as 0. If the upper or lower limit exceeds 20% of any tunnel, it is recorded as 1. Each level is recorded in this way.

[0246] 3) Methods for determining the level of extremely strong rockburst, such as Figure 5 As shown;

[0247] (1) When judging the level of extremely strong rockburst, the upper limit of energy is infinite and is not considered. The difference between the lower limits of the extremely strong rockburst energy threshold is compared. If the difference in the lower limit energy is less than 20% of any tunnel, it is recorded as 0. If the difference in the number exceeds 20% of any tunnel, it is recorded as 1.

[0248] (2) Then, the quantity is used as the main criterion for calibration and recording, and the recording method is the same as the energy calibration recording method (1) above;

[0249] (3) The above recorded values ​​are accumulated. If the final accumulated value is greater than 3, it is necessary to establish early warning judgment standards for double-track tunnels respectively. If the final accumulated value is less than or equal to 3, a unified tunnel early warning judgment standard is established.

[0250] The S8 specifically includes:

[0251] Add the cross discrimination method and the principle of taking the higher rather than the lower, and unify them on the basis of the threshold of the double-line tunnel;

[0252] (1) Unified quantitative thresholds for rockburst-free levels

[0253] The lower limit of no rock burst still starts at 0, and the upper limit is the minimum value and energy of the threshold of any tunnel in the double-track tunnel without rock burst;

[0254] (2) Unify the quantitative thresholds of rockburst levels from minor to severe

[0255] The upper limit of low-level rock burst is used as the lower limit of the adjacent high-level rock burst. When the lower limits are unified, the lower limit threshold is also established by the number and energy minimum value of the lower limit of any double-track tunnel. The medium-risk area is established by the average value of each level of rock burst in the double-track tunnel, and the high-risk upper limit is established by the minimum value of the maximum number of any double-track tunnel. In this way, the upper and lower limits of rock bursts of various levels can be unified.

[0256] (3) Unified quantification threshold of extremely strong rockburst level

[0257] The lower limit of extremely severe rockburst is the same as the upper limit of high risk of strong rockburst, with the same energy and quantity, and no upper limit.

[0258] The embodiment of the present invention provides a system for determining and distinguishing the quantitative early warning rockburst level of microseismic parameters of a double-line tunnel, and implementing the method for constructing the method for determining and distinguishing the quantitative early warning rockburst level of microseismic parameters of a double-line tunnel. The system includes:

[0259] Arrangement design and wave speed setting module, used for sensor arrangement design and wave speed setting of microseismic monitoring system;

[0260] Reliability determination module, used to determine the reliability of the same monitoring system for double-track tunnel monitoring;

[0261] The exposure comparison module is used to compare the geological exposure of the tunnel face in similar mileage sections of double-track tunnels;

[0262] A judgment criteria determination module is used to determine the rockburst grade classification and quantitative judgment criteria;

[0263] The criterion establishment module is used to distinguish and establish high-precision quantitative criteria for rock bursts of various levels in double-line tunnels;

[0264] A standard establishment module is used to determine whether to distinguish and establish a rockburst warning discrimination standard;

[0265] Method unification module, used to unify the tunnel warning judgment standard establishment method;

[0266] The threshold improvement module is used to judge the reliability of the method through subsequent rock burst occurrences and to improve the threshold value.

[0267] It should be noted that the embodiments of the present invention can be implemented by hardware, software, or a combination of software and hardware. The hardware part can be implemented using dedicated logic; the software part can be stored in a memory and executed by an appropriate instruction execution system, such as a microprocessor or dedicated design hardware. It can be understood by a person of ordinary skill in the art that the above-mentioned devices and methods can be implemented using computer executable instructions and / or contained in a processor control code, such as a carrier medium such as a disk, CD or DVD-ROM, a programmable memory such as a read-only memory (firmware), or a data carrier such as an optical or electronic signal carrier. Such code is provided on the carrier medium. The device and its modules of the present invention can be implemented by hardware circuits such as very large-scale integrated circuits or gate arrays, semiconductors such as logic chips, transistors, etc., or programmable hardware devices such as field programmable gate arrays, programmable logic devices, etc., can also be implemented by software executed by various types of processors, and can also be implemented by a combination of the above-mentioned hardware circuits and software, such as firmware.

[0268] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with the technical field within the technical scope disclosed by the present invention and within the spirit and principle of the present invention should be covered by the protection scope of the present invention.

Claims

1. A method for determining and distinguishing the quantitative early warning rockburst level of microseismic parameters of double-line tunnels, characterized in that: The method includes: S1. Design of sensor layout method for microseismic monitoring system: Microseismic sensors are arranged in the tunnel to monitor microseismic activities in real time. The layout method is determined according to the specific geological conditions, construction progress and monitoring requirements of the tunnel to ensure the accuracy and coverage of the monitoring data; S2. Wave velocity setting: According to the on-site geological conditions and experimental data, the wave velocity parameters of the monitoring area are set. Wave velocity is a key parameter for microseismic event location and energy calculation. Accurately setting the wave velocity helps improve the accuracy of microseismic event location. S3. Determine the reliability of the monitoring effect of the same monitoring system on the double-track tunnel: By comparing and analyzing the microseismic data of different monitoring points in the double-track tunnel, evaluate the monitoring effect of the same monitoring system in different tunnel sections to ensure its reliability and consistency; S4. Comparison of geological exposure of the tunnel faces in similar mileage sections of double-track tunnels: Comparative analysis of geological exposure of the tunnel faces in similar mileage sections of double-track tunnels to understand the impact of different geological conditions on microseismic activities, so as to accurately predict rock burst risks under different geological conditions; S5. Determine the rockburst classification and quantitative judgment criteria: Based on the microseismic monitoring data and geological conditions, formulate rockburst classification standards and quantitative judgment criteria, and classify rockburst levels according to parameters such as frequency, energy, and source location of microseismic events; S6. Differentiate and establish high-precision quantitative criteria for rockbursts of different levels in double-track tunnels: In different areas of double-track tunnels, based on microseismic data and geological conditions, establish high-precision quantitative criteria for rockburst levels, which can reflect the risk levels of rockbursts in different areas; S7. Method for determining whether to establish rockburst warning criteria: assess whether it is necessary to establish rockburst warning criteria under different geological and construction conditions. If necessary, further refine the warning criteria; S8. Unified tunnel warning identification standard establishment method: Under the premise of ensuring reliability and accuracy, unified tunnel rockburst warning identification standards are formulated to ensure that consistent warning standards are used throughout the double-track tunnel; S9. Judge the reliability of the method through subsequent rock burst occurrences and improve the thresholds: During the actual construction process, verify and improve the reliability of the early warning method and discrimination criteria based on the actual occurrence of rock bursts, and adjust and optimize the early warning thresholds in a timely manner.

2. The method for determining and distinguishing the quantitative early warning rockburst level of microseismic parameters of double-line tunnels according to claim 1 is characterized in that: The S1 specifically includes: S1. Sensor arrangement: 6 sensors are used, all arranged in the leading tunnel. The sensors are distributed in 4 sections, and each section is about 30 meters apart. The number of sensors can be increased or decreased appropriately according to the actual situation. 4 sensors are installed on the side close to the rear tunnel, and 2 sensors are installed on the side away from the rear tunnel. The sensors on both sides are installed at staggered elevations, and try not to be located in a straight line at the same elevation. S2. Determination of wave speed: by selecting a known earthquake source point in the tunnel as the test point, using the sound wave arrival time recorded by the sensor, calculate the positioning error under different wave speeds, and determine the wave speed with the minimum error; S3. Verification of microseismic parameters: In the drilling and blasting construction tunnel, the energy generated by the blasting events in the left and right tunnels is selected as the test point, and the average and standard deviation of the energy of each blasting event are compared to ensure the reliability of the microseismic parameter values; in the TBM construction tunnel, the reliability of the monitoring equipment is verified through quantitative fixed-point blasting tests or multi-point and multi-quantity blasting tests.

3. According to the construction method for judging and distinguishing the quantitative early warning rockburst level of microseismic parameters of double-line tunnels as described in claim 2, the sensor arrangement in S1 is characterized in that: the first section is 50 to 80 meters away from the heading of the pilot tunnel, and the sensors are installed on both sides in a staggered manner to maintain the comprehensiveness and accuracy of monitoring.

4. According to the construction method of judging and distinguishing the quantitative early warning rockburst level of microseismic parameters of double-line tunnels as described in claim 1, the microseismic parameter verification in S3 is further characterized by: in the drilling and blasting construction tunnel, if the energy comparison result generated by the blasting events in the left and right holes does not exceed one order of magnitude, and the difference does not exceed 20%, it indicates that the microseismic parameter values ​​in the double-line tunnel collected by the same system are reliable; in the TBM construction tunnel, through quantitative fixed-point blasting tests or multi-point and multi-volume blasting tests, the stability and reliability of the monitoring system under different conditions are ensured.

5. The method for determining and distinguishing the quantitative early warning rockburst level of microseismic parameters of double-line tunnels according to claim 1 is characterized in that: The S4 specifically includes: By continuously recording the geological exposure conditions of the adjacent faces of the leading tunnel and the trailing tunnel over a period of time, and comparing the geological differences of the exposure surfaces, the recorded contents include the number and occurrence of joints, fissures and structural surfaces, groundwater, and rock type data, and comparing the exposure conditions at the same mileage positions; according to the degree of difference, the difference level is divided into three levels: high, medium and low, which serves as the basis for judging whether the double-track tunnel is distinguished and establishing a method for quantitative early warning rockburst level of microseismic parameters of microseismic double-track tunnels.

6. The method for determining and distinguishing the quantitative early warning rockburst level of microseismic parameters of double-line tunnels according to claim 1 is characterized in that: The S5 includes: The classification standards for rockburst levels are usually no rockburst, slight rockburst, moderate rockburst, severe rockburst, and extremely severe rockburst; The quantification standards for each rockburst level are also specified, such as quantification by the depth of the blast pit, specifically: no damage is called no rockburst, blast pit depth <0.5m is called slight rockburst, blast pit depth 0.5m-1.5m is called moderate rockburst, blast pit depth 1.5m-3m is called strong rockburst, and blast pit depth >3m is called extremely strong rockburst; Among them, the specific quantitative criteria for the depth level of the blast pit need to be determined jointly by multiple units on site.

7. The method for determining and distinguishing the quantitative early warning rockburst level of microseismic parameters of double-line tunnels according to claim 1 is characterized in that: The S6 includes: By continuously recording the number and energy of microseismic events in the double-line tunnel, the activity of microseismic activity is analyzed to predict the level and probability of rock burst; Specific methods include: (1) Determine the quantitative threshold of the rockburst-free level of the double-track tunnel, and take the maximum energy and number of each double-track tunnel before the rockburst occurs as the upper limit of the quantitative threshold of the rockburst-free level; (2) Determine the quantitative thresholds for the level of minor to severe rockburst in double-track tunnels. By selecting the number and energy data of microseismic events of three (or more) rockbursts, set high, medium, and low probability thresholds, respectively, and adjust them according to the quantitative standards of the previous level; (3) Determine the quantitative threshold of the extremely strong rockburst level in a double-track tunnel, with the energy and number of strong rockburst events as the lower threshold and no upper limit; Through the above method, the high, medium and low probability thresholds of each rockburst level in the two tunnels are determined respectively.

8. The method for determining and distinguishing the quantitative early warning rockburst level of microseismic parameters of double-line tunnels according to claim 1 is characterized in that: The S7 specifically includes: (1) First, calibrate and record using energy as the main criterion; 1) Method for judging the rock burst level: When judging the level of no rock burst, the lower limit of energy is 0 and is not considered; the difference between the upper and lower limits of the no rock burst energy threshold is compared. If the difference in the upper limit energy is less than 20% of any tunnel, it is recorded as 0; if the difference in the upper limit energy is more than 20% of any tunnel, it is recorded as 1; 2) Method for judging the level of minor rockburst to severe rockburst When judging the level from slight rockburst to severe rockburst, the upper and lower limits need to be compared by difference respectively, which is the same as the method of judging the level without rockburst. If the energy difference between the upper or lower limit is less than 20% of any tunnel, it is recorded as 0. If the upper or lower limit exceeds 20% of any tunnel, it is recorded as 1. Each level is recorded in this way. 3) Method for determining the level of extremely strong rockburst When judging the level of extremely strong rockburst, the upper limit of energy is infinite and is not considered. The difference between the lower limits of the extremely strong rockburst energy threshold is compared. If the difference in the lower limit energy is less than 20% of any tunnel, it is recorded as 0. If the difference in the number exceeds 20% of any tunnel, it is recorded as 1. (2) Then, the quantity is used as the main criterion for calibration and recording, and the recording method is the same as the energy calibration recording method (1) above; (3) The above recorded values ​​are accumulated. If the final accumulated value is greater than 3, it is necessary to establish early warning judgment standards for double-track tunnels respectively. If the final accumulated value is less than or equal to 3, a unified tunnel early warning judgment standard is established.

9. The method for determining and distinguishing the quantitative early warning rockburst level of microseismic parameters of double-line tunnels according to claim 1 is characterized in that: The S8 specifically includes: Add the cross discrimination method and the principle of taking the higher rather than the lower, and unify them on the basis of the threshold of the double-line tunnel; (1) Unified quantitative threshold for rockburst level The lower limit of no rock burst still starts at 0, and the upper limit is the minimum value and energy of the threshold of any tunnel in the double-track tunnel without rock burst; (2) Unify the quantitative thresholds of rockburst levels from minor to severe The upper limit of low-level rock burst is used as the lower limit of the adjacent high-level rock burst. When the lower limits are unified, the lower limit threshold is also established by the number and energy minimum value of the lower limit of any double-track tunnel. The medium-risk area is established by the average value of each level of rock burst in the double-track tunnel, and the high-risk upper limit is established by the minimum value of the maximum number of any double-track tunnel. In this way, the upper and lower limits of rock bursts of various levels can be unified. (3) Unified quantification threshold of extremely strong rockburst level The lower limit of extremely severe rockburst is the same as the upper limit of high risk of strong rockburst, with the same energy and quantity, and no upper limit.

10. A system for determining and distinguishing the quantitative early warning rockburst level of microseismic parameters of a double-line tunnel according to any one of claims 1 to 9, characterized in that: The system includes: Arrangement design and wave speed setting module, used for sensor arrangement design and wave speed setting of microseismic monitoring system; Reliability determination module, used to determine the reliability of the same monitoring system for double-track tunnel monitoring; The exposure comparison module is used to compare the geological exposure of the tunnel face in similar mileage sections of double-track tunnels; A judgment criteria determination module is used to determine the rockburst grade classification and quantitative judgment criteria; The criterion establishment module is used to distinguish and establish high-precision quantitative criteria for rock bursts of various levels in double-line tunnels; A standard establishment module is used to determine whether to distinguish and establish a rockburst warning discrimination standard; Method unification module, used to unify the tunnel warning judgment standard establishment method; The threshold improvement module is used to judge the reliability of the method through subsequent rock burst occurrences and to improve the threshold value.

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