A method for distinguishing and locating microseismic events in double-line tunnels

Abstract

The present invention discloses a method for distinguishing and locating microseismic events in dual-track tunnels. The method includes several steps: deploying sensor arrays, inversely estimating wave velocity in the dual-track tunnels, picking and adjusting the arrival time of the microseismic monitoring system waveforms, and determining the spatial location of the microseismic events based on the arrival time of the P-wave at each sensor. This method enables simultaneous monitoring of two tunnels using a single monitoring system. By leveraging the time and location differences in data received by different sensors, the method quickly and accurately determines the likely location of the collected monitoring data. This method is used to address current practical monitoring and early warning issues in highway and railway tunnels.

Description

Technical Field

[0001] The present invention belongs to the field of microseismic monitoring of underground engineering, and in particular relates to a method for distinguishing and locating microseismic events in a double-line tunnel. Background Art

[0002] Microseismic monitoring technology within tunnels is a three-dimensional display technology based on acoustic emission phenomena, which can be used to visualize changes in rock mass fractures within a specific range. It primarily analyzes source parameters based on seismological principles, establishing a quantitative relationship between the spatiotemporal intensity of rock mass fractures within a unit and the macroscopic characteristics of rockburst occurrence, thereby predicting the risk of rockburst within the next unit time. The prerequisite for source parameter analysis is to extract source information. For single-line tunnels, microseismic events do not need to be differentiated and analyzed. However, for dual-line tunnels monitored under the same monitoring system, it is necessary to differentiate and analyze the leading and lagging tunnels, thereby obtaining more targeted analysis of different tunnel sections. However, most current microseismic monitoring technologies for rockburst early warning are based on single-line tunnels, or the leading and lagging tunnels are separated by a large distance, requiring the use of multiple microseismic systems for monitoring, without the need for differentiation. There is currently a lack of a method to simultaneously monitor dual-track tunnels through a single system and quickly distinguish the types of microseismic events for quantitative early warning. As a result, the quantitative monitoring of dual-track tunnels consumes a lot of manpower and material resources to distinguish events. Therefore, a quantitative method that can quickly distinguish the types of microseismic events in dual-track tunnels is urgently needed to solve the existing problem. Summary of the Invention

[0003] The main purpose of the present invention is to provide a method for distinguishing and locating microseismic events in dual-track tunnels. This method can realize simultaneous monitoring of two tunnels through a single monitoring system, and through the time and position differences of data received by different sensors, quickly and accurately determine the possible locations of the collected monitoring data, which is used to solve the current actual monitoring and early warning problems of highway tunnels or railway tunnels.

[0004] To this end, the present invention provides a method for distinguishing and locating microseismic events in a double-line tunnel, comprising the following steps:

[0005] Step 1: Sensor array layout

[0006] The cross section of the advance tunnel at a distance of M meters from the tunnel face is defined as the first section. Based on the first section, the cross section at a distance of N meters behind the tunnel face of the advance tunnel is defined as the second section.

[0007] The first, second, third and fourth sensors are installed at the right arch foot, right spandrel, left arch foot and left spandrel of the first section respectively; the fifth and sixth sensors are installed at the arch foot and spandrel of the rock mass on the side of the second section close to the hysteresis hole respectively; the seventh and eighth sensors are installed at the arch foot and spandrel on the other side of the second section respectively;

[0008] Step 2: Double-line tunnel wave velocity inversion

[0009] Based on the cannon firing information of the leading hole, namely the coordinates and firing time of the cannon, as well as the spatial coordinates of each sensor and the time of signal arrival, the travel time equation is used to obtain the wave velocity of each sensor. Then, the average wave velocity is taken to obtain the average wave velocity in the leading hole. The same method can be used to obtain the average wave velocity in the lagging hole.

[0010] Step 3: Microseismic monitoring system waveform timing pickup and adjustment

[0011] Compare the average wave velocities of the leading tunnel and the lagging tunnel obtained in step 2. If the wave velocities of the two tunnels are consistent, use the same arrival time picking of the same monitoring system to pick up the P and S waves of the waveform information; if the wave velocities of the two tunnels are inconsistent, use the wave velocity of the leading tunnel as the main one, set the wave velocity, and then, according to the travel time equation, set the arrival time as an unknown number, obtain the arrival time difference of the leading tunnel and the lagging tunnel under each identical sensor. When picking the obtained waveform, manually adjust each sensor of the lagging tunnel according to the obtained time difference, thereby realizing accurate monitoring and positioning of rock mass fractures with different wave velocities based on the same microseismic monitoring system;

[0012] The manual adjustment process is as follows: When picking waveforms, first pick the actual P-wave arrival time in the waveform. Then, based on the calculated time difference, adjust the P-wave arrival time to achieve a consistent arrival time. This eliminates errors between sensors caused by wave velocity attenuation due to rock mass inhomogeneity, making the spatial location of microseismic events located by the leading and lagging holes more accurate.

[0013] Step 4: Determine the spatial location of the microseismic event based on the arrival time of the P wave at each sensor.

[0014] Specifically, in case 1, when the sensors of the first section and the second section are located between the leading tunnel face and the lagging tunnel face, the spatial position of the microseismic event is distinguished and located using the following method; wherein:

[0015] (1) If the second and fourth sensors receive microseismic signals almost simultaneously, and the first and third sensors receive microseismic signals almost simultaneously, and the second section receives signals later than the first section, then the microseismic event is located above the spandrel of the leading hole, eccentrically.

[0016] (2) If the second sensor, the fourth sensor, the first sensor, and the third sensor receive microseismic signals in sequence from front to back, and the second section receives signals later than the first section, then the microseismic signal is located above and slightly to the right of the spandrel of the leading hole;

[0017] (3) If the fourth sensor, the second sensor, the third sensor, and the first sensor receive microseismic signals in sequence from front to back, and the second section receives signals later than the first section, then the microseismic signal is located above and to the left of the spandrel of the leading hole;

[0018] (4) If the first and third sensors receive microseismic signals almost simultaneously, followed by the second and fourth sensors, and the second section receives signals later than the first section, then the microseismic event is located below the arch foot of the advance tunnel, eccentrically.

[0019] (5) If the first sensor, the third sensor, the second sensor, and the fourth sensor receive microseismic signals in sequence from front to back, and the second section receives signals later than the first section, then the microseismic signal is located to the right of the arch foot of the leading tunnel;

[0020] (6) If the third sensor, the first sensor, the fourth sensor, and the second sensor receive microseismic signals in sequence from front to back, and the second section receives signals later than the first section, then the microseismic signal is located to the left of the arch foot of the leading tunnel;

[0021] (7) If the first and second sensors receive microseismic signals before the third and fourth sensors, the first and second sensors receive microseismic signals almost simultaneously, the third and fourth sensors receive microseismic signals almost simultaneously, and the second section receives signals later than the first section, then the microseismic signal is located at the right arch waist of the advance tunnel;

[0022] (8) If the third and fourth sensors receive microseismic signals before the first and second sensors, the first and second sensors receive microseismic signals almost simultaneously, the third and fourth sensors receive microseismic signals almost simultaneously, and the second section receives the signal later than the first section, then the microseismic event is located at the left side of the lead tunnel;

[0023] (9) The first section receives signals later than the second section, and the seventh, eighth, fifth, and sixth sensors receive microseismic signals at similar times;

[0024] Alternatively, if the seventh and eighth sensors receive microseismic signals before the fifth and sixth sensors, the microseismic signal is generated far behind the tunnel face of the leading tunnel, which is a delayed event or a disturbance event caused by the lagging tunnel to the leading tunnel.

[0025] (10) If the sixth sensor, the fifth sensor, the eighth sensor, and the seventh sensor receive microseismic signals in sequence from front to back, and the first section receives signals later than the second section, then the microseismic signal is located at or above the spandrel of the lagging hole;

[0026] (11) If the fifth sensor, the sixth sensor, the seventh sensor, and the eighth sensor receive microseismic signals in sequence from front to back, and the first section receives signals later than the second section, then the microseismic event is located at or below the arch foot of the lagging cave;

[0027] (12) If the fifth and sixth sensors receive microseismic signals almost simultaneously, and the seventh and eighth sensors receive microseismic signals almost simultaneously, and the first section receives signals later than the second section, then the microseismic signal is located at the waist of the lagging tunnel.

[0028] Specifically, in case 2, when the sensor of the first section is located between the leading tunnel face and the lagging tunnel face, and the sensor of the second section is behind the lagging tunnel face, the spatial position of the microseismic is distinguished and located using the following method; wherein:

[0029] (1) If any of the cases (1) to (8) occurs, the spatial location of the microseismic event is distinguished and located in the same manner as in case 1;

[0030] (2) If the second sensor (9), the fourth sensor (11), the sixth sensor (15) and the eighth sensor (13) first receive the microseismic signal almost simultaneously, and the first sensor (8), the third sensor (10), the fifth sensor (12) and the seventh sensor (14) then receive the microseismic signal almost simultaneously, then the microseismic signal is located at or above the spandrel between the first section (5) and the second section (6) of the advance tunnel (1);

[0031] (3) If the second sensor (9) and the eighth sensor (15) receive the microseismic signal first, followed by the first sensor (8) and the seventh sensor (14), then the fourth sensor (11) and the sixth sensor (13), and finally the third sensor (10) and the fifth sensor (12), then the microseismic signal is located at the spandrel between the first and second sections (6) of the advance hole (1) and above the right position;

[0032] (4) If the first sensor (8), the third sensor (10), the fifth sensor (12) and the seventh sensor (14) receive the microseismic signal almost simultaneously, and the second sensor (9), the fourth sensor (11), the sixth sensor (15) and the eighth sensor receive the microseismic signal almost simultaneously, then the microseismic signal is located at the arch foot and the lower center position between the first section (5) and the second section (6) of the advance tunnel (1);

[0033] (5) If the first and seventh sensors receive microseismic signals first, followed by the second and eighth sensors, then the third and fifth sensors, and finally the fourth and sixth sensors, then the microseismic signal is located at the arch foot and below the right side between the first and second sections of the advance tunnel;

[0034] (6) If the first, second, seventh, and eighth sensors receive microseismic signals at similar times, and the third, fourth, fifth, and sixth sensors receive signals at similar times, then the microseismic signal is located in the waist and to the right of the first and second sections of the advance tunnel.

[0035] (7) If the fourth and sixth sensors receive microseismic signals before the third and fifth sensors, followed by the second and eighth sensors, and finally by the first and seventh sensors, then the microseismic signal is located at or above the spandrel of the lagging hole, or above and to the left of the spandrel between the first and second sections of the leading hole;

[0036] (8) If the third and fifth sensors receive microseismic signals before the fourth and sixth sensors, followed by the first and seventh sensors, and finally by the second and eighth sensors, then the microseismic signal is located at or below the arch foot of the lagging tunnel, or to the left of or below the arch foot between the first and second sections of the leading tunnel;

[0037] (9) If the third sensor, the fourth sensor, the fifth sensor, and the sixth sensor receive the microseismic signal first within a similar time period, and the first sensor, the second sensor, the seventh sensor, and the eighth sensor receive the microseismic signal second within a similar time period, then the microseismic signal is located at the arch waist of the lagging tunnel, or at the left arch waist between the first and second sections of the leading tunnel.

[0038] Specifically, the value of M is 30-40.

[0039] Specifically, the value of N is 50-60.

[0040] Specifically, microseismic events are differentiated and calibrated according to their positions in space. The microseismic events in the leading tunnel are defined as E1, and the microseismic events in the lagging tunnel are defined as E2. According to the needs of rock burst warning, microseismic events in different tunnels can be distinguished and selected, thereby realizing differentiated quantitative warning of double-track tunnels.

[0041] Compared with existing technologies, this method offers the following advantages: It utilizes the same monitoring system to simultaneously monitor two tunnels. By leveraging the time and location differences between data received by different sensors, it quickly and accurately determines the likely location of the acquired monitoring data. This enables differentiated prediction of rockburst risks in dual-track tunnels using the same microseismic monitoring system, saving significant labor and material costs while ensuring data reliability. Furthermore, distinguishing microseismic data from dual-track tunnels enables the development of differentiated quantitative early warning models for these tunnels, laying the foundation for improving the accuracy of rockburst warnings. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0043] Figure 1 The first and second cross-sectional distribution diagrams provided by the embodiment of the present invention are as follows: Figure 1 ;

[0044] Figure 2 The first and second cross-sectional distribution diagrams provided by the embodiment of the present invention are as follows: Figure 2 ;

[0045] Figure 3 is a schematic diagram of sensor arrangement on a first section provided by an embodiment of the present invention;

[0046] Figure 4 is a schematic diagram of sensor arrangement on a second section provided by an embodiment of the present invention;

[0047] Among them: 1. Advance tunnel; 2. Lagging tunnel; 3. Advance tunnel face; 4. Lagging tunnel face; 5. First section; 6. Second section; 7. Unexcavated rock mass; 8. First sensor; 9. Second sensor; 10. Third sensor; 11. Fourth sensor; 12. Fifth sensor; 13. Sixth sensor; 14. Seventh sensor; 15. Eighth sensor. DETAILED DESCRIPTION

[0048] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0049] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0050] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0051] A method for distinguishing and locating microseismic events in a double-line tunnel comprises the following steps:

[0052] Step 1: Sensor array layout:

[0053] See also Figures 1-4 , at the same section within 30-40 meters from the leading tunnel face 3 (set as the first section 5), the first sensor 8, the second sensor 9, the third sensor 10, and the fourth sensor 11 are installed at the right arch foot, right arch spandrel, left arch foot, and left arch spandrel respectively. Based on this section, at the same section 50-60 meters behind the tunnel face (set as the second section 6), the fifth sensor 12 and the sixth sensor 13 are installed at the arch foot and arch spandrel position of the rock mass on one side of the lagging tunnel 2. The seventh sensor 14 and the eighth sensor 15 are installed at the arch foot and arch spandrel position on the other side of the same section. The lagging tunnel 2 is located on the left side of the leading tunnel 1. All sensors are connected to the same microseismic monitoring system through cables. There is unexcavated rock mass 7 in front of the tunnel face.

[0054] Step 2: Inverse calculation of wave velocity in double-line tunnel:

[0055] Based on the cannon firing information from Leading Hole 1, namely the coordinates and firing time of the cannon, as well as the spatial coordinates of each sensor and the time of signal reception, the travel time equation can be used to obtain the wave velocity of each sensor. Then, by taking the average wave velocity, the average wave velocity in Leading Hole 1 can be obtained. The same method can be used to obtain the average wave velocity in Lagging Hole 2.

[0056] Step 3: Pick up and adjust the microseismic monitoring system waveform:

[0057] Compare the average wave velocities of the leading tunnel 1 and the lagging tunnel 2 obtained in step 2. ① If the wave velocities of the two tunnels are consistent, the same arrival time picking of the same monitoring system can be used to pick up the P and S waves of the waveform information. ② If the wave velocities of the two tunnels are inconsistent, the wave velocity of the leading tunnel 1 is mainly used to set the wave velocity of the microseismic system. Then, according to the travel time equation, set the arrival time as an unknown number, and obtain the arrival time difference of the leading tunnel 1 and the lagging tunnel 2 under each identical sensor. When the obtained waveform is picked up, the sensors of the lagging tunnel 2 are manually adjusted according to the obtained time difference, thereby realizing accurate monitoring and positioning of rock fractures with different wave velocities based on the same microseismic monitoring system.

[0058] The specific process of manual adjustment is as follows: when performing waveform picking, the waveform is first picked based on the actual P-wave arrival time in the waveform. Then, based on the calculated time difference, the P-wave arrival time is adjusted to achieve the goal of uniform arrival time. This operation eliminates the error caused by wave velocity attenuation caused by rock mass heterogeneity between different sensors, making the spatial location of microseismic events located in the leading hole 1 and the lagging hole 2 more accurate.

[0059] Step 4: Determine the spatial location of the microseismic event based on the arrival time of the P wave at each sensor: This can be divided into two situations. For the construction safety of double-line tunnels, the minimum safe spacing between the faces of the leading tunnel 1 and the lagging tunnel 2 is generally more than 50 meters. According to the cross-sectional arrangement of the sensor array, in the first situation, the first and second section 6 sensors are both behind the leading tunnel face 3 and in front of the lagging tunnel face 4. In the second situation, the first section 5 sensors are between the leading tunnel 1 and the lagging tunnel face 4, and the second section 6 sensors are behind the leading tunnel 1 and the lagging tunnel 2. The spatial location of the microseismic event is distinguished and located in two situations.

[0060] Specifically, microseismic events are differentiated and calibrated according to their positions in space. The microseismic event of the leading tunnel 1 is defined as E1, and the microseismic event of the lagging tunnel 2 is defined as E2. According to the needs of rock burst warning, microseismic events in different tunnels can be distinguished and selected, thereby realizing differentiated quantitative warning of double-track tunnels.

[0061] Case 1: If Figure 1 As shown, the sensors of the first and second sections 6 are both behind the leading tunnel face 3 and in front of the lagging tunnel face 4:

[0062] (1) If the second sensor 9 and the fourth sensor 11 receive the microseismic signal almost simultaneously, and the first sensor 8 and the third sensor 10 receive the microseismic signal almost simultaneously, and the second section 6 receives the signal later than the first section 5, then the microseismic signal is located above the spandrel of the advance tunnel 1, eccentrically.

[0063] (2) If the second sensor 9, the fourth sensor 11, the first sensor 8, and the third sensor 10 receive microseismic signals in sequence from front to back, and the second section 6 receives signals later than the first section 5, then the microseismic signal is located above and slightly to the right of the spandrel of the leading tunnel 1;

[0064] (3) If the fourth sensor 11, the second sensor 9, the third sensor 10, and the first sensor 8 receive microseismic signals in sequence from front to back, and the second section 6 receives signals later than the first section 5, then the microseismic signal is located above and to the left of the spandrel of the leading tunnel 1;

[0065] (4) If the first sensor 8 and the third sensor 10 receive microseismic signals almost simultaneously, followed by the second sensor 9 and the fourth sensor 11, and the second section 6 receives signals later than the first section 5, then the microseismic signal is located below the arch foot of the advance tunnel 1, eccentrically.

[0066] (5) If the first sensor 8, the third sensor 10, the second sensor 9, and the fourth sensor 11 receive microseismic signals in sequence from front to back, and the second section 6 receives signals later than the first section 5, then the microseismic signal is located to the right of the arch foot of the leading tunnel 1;

[0067] (6) If the third sensor 10, the first sensor 8, the fourth sensor 11, and the second sensor 9 receive microseismic signals in sequence from front to back, and the second section 6 receives signals later than the first section 5, then the microseismic signal is located to the left of the arch foot of the leading tunnel 1;

[0068] (7) If the first sensor 8 and the second sensor 9 receive microseismic signals before the third sensor 10 and the fourth sensor 11, the first sensor 8 and the second sensor 9 receive microseismic signals almost simultaneously, the third sensor 10 and the fourth sensor 11 receive microseismic signals almost simultaneously, and the second section 6 receives signals later than the first section 5, then the microseismic event is located at the right waist of the advance tunnel 1;

[0069] (8) If the third sensor 10 and the fourth sensor 11 receive microseismic signals before the first sensor 8 and the second sensor 9, the first sensor 8 and the second sensor 9 receive microseismic signals almost simultaneously, the third sensor 10 and the fourth sensor 11 receive microseismic signals almost simultaneously, and the second section 6 receives the signal later than the first section 5, then the microseismic event is located at the left waist of the advanced tunnel 1;

[0070] (9) The first section 5 receives signals later than the second section 6, and the seventh sensor 14, the eighth sensor 15, the fifth sensor 12, and the sixth sensor 13 receive microseismic signals at similar times;

[0071] Alternatively, if the seventh sensor 14 and the eighth sensor 15 receive the microseismic signal before the fifth sensor 12 and the sixth sensor 13, the microseismic signal is generated far behind the leading tunnel face 3, which is a delayed event or a disturbance event caused by the lagging tunnel 2 to the leading tunnel 1.

[0072] (10) If the sixth sensor 13, the fifth sensor 12, the eighth sensor 15, and the seventh sensor 14 receive microseismic signals in sequence from front to back, and the first section 5 receives signals later than the second section 6, then the microseismic signal is located at or above the spandrel of the lag hole 2;

[0073] (11) If the fifth sensor 12, the sixth sensor 13, the seventh sensor 14, and the eighth sensor 15 receive microseismic signals in sequence from front to back, and the first section 5 receives signals later than the second section 6, then the microseismic event is located at or below the arch foot of the delayed hole 2;

[0074] (12) If the fifth sensor 12 and the sixth sensor 13 receive the microseismic signal almost simultaneously, and the seventh sensor 14 and the eighth sensor 15 receive the microseismic signal almost simultaneously, and the first section 5 receives the signal later than the second section 6, then the microseismic signal is located at the waist of the lagging hole 2.

[0075] Case 2: If Figure 2 As shown, the leading tunnel face 3 is behind the first and second section 6 sensors, and the lagging tunnel face 4 is behind the first section 5 and in front of the second section 6:

[0076] (1) If the second sensor 9 and the fourth sensor 11 receive the microseismic signal almost simultaneously, and the first sensor 8 and the third sensor 10 receive the microseismic signal almost simultaneously, and the second section 6 receives the signal later than the first section 5, then the microseismic signal is located above the spandrel of the advance tunnel 1, eccentrically.

[0077] (2) If the second sensor 9, the fourth sensor 11, the sixth sensor 15 and the eighth sensor 13 first receive the microseismic signal almost simultaneously, and the first sensor 8, the third sensor 10, the fifth sensor 12 and the seventh sensor 14 then receive the microseismic signal almost simultaneously, then the microseismic signal is located at or above the spandrel between the first section (5) and the second section (6) of the advance tunnel (1);

[0078] (3) If the fourth sensor 11, the second sensor 9, the third sensor 10, and the first sensor 8 receive microseismic signals in sequence from front to back, and the second section 6 receives signals later than the first section 5, then the microseismic signal is located above and to the left of the spandrel of the leading tunnel 1;

[0079] (4) If the first sensor 8 and the third sensor 10 receive microseismic signals almost simultaneously, followed by the second sensor 9 and the fourth sensor 11, and the second section 6 receives signals later than the first section 5, then the microseismic signal is located below the arch foot of the advance tunnel 1, eccentrically.

[0080] (4) If the first sensor 8, the third sensor 10, the fifth sensor 12 and the seventh sensor 14 receive the microseismic signal almost simultaneously, and the second sensor 9, the fourth sensor 11, the sixth sensor 15 and the eighth sensor 13 receive the microseismic signal almost simultaneously, then the microseismic signal is located at the arch foot and the center position below between the first section 5 and the second section 6 of the advance tunnel 1;

[0081] (5) If the first sensor 8, the third sensor 10, the second sensor 9, and the fourth sensor 11 receive microseismic signals in sequence from front to back, and the second section 6 receives signals later than the first section 5, then the microseismic signal is located to the right of the arch foot of the leading tunnel 1;

[0082] (6) If the third sensor 10, the first sensor 8, the fourth sensor 11, and the second sensor 9 receive microseismic signals in sequence from front to back, and the second section 6 receives signals later than the first section 5, then the microseismic signal is located to the left of the arch foot of the leading tunnel 1;

[0083] (7) If the first sensor 8 and the second sensor 9 receive microseismic signals before the third sensor 10 and the fourth sensor 11, the first sensor 8 and the second sensor 9 receive microseismic signals almost simultaneously, the third sensor 10 and the fourth sensor 11 receive microseismic signals almost simultaneously, and the second section 6 receives signals later than the first section 5, then the microseismic event is located at the right waist of the advance tunnel 1;

[0084] (8) If the third sensor 10 and the fourth sensor 11 receive microseismic signals before the first sensor 8 and the second sensor 9, the first sensor 8 and the second sensor 9 receive microseismic signals almost simultaneously, the third sensor 10 and the fourth sensor 11 receive microseismic signals almost simultaneously, and the second section 6 receives the signal later than the first section 5, then the microseismic event is located at the left waist of the advanced tunnel 1;

[0085] (9) The first section 5 receives signals later than the second section 6, and the seventh sensor 14, the eighth sensor 15, the fifth sensor 12, and the sixth sensor 13 receive microseismic signals at similar times;

[0086] Alternatively, if the seventh sensor 14 and the eighth sensor 15 receive the microseismic signal before the fifth sensor 12 and the sixth sensor 13, the microseismic signal is generated far behind the leading tunnel face 3, which is a delayed event or a disturbance event caused by the lagging tunnel 2 to the leading tunnel 1.

[0087] (10) If the sixth sensor 13, the fifth sensor 12, the eighth sensor 15, and the seventh sensor 14 receive microseismic signals in sequence from front to back, and the first section 5 receives signals later than the second section 6, then the microseismic signal is located at or above the spandrel of the lag hole 2;

[0088] (11) If the fifth sensor 12, the sixth sensor 13, the seventh sensor 14, and the eighth sensor 15 receive microseismic signals in sequence from front to back, and the first section 5 receives signals later than the second section 6, then the microseismic event is located at or below the arch foot of the delayed hole 2;

[0089] (12) If the fifth sensor 12 and the sixth sensor 13 receive the microseismic signal almost simultaneously, and the seventh sensor 14 and the eighth sensor 15 receive the microseismic signal almost simultaneously, and the first section 5 receives the signal later than the second section 6, then the microseismic signal is located at the waist of the lagging hole 2.

[0090] Specifically, in case 2, when the sensor of the first section 5 is located between the leading tunnel face 3 and the lagging tunnel face 4, and the sensor of the second section 6 is behind the lagging tunnel face 4, the spatial position of the microseismic is distinguished and located using the following method; wherein:

[0091] (1) If any of the cases (1) to (8) occurs, the spatial location of the microseismic event is distinguished and located in the same manner as in case 1;

[0092] (2) If the second sensor 9 and the fourth sensor 11 first receive the microseismic signal almost simultaneously; or,

[0093] If the eighth sensor 15 and the sixth sensor 13 first receive the microseismic signal almost simultaneously, the microseismic signal is located at the spandrel between the first section 5 and the second section 6 of the advance tunnel 1 and above the center position;

[0094] (3) If the second sensor 9 and the eighth sensor 15 receive the microseismic signal first, followed by the first sensor 8 and the seventh sensor 14, then the fourth sensor 11 and the sixth sensor 13, and finally the third sensor 10 and the fifth sensor 12, then the microseismic signal is located at the spandrel between the first and second sections 6 of the advance tunnel 1 and above the right position;

[0095] (4) If the first sensor 8 and the third sensor 10 first receive the microseismic signal almost simultaneously; or,

[0096] If the fifth sensor 12 and the seventh sensor 14 receive the microseismic signal almost simultaneously, the microseismic signal is located at the arch foot and the center position below it between the first section 5 and the second section 6 of the advance tunnel 1.

[0097] (5) If the first sensor 8 and the seventh sensor 14 receive the microseismic signal first, followed by the second sensor 9 and the eighth sensor 15, then the third sensor 10 and the fifth sensor 12, and finally the fourth sensor 11 and the sixth sensor 13, then the microseismic signal is located at the arch foot between the first and second sections 6 of the advance tunnel 1 and below the right position;

[0098] (6) If the first sensor 8, the second sensor 9, the seventh sensor 14, and the eighth sensor 15 receive microseismic signals at similar times, and the third sensor 10, the fourth sensor 11, the fifth sensor 12, and the sixth sensor 13 receive signals at similar times, then the microseismic signal is located in the waist and right side between the first and second sections 6 of the advance tunnel 1;

[0099] (7) If the fourth sensor 11 and the sixth sensor 13 receive microseismic signals before the third sensor 10 and the fifth sensor 12, followed by the second sensor 9 and the eighth sensor 15, and finally by the first sensor 8 and the seventh sensor 14, then the microseismic signal is located at or above the spandrel of the lagging hole 2, or above and to the left of the spandrel between the first section 5 and the second section 6 of the leading hole 1;

[0100] (8) If the third sensor 10 and the fifth sensor 12 receive microseismic signals before the fourth sensor 11 and the sixth sensor 13, and the first sensor 8 and the seventh sensor 14 receive them secondarily, and the second sensor 9 and the eighth sensor 15 receive them last, then the microseismic signal is located at or below the arch foot of the lagging hole 2, or at or below the arch foot and to the left between the first and second sections 6 of the leading hole 1;

[0101] (9) If the third sensor 10, the fourth sensor 11, the fifth sensor 12, and the sixth sensor 13 receive the microseismic signal first within a similar time period, and the first sensor 8, the second sensor 9, the seventh sensor 14, and the eighth sensor 15 receive the microseismic signal second within a similar time period, then the microseismic signal is located at the arch waist position of the lagging tunnel 2, or at the arch waist position on the left side between the first and second sections 6 of the leading tunnel 1.

[0102] After all event types are distinguished, the internal data of the microseismic monitoring system can be converted into an Excel table, and the "conditional formatting" function can be used to achieve a thorough distinction of the dual-line microseismic parameters.

[0103] This method uses the same monitoring system to monitor two tunnels simultaneously. By taking advantage of the time and location differences in data received by different sensors, it can quickly and accurately determine the possible locations of the collected monitoring data. This method achieves differentiated prediction of rockburst risks in dual-line tunnels based on the same microseismic monitoring system, saving a large amount of labor and material costs while ensuring data reliability.

[0104] Unless otherwise stated, for any of the technical solutions disclosed in the present invention, if a numerical range is disclosed, the disclosed numerical range is a preferred numerical range. Any person skilled in the art should understand that the preferred numerical range is merely a numerical range that is representative or has a more obvious technical effect among many feasible numerical values. Due to the large number of numerical values, it is impossible to enumerate them exhaustively. Therefore, the present invention discloses some numerical values ​​to illustrate the technical solutions of the present invention. Moreover, the numerical values ​​listed above should not be construed as limiting the scope of protection of the present invention.

[0105] At the same time, if the above-mentioned invention discloses or involves components or structural parts that are fixedly connected to each other, then, unless otherwise stated, the fixed connection can be understood as: a detachable fixed connection (for example, using bolts or screws to connect), and can also be understood as: a non-detachable fixed connection (for example, riveting, welding). Of course, the mutual fixed connection can also be replaced by an integrated structure (for example, manufactured by a casting process) (except where it is obviously impossible to use an integrated forming process).

[0106] In addition, unless otherwise stated, terms used in any of the technical solutions disclosed herein to represent positional relationships or shapes include states or shapes that are similar, analogous, or approximate. Any component provided by the present invention may be assembled from multiple separate components or may be a single component manufactured using an integral molding process.

[0107] The above embodiments are merely examples to clearly illustrate the present invention and are not intended to limit its implementation. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to provide an exhaustive list of all embodiments. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A method for distinguishing and locating microseismic events in a double-line tunnel, characterized in that: The steps include: Step 1: Sensor array layout The cross section of the advance tunnel (1) at a distance of M meters from the tunnel face is defined as the first section (5). Based on the first section (5), the cross section at a distance of N meters behind the tunnel face of the advance tunnel (1) is defined as the second section (6). A first sensor (8), a second sensor (9), a third sensor (10) and a fourth sensor (11) are respectively installed at the arch foot, the right spandrel, the left arch foot and the left spandrel of the first section (5); a fifth sensor (12) and a sixth sensor (13) are respectively installed at the arch foot and the spandrel of the rock mass on one side of the second section (6) close to the hysteresis hole (2); and a seventh sensor (14) and an eighth sensor (15) are respectively installed at the arch foot and the spandrel on the other side of the second section (6); Step 2: Double-line tunnel wave velocity inversion According to the firing information of the leading hole (1), that is, the coordinates and firing time of the firing, as well as the spatial coordinates of each sensor and the time of receiving the signal, the wave velocity under each sensor is obtained through the travel time equation, and then the average wave velocity is taken to obtain the average wave velocity in the leading hole (1). The same method is used to obtain the average wave velocity in the lagging hole (2); Step 3: Microseismic monitoring system waveform timing pickup and adjustment Compare the average wave velocities of the leading tunnel (1) and the lagging tunnel (2) obtained in step 2. If the wave velocities of the two tunnels are consistent, use the same arrival time picking of the same monitoring system to pick up the P and S waves of the waveform information; if the wave velocities of the two tunnels are inconsistent, take the wave velocity of the leading tunnel (1) as the main one and set the wave velocity. Then, according to the travel time equation, set the arrival time as an unknown number and obtain the arrival time difference of the leading tunnel (1) and the lagging tunnel (2) under each identical sensor. When the waveform is picked up, manually adjust the arrival time of the waveform received by each sensor of the lagging tunnel (2) according to the obtained time difference, thereby realizing accurate monitoring and positioning of rock fractures with different wave velocities based on the same microseismic monitoring system. Step 4: Determine the spatial location of the microseismic event based on the arrival time of the P wave at each sensor.

2. The method for distinguishing and locating microseismic events in a double-line tunnel according to claim 1, characterized in that: Case 1: When the sensors of the first section (5) and the second section (6) are located between the leading tunnel face (3) and the lagging tunnel face (4), the spatial position of the microseismic event is distinguished and located in the following manner; wherein: (1) If the second sensor (9) and the fourth sensor (11) receive the microseismic signal almost simultaneously, and the first sensor (8) and the third sensor (10) receive the microseismic signal almost simultaneously, and the second section (6) receives the signal later than the first section (5), then the microseismic event is located above the spandrel of the advance hole (1) and at a more or less central position; (2) If the second sensor (9), the fourth sensor (11), the first sensor (8), and the third sensor (10) receive microseismic signals in sequence from front to back, and the second section (6) receives signals later than the first section (5), then the microseismic event is located above and slightly to the right of the spandrel of the lead hole (1); (3) If the fourth sensor (11), the second sensor (9), the third sensor (10), and the first sensor (8) receive microseismic signals in sequence from front to back, and the second section (6) receives signals later than the first section (5), then the microseismic event is located above and to the left of the spandrel of the lead hole (1); (4) If the first sensor (8) and the third sensor (10) receive microseismic signals almost simultaneously, followed by the second sensor (9) and the fourth sensor (11), and the second section (6) receives signals later than the first section (5), then the microseismic signal is located below the arch foot of the advance tunnel (1) and at a position slightly off-center; (5) If the first sensor (8), the third sensor (10), the second sensor (9), and the fourth sensor (11) receive microseismic signals in sequence from front to back, and the second section (6) receives signals later than the first section (5), then the microseismic event is located to the right of the arch foot of the leading hole (1); (6) If the third sensor (10), the first sensor (8), the fourth sensor (11), and the second sensor (9) receive microseismic signals in sequence from front to back, and the second section (6) receives signals later than the first section (5), then the microseismic event is located to the left of the arch foot of the leading hole (1); (7) If the first sensor (8) and the second sensor (9) receive the microseismic signal before the third sensor (10) and the fourth sensor (11), the first sensor (8) and the second sensor (9) receive the microseismic signal almost simultaneously, the third sensor (10) and the fourth sensor (11) receive the microseismic signal almost simultaneously, and the second section (6) receives the signal later than the first section (5), then the microseismic event is located at the right arch waist of the advance hole (1); (8) If the third sensor (10) and the fourth sensor (11) receive the microseismic signal before the first sensor (8) and the second sensor (9), the first sensor (8) and the second sensor (9) receive the microseismic signal almost simultaneously, the third sensor (10) and the fourth sensor (11) receive the microseismic signal almost simultaneously, and the second section (6) receives the signal later than the first section (5), then the microseismic event is located at the left side of the arch waist of the advance hole (1); (9) The first section (5) receives signals later than the second section (6), and the seventh sensor (14), the eighth sensor (15), the fifth sensor (12), and the sixth sensor (13) receive microseismic signals at similar times; Alternatively, if the seventh sensor (14) and the eighth sensor (15) receive the microseismic signal before the fifth sensor (12) and the sixth sensor (13), the microseismic event is generated far behind the leading tunnel face (3), and is a lag event or a disturbance event caused by the lagging tunnel (2) to the leading tunnel (1); (10) If the sixth sensor (13), the fifth sensor (12), the eighth sensor (15), and the seventh sensor (14) receive microseismic signals in sequence from front to back, and the first section (5) receives signals later than the second section (6), then the microseismic signal is located at or above the spandrel of the lag hole (2); (11) If the fifth sensor (12), the sixth sensor (13), the seventh sensor (14), and the eighth sensor (15) receive microseismic signals in sequence from front to back, and the first section (5) receives signals later than the second section (6), then the microseismic event is located at or below the arch foot of the lagging hole (2); (12) If the fifth sensor (12) and the sixth sensor (13) receive the microseismic signal almost simultaneously, and the seventh sensor (14) and the eighth sensor (15) receive the microseismic signal almost simultaneously, and the first section (5) receives the signal later than the second section (6), then the microseismic signal is located at the waist of the lagging hole (2).

3. The method for distinguishing and locating microseismic events in a double-line tunnel according to claim 2, characterized in that: Case 2: When the sensor of the first section (5) is located between the leading tunnel face (3) and the lagging tunnel face (4), and the sensor of the second section (6) is behind the lagging tunnel face (4), the spatial position of the microseismic event is distinguished and located in the following manner; wherein: (1) If any of the cases (1) to (8) occurs, the spatial location of the microseismic event is distinguished and located in the same manner as in case 1; (2) If the second sensor (9), the fourth sensor (11), the sixth sensor (13) and the eighth sensor (15) first receive the microseismic signal almost simultaneously, and the first sensor (8), the third sensor (10), the fifth sensor (12) and the seventh sensor (14) then receive the microseismic signal almost simultaneously, then the microseismic signal is located at or above the spandrel between the first section (5) and the second section (6) of the advance tunnel (1); (3) If the second sensor (9) and the eighth sensor (15) receive the microseismic signal first, followed by the first sensor (8) and the seventh sensor (14), then the fourth sensor (11) and the sixth sensor (13), and finally the third sensor (10) and the fifth sensor (12), then the microseismic signal is located at the spandrel between the first and second sections (6) of the advance hole (1) and above the right position; (4) If the first sensor (8), the third sensor (10), the fifth sensor (12) and the seventh sensor (14) receive the microseismic signal almost simultaneously, and the second sensor (9), the fourth sensor (11), the sixth sensor (13) and the eighth sensor receive the microseismic signal almost simultaneously, then the microseismic signal is located at the arch foot and the lower center position between the first section (5) and the second section (6) of the advance tunnel (1); (5) If the first sensor (8) and the seventh sensor (14) receive the microseismic signal first, followed by the second sensor (9) and the eighth sensor (15), then the third sensor (10) and the fifth sensor (12), and finally the fourth sensor (11) and the sixth sensor (13), then the microseismic signal is located at the arch foot between the first and second sections (6) of the advance tunnel (1) and below and slightly to the right; (6) If the first sensor (8), the second sensor (9), the seventh sensor (14), and the eighth sensor (15) receive microseismic signals at approximately the same time, and the third sensor (10), the fourth sensor (11), the fifth sensor (12), and the sixth sensor (13) receive signals at approximately the same time, then the microseismic signal is located in the arch waist and slightly to the right between the first and second sections (6) of the advance tunnel (1); (7) If the fourth sensor (11) and the sixth sensor (13) receive the microseismic signal before the third sensor (10) and the fifth sensor (12), followed by the second sensor (9) and the eighth sensor (15), and finally by the first sensor (8) and the seventh sensor (14), then the microseismic signal is located at or above the spandrel of the lagging hole (2), or at a position above and to the left of the spandrel between the first section (5) and the second section (6) of the leading hole (1); (8) If the third sensor (10) and the fifth sensor (12) receive the microseismic signal before the fourth sensor (11) and the sixth sensor (13), followed by the first sensor (8) and the seventh sensor (14), and finally by the second sensor (9) and the eighth sensor (15), then the microseismic signal is located at or below the arch foot of the lagging hole (2), or at or below the arch foot and to the left between the first and second sections (6) of the leading hole (1); (9) If the third sensor (10), the fourth sensor (11), the fifth sensor (12), and the sixth sensor (13) receive the microseismic signal first within a similar time period, and the first sensor (8), the second sensor (9), the seventh sensor (14), and the eighth sensor (15) receive the microseismic signal second within a similar time period, then the microseismic signal is located at the arch waist position of the lagging hole (2), or at the arch waist position on the left side between the first and second sections (6) of the leading hole (1).

4. The method for distinguishing and locating microseismic events in a double-line tunnel according to claim 2, characterized in that: The value of M is 30-40.

5. The method for distinguishing and locating microseismic events in a double-line tunnel according to claim 2, characterized in that: The value of N is 50-60.

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