A small-scale gauge function determination method based on a microseismic monitoring system

Abstract

A kind of small scale gauge function determination method based on microseismic monitoring system, steps include in the small scale range of mine, according to the gauge function formula to be fitted and the installation of mining area range receiving strong mine seismic event multiple microseismic monitoring station;Strong mine seismic event vibration waveforms generated by mining activity are recorded completely using microseismic monitoring station, and maximum displacement amplitude is obtained by calculation;According to maximum displacement amplitude and the magnitude and focus position of strong mine seismic event monitored by seismic monitoring network, the gauge function value corresponding to each microseismic monitoring station in small scale range and the distance between microseismic monitoring station and focus are obtained by inverse calculation;The numerical fitting of gauge function value and the distance between monitoring station and focus is obtained, and the gauge function calculation formula of small scale range is obtained.The present application realizes to provide more accurate gauge function for the calculation of strong mine seismic magnitude under specific region or specific condition, improves the accuracy and reliability of strong mine seismic magnitude calculation under small scale range.

Description

Technical Field

[0001] This invention relates to a method for determining small-scale gauge functions based on a microseismic monitoring system, belonging to the technical field of strong mining earthquake magnitude. Background Technology

[0002] In the field of seismology, gauge functions are key tools for converting observed seismic wave amplitudes into earthquake magnitudes. They can accurately correct for the effects of distance variation in seismic wave amplitudes and have a significant impact on earthquake monitoring and research.

[0003] Traditional seismic gauge functions are typically derived from extensive seismic data and geological surveys, particularly effective for mid- to long-distance seismic observation points, reflecting the impact of distance on amplitude. However, this method is less precise at smaller scales (0–5 km). For example, in the case of strong mine-induced earthquakes, existing gauge functions cannot adequately reflect regional geological differences in microseismic monitoring at small scales, making it impossible to accurately calculate the magnitude of strong mine-induced earthquakes. This inaccuracy leads to inconsistencies between the magnitudes calculated by microseismic monitoring and those published by seismic authorities. Furthermore, even with the same instruments and foundations, significant differences in magnitudes measured at different observation points prevent equivalent comparisons of magnitudes across different regions. Summary of the Invention

[0004] This invention provides a method for determining small-scale gauge functions based on a microseismic monitoring system. This method can accurately calculate gauge function values ​​within a small-scale range, thereby improving the accuracy and reliability of strong mining earthquake magnitude calculations within a small-scale range.

[0005] To achieve the above objectives, the present invention provides a method for determining a small-scale gauge function based on a microseismic monitoring system, comprising the following steps:

[0006] S1. Within a small-scale area of ​​the mine, multiple microseismic monitoring stations are installed to receive strong mine earthquake events, based on the gauge function formula to be fitted and the mining area.

[0007] S2. Use microseismic monitoring stations to record the waveform of strong mine seismic events generated by mining activities, and calculate the maximum displacement amplitude A.

[0008] S3. Based on the maximum displacement amplitude obtained in S2 and the magnitude and source location of the strong mining earthquake event monitored by the seismic monitoring network, the gauge function values ​​corresponding to each microseismic monitoring station within the small scale range and the distance between the microseismic monitoring station and the source are calculated in reverse.

[0009] S4. By fitting the gauge function value with the distance between the monitoring station and the seismic source, the calculation formula of the gauge function in a small-scale range is obtained.

[0010] Furthermore, the strong mine earthquake event in S1 refers to an event whose seismic wave propagation distance is not less than 10km and is recorded by the seismic monitoring network; the small-scale range refers to the spatial distance r from the location of the strong mine earthquake event to the microseismic monitoring station being between 0 and 5km; the formula for the gauge function to be fitted is: R=αln(r)+β, where R is the gauge function value, and α and β are fitting coefficients.

[0011] Furthermore, the multiple microseismic monitoring stations in S1 include velocity-type, acceleration-type, and displacement-type stations, corresponding to the velocity, acceleration, and displacement values ​​of receiving strong mining seismic wave signals, respectively; the microseismic monitoring stations are arranged at approximately proportional distances from the center point of the mining area, starting at a distance of 100-300m from the center point. The ratio ranges from q = 1.0 to 3.0, ensuring at least 8 monitoring stations within a range of 0–10 km, where r i and r i+1 These are the distances between the i-th microseismic monitoring station and the center point of the mining area, respectively, and the (i+1)-th microseismic monitoring station and the center point of the mining area.

[0012] Furthermore, when a strong mine earthquake event occurs in S2, the microseismic monitoring station is triggered and fully records the seismic wave signal of the strong mine earthquake. When the microseismic monitoring station is velocity-type, the recorded seismic wave signal is a velocity signal; when the microseismic monitoring station is displacement-type, the recorded seismic wave signal is a displacement signal; when the microseismic monitoring station is acceleration-type, the recorded seismic wave signal is an acceleration signal. The maximum displacement amplitude A refers to: when the recorded signal of the microseismic monitoring station is a velocity signal, the displacement signal is obtained by using a first discrete integration method over the sampling time, and then the maximum value A of the absolute value of the displacement signal is directly found; when the recorded signal is a displacement signal, the maximum value A of the absolute value of the displacement signal is directly found; when the recorded signal is an acceleration signal, the displacement signal is obtained by using a second discrete integration method over the sampling time, and then the maximum value A of the absolute value of the displacement signal is directly found.

[0013] Furthermore, the magnitude of the strong mining earthquake event monitored by the seismic monitoring network in S3 is calculated using the following formula: M L =lg(A)+R; The formula for back-calculating the gauge function values ​​corresponding to each microseismic monitoring station within a small scale range is: R j =M L -lg(A j In the formula, R j Let A be the gauge function value corresponding to the j-th station within a small-scale range. j M represents the maximum displacement amplitude of the j-th station. L The magnitude is calculated; the distance r between the microseismic monitoring station and the epicenter is then obtained through back-calculation. j The formula is: In the formula, xj y j z j Let x0, y0, and z0 be the spatial coordinates of the j-th microseismic monitoring station; x0, y0, and z0 are the spatial coordinates of the source of the strong mine earthquake.

[0014] Furthermore, in S4, the numerical fitting of the gauge function value with the distance between the monitoring station and the seismic source is performed using the linear least squares method to obtain α and β, with the specific formula as follows:

[0015]

[0016] In the formula, m is the total number of installed microseismic monitoring stations; by determining the gauging function calculation formula R=αln(r)+β for a small scale range, the gauging function R corresponding to the distance between any seismic source and the monitoring station at a small scale is obtained.

[0017] This invention involves installing multiple microseismic monitoring stations within a small-scale mining area, based on a gauge function formula to be fitted and the mining zone's boundaries, to receive strong mining earthquake events. These stations record the complete waveforms of the strong mining earthquake events generated by mining activities and calculate the maximum displacement amplitude. Based on the maximum displacement amplitude and the magnitude and source location of the strong mining earthquake events monitored by the seismic monitoring network, the gauge function values ​​corresponding to each microseismic monitoring station within the small-scale area, as well as the distance between the microseismic monitoring station and the source, are calculated. By fitting the gauge function values ​​to the distances between the monitoring stations and the source, a gauge function calculation formula for the small-scale area is obtained. This invention provides a more accurate gauge function for calculating the magnitude of strong mining earthquakes in specific regions or under specific conditions, contributing to strong mining earthquake risk assessment, the design of strong mining earthquake early warning systems, and improving the accuracy and reliability of strong mining earthquake magnitude calculations at small scales. Attached Figure Description

[0018] Figure 1 This is a flowchart of the process of this invention;

[0019] Figure 2 This is a schematic diagram of the microseismic monitoring station layout in an embodiment of the present invention;

[0020] Figure 3 This is a waveform diagram of a strong mine earthquake event in an embodiment of the present invention;

[0021] Figure 4 This is a graph showing the velocity signal integration and maximum displacement amplitude results of microseismic monitoring station No. 2 in this embodiment of the invention;

[0022] Figure 5 This is a schematic diagram of fitting the gauge function expression in an embodiment of the present invention. Detailed Implementation

[0023] The invention will now be further described with reference to the accompanying drawings.

[0024] like Figure 1 As shown, a method for determining a small-scale gauge function based on a microseismic monitoring system includes the following steps:

[0025] S1. Within a small-scale area of ​​the mine, multiple microseismic monitoring stations are installed to receive strong mine earthquake events, based on the gauge function formula to be fitted and the mining area.

[0026] S2. Use microseismic monitoring stations to record the waveform of strong mine seismic events generated by mining activities, and calculate the maximum displacement amplitude A.

[0027] S3. Based on the maximum displacement amplitude obtained in S2 and the magnitude and source location of the strong mining earthquake event monitored by the seismic monitoring network, the gauge function values ​​corresponding to each microseismic monitoring station within the small scale range and the distance between the microseismic monitoring station and the source are calculated in reverse.

[0028] S4. By fitting the gauge function value with the distance between the monitoring station and the seismic source, the calculation formula of the gauge function in a small-scale range is obtained.

[0029] This paper analyzes the case of determining small-scale gauge functions using a microseismic monitoring system and strong seismic signals at the 6306 working face of a certain mine. The analysis and implementation steps of the method of this invention are as follows:

[0030] (1) As Figure 2 As shown, 16 microseismic monitoring stations, all velocity-type, were deployed near the 6306 working face of a certain mine. Starting 150m from the center point of the 6306 working face, based on the gauge function formula R=αln(r)+β, ... The ratio q is located in the range of [1 2.5] and is distributed further away. The spatial coordinates of the station locations are shown in Table 1:

[0031] Table 1 Spatial coordinates of microseismic monitoring stations

[0032] Serial number j <![CDATA[x j ]]> <![CDATA[y j ]]> <![CDATA[z j ]]> 1 39489749 3921194 -652.097 2 39489898 3921495 -650.04 3 39488884 3921842 -645.7 4 39490241 3921283 -659.6 5 39490587 3921620 -657.83 6 39489486 3922456 -453.4 7 39488514 3921940 -446.8 8 39490566 3922241 -739.15 9 39490410 3922141 -447.407 10 39490079 3923066 -555.9 11 39490665 3923302 -449.6 12 39486865 3924466 -549.2 13 39486295 3925638 -506.1 14 39486582 3926050 -477.25 15 39486906 3926367 -476.1 16 39492074 3928063 -622.6

[0033] (2) A strong mine earthquake event was induced in the 6306 working face during the production process, and the event was recorded by the National Earthquake Monitoring Network.

[0034] (3) Figure 3 As shown, the microseismic monitoring station fully recorded the seismic wave waveform of this strong mine earthquake event, and the recorded seismic wave signal is a velocity signal;

[0035] (4) Figure 4 As shown, the velocity signal is obtained by integrating the velocity signal over the sampling time using the first discrete integration method. The maximum absolute value A of the displacement signal at each of the microseismic monitoring stations is determined sequentially, as shown in Table 2.

[0036] Table 2 Maximum absolute value of displacement signal

[0037] Serial number j <![CDATA[A j / um]]> Serial number j <![CDATA[A j / um]]> 1 96.2 9 85.1 2 132.6 10 48.7 3 85.7 11 30.6 4 91.1 12 17.0 5 89.2 13 13.9 6 48.1 14 13.5 7 97.1 15 12.0 8 94.5 16 5.2

[0038] (5) The magnitude of the strong mining earthquake event released by the National Seismological Bureau is M. L = Level 2.2;

[0039] (6) Based on the inverse calculation formula R j =M L -lg(A j ), using magnitude M L =2.2 Back-calculation of the gauge function values ​​corresponding to each monitoring station within the small-scale range, as shown in Table 3:

[0040] Table 3. Gauge function values ​​corresponding to each microseismic monitoring station.

[0041]

[0042]

[0043] (7) The China Earthquake Administration announced the focal locations of this strong mining earthquake as x0 = 39,489,521.38, y0 = 3,921,310.51, and z0 = -420.71. According to the formula... The calculated distance from the seismic source to the station is shown in Table 4.

[0044] Table 4. Distances of each microseismic monitoring station from the epicenter of a strong mining earthquake event.

[0045] Serial number j <![CDATA[r j / km]]> Serial number j <![CDATA[r j / km]]> 1 3.45E-01 9 1.22E+00 2 4.78E-01 10 1.85E+00 3 8.59E-01 11 2.30E+00 4 7.59E-01 12 4.13E+00 5 1.13E+00 13 5.40E+00 6 1.15E+00 14 5.58E+00 7 1.19E+00 15 5.69E+00 8 1.43E+00 16 7.22E+00

[0046] (8) The following was obtained by fitting the formula using the linear least squares method:

[0047]

[0048] The inverse calculation yields R = αln(r) + β = 0.4319ln(r) + 0.339, and its fitted curve is as follows: Figure 5 As shown.

Claims

1. A method for determining small-scale gauge functions based on a microseismic monitoring system, characterized in that, Includes the following steps: S1. Within a small-scale area of ​​the mine, multiple microseismic monitoring stations are installed to receive strong mine earthquake events, based on the gauge function formula to be fitted and the mining area. S2. Use microseismic monitoring stations to record the waveform of strong mine seismic events generated by mining activities, and calculate the maximum displacement amplitude A. S3. Based on the maximum displacement amplitude obtained in S2 and the magnitude and source location of the strong mining earthquake event monitored by the seismic monitoring network, the gauge function values ​​corresponding to each microseismic monitoring station within the small scale range and the distance between the microseismic monitoring station and the source are calculated in reverse. S4. By fitting the values ​​of the gauge function with the distance between the monitoring station and the seismic source, the calculation formula of the gauge function in a small-scale range is obtained. The aforementioned multiple microseismic monitoring stations include velocity-type, acceleration-type, and displacement-type stations, corresponding to the velocity, acceleration, and displacement values ​​of receiving strong mining seismic wave signals, respectively. The microseismic monitoring stations are arranged at approximately proportional distances from the center point of the mining area, starting at a distance of 100-300m from the center point. The ratio ranges from q = 1.0 to 3.0, ensuring at least 8 monitoring stations within a range of 0 to 10 km, where r i and r i+1 These are the distances between the i-th microseismic monitoring station and the center point of the mining area, respectively; The magnitude of strong mining earthquakes monitored by the aforementioned seismic monitoring network is calculated using the following formula: The formula for back-calculating the gauge function values ​​corresponding to each microseismic monitoring station within a small scale range is as follows: In the formula, Let be the gauge function value corresponding to the j-th station within a small-scale range. Let j be the maximum displacement amplitude of the j-th station. The magnitude was calculated; the distance between the microseismic monitoring station and the epicenter was then obtained through inverse calculation. The formula is: In the formula, , , Let J represent the spatial coordinates of the j-th microseismic monitoring station. , , The spatial coordinates of the epicenter location of the strong mine earthquake; The numerical fitting of the gauge function value and the distance between the monitoring station and the seismic source was obtained using the linear least squares method. and The specific formula is as follows: ； ； In the formula, m represents the total number of installed microseismic monitoring stations; the calculation formula is determined by the gauge function within a small-scale range. This yields the gauge function corresponding to the distance between any seismic source and monitoring station at a small scale. .

2. The method for determining the small-scale gauge function based on a microseismic monitoring system according to claim 1, characterized in that, The strong mining earthquake event in S1 refers to an event whose seismic wave propagation distance is not less than 10 km and is recorded by the seismic monitoring network; the small-scale range refers to the spatial distance r from the location of the strong mining earthquake event to the microseismic monitoring station being between 0 and 5 km; the formula for the gauge function to be fitted is: In the formula, For gauge function values, and represents the fitting coefficient.

3. The method for determining the small-scale gauge function based on a microseismic monitoring system according to claim 1, characterized in that, When a strong mine tremor event occurs in S2, the microseismic monitoring station is triggered and records the seismic wave signal of the strong mine tremor completely. When the microseismic monitoring station is velocity-type, the recorded seismic wave signal is a velocity signal; when the microseismic monitoring station is displacement-type, the recorded seismic wave signal is a displacement signal; when the microseismic monitoring station is acceleration-type, the recorded seismic wave signal is an acceleration signal. The maximum displacement amplitude A refers to: when the recorded signal of the microseismic monitoring station is a velocity signal, the displacement signal is obtained by using a first discrete integration method over the sampling time, and then the maximum value A of the absolute value of the displacement signal is directly found; when the recorded signal is a displacement signal, the maximum value A of the absolute value of the displacement signal is directly found; when the recorded signal is an acceleration signal, the displacement signal is obtained by using a second discrete integration method over the sampling time, and then the maximum value A of the absolute value of the displacement signal is directly found.

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