Profile projection analysis method for coal mine micro-seismic event

Abstract

The invention provides a coal mine micro-seismic event profile projection analysis method, which comprises the following steps of: calculating profile distribution of micro-seismic events according to micro-seismic event data of a coal mine working surface, and directly reflecting roof fracture height and horizon of the micro-seismic events through a working surface micro-seismic event profile projection drawing. According to the method, a basis is provided for managing roof and floor disasters in a mine, and the analysis requirements of the mine on the distribution rule, the aggregation, the seismic source depth and the fault position relation of the micro-seismic events are met.

Description

Technical Field

[0001] The invention relates to the technical field of coal mine microseismic event analysis, and specifically provides a method for profile projection analysis of coal mine microseismic events. Background Art

[0002] Coal mine microseismic events refer to low-energy seismic activities that occur in underground rock formations during coal mining. These microseismic events usually reflect geological processes such as deformation of underground rock masses, stress release, fault activity, and coal seam rupture. Usually, the energy released by microseismic events is small and not enough to cause significant ground vibrations, but it is enough to affect the underground structure of coal mines. Frequent microseismic events can cause shaft and personnel injuries, soil damage, and in some cases, brick and dust explosions, posing a threat to mine safety and stability.

[0003] In order to reduce the impact of the above mine disasters, microseismic monitoring and microseismic data are usually collected through underground monitoring equipment to analyze changes in the distribution, frequency, energy release, etc. of events, providing a basis for rock stability assessment and disaster warning within the monitoring range.

[0004] At present, the analysis of microseismic events is basically to analyze a single event, or to analyze all microseismic events within a period of time in the form of a list. The analysis indicators are mainly the microseismic energy size, location, and magnitude. The maximum event energy, total energy, frequency and other data within a period of time are summarized. This analysis method is relatively scattered and not intuitive, and cannot meet the needs of coal mines for specific analysis of microseismic events in the monitoring working surface. Summary of the invention

[0005] The technical task of the present invention is to provide a method for profile projection analysis of microseismic events in coal mines in response to the above-mentioned problems.

[0006] A method for cross-sectional projection analysis of microseismic events in coal mines. The method calculates the cross-sectional distribution of microseismic events based on the microseismic event data of the coal mine working face, and directly reflects the roof rupture height, the layer position of the microseismic event, and the height of the microseismic event above or below the roof through the cross-sectional projection diagram of the microseismic events of the working face, so as to provide a basis for mine management of roof and floor disasters and meet the mine's analysis needs on the distribution law, aggregation, focal depth and fault position relationship of microseismic events.

[0007] Furthermore, the implementation steps of the method are as follows: Step 1: Obtain the working face coordinate information, strike or dip length, elevation information, and working face tunnel coordinate information to define the working face scope; Step 2: Determine the coordinate system and coordinate axis of the current working surface; Step 3: Query the microseismic events in the current working surface, transform the microseismic calculation results into coordinates in the new coordinate system; Step 4: Draw the cross-sectional projection diagram of the microseismic events on the working face according to the coordinates in the new coordinate system.

[0008] Furthermore, the working surface range definition is used to determine whether each microseismic event falls within the current working surface range, and the determination process is as follows: Set the work surface range point coordinate dataset to { p i （x i ，y i ）},in p i ( x i , y i ) represents the first i Point coordinates; Using the convex hull algorithm - Graham scanning method, the coordinates of all points are translated so that the starting point of the current working surface p 1 ( x 1 , y 1 ) as the origin, traverse all the data in the data set, and calculate the convex hull; Then, the minimum area circumscribed rectangle of the convex hull is calculated by the rotating caliper algorithm to ensure that the range is the minimum rectangle containing the working surface, which is set to ABCD as the boundary of the current working surface.

[0009] Furthermore, in step 2, the coordinate system and coordinate axis of the current working surface are determined as follows: The starting point A of the working face is used as the origin of the new coordinate axis for rotation, and a relative coordinate system is established with the x' axis in the mining direction of the working face and the y' axis in the direction of the straight line where the vertical roadway is located. The rotation angle is θ, according to the formula: , Rotate the ABCD points on the boundary of the work surface, and the calculation method is as follows: , ,

[0010] Thus, the rotated coordinates A', B', C', D' are obtained.

[0011] Furthermore, in step 3, the coordinate conversion process is as follows: According to the new coordinate system, the coordinates of the microseismic events occurring at the current working face are offset corrected; Firstly, according to the rotation angle of the new coordinates of the current working surface, the coordinate data of the microseismic event after rotation is calculated; Then, according to the translation of the starting point coordinates of working surface A, the distance after translation is calculated, and finally the coordinates after microseismic event correction are obtained according to the translation distance and the rotated data.

[0012] Furthermore, the coordinate transformation calculation process is as follows: Suppose a microseismic event on the current working face is P(x p ,y p ), according to the trigonometric function, calculate the converted microseismic event P'(x P' ,y P' ), the calculation formula is as follows: , ,

[0013] Where: (x v ,y v ) is the rotated coordinate, Then the relative distance is used to calculate the horizontal coordinate after translation. The calculation process is as follows: After rotation and translation, the distance from point P' to the starting point A of the current working surface and the vertical distance from point P to AB will not change. Using this relationship, the projection length of P on AB is obtained and set to L; Using the following formula: , Let M be the foot of the perpendicular from microseismic event P to AB, ( x d , y d ) is the coordinate of M, which is obtained from the linear equations of P and AB; Finally, we get the coordinate x of the microseismic event P' P' = L + x v ,y P' =y v .

[0014] The coordinates of other microseismic events within the query time period are also cyclically offset corrected using the above method.

[0015] Furthermore, the process of drawing the cross-sectional projection diagram of the microseismic event in step 4 is as follows: The elevation information is used as the vertical coordinate, the starting point of the current working face and the acquired working face strike length or dip length are used as the horizontal coordinate, the acquired current working face tunnel coordinates are rendered in the profile projection diagram as a reference, and finally displayed in the form of a microseismic event profile projection diagram for analysis.

[0016] Compared with the prior art, the method for cross-sectional projection analysis of microseismic events in coal mines of the present invention has the following outstanding beneficial effects: The method of the present invention enables the mine to conduct a specific analysis of the microseismic events in the monitored working face, so that it can meet the needs of mine production hazard research. The cross-sectional projection diagram of the microseismic events in the working face can directly reflect the height of the roof rupture, the layer where the microseismic event is located, and how many meters the microseismic event is located on the roof (or below the roof), providing a basis for the mine to manage roof and floor disasters. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is the ABCD rectangular diagram of the current working surface range; Figure 2 It is a schematic diagram of the coordinate system of the current working surface after rotation; Figure 3 It is the projection diagram of the microseismic event profile of the current working face. DETAILED DESCRIPTION

[0018] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0019] A method for cross-sectional projection analysis of microseismic events in coal mines. The method calculates the cross-sectional distribution of microseismic events based on the microseismic event data of the coal mine working face, and directly reflects the roof rupture height, the layer position of the microseismic event, and the height of the microseismic event above or below the roof through the cross-sectional projection diagram of the microseismic events of the working face, so as to provide a basis for mine management of roof and floor disasters and meet the mine's analysis needs on the distribution law, aggregation, focal depth and fault position relationship of microseismic events.

[0020] The implementation steps of the method are as follows: Step 1: Obtain the working face coordinate information, strike or dip length, elevation information, and working face tunnel coordinate information to define the working face scope; For example, a coal mine under mining is obtained, and the scope of its current working face is defined as follows: the starting point of the working face is A (20490100.10, 3921500.60), B (20490300, 3921600), C (20490800.20, 3921200.11), D (20490200.10, 3921200.11), the angle between the mining direction and the plane , Step 2: Determine the coordinate system and coordinate axis of the current working surface; Step 3: Query the microseismic events in the current working surface, transform the microseismic calculation results into coordinates in the new coordinate system; Step 4: Draw the cross-sectional projection diagram of the microseismic events on the working face according to the coordinates in the new coordinate system.

[0021] like Figure 1 As shown, the working surface range definition is used to determine whether each microseismic event falls within the current working surface range, and the determination process is as follows: Set the work surface range point coordinate dataset to { p i （x i ，y i ）},in p i ( x i , y i ) represents the first i Point coordinates; Using the convex hull algorithm - Graham scanning method, the coordinates of all points are translated so that the starting point of the current working surface p 1 ( x 1 , y 1 ) as the origin, traverse all the data in the data set, and calculate the convex hull; Then, the minimum area circumscribed rectangle of the convex hull is calculated by the rotating caliper algorithm to ensure that the range is the minimum rectangle containing the working surface, which is set to ABCD as the boundary of the current working surface.

[0022] In step 2, the process of determining the coordinate system and coordinate axis of the current working surface is as follows: like Figure 2 As shown, the starting point A of the working face is rotated as the origin of the new coordinate axis, and a relative coordinate system is established with the x' axis in the mining direction of the working face and the y' axis in the direction of the straight line where the vertical roadway is located. The rotation angle is θ, according to the formula: ,

[0023] Rotate the ABCD points on the boundary of the work surface, and the calculation method is as follows: , ,

[0024] Thus, the rotated coordinates A', B', C', D' are obtained.

[0025] The specific calculation is as follows: Rotate with A (20490100.10, 3921500.60) as the origin of the new coordinates, and substitute the coordinates of point A into the formula: , ,

[0026] We get A' (6911463.043, 12268232.86), and we also substitute the coordinates of point B, and get B' (6911499.9, 12268405.5) according to the formula. We substitute the coordinates of point C, and get C' (6911916.43, 12268275.78). We substitute the coordinates of point D, and get D' (6911656.59, 12268015.94). The current working surface range after rotation is obtained as A'B'C'D'.

[0027] In step 3, the coordinate conversion process is as follows: According to the new coordinate system, the coordinates of the microseismic events occurring at the current working face are offset corrected; Firstly, according to the rotation angle of the new coordinates of the current working surface, the coordinate data of the microseismic event after rotation is calculated; Then, according to the translation of the starting point coordinates of working surface A, the distance after translation is calculated, and finally the coordinates after microseismic event correction are obtained according to the translation distance and the rotated data.

[0028] The coordinate transformation calculation process is as follows: Suppose a microseismic event on the current working face is P(x p ,y p ), according to the trigonometric function, calculate the converted microseismic event P'(x P' ,y P' ), the calculation formula is as follows: , ,

[0029] Where: (x v ,y v ) is the rotated coordinate, Take event P1 (20490461.41, 3921372.29) in Table 1 as an example. After rotation, the horizontal and vertical coordinates are calculated as follows: , ,

[0030] Get (x v ,y v ) is (6911683.65, 12268278.19), Then the relative distance is used to calculate the horizontal coordinate after translation. The calculation process is as follows: After rotation and translation, the distance from point P' to the starting point A of the current working surface and the vertical distance from point P to AB will not change. Using this relationship, the projection length of P on AB is obtained and set to L; Using the following formula: ,

[0031] Let M be the foot of the perpendicular from microseismic event P to AB, ( x d , y d ) is the coordinate of M, which is obtained from the linear equations of P and AB; The equation of the line where AB is located is obtained from the coordinates of points AB: (y-3921500.60)*99.4=(x-20490100.10)*199.9, From the microseismic event P1 in Table 1 (20490461.41, 3921372.29), we get the foot of the perpendicular from P1 to AB (20490120.57, 3921541.76), and use the above projection formula: ,

[0032] Finally, we get the coordinate x of the microseismic event P' P' = L + x v ,y P' =y v , Substituting the values ​​calculated above, the projection coordinates of the microseismic event P1 are (6911729.62, 12268278.19).

[0033] The coordinates of other microseismic events in Table 1 can also be cyclically corrected using the above method.

[0034] Table 1 Original microseismic event data in the current working face:

[0035] The process of drawing the cross-sectional projection diagram of the microseismic event in step 4 is as follows: like Figure 3 As shown, the elevation information is used as the vertical coordinate, the starting point of the current working face and the obtained working face strike length or dip length are used as the horizontal coordinate, and the obtained current working face tunnel coordinates are rendered in the profile projection diagram as a reference, and finally displayed in the form of a microseismic event profile projection diagram for analysis. By analyzing all the corrected microseismic event projections of the current face, the distribution position of the vibration, the position from the tunnel, the layer and other information can be intuitively seen.

[0036] The embodiments described above are only preferred specific implementations of the present invention. Common changes and substitutions made by those skilled in the art within the scope of the technical solution of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for cross-sectional projection analysis of microseismic events in coal mines, characterized in that: The method calculates the profile distribution of microseismic events based on the microseismic event data of the coal mine working face, and directly reflects the roof rupture height, the layer position of the microseismic event, and the length of the microseismic event on or below the roof through the microseismic event profile projection diagram of the working face.

2. The method for cross-sectional projection analysis of microseismic events in coal mines according to claim 1, characterized in that: The implementation steps of the method are as follows: Step 1: Obtain the working face coordinate information, strike or dip length, elevation information, and working face tunnel coordinate information to define the working face scope; Step 2: Determine the coordinate system and coordinate axis of the current working surface; Step 3: Query the microseismic events in the current working surface, transform the microseismic calculation results into coordinates in the new coordinate system; Step 4: Draw the cross-sectional projection diagram of the microseismic events on the working face according to the coordinates in the new coordinate system.

3. The method for cross-sectional projection analysis of microseismic events in coal mines according to claim 1, characterized in that: The working surface range definition is used to determine whether each microseismic event falls within the current working surface range. The determination process is as follows: Set the work surface range point coordinate dataset to { p i （x i ，y i ） },in p i ( x i , y i ) represents the first i Point coordinates; Using the convex hull algorithm - Graham scanning method, the coordinates of all points are translated so that the starting point of the current working surface p 1 ( x 1 , y 1 ) as the origin, traverse all the data in the data set, and calculate the convex hull; Then, the minimum area circumscribed rectangle of the convex hull is calculated by the rotating caliper algorithm to ensure that the range is the minimum rectangle containing the working surface, which is set to ABCD as the boundary of the current working surface.

4. The method for cross-sectional projection analysis of microseismic events in coal mines according to claim 2, characterized in that: In step 2, the process of determining the coordinate system and coordinate axis of the current working surface is as follows: The starting point A of the working face is used as the origin of the new coordinate axis for rotation, and a relative coordinate system is established with the x' axis in the mining direction of the working face and the y' axis in the direction of the straight line where the vertical roadway is located. The rotation angle is θ, according to the formula: ， Rotate the ABCD points on the boundary of the work surface, and the calculation method is as follows: ， ， Thus, the rotated coordinates A', B', C', D' are obtained.

5. The method for cross-sectional projection analysis of microseismic events in coal mines according to claim 4, characterized in that: In step 3, the coordinate conversion process is as follows: According to the new coordinate system, the coordinates of the microseismic events occurring at the current working face are offset and corrected; Firstly, according to the rotation angle of the new coordinates of the current working surface, the coordinate data of the microseismic event after rotation is calculated; Then, according to the translation of the starting point coordinates of working surface A, the distance after translation is calculated, and finally the coordinates after microseismic event correction are obtained according to the translation distance and the rotated data.

6. The method for cross-sectional projection analysis of microseismic events in coal mines according to claim 5, characterized in that: The coordinate transformation calculation process is as follows: Suppose a microseismic event on the current working face is P(x p ,y p ), according to the trigonometric function, calculate the converted microseismic event P'(x P' ,y P' ), the calculation formula is as follows: ， ， Where: (x v ,y v ) is the rotated coordinate, Then the relative distance is used to calculate the horizontal coordinate after translation. The calculation process is as follows: After rotation and translation, the distance from point P' to the starting point A of the current working surface and the vertical distance from point P to AB will not change. Using this relationship, the projection length of P on AB is set to L; Using the following formula: ， Let M be the foot of the perpendicular from the microseismic event P to AB, ( x d , y d ) is the coordinate of M, which is obtained from the linear equations of P and AB; Finally, we get the coordinate x of the microseismic event P' P' = L + x v ,y P' =y v .

7. The method for cross-sectional projection analysis of microseismic events in coal mines according to claim 6, characterized in that: The process of drawing the cross-sectional projection diagram of the microseismic event in step 4 is as follows: The elevation information is used as the vertical coordinate, the starting point of the current working face and the acquired working face strike length or dip length are used as the horizontal coordinate, the acquired current working face tunnel coordinates are rendered in the profile projection diagram as a reference, and finally displayed in the form of a microseismic event profile projection diagram for analysis.

Images