A mine roadway surface displacement monitoring method and system

Abstract

This invention discloses a method and system for monitoring surface displacement in mine roadways, belonging to the field of mine safety monitoring technology. The method includes: setting up five monitoring points in a newly excavated roadway after support has been completed, located at the roadway top, left shoulder, right shoulder, left side, and right side, respectively; using a digital convergence meter to perform baseline measurements and obtain initial length data between each monitoring point; performing multiple comparative measurements at a preset cycle; calculating the surface displacement and displacement rate of the roadway top, left shoulder, right shoulder, left side, and right side by comparing the baseline data with the cycle measurement data; and issuing an early warning signal when the displacement rate exceeds a preset threshold. This invention also discloses a monitoring system applying the above method. By scientifically deploying monitoring points, standardizing measurement procedures, and using precise displacement calculation formulas, this invention achieves dynamic monitoring of the surface displacement of the surrounding rock in roadways, providing reliable protection for roadway construction safety.

Description

Technical Field

[0001] This invention relates to the field of mine safety monitoring technology, specifically to a method and system for monitoring surface displacement in mine roadways, applicable to monitoring the surface displacement of surrounding rock in newly excavated mine roadways, and especially suitable for roadways that have just completed support. Background Technology

[0002] During mine tunnel excavation, the stability of the surrounding rock directly affects construction safety. Especially in newly excavated tunnels, factors such as the degree of rock fragmentation, groundwater seepage, and stress on the support structure can cause displacement and deformation in the tunnel roof, left shoulder, right shoulder, left side, and right side. If these are not monitored and warned in time, tunnel collapses can easily occur, threatening the lives of construction workers and the safety of equipment and property.

[0003] The existing surface displacement monitoring technology for mine roadways has the following shortcomings: First, the layout of monitoring points lacks specificity, and most monitoring points are not properly laid out, failing to fully cover the key stress-bearing parts of the roadway, resulting in monitoring data that cannot accurately reflect the deformation state of the surrounding rock; second, the monitoring process is cumbersome and the measurement accuracy is insufficient, with existing methods mostly using single equipment for measurement, resulting in incomplete data collection; third, the displacement calculation method is not accurate enough, and without combining comparative analysis of multiple measurements, it is difficult to accurately reflect the dynamic deformation trend of the surrounding rock in the roadway.

[0004] Therefore, there is an urgent need for a scientifically designed, easy-to-operate, and accurate method and system for monitoring surface displacement in mine roadways. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a method and system for monitoring surface displacement in mine roadways. By scientifically setting up five monitoring points based on the working characteristics of newly excavated roadways, data is collected through standardized measurement procedures and combined with precise displacement calculation formulas to achieve dynamic monitoring of the surface displacement of the surrounding rock in the roadway, providing a reliable guarantee for the safety of roadway construction.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A method for monitoring surface displacement in mine roadways includes the following steps: A1. Monitoring point layout: Five monitoring points are set up in the newly excavated roadway after the support has been completed, namely monitoring point , monitoring point , monitoring point , monitoring point , and monitoring point . The monitoring points are set up at the top of the roadway, the monitoring point is set up on the left shoulder, the monitoring point is set up on the left side, the monitoring point is set up on the right shoulder, and the monitoring point is set up on the right side. Each monitoring point is installed with expansion bolts through drilling and is marked with numbers. A2. Benchmark Measurement: After the monitoring points are deployed, the first benchmark measurement is carried out. The benchmark length data between each monitoring point is measured using a digital convergence meter. Each set of data is measured three times and the average value is taken as the benchmark value. A3. Periodic Comparison Measurement: Perform multiple comparison measurements according to a preset period, using the same measurement method as the benchmark measurement, and record the length data between each monitoring point. Each set of data is measured three times and the average value is taken. A4. Displacement Calculation: By comparing the baseline measurement data with the periodic comparison measurement data, calculate the surface displacement and displacement rate of the top, left shoulder, right shoulder, left side, and right side of the roadway. A5. Safety Warning: When the rate of displacement change exceeds a preset threshold, a warning signal is issued.

[0007] Furthermore, in step S1, the specific locations of the five monitoring points are as follows: The monitoring points are located at the center of the top of the tunnel; The monitoring point is located on the left shoulder where the top of the tunnel connects to the left side. The monitoring points are located in the middle of the left side of the tunnel, 1.0-1.5m from the floor. The monitoring point is located on the right shoulder where the top of the tunnel connects to the right side; The monitoring points are located in the middle of the right side of the roadway, 1.0-1.5m from the floor. The drilling depth at each monitoring point is 10-15cm, and the expansion bolts are firmly fixed, waterproof, and prevent loosening.

[0008] Furthermore, in step S2, the reference length data includes: L 20 The straight-line distance between monitoring point (2) and monitoring point (3); L 40 The straight-line distance between monitoring point (4) and monitoring point (5); L 50 The straight-line distance between monitoring point (3) and monitoring point (5); H: Vertical distance between monitoring point (1) and the horizontal lines connecting the left and right sides; S1: Monitoring point (2) and L 50 The vertical distance between horizontal lines; S 10 The horizontal distance between the vertical laser line at monitoring point (2) and the vertical laser line at monitoring point (1); S2: Monitoring point (4) and L 50 The vertical distance between horizontal lines; S 20 : The horizontal distance between the vertical laser line of monitoring point (4) and the vertical laser line of monitoring point (1).

[0009] Furthermore, in step S3, the preset cycle is determined according to the degree of rock mass fracturing in the tunnel: the measurement cycle is 12 hours / time when the rock mass is fracturing, and the measurement cycle is 24 hours / time when the rock mass is stable.

[0010] Furthermore, in step S4, the formula for calculating the surface displacement includes: Top displacement: ΔH=H n - H， Total displacement of left shoulder: , Total displacement of the right shoulder: , Left side displacement: ΔL 3 =S 1 +S 10 - S 1n - S 1m ， Right side displacement: ΔL 5 =S 2 +S 20 - S 2n - S 2m ， The horizontal convergence displacement of the two sides: ΔL=L 5n - L 50 .

[0011] Furthermore, in step S4, the formula for calculating the displacement change rate is: , Where, ΔL n Let ΔL be the displacement measured in the nth measurement. n-1 Let t be the displacement measured in the (n-1)th time. n Let t be the time of the nth measurement. n-1 The time for the (n-1)th measurement.

[0012] Furthermore, in step S5, the preset threshold is 0.1 mm / h.

[0013] A surface displacement monitoring system for mine roadways, applied to the above-described method, includes: The monitoring point assembly consists of five monitoring points, namely, monitoring point 1, monitoring point 2, monitoring point 3, monitoring point 4, and monitoring point 5, which are respectively deployed on the top of the tunnel, left shoulder, right shoulder, left side, and right side. Each monitoring point is installed with expansion bolts through drilling and is marked with a number. The monitoring equipment includes a digital convergence meter, a laser emitter, a laser plumb bob, and a telescopic rod, wherein the telescopic rod is horizontally installed between the left and right sides of the tunnel. The data acquisition module is used to record baseline measurement data and multiple periodic comparison measurement data; The data processing module is used to calculate the displacement and displacement rate of the surrounding rock surface according to a preset formula.

[0014] Furthermore, in the monitoring equipment, a laser emitter is installed at each monitoring point, with the laser emission direction vertically downwards, intersecting with the telescopic rod.

[0015] Furthermore, the measurement range of the digital convergence meter is 0-5000mm, and the measurement accuracy is ±0.1mm.

[0016] The present invention has the following beneficial effects: (1) The monitoring points are highly targeted and have comprehensive coverage: the five monitoring points cover the top, left shoulder, right shoulder, left side and right side of the roadway respectively, and comprehensively capture the displacement and deformation of key parts of the roadway, which solves the problem of incomplete deployment of existing monitoring points.

[0017] (2) The monitoring method is simple to operate and highly accurate: The digital display convergence meter is used as the core monitoring equipment. The monitoring method of "benchmark measurement + periodic comparison measurement" is combined. The measurement cycle can be flexibly adjusted according to the degree of rock mass fragmentation to meet the needs of different working conditions.

[0018] (3) The displacement calculation method is scientific and accurate: the displacement and deformation rate of each monitoring point are quickly calculated by the difference formula and the rate of change formula. The seven core measurement parameters fully cover the geometric relationship changes of key parts of the roadway, providing reliable data support for safety early warning. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the initial state of the tunnel in this invention; Figure 2 This is a schematic diagram of the state of the tunnel after the surrounding rock displacement occurs according to the present invention.

[0020] In the diagram, 1-monitoring point, 2-monitoring point, 3-monitoring point, 4-monitoring point, 5-monitoring point. Detailed Implementation

[0021] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings. It should be noted that these descriptions are for the purpose of aiding understanding the present invention, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0022] Example 1

[0023] Please see the appendix Figure 1-2 As shown in the figure, this embodiment takes a newly excavated roadway in a mine as an example to illustrate the specific implementation process of the mine roadway surface displacement monitoring method of the present invention.

[0024] Step A1: Monitoring Point Layout: Select the newly excavated roadway that has just completed anchor bolt support as the monitoring area. Layout five monitoring points within the roadway: Monitoring point 1 is located at the center of the roadway top, a location where the surrounding rock is under concentrated stress and prone to subsidence; Monitoring point 2 is located on the left shoulder of the roadway top where it connects to the left sidewall, with an appropriate horizontal distance between it and the top monitoring point; Monitoring point 3 is located in the middle of the left sidewall, 1.0-1.5m from the roadway floor, perpendicularly corresponding to the left shoulder monitoring point; Monitoring point 4 is located on the right shoulder of the roadway top where it connects to the right sidewall, with an appropriate horizontal distance between it and the top monitoring point, symmetrically positioned with the left shoulder monitoring point; Monitoring point 5 is located in the middle of the right sidewall, 1.0-1.5m from the roadway floor, perpendicularly corresponding to the right shoulder monitoring point, symmetrically positioned with the left side monitoring point.

[0025] Drill holes at each monitoring point location to a depth of 10-15cm, with the hole diameter matching the expansion bolt. After drilling, insert the expansion bolt into the hole and secure it firmly, ensuring a tight fit between the bolt and the surrounding rock of the tunnel without any loosening. Clearly mark the top of each expansion bolt, such as by applying different colored paint or attaching a label, clearly indicating the monitoring point number corresponding to each mark. Install a laser emitter at each expansion bolt location at the monitoring points on both shoulders, ensuring the laser line is perpendicular to the ground. Simultaneously, erect a telescopic rod between the left and right sides of the tunnel as a horizontal measurement baseline.

[0026] Step A2, Baseline Measurement: After the monitoring points are set up and securely fixed, immediately perform the first measurement as the baseline measurement. Hang the two hooks of the digital convergence meter on the expansion screw markings corresponding to the two monitoring points, ensuring the hooks are securely fixed and do not slip. After the readings stabilize, record the data. Repeat the measurement three times for each set of data and take the average. The baseline measurement requires the collection of seven sets of core length data: L 20 L is the straight-line distance between monitoring point 2 and monitoring point 3. 40 L is the straight-line distance between monitoring point 4 and monitoring point 5. 50H is the straight-line distance between monitoring point 3 and monitoring point 5; H is the vertical distance between monitoring point 1 and the horizontal lines connecting the left and right sides; S1 is the distance between monitoring point 2 and L. 50 The vertical distance between horizontal lines; S 10 S2 is the horizontal distance between the vertical laser line at monitoring point 2 and the vertical laser line at monitoring point 1; S2 is the distance between monitoring point 4 and L. 50 The vertical distance between horizontal lines; S 20 The horizontal distance between the vertical laser line at monitoring point 4 and the vertical laser line at monitoring point 1 is defined. All the above data are recorded as baseline values ​​to establish an initial monitoring log.

[0027] Step A3, Periodic Comparison Measurement: After the baseline measurement is completed, the measurement cycle is determined based on the degree of rock fragmentation in the tunnel. When the rock mass is fragmented, a remeasurement is performed every 12 hours; when the rock mass is stable, a remeasurement is performed every 24 hours. Each remeasurement uses the same measurement methods and procedures as the baseline measurement, and L is measured and recorded. 2n L 4n L 5n H n S 1n S 1m S 2n S 2m Each set of data was measured three times and the average value was taken. The measurement time and the length data between each monitoring point were recorded to establish a complete monitoring data ledger.

[0028] Step A4, Displacement Calculation: The data processing module automatically calculates the displacement and rate of change of displacement at each monitoring point using a preset formula. The specific calculation formula is as follows: (1) Top displacement ΔH: Reflects the vertical downward or upward displacement of the top, and the calculation formula is: ΔH=H n - H， Wherein, ΔH is the top displacement, in mm; when ΔH < 0, it indicates that the top of the roadway has subsided, and the larger the absolute value, the greater the subsidence; when ΔH > 0, it indicates that the top has risen.

[0029] (2) Total displacement of the left shoulder ΔL2: Reflects the total displacement of the left shoulder area, calculated by combining the length changes of the top - left shoulder - left side. The calculation formula is as follows: , Wherein, ΔL2 is the displacement of the left shoulder, in mm; when ΔL2>0, it indicates that the left shoulder has displaced into the roadway; when ΔL2<0, it indicates that the left shoulder has displaced outward from the roadway.

[0030] (3) Comprehensive displacement of the right shoulder ΔL4: Reflects the comprehensive displacement of the right shoulder area, calculated in conjunction with the length changes of the top-right shoulder-right sidewall. The calculation formula is as follows: , ΔL4 represents the displacement of the right shoulder, in mm. The positive and negative values ​​of the displacement have the same meaning as those of the left shoulder. The difference between ΔL2 and ΔL4 can be used to determine whether the displacements on both sides of the roadway top are symmetrical.

[0031] (4) Left side displacement ΔL3: Reflects the overall displacement of the left side, calculated in conjunction with the length change of the left shoulder-left side. The calculation formula is as follows: Δ L 3 = S 1 +S 10 -S 1n -S 1m , Wherein, ΔL3 is the displacement of the left side, in mm; when ΔL3>0, it indicates that the left side is squeezed into the roadway; when ΔL3<0, it indicates that the left side is expanded outward from the roadway.

[0032] (5) Right side displacement ΔL5: Reflects the overall displacement of the right side section, calculated in conjunction with the length change of the right shoulder-right side section. The calculation formula is as follows: ΔL 5 =S 2 +S 20 -S 2n -S 2m ， ΔL5 represents the displacement of the right side, in mm. The positive and negative meanings of the displacement are the same as those of the left side. The difference between ΔL3 and ΔL5 can be used to determine whether the displacements of the sidewalls on both sides of the roadway are symmetrical.

[0033] (6) Horizontal convergence displacement ΔL: reflects the overall convergence degree of the two sides of the roadway, and the calculation formula is: ΔL=L 5n - L 50 , Wherein, ΔL is the horizontal convergence displacement of the two sides, in mm; when ΔL < 0, it indicates that the two sides are converging and squeezing towards the middle, and the larger the absolute value, the more severe the convergence; when ΔL > 0, it indicates that the two sides are expanding to both sides.

[0034] (7) Displacement change rate v: reflects the speed of displacement of the surrounding rock in the roadway, and is used to judge the deformation trend. The calculation formula is: , Where v is the rate of displacement change, in mm / h; ΔL n ΔL represents the displacement measured in the nth measurement. n-1 t represents the displacement measured in the (n-1)th measurement. n t is the time of the nth measurement; n-1 This is the time for the (n-1)th measurement. When v exceeds the preset threshold, staff are alerted to take timely support and reinforcement measures.

[0035] Step A5, Safety Warning: When the displacement rate exceeds the preset threshold of 0.1 mm / h, it indicates that the surrounding rock displacement speed is too fast, and a warning signal is issued to remind the staff to take timely support and reinforcement measures.

[0036] A surface displacement monitoring system for mine roadways, applied to the method described above, includes a monitoring point assembly, monitoring equipment, a data acquisition module, and a data processing module. The monitoring point assembly consists of five monitoring points: monitoring point 1, monitoring point 2, monitoring point 3, monitoring point 4, and monitoring point 5. Each monitoring point is installed with expansion bolts through drilled holes and is numbered and marked, and is respectively located at the top, left shoulder, right shoulder, left side, and right side of the roadway. The monitoring equipment includes a digital convergence meter, a laser emitter, a laser plumb bob, and a telescopic rod. The telescopic rod is horizontally erected between the left and right sides of the roadway. A laser emitter is installed at monitoring points 2 and 4, with the laser emission direction vertically downwards, intersecting the telescopic rod. The digital convergence meter has a measurement range of 0-5000 mm and a measurement accuracy of ±0.1 mm. The data acquisition module records baseline measurement data and multiple periodic comparison measurement data. The data processing module calculates the displacement and displacement rate of the surrounding rock surface according to a preset formula. All the above modules and components have corresponding applications in the method described in Embodiment 1 of this invention, and will not be elaborated further here.

[0037] Example 2

[0038] The difference between this embodiment and Embodiment 1 lies in the measurement cycle. In this embodiment, the roadway rock mass is relatively stable, and a measurement cycle of 24 hours / time is used in step A3. After the baseline measurement is completed, a comparative measurement is performed according to this cycle. After continuous monitoring, the displacement of each monitoring point is stable, and the rate of displacement change remains at a low level, indicating that the roadway surrounding rock is in a stable state. The remaining steps are the same as in Embodiment 1.

[0039] Example 3

[0040] The difference between this embodiment and Embodiment 1 lies in the range configuration of the digital convergence meter. In this embodiment, the tunnel span is relatively large, so a digital convergence meter with a measurement range of 0-10000mm is used. The remaining steps are the same as in Embodiment 1.

[0041] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method of monitoring surface displacement in a mine roadway, characterised by, Includes the following steps: A1. Monitoring point layout: Five monitoring points are set up in the newly excavated roadway after the support has been completed, namely monitoring point (1), monitoring point (2), monitoring point (3), monitoring point (4), and monitoring point (5). The monitoring point (1) is set up at the top of the roadway, the monitoring point (2) is set up at the left shoulder, the monitoring point (3) is set up at the left side, the monitoring point (4) is set up at the right shoulder, and the monitoring point (5) is set up at the right side. Each monitoring point is installed with expansion bolts through drilling and is numbered and marked. A2. Benchmark Measurement: After the monitoring points are deployed, the first benchmark measurement is carried out. The benchmark length data between each monitoring point is measured using a digital convergence meter. Each set of data is measured three times and the average value is taken as the benchmark value. A3. Periodic Comparison Measurement: Perform multiple comparison measurements according to a preset period, using the same measurement method as the benchmark measurement, and record the length data between each monitoring point. Each set of data is measured three times and the average value is taken. A4. Displacement Calculation: By comparing the baseline measurement data with the periodic comparison measurement data, calculate the surface displacement and displacement rate of the top, left shoulder, right shoulder, left side, and right side of the roadway. A5. Safety Warning: When the rate of displacement change exceeds a preset threshold, a warning signal is issued.

2. The mine drift surface displacement monitoring method of claim 1, wherein, In step S1, the specific locations of the five monitoring points are as follows: The monitoring point (1) is located at the center of the top of the tunnel; Monitoring point (2) is located on the left shoulder where the top of the tunnel connects to the left side; The monitoring point (3) is located in the middle of the left side of the roadway, 1.0-1.5m away from the bottom plate; Monitoring point (4) is located on the right shoulder where the top of the tunnel connects to the right side; The monitoring point (5) is located in the middle of the right side of the roadway, 1.0-1.5m away from the bottom plate; The drilling depth at each monitoring point is 10-15cm, and the expansion bolts are firmly fixed, waterproof, and prevent loosening.

3. The mine drift surface displacement monitoring method of claim 1, wherein, In step S2, the reference length data includes: L 20 : straight-line distance between monitoring point (2) and monitoring point (3); L 40 The straight-line distance between monitoring point (4) and monitoring point (5); L 50 : straight-line distance between monitoring point (3) and monitoring point (5); H: Vertical distance between monitoring point (1) and the horizontal lines connecting the left and right sides; S1: monitoring point (2) and L 50 vertical distance between horizontal lines; S 10 : monitor the horizontal distance between the vertical laser line of monitoring point (2) and the vertical laser line of monitoring point (1); S2: monitoring point (4) and L 50 vertical distance between horizontal lines; S 20 : Monitor the horizontal distance between the vertical laser line of monitoring point (4) and the vertical laser line of monitoring point (1).

4. The method for monitoring surface displacement in mine roadways according to claim 1, characterized in that, In step S3, the preset cycle is determined according to the degree of rock mass fracturing in the tunnel: the measurement cycle is 12 hours / time when the rock mass is fracturing, and the measurement cycle is 24 hours / time when the rock mass is stable.

5. The mine drift surface displacement monitoring method of claim 1, wherein, In step S4, the formula for calculating the surface displacement includes: Top displacement: ΔH=H n -H， Total displacement of left shoulder: ， Total displacement of the right shoulder: ， Left side displacement: ΔL 3 =S 1 +S 10 -S 1n -S 1m ， Right side displacement: ΔL 5 =S 2 +S 20 -S 2n -S 2m ， The horizontal convergence displacement of the two sides: ΔL=L 5n -L 50 。 6. The mine drift surface displacement monitoring method of claim 1, wherein, In step S4, the formula for calculating the displacement change rate is: ， Where, ΔL n Let ΔL be the displacement measured in the nth measurement. n-1 Let t be the displacement measured in the (n-1)th time. n Let t be the time of the nth measurement. n-1 The time for the (n-1)th measurement.

7. The mine drift surface displacement monitoring method of claim 1, wherein, In step S5, the preset threshold is 0.1 mm / h.

8. A mine roadway surface displacement monitoring system characterised by, The method applied to any one of claims 1 to 7 includes: The monitoring point assembly consists of five monitoring points, namely monitoring point (1), monitoring point (2), monitoring point (3), monitoring point (4), and monitoring point (5), which are respectively located on the top, left shoulder, right shoulder, left side, and right side of the tunnel. Each monitoring point is installed with expansion bolts through drilling and is marked with a number. The monitoring equipment includes a digital convergence meter, a laser emitter, a laser plumb bob, and a telescopic rod, wherein the telescopic rod is horizontally installed between the left and right sides of the tunnel. The data acquisition module is used to record baseline measurement data and multiple periodic comparison measurement data; The data processing module is used to calculate the displacement and displacement rate of the surrounding rock surface according to a preset formula.

9. A mine roadway surface displacement monitoring system according to claim 8, characterised in that, In the monitoring equipment, a laser emitter is installed at each monitoring point (2) and monitoring point (4), with the laser emission direction vertically downward and intersecting the telescopic rod.

10. The mine roadway surface displacement monitoring system of claim 8, wherein, The digital convergence meter has a measurement range of 0-5000mm and a measurement accuracy of ±0.1mm.

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