Rock burst monitoring system and monitoring method

Abstract

The invention relates to the technical field of mine safety, and discloses a rock burst monitoring system and method.The rock burst monitoring system comprises a plurality of monitoring units distributed at intervals in the extending direction of a roadway, and each monitoring unit comprises a supporting shell, a control module and a sensor array; a plurality of placing grooves are formed in the supporting shell; the sensor array is composed of a plurality of vibration sensors, the vibration sensors are arranged in the placing grooves in a one-to-one correspondence mode, and the vibration sensors can receive vibration signals in the target direction; the control module is in communication connection with all the vibration sensors. The problem that the misjudgment probability of rock burst vibration monitored by a rock burst monitoring system in the prior art is large is solved.

Description

Technical Field

[0001] This invention relates to the field of mine safety technology, specifically to a rockburst monitoring system and method. Background Technology

[0002] Rockbursts are a major dynamic disaster faced during deep mining operations. Essentially, they are the sudden release of the elastic potential energy of coal and rock masses under high ground stress, triggering violent vibrations, rockfalls, and tunnel deformation. This directly threatens the lives of workers and causes enormous equipment and property losses. As mining depths continue to increase and geological conditions become increasingly complex, the frequency and intensity of rockbursts are constantly rising. Therefore, accurate monitoring and early warning of rockbursts have become a core issue in ensuring safe mining operations.

[0003] Current mainstream methods for monitoring rockbursts rely on single-type monitoring units, assessing risk by capturing parameters such as vibration signals and stress changes. However, this approach has certain limitations in practical applications. In the environment of mine roadways, numerous external disturbances arise, including heavy transport equipment operation, aftershocks from blasting, and personnel construction. The vibration signals generated by these disturbances partially overlap with the precursory signals of rockbursts in the time and frequency domains. Single monitoring units lack the ability to identify location and differentiate signals, making them highly susceptible to misjudgment. Misjudgment not only reduces the reliability of the early warning system and causes unnecessary production losses, but it can also lead to complacency among workers, causing them to ignore genuine disaster precursors. Summary of the Invention

[0004] The purpose of this invention is to solve the problem that the existing rockburst monitoring system has a high probability of misjudging rockburst vibrations, and to provide a rockburst monitoring system and monitoring method.

[0005] To address the shortcomings of the aforementioned technical problems, the present invention adopts the following technical solution: A rockburst monitoring system includes multiple monitoring units spaced apart along the direction of roadway extension. Each monitoring unit includes a support shell, a control module, and a sensor array. The support shell is provided with multiple placement slots; The sensor array consists of multiple vibration sensors, which are arranged one-to-one in the placement slot. The vibration sensors can receive vibration signals in the target direction. The control module is communicatively connected to all vibration sensors.

[0006] As a further optimization of the rockburst monitoring system of the present invention: the support shell has multiple mounting surfaces facing different directions, and the placement slots are set corresponding to the mounting surfaces.

[0007] As a further optimization of the rockburst monitoring system of the present invention: the support shell is connected to a support part, the support part includes a support foot with a bearing turntable fixedly connected to the top, the bearing turntable is rotatably connected to the bearing rail, and the bearing rail is fixedly connected to the support shell.

[0008] As a further optimization of the rockburst monitoring system of the present invention: a polygonal limiting sleeve is fixedly connected to the side of the bearing turntable facing the support shell, and a polygonal limiting groove adapted to the limiting sleeve is opened on the side of the support shell facing the support foot.

[0009] As a further optimization of the rockburst monitoring system of the present invention: the vibration sensor includes a vibrating diaphragm that can vibrate, the vibrating diaphragm is sealed with a conical docking groove, the docking groove is opened on the support shell, and the flared opening of the docking groove coincides with the mounting surface of the support shell.

[0010] As a further optimization of the rockburst monitoring system of the present invention: a reflective bucket is provided in the docking groove, and a vibrating plate is provided in the narrow opening of the reflective bucket. The vibrating plate is connected to the first end of the transmission rod; the second end of the transmission rod passes through the support shell and is connected to the sensing element of the vibration sensor.

[0011] As a further optimization of the rockburst monitoring system of the present invention: the support shell is provided with a trigger sensor that is communicatively connected to the control module, and the trigger sensor is fixedly connected to the roadway rock mass through a transmission column.

[0012] As a further optimization of the rockburst monitoring system of the present invention: the first end of the transmission column is connected to a trigger sensor, and the second end of the transmission column extends out of the support shell and is fixedly connected to the rock mass of the roadway.

[0013] As a further optimization of the rockburst monitoring system of the present invention: the end face of the support shell is provided with a storage slot, the storage slot is connected to the control module, the control module includes a positioning frame that can be inserted into the storage slot, the outer side of the positioning frame is provided with a third isolation layer, and an energy control module and a wireless communication module are fixedly connected inside the positioning frame.

[0014] A method for monitoring rockburst includes the following steps: Multiple monitoring units were deployed along the tunnel, and the angle of the support shell in the monitoring units was adjusted. Multiple vibration signals are simultaneously acquired using the sensor array of the monitoring unit; The control module calculates the time difference of arrival of vibration signals in different monitoring units corresponding to the target direction based on the vibration signal, and preliminarily determines the roadway section and horizontal orientation of the vibration source based on the time difference of arrival of the signal, thus forming a predicted direction. Using the predicted direction as a spatial constraint, the three-dimensional coordinates of the vibration source are calculated and the location area of ​​the vibration source is determined. The vibration signals from vibration sensors near the location area are matched and verified with the rockburst feature database. If the match is successful, an early warning message and location result are output; otherwise, normal monitoring is resumed.

[0015] Compared with the prior art, the present invention has the following beneficial effects: This invention achieves high-precision three-dimensional spatial positioning of vibration sources through a distributed sensor array and full-network synchronization technology. Simultaneously, it employs a hierarchical working mode of high-sensitivity triggering and precise array positioning. The triggering sensor is dedicated to wake-up, while the array sensor is dedicated to positioning tasks. This division of labor ensures both rapid response to weak precursors and the purity of positioning data and algorithm effectiveness, reducing the false positive rate. Furthermore, the monitoring unit adopts a modular structure with adjustable orientation, facilitating flexible deployment according to the shape of the tunnel cross-section, thereby forming an optimal spatial sensing network and effectively improving the system's environmental adaptability and monitoring reliability. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the axial structure of the monitoring unit of the present invention; Figure 2 This is a schematic diagram of the first cross-sectional structure of the monitoring unit of the present invention; Figure 3 This is a schematic diagram of the second cross-sectional structure of the monitoring unit of the present invention; Figure 4 This is a schematic diagram of the process structure of the monitoring method of the present invention; The diagram shows the following markings: 1. Support unit; 101. Support foot; 102. Reinforcing rib; 103. Bearing turntable; 104. Bearing rail; 105. Limiting sleeve; 2. Vibration sensor; 201. Pressing frame; 202. Vibration diaphragm; 203. Reflector; 204. First isolation layer; 205. Vibrating plate; 206. Conducting rod; 207. Second isolation layer; 208. Sensing element; 3. Control module; 301. Cover; 302. Energy control module; 303. Third isolation layer; 304. Positioning frame; 4. Support shell; 401. Docking groove; 402. Placement slot; 403. Storage slot; 404. Limiting slot; 5. Trigger sensor; 6. Transmission column. Detailed Implementation

[0017] To better understand the present invention, the following embodiments further illustrate the content of the present invention, but the content of the present invention is not limited to the following embodiments.

[0018] This invention discloses a rockburst monitoring system and method, aiming to solve the technical problems of existing rockburst monitoring being susceptible to external interference, inaccurate vibration source location, and high misjudgment rate, so as to achieve accurate monitoring and reliable early warning of rockburst and ensure the safety of mine roadway operations.

[0019] like Figure 1-3 As shown, a rockburst monitoring system includes a vibration monitoring network. The network consists of multiple monitoring units spaced 5-8 meters apart along the roadway extension direction. Each monitoring unit is a functional node, comprising three core parts: a support 1 for spatial attitude fixing and adjustment, a support shell 4 for carrying the sensor array and defining its spatial orientation, and a control module 3 for signal processing, control, and communication. The monitoring unit includes a sensor array for performing spatial positioning tasks. Optionally, each monitoring unit also includes a trigger sensor 5 for low-latency wake-up of the entire network.

[0020] Specifically, the support 1 includes an L-shaped support leg 101. A reinforcing rib 102 is provided at the lower bend of the support leg 101 to improve the stability of the support structure. The support leg 101 can be bolted to a monitoring port located at a suitable height in the roadway. A bearing turntable 103 is fixedly connected to the top of the support leg 101. The bearing turntable 103 is rotatably connected to a bearing rail 104, and the bearing rail 104 is fixedly connected to the support shell 4 by screws. A polygonal limiter is fixedly connected to the side of the bearing turntable 103 facing the support shell 4. The limiting sleeve 105 is made of elastic material and is adapted to the polygonal limiting groove 404 opened on the side of the support shell 4 facing the support foot 101. Through the cooperation of the limiting sleeve 105 and the limiting groove 404, the rotation angle of the support shell 4 under the support of the support foot 101 can be limited, which makes it convenient for operators to adjust the installation angle of the support shell 4 so that one plane of the hexagonal support shell 4 is flush with the top surface of the roadway, ensuring that the six faces of the support shell 4 correspond to the six angles of the roadway section, and achieving relatively blind-angle vibration monitoring coverage within the roadway section.

[0021] The support shell 4 is preferably configured as a regular hexagonal structure. For small cross-section roadway scenarios, the support shell 4 can also be replaced with a regular quadrilateral structure to reduce the number of vibration sensors 2 used to form the sensor array, thereby reducing the equipment manufacturing and deployment costs. A storage slot 403 is provided on the side of the support shell 4 away from the support part 1. The control module 3 is placed in the storage slot 403. The control module 3 includes a positioning frame 304 that can be inserted into the storage slot 403. A third isolation layer 303 is fixedly connected to the outer side of the positioning frame 304. The third isolation layer 303 can effectively reduce the vibration transmission inside the control module 3 and avoid interference with the vibration monitoring accuracy of the sensor array. An energy control module 302 and a wireless communication module are fixedly connected in the positioning frame 304. The energy control module 302 includes a battery. The battery can be electrically connected to the trigger sensor 5 and multiple vibration sensors 2 respectively, thereby completing the power supply control of the trigger sensor 5 and vibration sensors 2. The wireless communication module is signal connected to the trigger sensor 5 and multiple vibration sensors 2. The storage slot 403 of the support shell 4 is provided with a cover 301. The cover 301 is fixedly engaged with the support shell 4 by bolts, which can stably fix the positioning frame 304, energy control module 302 and wireless communication module in the storage slot 403 in the support shell 4, and at the same time achieve the sealing protection of the storage slot 403.

[0022] In this embodiment, the trigger sensor 5, located at the center of the support shell 4, is independently configured. The trigger sensor 5 is a high-sensitivity MEMS triaxial accelerometer, designed to detect subtle vibrations of the rock mass rather than for positioning. To achieve high signal fidelity, the trigger sensor 5 is fixed to one end of the transmission column 6. The other end of the transmission column 6 is threaded, and the threaded end passes through through holes in the support shell 4 and the support foot 101 to connect with a threaded sleeve pre-embedded in the tunnel rock mass. To ensure the adjustable angle of the support shell 4 and maintain the installation stability of the trigger sensor 5, a bearing is embedded in the through hole. The bearing allows the transmission column 6 to remain anchored and stationary at the rock mass end while the support shell 4 can rotate smoothly around its axis. After adjustment, the relative positions of the support shell 4 and the transmission column 6 are temporarily fixed by the limiting sleeve 105 and the limiting groove 404 to prevent accidental displacement caused by operational vibrations. Six placement slots 402 are provided on the outer side of the center of the support shell 4. The six placement slots 402 correspond one-to-one with the six sides of the support shell 4. The sensing element 208 of the vibration sensor 2 is correspondingly placed in the placement slot 402. A second isolation layer 207 is provided on the inner wall of the placement slot 402. The second isolation layer 207 can protect the sensing element 208 to reduce the degree of external interference to the sensing element 208. The sensing element 208 can be set as a diaphragm to collect vibration in the corresponding direction in real time, providing data support for the prediction of vibration direction.

[0023] A conical docking groove 401 is provided on the outer periphery of the support shell 4 corresponding to the position of each vibration sensor 2. A matching conical reflector 203 is nested within the docking groove 401. The flared end face of the reflector 203 coincides with the side surface of the support shell 4, i.e., the mounting surface. The mounting surface of the support shell 4 directly faces the tunnel space to maximize the reception of vibration waves in the target direction. The conical inner wall of the reflector 203 can gradually constrain and guide the divergent vibration acting on a large receiving area to its narrow end. A vibrating plate 205 is provided at the narrow end of the reflector 203. One end of the vibrating plate 205 is fixedly connected to a transmission rod 206. The transmission rod 206 passes through the support shell 4 and is connected to a sensing element 208. When the vibration converged by the reflector 203 drives the narrow area of ​​the reflector 203 to vibrate, the vibrating plate 205 vibrates accordingly. This vibration is then transmitted efficiently and with low loss to the sensing element 208 at the center of the support shell 4 through the transmission rod 206. The length, diameter, and material properties of the conduction rod 206 can be set according to the vibration of the rockburst, so that the conduction rod 206 has better wave guiding efficiency in the vibration band of the rockburst, while suppressing vibrations at out-of-band frequencies, thus realizing a preliminary bandpass filtering function at the mechanical level. The outer periphery of the reflector 203 is firmly covered by a first insulating layer 204. The first insulating layer 204 is made of high-damping composite material, and its core function is to physically isolate non-axial interference. When vibration is incident from non-target directions such as the side or rear, most of the vibration is absorbed by the first insulating layer 204 and dissipated as heat energy, rather than being transmitted through the reflector 203. The setting of the reflector 203 enables the monitoring unit to have a certain degree of selectivity for axial vibration, which improves the directivity of a single sensing element 208 to a certain extent, providing a data basis with a higher signal-to-noise ratio for subsequent prediction of the vibration source location based on the signal strength differences of multiple sensing elements 208. Furthermore, the vibrating diaphragm 202 covering the docking groove 401 and the flared opening of the reflector 203 not only effectively blocks the intrusion of dust and impurities, protecting the sensitivity of the internal structure, but also assists in energy transmission through its own vibration when subjected to impact, further ensuring the stability of signal input. The vibrating diaphragm 202 is also secured and positioned by a clamping frame 201 bolted to the mounting surface.

[0024] like Figure 4 As shown, based on the above-mentioned rockburst monitoring system, this invention also discloses a corresponding rockburst monitoring method, which specifically includes the following steps: Step 1: Network Deployment and System Calibration. Deploy a monitoring unit every five to eight meters along the tunnel's extension direction. Adjust the angle adjustment mechanism of the support unit 1 so that each side of the support shell 4, i.e., each vibration sensor 2, faces the target direction, possessing a known azimuth angle in the tunnel's global coordinate system. Establish clock synchronization for the monitoring network composed of multiple monitoring units, for example, using a conventional time synchronization protocol. Based on the tunnel geological survey map and mining plan, divide the area into different functional zones, such as transport tunnels, areas near the excavation face, and geological anomaly zones, and preset differentiated initial trigger thresholds for the trigger sensors 5 in each zone.

[0025] After all monitoring units are deployed in the roadway, a unified spatial orientation calibration is required. The specific method is as follows: Establish a global coordinate system for the roadway, with the roadway entrance or a fixed reference point as the origin, the roadway extension direction as the X-axis, the direction perpendicular to the roadway floor upwards as the Z-axis, and the Y-axis determined according to the right-hand rule. Define the orientation of the vibration sensor 2. For the regular hexagonal support shell 4, define the face of the support shell 4 facing the roadway top as face 0, and the sensing element 208 corresponding to face 0 is sensing element 208 0. All subsequently installed monitoring units must have their support shell 4 angles adjusted so that face 0 also aligns with the roadway top. Equipment such as a total station, laser pointer, or built-in electronic compass module can be used to verify the actual spatial normal vector of face 0 of each monitoring unit, ensuring its pointing error in the global coordinate system is less than ±3 degrees. Based on the setting position and corresponding placement posture of each monitoring unit, a three-dimensional attitude coordinate model composed of multiple monitoring units within the roadway is established.

[0026] Step Two: Continuous Monitoring and Triggered Acquisition. All trigger sensors 5 enter a continuous low-power listening state. Trigger sensors 5 do not perform regular data transmission; they only send a signal to their respective control module 3 when their local signal processor determines that the acceleration amplitude exceeds its current dynamic threshold. Upon receiving the signal, the control module 3 immediately designates the corresponding monitoring unit as the master node and synchronously sends data acquisition commands to nearby monitoring units. After receiving the data acquisition command, all neighboring monitoring units' control modules 3 wake up their internal sensor arrays and synchronously begin acquiring vibration signals. Signal acquisition will continue for a preset duration, such as two seconds.

[0027] Step 3: Preliminary Vibration Source Location and Prediction. After acquiring signal data, multiple monitoring units upload the data to the central server. The central server performs data quality screening, selecting data from the three to five monitoring units with the highest signal-to-noise ratio (SNR) for preliminary processing. The screening criterion is the SNR obtained by all sensing elements 208 after the monitoring unit is triggered. The SNR is the ratio of average energy to background noise energy in a certain frequency band. For the sensing elements 208 with the closest spatial orientation among the monitoring units, such as all sensing elements 208 pointing due east, the arrival time difference of the signals is obtained by comparing the data acquired by adjacent sensing elements 208. After obtaining the arrival time difference, a preliminary coordinate of the vibration source on the roadway horizontal plane can be quickly calculated based on the known spatial coordinates of the sensing elements 208 and the average wave velocity of the rock mass. A fan-shaped area centered on this coordinate with an angle of ±30 degrees is then determined as the prediction area. This step aims to significantly reduce the calculation search range and improve efficiency for the next step of precise location. The calculation method can employ simplified solutions to conventional hyperbolic positioning equations or grid search methods.

[0028] Step 4: Precise 3D positioning of the vibration source, using the predicted area obtained in Step 3 as a spatial constraint. Complete waveform data collected by all sensing elements 208 of all monitoring units located within and around the predicted area is retrieved. Specifically, only data obtained from all monitoring units within the predicted area is used to quickly output the 3D coordinates of the vibration source as the calculation result. The specific positioning calculation method is a conventional technique.

[0029] Step 5: Event Feature Analysis and Early Warning Decision. The data obtained from the signals collected by the monitoring units is analyzed, specifically focusing on the dominant frequency, time domain, kurtosis, and energy. The analyzed feature vectors are then matched with a pre-stored rockburst feature database for similarity. If the overall matching score exceeds a set threshold, the vibration event is determined to be a potential precursor to rockburst. Control module 3 immediately issues a graded early warning message via the wireless communication module, including the three-dimensional coordinates of the vibration source, the estimated energy level, and the occurrence time. If the matching score is below the threshold, it is determined to be rock mass micro-vibration, equipment vibration, or other interference. The system does not issue an early warning, and all monitoring units return to the continuous monitoring state of Step 2. The detailed data collected in this step can be archived for subsequent analysis. Specifically, the rockburst feature database is an integration of data from existing known rockburst vibration frequency bands, and the specific data for these frequency bands are based on existing technology.

[0030] It should be noted that the specific models of some structures and equipment involved in this embodiment can be selected and adapted according to actual monitoring needs. The relevant principles all fall within the scope of existing technology, summarized as follows: Bolts, screws, reinforcing ribs 102, caps 301, and pressure frames 201, etc., are all common standard parts in the mechanical field. Their connection and fixing principles and structural design specifications are all existing mature technologies. Standard parts of corresponding specifications can be selected according to the load-bearing requirements of the monitoring unit and the installation environment. The rotational connection structure between the load-bearing turntable 103 and the load-bearing rotating rail 104 adopts existing conventional slewing bearings or sliding friction rotational structures. Its core principle is through phase... Rotary joints enable rotatable connections between two components, and limiting structures limit angles. This type of structure is widely used in various adjustable installation equipment. The wireless communication module can use existing mature technologies such as LoRa, BLE, industrial Ethernet, or ZigBee. Its core principle is to achieve long-distance data transmission through wireless communication protocols. The specific model can be selected according to the transmission distance and signal obstruction in the tunnel. The relevant communication protocols and transmission principles are all existing technologies. Hyperbolic algorithms, spatial geometric operations, and Kalman filtering algorithms are all existing mature positioning and signal processing algorithms. The implementation logic and calculation process of each algorithm are supported by clear existing technical literature.

[0031] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention.

Claims

1. A rockburst monitoring system, characterized in that: It includes multiple monitoring units spaced apart along the direction of the roadway extension. Each monitoring unit includes a support shell (4), a control module (3), and a sensor array. The support shell (4) has multiple placement slots (402). The sensor array consists of multiple vibration sensors (2), which are arranged one-to-one in the placement slot (402). The vibration sensors (2) can receive vibration signals in the target direction. The control module (3) is communicatively connected to all vibration sensors (2).

2. The rockburst monitoring system as described in claim 1, characterized in that: The support shell (4) has multiple mounting surfaces facing different directions, and the placement groove (402) is set corresponding to the mounting surface.

3. The rockburst monitoring system as described in claim 1, characterized in that: The support shell (4) is connected to a support part (1), which includes a support foot (101) with a bearing turntable (103) fixedly connected to the top. The bearing turntable (103) is rotatably connected to the bearing rail (104), and the bearing rail (104) is fixedly connected to the support shell (4).

4. The rockburst monitoring system as described in claim 3, characterized in that: The bearing turntable (103) is fixedly connected to a polygonal limiting sleeve (105) on the side facing the support shell (4), and the support shell (4) is provided with a polygonal limiting groove (404) that is adapted to the limiting sleeve (105) on the side facing the support foot (101).

5. The rockburst monitoring system as described in claim 1, characterized in that: The vibration sensor (2) includes a vibrating diaphragm (202) capable of vibrating. The vibrating diaphragm (202) has a conical mating groove (401) with an flared opening. The mating groove (401) is opened on the support shell (4), and the flared opening of the mating groove (401) coincides with the mounting surface of the support shell (4).

6. The rockburst monitoring system as described in claim 5, characterized in that: The docking groove (401) is provided with a reflective bucket (203), and the narrow opening of the reflective bucket (203) is provided with a vibrating plate (205). The vibrating plate (205) is connected to the first end of the transmission rod (206). The second end of the transmission rod (206) passes through the support shell (4) and is connected to the sensing element (208) included in the vibration sensor (2).

7. The rockburst monitoring system as described in claim 1, characterized in that: The support shell (4) is equipped with a trigger sensor (5) that is connected to the control module (3) in communication. The trigger sensor (5) is fixedly connected to the tunnel rock mass through a transmission column (6).

8. The rockburst monitoring system as described in claim 7, characterized in that: The first end of the transmission column (6) is connected to the trigger sensor (5), and the second end of the transmission column (6) passes through the support shell (4) and is fixedly connected to the tunnel rock mass.

9. The rockburst monitoring system as described in claim 1, characterized in that: The support shell (4) has a storage slot (403) on its end face. The storage slot (403) is connected to the control module (3). The control module (3) includes a positioning frame (304) that can be inserted into the storage slot (403). The outer side of the positioning frame (304) is provided with a third isolation layer (303). An energy control module (302) and a wireless communication module are fixedly connected inside the positioning frame (304).

10. A method for monitoring rockburst, characterized in that: The steps include using a rockburst monitoring system according to any one of claims 1-9: Multiple monitoring units were deployed along the tunnel, and the angle of the support shell (4) in the monitoring unit was adjusted; Multiple vibration signals are simultaneously acquired using the sensor array of the monitoring unit; The control module (3) calculates the signal arrival time difference between vibration signals in different monitoring units corresponding to the target direction based on the vibration signal, and preliminarily determines the roadway section and horizontal orientation of the vibration source based on the signal arrival time difference, thus forming a predicted direction; Using the predicted direction as a spatial constraint, the three-dimensional coordinates of the vibration source are calculated and the location area of ​​the vibration source is determined. The vibration signal of the vibration sensor (2) near the positioning area is matched and verified with the rockburst feature library. If the match is successful, the warning information and positioning result are output; otherwise, normal monitoring is restored.

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