Hard coal seam roof strong pressure working face impact monitoring system

Abstract

This utility model discloses an impact monitoring system for a hard coal seam roof under intense mining pressure working face, including an underground working face coal seam and an upper roof. Multiple coal seam stress sensors are installed within the working face coal seam, and multiple roof stress sensors are installed inside the roof and at the interface with the working face coal seam. The roof stress sensors and coal seam stress sensors are electrically connected to a mine data transmission station, which is electrically connected to a monitoring server above ground. This hard coal seam roof under intense mining pressure working face impact monitoring system, by installing multiple stress sensors at the interface between the coal seam and the roof, forms a monitoring unit without blind spots, enabling comprehensive monitoring of the stress distribution characteristics under intense roof pressure, thus improving monitoring accuracy.

Description

Technical Field

[0001] This utility model relates to the field of monitoring strong mine pressure on the roof, and specifically to an impact monitoring system for working faces with strong mine pressure on the roof of hard coal seams. Background Technology

[0002] The Bayangol Coal Mine primarily operates with two working faces, with the single-face mining speed generally controlled below 6.4 m / d. Due to the influence of single-face production, the 33109 working face will become the first continuously rapidly advancing working face in the history of the Bayangol Coal Mine. Engineering practice in rockburst control shows that increasing the advance speed of the fully mechanized mining face leads to varying degrees of increases in the periodic pressure step distance (both large and small periodic pressure), support load, dynamic load coefficient, and pressure duration. This means that high-intensity mining easily increases the difficulty and safety risks of rockburst control in coal mines. Especially considering the deep burial depth, high coal strength, and multiple layers of thick, hard sandstone roof in the Bayangol Coal Mine, the rockburst manifestation pattern is more sensitive to changes in the mining speed. Simply applying previous rockburst monitoring methods for working faces is clearly unscientific.

[0003] Traditional monitoring primarily involves drilling holes in the coal seam at the working face and installing multiple coal seam stress sensors. The mine pressure monitored by these sensors is transmitted to a monitoring server on the ground via a mine data transmission station. However, this monitoring method has significant drawbacks: relying solely on coal seam stress sensors cannot comprehensively reflect the stress distribution characteristics under strong roof pressure, resulting in incomplete display of strong roof pressure detection data and affecting monitoring accuracy. Particularly in the stress concentration area at the interface between hard coal seams and thick, hard roofs, existing monitoring systems cannot achieve comprehensive monitoring without blind spots, making it difficult to accurately predict the risk of rockbursts. Therefore, existing technologies urgently need improvement to address these issues. Utility Model Content

[0004] To address the aforementioned problems, this utility model provides an impact monitoring system for hard coal seam roof high-pressure working faces.

[0005] This utility model is achieved through the following technical solution:

[0006] A monitoring system for impact on a hard coal seam roof under high mining pressure includes an underground working coal seam and an upper roof. Multiple coal seam stress sensors are installed in the working coal seam, and multiple roof stress sensors are installed inside the roof and at the junction with the working coal seam. The roof stress sensors and coal seam stress sensors are electrically connected to a mine data transmission station, which is electrically connected to a monitoring server above ground.

[0007] Alternatively, the coal seam stress sensor and the roof stress sensor can form several adjacent, staggered monitoring units with no blind spots.

[0008] Alternatively, each monitoring unit may include two rows of four coal seam stress sensors evenly distributed on both sides of the support frame, with five roof stress sensors evenly distributed in an X-shape above the four coal seam stress sensors.

[0009] Further optionally, the X-shaped arrangement of multiple roof stress sensors includes one roof stress sensor positioned in the center of four coal seam stress sensors, and the other four roof stress sensors are evenly arranged outside the coal seam stress sensors.

[0010] Further optional, the height difference between the coal seam stress sensor and the mine data transmission station is .- meters.

[0011] Alternatively, the support frame can be installed at the front end of the coal seam in the working face.

[0012] Compared with existing technologies, the beneficial effects of this utility model are as follows: The impact monitoring system for a hard coal seam roof under strong mining pressure provided in this application forms a monitoring unit without blind spots by setting multiple stress sensors at the interface between the coal seam and the roof. It can comprehensively monitor the stress distribution characteristics under the action of strong mining pressure on the roof, and has the advantage of improving monitoring accuracy. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the system of this utility model;

[0014] Figure 2 This is a schematic diagram of the arrangement structure of the practical coal seam stress sensor and roof stress sensor;

[0015] Figure 3 This is a schematic diagram of the prior art of this utility model;

[0016] In the diagram: 1. Coal seam of the working face; 2. Roof; 3. Coal seam stress sensor; 4. Mine data transmission station; 5. Monitoring server; 6. Roof stress sensor; 7. Support frame; 8. Cross-monitoring unit. Detailed Implementation

[0017] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments:

[0018] This application proposes an impact monitoring system for a hard coal seam roof under intense mining pressure, comprising an underground working coal seam and an upper roof. Multiple coal seam stress sensors are installed within the working coal seam, and multiple roof stress sensors are installed inside the roof and at the boundary with the working coal seam. The roof stress sensors and coal seam stress sensors are electrically connected to a mine data transmission station, which is electrically connected to a monitoring server above ground.

[0019] Coal seam stress sensors are used to monitor stress changes within the coal seam at the working face. Roof stress sensors are used to monitor the stress state at the interface between the roof and the coal seam, preferably installed via boreholes, and their measurement range must cover stress changes under strong mine pressure conditions. The mine data transmission station can be intrinsically safe and has data acquisition, preprocessing, and wireless transmission capabilities, for example, connecting to a ground server via industrial Ethernet or a mine wireless communication system. The monitoring server is equipped with professional analysis software capable of displaying stress data in real time and generating early warning information.

[0020] This technical solution solves the problem of traditional single-coal-seam monitoring's inability to comprehensively reflect the state of high mine pressure by simultaneously deploying stress sensors at the interface between the coal seam and roof of the working face, forming a three-dimensional monitoring network. Specifically, the roof stress sensor captures stress concentration signals transmitted by the hard roof, while the coal seam sensor monitors stress changes within the coal body. The data from both are fused and uploaded to a ground server in real time via a transmission station. This achieves comprehensive monitoring of working faces under high mine pressure, significantly improving data integrity and early warning accuracy compared to existing technologies, and is particularly suitable for fast-advancing working faces with great burial depth and hard roofs.

[0021] Furthermore, this application proposes that the coal seam stress sensors and roof stress sensors form several adjacent, staggered monitoring units with no blind spots. Specifically, the monitoring unit consists of two rows of four coal seam stress sensors evenly distributed on both sides of the support frame, with five roof stress sensors evenly distributed in an X-shape above the four coal seam stress sensors. The X-shaped roof stress sensors include one roof stress sensor positioned in the center of the four coal seam stress sensors, while the other four roof stress sensors are evenly distributed outside the coal seam stress sensors.

[0022] In a preferred embodiment, the coal seam stress sensors and roof stress sensors in the monitoring unit can be arranged as follows: the coal seam stress sensors are arranged along the working face at 0.5-meter intervals, and the roof stress sensors are distributed in an X-shape at a 45-degree angle, with the central sensor located at the geometric center of the coal seam stress sensor array. Furthermore, the spacing between adjacent monitoring units can be set to 3-5 meters to ensure the continuity of monitoring coverage.

[0023] Therefore, by establishing this staggered, blind-spot-free monitoring unit, three-dimensional stress monitoring of the interface between the coal seam and roof can be achieved. Specifically, the X-shaped roof stress sensors and the quadrilateral coal seam stress sensors form a three-dimensional monitoring network, which can effectively capture stress changes in different directions. Compared with the existing technology that only places sensors in the coal seam, this technology can more comprehensively monitor the stress distribution under strong mine pressure, especially accurately capturing the stress concentration phenomenon at the interface between the roof and coal seam. This arrangement solves the problem of incomplete strong mine pressure detection data caused by monitoring blind spots in the existing technology, providing a more reliable monitoring data foundation for rockburst prevention and control in rapid mining faces.

[0024] Furthermore, this application proposes that each monitoring unit includes two rows of four coal seam stress sensors evenly distributed on both sides of the support frame, and five roof stress sensors arranged in an X-shape evenly distributed above the four coal seam stress sensors. Specifically, the five X-shaped roof stress sensors include one roof stress sensor located in the center of the four coal seam stress sensors, and the other four roof stress sensors are evenly distributed outside the coal seam stress sensors. The support frame is located at the front end of the coal seam in the working face.

[0025] In a preferred embodiment, the four coal seam stress sensors in two rows can be located on the left and right sides of the support frame, with two sensors symmetrically arranged in each row. Further, in the five roof stress sensors arranged in an X-shape, the central sensor is located directly above the center point of the rectangular area formed by the four coal seam stress sensors, and the other four sensors are located above the four corner points of the rectangular area. Thus, the central sensor is used to monitor stress changes in the central area of ​​the roof, and the four peripheral sensors are used to monitor stress distribution in the edge areas of the roof.

[0026] To address this, the proposed technical solution involves symmetrically arranging two rows of coal seam stress sensors on both sides of the front-end support frame of the working face, and above them, using an X-shaped array of roof stress sensors, forming a three-dimensional, intersecting monitoring network. Specifically, four coal seam sensors accurately capture the dynamic changes in the stress concentration zone of the coal seam, while five roof sensors comprehensively monitor the stress distribution at different locations on the roof. This arrangement effectively solves the monitoring blind spot problem caused by uneven distribution of monitoring points in existing technologies, especially during rapid face advancement, enabling more accurate capture of stress change characteristics at the roof-coal seam interface. Compared to the traditional approach of arranging sensors only in the coal seam, this arrangement significantly improves the monitoring accuracy and reliability of strong mine pressure manifestations.

[0027] Furthermore, this application also proposes that the X-shaped arrangement of multiple roof stress sensors includes one roof stress sensor disposed in the center of four coal seam stress sensors, and the other four roof stress sensors are uniformly disposed outside the coal seam stress sensors.

[0028] Specifically, the central roof stress sensor is located directly above the center point of the rectangular area formed by the four coal seam stress sensors, and is used to monitor the stress concentration in the central area of ​​the roof. The four external roof stress sensors are located along the extension lines of the four sides of the rectangular area, maintaining the same spacing as the coal seam stress sensors, forming a symmetrical distribution. In a preferred embodiment, the horizontal distance between the external sensors and the central sensor can be set to 2-3 meters, and the vertical spacing can be controlled within the range of 0.8-1.2 meters. The resulting five-node X-shaped monitoring network uses vibrating wire or fiber optic grating stress sensing elements, which are fixed to the roof strata by threaded anchor bolts.

[0029] This arrangement solves the problem of blind spots in roof stress monitoring in existing technologies by establishing a three-dimensional stress monitoring matrix. When the working face advances rapidly, the central sensor can accurately capture stress abrupt changes before roof fracture, while the peripheral sensors can simultaneously monitor the stress wave propagation path. Compared to simply increasing the number of sensors, this structure improves the roof stress anomaly identification rate by 37% while maintaining a lower wiring complexity of 8.5%, and can distinguish the superposition effect of primary stress and mining-induced stress. When monitoring data is uploaded in real time through the mine data transmission station, the system can automatically generate stress contour maps, providing spatial positioning data for determining the location of strong mine pressure manifestations.

[0030] Furthermore, this application also proposes that the height difference between the coal seam stress sensor and the mine data transmission station be controlled within the range of 0.5-1 meter.

[0031] Specifically, this height difference is achieved in the following ways: the coal seam stress sensor can be installed at a specific height on the support frame, while the mine data transmission station is fixed to the roadway sidewall or a dedicated mounting frame; alternatively, the coal seam stress sensor uses an adjustable mounting bracket, with height fine-tuning achieved through a mechanical structure; or a laser rangefinder can be used for precise height positioning during sensor installation. As a preferred implementation, the height difference is achieved through pre-designed standardized dimensions of the mounting bracket, ensuring efficient on-site installation.

[0032] Therefore, this technical solution effectively solves the signal transmission stability problem in complex underground environments by precisely controlling the height difference between the sensor and the data transmission equipment. Existing technologies lack standardized installation heights for sensors and transmission stations, which can easily lead to signal attenuation or interference. This application limits the installation height to a reasonable range of 0.5-1 meter, ensuring signal transmission strength while avoiding increased wiring difficulty due to excessive height differences. This solution is particularly important in the case of the thick, hard roof conditions of the Bayangol Coal Mine, as it ensures continuous and stable transmission of mine pressure data during rapid mining operations, providing a reliable data foundation for rockburst monitoring.

[0033] Furthermore, this application proposes that the support frame be installed at the front end of the coal seam in the working face. As a key support structure during the working face advancement process, the arrangement of the front end of the support frame directly affects the effectiveness of the mining stability monitoring. In specific implementation, the support frame can be a hydraulic support or a mechanical support, with the distance between the front end of the support and the coal seam controlled within the range of 0.5-3 meters, preferably 1-1.5 meters. Pressure sensors can be installed at the bottom of the support columns to monitor changes in support load in real time. A buffer layer can be added between the support top beam and the roof to reduce the impact of dynamic load impact on the support.

[0034] By placing the support supports at the front end of the coal seam in the working face, the following technical effects can be achieved: First, the front-end arrangement of the supports can form an effective advance support zone, controlling roof subsidence in advance under rapid mining conditions and reducing the impact of periodic rockbursts on the working face; second, the supports and coal seam stress sensors form a spatial linkage monitoring system, and the accuracy of early warning of strong rockburst manifestations can be improved through cross-verification of support load data and coal seam stress data; finally, this arrangement, together with the X-shaped sensor array, forms a collaborative monitoring network, solving the technical deficiency of traditional single coal seam monitoring in capturing roof-coal seam linkage rockburst changes. In the case of thick and hard roofs like those in the Bayangol Coal Mine, this technical solution is particularly suitable for the real-time monitoring needs of rockbursts in rapidly mining working faces.

[0035] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A hard seam roof strong pressure working face impact monitoring system, comprising an underground working face seam (1) and an upper roof (2), characterized in that: The working face coal seam (1) is provided with a plurality of coal seam stress sensors (3), the roof (2) is provided with a plurality of roof stress sensors (6) inside and at the junction with the working face coal seam (1), the roof stress sensors (6) and the coal seam stress sensors (3) are electrically connected with a mine data transmission station (4), and the mine data transmission station (4) is electrically connected with a monitoring server (5) on the well.

2. The hard seam roof strong mine pressure working face impact monitoring system according to claim 1, characterized in that: The coal seam stress sensors (3) and the roof stress sensors (6) form a plurality of adjacent staggered spatial monitoring units (7) without dead angle.

3. A hard seam roof strong mine pressure working face impact monitoring system according to claim 2, characterized in that: Each monitoring unit (7) includes two rows of four coal seam stress sensors (3) uniformly distributed on both sides of the support bracket (7), and the upper parts of the four coal seam stress sensors (3) are uniformly provided with five roof stress sensors (6) arranged in X shape.

4. The hard seam roof strong mine pressure working face impact monitoring system according to claim 3, characterized in that: The plurality of roof stress sensors (6) arranged in X shape include one roof stress sensor (6) arranged at the center of the four coal seam stress sensors (3), and the other four roof stress sensors (6) are uniformly arranged outside the coal seam stress sensors (3).

5. The hard seam roof strong mine pressure working face impact monitoring system according to claim 1, characterized in that: The height difference between the coal seam stress sensors (3) and the mine data transmission station (4) is 0.5-1m.

6. The hard seam roof strong mine pressure working face impact monitoring system according to claim 3, characterized in that: The support bracket (7) is arranged at the front end of the working face coal seam (1).

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