A method for laying out a mine-shock well-ground combined monitoring network

Abstract

The application discloses a kind of mine seismic well ground joint monitoring network layout method, using the following steps: determining the area and boundary conditions of the monitored mining area;According to the geological factors and mining technical factors, the underground key area is divided;Establish the underground monitoring system;According to the effective monitoring coverage of ground microseismic sensor, the distribution of underground goaf, the ground monitoring key area is divided according to the direction of coal mining and tunneling;Exploring the bedrock of the ground monitoring area and determining the distribution position of the bedrock in the ground monitoring area;Select the bedrock in step five to establish the ground monitoring system.The underground monitoring system of the application can realize accurate monitoring of multiple parameters, effectively obtain the accurate change of coal rock attachment state, the ground monitoring system can realize large area monitoring on the ground, can cover the scale of mining area, command the overall situation, avoid omission, realize early warning, and ensure the safety of coal mining.

Description

Technical Field

[0001] This invention relates to the field of coal mine safety technology, and more specifically to a method for deploying a joint mine-ground monitoring network for seismic activity. Background Technology

[0002] Mine tremors are a type of seismic phenomenon primarily caused by the destabilization and disruption of coal and rock masses due to human mining activities. Mine tremors involve the instantaneous release of a large amount of elastic energy, which propagates as waves within the surrounding rock mass, posing a serious threat to the stability of underground goaf areas and roadways. To reduce the hazards of mine tremors and prevent further escalation of disasters, experts utilize underground microseismic monitoring systems for monitoring and early warning. By analyzing the frequency and magnitude of mine tremors, the state of coal and rock deposits can be determined, thereby providing a warning of potential dangers. Therefore, underground microseismic monitoring can effectively provide early warnings of mine tremor disasters.

[0003] Currently, underground microseismic monitoring systems are widely used, but they still suffer from technical limitations such as short monitoring distance and limited monitoring range. Deploying sensors over large areas leads to resource waste. To address this issue, some experts have proposed ground-based monitoring. However, due to the small magnitude and high frequency of mine seismic events, traditional ground-based monitoring is easily affected by environmental interference, resulting in insufficient monitoring accuracy. Currently, there is no high-precision, large-scale method for monitoring mine seismic events. Existing technologies are widely susceptible to environmental influences and have short monitoring distances, making it difficult to achieve monitoring at the mine-scale.

[0004] For example, the invention patent application (publication number CN 115963545 A, publication date 2023.04.14) discloses a microseismic location method and system for multi-well joint monitoring. It still relies on downhole sensors for monitoring, and improves the detection accuracy by relying on sensors from different mines. It requires a large number of sensors and involves a large amount of installation work, which is not economical.

[0005] The invention patent application (application publication number CN 116559958 A, application publication date 2023.08.08) discloses a method for evaluating and improving the effect of well-ground joint microseismic monitoring. It is only an upgrade at the algorithm level, evaluating the effect of well-ground joint microseismic monitoring under the current network deployment, without involving the station construction plan, and without proposing specific measures and steps on how to achieve well-ground joint observation.

[0006] The invention patent (authorization announcement number CN 111208571 B, authorization announcement date 2022.03.11) discloses a method for joint well-ground detection of multi-layer goaf water accumulation areas, involving ground and underground transient electromagnetic detection technology and ground and underground induced polarization detection technology. However, it is only for the detection of overlying multi-layer goaf water accumulation areas and does not have the conditions for monitoring the state of coal and rock.

[0007] Therefore, how to provide a method for deploying a mine seismic joint monitoring network that can monitor the coal and rock attachment status in different underground areas, utilize a ground monitoring network for monitoring within the mining area, and construct ground observation piers or ground detection wells based on actual ground conditions, thereby achieving accurate monitoring of mine seismic waves by ground stations, and thus improving the monitoring range and monitoring capabilities of coal and rock dynamic disasters, is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0008] In view of this, the present invention provides a method for deploying a mine seismic ground-ground joint monitoring network that, on the basis of meeting the monitoring requirements of coal and rock attachment status in different underground areas, utilizes a ground monitoring network for monitoring within the mining area, and constructs ground observation piers or ground detection wells based on actual ground conditions, thereby achieving accurate monitoring of mine seismic waves by ground stations, improving the monitoring range of coal and rock dynamic disasters, and enhancing monitoring capabilities.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] A method for deploying a joint mine-ground monitoring network for seismic activity includes the following steps:

[0011] Step 1: Determine the area and boundary conditions of the mining area to be monitored;

[0012] Step Two: Delineate key underground areas based on geological and mining technology factors;

[0013] Step 3: Establish a downhole monitoring system;

[0014] Step 4: Divide the key monitoring areas on the ground according to the effective monitoring coverage of the ground microseismic sensors, the distribution of underground goaf areas, and the direction of coal mining and tunneling;

[0015] Step 5: Explore the bedrock in the ground monitoring area and determine the distribution location of the bedrock within the ground monitoring area;

[0016] Step Six: Select the intact and solid bedrock from Step Five to establish a ground monitoring system.

[0017] The beneficial effects of the above technical solutions are that the underground monitoring system can achieve accurate monitoring of multiple parameters and effectively obtain accurate changes in the state of coal and rock attachment, while the ground monitoring system can achieve large-area monitoring on the ground, covering the mining area scale, taking a holistic view, avoiding omissions, achieving early warning, and ensuring the safety of coal mining.

[0018] Preferably, in step one, the key monitoring areas of the mining area are determined according to the areas with high incidence of mining earthquakes.

[0019] Preferably, in step two, the geological factors are determined by taking the coal seam thickness, geological structure, coal seam roof and floor conditions, coal mine gas storage, coal mine gas pressure, ground pressure, geothermal and groundwater distribution in the mining area as geological factors, and the mining technology factors are taken by taking the tunneling location, tunneling direction, mining technology, mining sequence and mining history of different roadways as mining technology factors. The two factors are combined to determine the key underground areas within the monitoring area of ​​the mining area.

[0020] Preferably, in step three, an underground monitoring system is established on the ground and underground along both sides of the goaf or roadway, following the direction of the underground key area's spread. The underground monitoring system includes underground sensors, a signal amplification module, an underground signal transmission module, and an underground signal processing module. The underground sensors are electrically connected to the signal amplification module, and the underground information is aggregated to the underground signal processing module through the underground signal transmission module. Due to the complex underground environment, an underground signal processing module can be set up in different areas.

[0021] Preferably, the downhole sensor is one or more combinations of microseismic monitoring sensors, electromagnetic monitoring sensors, stress monitoring sensors, strain monitoring sensors, gas concentration sensors, temperature sensors, and humidity sensors. Depending on the different coal and rock dynamic hazard tendencies in different mines, one or more combinations of downhole sensors can be selected according to local conditions to strengthen monitoring in areas prone to mine seismic activity, thereby achieving the best downhole detection results.

[0022] Preferably, in step six, the ground monitoring system includes observation piers, probe wells, a surface signal transmission module, and a surface information processing module. Data monitored by the observation piers and probe wells is aggregated to the surface information processing module via the surface signal transmission module. Under the condition of a clearly defined mining area, the ground monitoring system selects points on the surface of the mining area according to the coverage of the underground sensors, following a triangular arrangement, honeycomb structure, or parallelogram rule, and constructs observation piers or probe wells based on the actual bedrock depth.

[0023] Preferably, the observation pier is set at the bedrock at the top of the ground and a ground sensor is fixed on its top surface. It is 0.4m long and 0.4m wide. The observation pier is provided with a vibration isolation groove around its perimeter. The bottom of the vibration isolation groove is provided with a moisture-proof layer and the cavity inside the vibration isolation groove is filled with a filling material.

[0024] Preferably, the detection well is located in the bedrock buried underground. The detection well is oriented deep well using a gyro-direction instrument. The bottom of the well is located on the top surface of the bedrock and is provided with an anti-seepage layer. The ground sensor is fixed on the top surface of the anti-seepage layer. The detection well is enclosed by seamless steel pipe or plastic pipe, and its wellhead is provided with a protective cover.

[0025] Ground sensors include, but are not limited to, velocity sensors and acceleration sensors. The selection of ground sensors is based on the seismic microfrequency, depth, magnitude, and geological conditions of the mining area to obtain effective information such as different mine seismic acceleration, amplitude, and frequency. This information is then compared and analyzed with underground data to achieve early warning of coal and rock dynamic disasters.

[0026] Preferably, the system also includes a data processing system. The data processing system's acquisition and conversion circuitry is housed in a data acquisition cabinet, and it transmits the data monitored by the well-to-surface joint monitoring network to a computer for display, recording, and storage. The data processing system operates on a Chinese operating system, and the computer is a stable industrial control computer that has undergone comprehensive testing to ensure safe experimental testing. It can acquire relevant data in real time and adjust control parameters as needed.

[0027] Preferably, the system also includes an early warning system. The well-to-surface joint monitoring network is equipped with a safety threshold. When the data transmitted to the computer exceeds the safety threshold, an alarm will be triggered. Both the downhole sensors and the surface sensors are equipped with safety thresholds. Once the safety threshold is exceeded, an alarm will be triggered, and the alarm will only be deactivated after the system algorithm and human intervention confirm that there is no error. The safety threshold is used for protection against false alarms in the monitoring system and for localized alarms. It can both prevent the monitoring system from issuing false alarms due to misjudgment and serve as an alarm for dangerous areas.

[0028] As can be seen from the above technical solution, compared with the prior art, the present invention discloses a method for deploying a mine-ground joint monitoring network for seismic events. The monitoring network has a simple structure, accurate monitoring of multiple parameters underground, and, in conjunction with ground monitoring, achieves accurate identification and early warning of coal and rock dynamic disasters through the joint operation of the mine and ground systems. According to the actual situation, the underground monitoring system and the ground monitoring system are linked together, and comprehensive analysis is carried out accurately through the setting of standards to improve the accuracy of monitoring and early warning, provide early warning of coal and rock dynamic disasters, and ensure the safety of coal mining. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0030] Figure 1 The well-ground joint monitoring network deployment flowchart provided by this invention;

[0031] Figure 2 A schematic diagram of the mining area provided by this invention;

[0032] Figure 3This is a schematic diagram of the observation pier structure provided by the present invention;

[0033] Figure 4 This is a schematic diagram of the exploration well structure provided by the present invention;

[0034] Figure 5 This is a cross-sectional view of the well-ground integrated monitoring network provided by the present invention.

[0035] in:

[0036] 1-Ground sensor; 2-Pad; 3-Observation pier; 4-Filling material; 5-Bedrock; 6-Ground; 7-Leveling layer; 8-Subbase layer; 9-Moisture-proof layer; 10-Protective cover; 11-Seamless steel pipe; 12-Soil layer; 13-Imperile layer; 14-Mining area boundary; 15-Mining area; 16-High-incidence area of ​​mine earthquakes; 17-Ground monitoring system; 18-Coal seam; 19-Underground monitoring system; 20-Roadway or goaf. Detailed Implementation

[0037] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] See appendix Figures 1-5 This invention discloses a method for deploying a joint mine-ground monitoring network, comprising the following steps:

[0039] Step 1: Determine the area and boundary conditions of the mining area to be monitored; see appendix. Figure 2 The boundaries of the entire mining area were determined 14, and the high-incidence area of ​​mining earthquakes 16 within the mining area 15 was identified as the area to be monitored.

[0040] Step Two: Delineate key underground areas based on geological and mining technology factors; use the thickness of the coal seam, geological structure, roof and floor conditions, coal mine gas storage, coal mine gas pressure, ground pressure, geothermal energy, and groundwater distribution in the mining area as geological factors, and the location, direction, mining technology, mining sequence, and mining history of different roadways as mining technology factors, and combine the two to determine the key underground areas within the monitored area of ​​the mining area;

[0041] Step 3: Establish an underground monitoring system 19; Deploy the underground monitoring system 19 in the roadway or goaf 20 and underground along the direction of the spread of the high-incidence area of ​​mining earthquakes. The spatial range of the underground sensor deployment in the area with a length of A in the roadway or goaf 20 is B; From the basic data of the initially planned site selection spatial range B, query relevant mining technology factors, geological factors and other key factors, and establish a set of key factors C;

[0042] Step 4: Based on the effective monitoring coverage of the ground microseismic sensors, the distribution of underground goaf areas, and the direction of coal mining and tunneling, key areas for ground monitoring are divided; the key factors are scored using the comprehensive index method, and the optimal solution is calculated for the set of key factors C for different locations to obtain the hazard level of mine seismic events in the area, which serves as the evaluation standard for necessary areas for mine seismic monitoring.

[0043] Step 5: Explore the bedrock in the ground monitoring area and determine the distribution location of the bedrock within the ground monitoring area; when the area in Step 4 is determined to be a necessary monitoring area, explore the bedrock near the area to obtain the distribution location of the bedrock in the area;

[0044] Step Six: Select the intact and solid bedrock from Step Five to establish a ground monitoring system 17.

[0045] The underground monitoring system works in conjunction with the surface monitoring system to complete the deployment of a joint monitoring network for mine seismic activity.

[0046] In this embodiment, the downhole monitoring system includes a downhole sensor, a signal amplification module, a downhole signal transmission module, and a downhole signal processing module. The downhole sensor is electrically connected to the signal amplification module, and the downhole information is aggregated to the downhole signal processing module through the downhole signal transmission module.

[0047] To further optimize the above technical solution, the downhole sensor is one or more combinations of microseismic monitoring sensors, electromagnetic monitoring sensors, stress monitoring sensors, strain monitoring sensors, gas concentration sensors, temperature sensors, and humidity sensors.

[0048] In this embodiment, the ground monitoring system includes an observation pier, a probe well, a surface signal transmission module, and a surface information processing module. The data monitored by the observation pier and the probe well are aggregated to the surface information processing module through the surface signal transmission module.

[0049] In this embodiment, the observation pier 3 is set at the bedrock 5 at the top of the ground and a ground sensor 1 is fixed on its top surface. The pier is 0.4m long and 0.4m wide. The observation pier 3 is provided with a vibration isolation groove around its perimeter. The bottom of the vibration isolation groove is provided with a moisture-proof layer 9 and the cavity inside the vibration isolation groove is filled with a filling material 4.

[0050] See appendix Figure 3 and 5 When the bedrock 5 is located near the ground, an observation pier 3 is set up. The observation pier 3 is surrounded by a seismic isolation groove, and a filling material 4 is provided between the observation pier 3 and the seismic isolation groove. The filling material 4 is a loose material. From bottom to top, the seismic isolation groove consists of a moisture-proof layer 9, a concrete cushion layer 8, a cement mortar leveling layer 7, and a ground surface 6. A gasket 2 is bolted to the top of the observation pier 3, and a ground sensor 1 is fixed to the top of the gasket 2.

[0051] To further optimize the above technical solution, when setting up observation pier 3, the length of observation pier 3 is 0.4m, the width is 0.4m, the observation pier 3 is 0.2 to 0.3m above the floor inside the room, the flatness of the observation pier surface is not less than 3mm, and blasting operations should not be used in the foundation chiseling process of observation pier 3.

[0052] Observation pier 3 can be used directly from bedrock 5 for observation, but the weathered rock debris on the surface should be removed first, and then the surface of bedrock 5 should be ground smooth. Alternatively, concrete can be poured after removing the weathered rock debris to use it as an observation pier. (Bedrock criteria: soil layers with shear wave velocities greater than 500 m / s. For special monitoring requirements, soil layers with shear wave velocities greater than 800 m / s are identified as bedrock layers).

[0053] The observation pier is not connected to any building. A seismic isolation trough with a width of not less than 0.02m and a depth of not less than 0.2m is set around the observation pier. A moisture-proof layer 9 is set at the bottom and around the seismic isolation trough. If there is water seepage, anti-seepage measures should be taken. The seismic isolation trough is filled with loose material.

[0054] In this embodiment, the detection well is set in the bedrock 5 buried under the ground. The detection well is oriented deep well using a gyroscope. The bottom of the well is located on the top surface of the bedrock 5 under the ground and is provided with an anti-seepage layer 13. A ground sensor 1 is fixed on the top surface of the anti-seepage layer. The detection well is enclosed by a seamless steel pipe 11 or a plastic pipe, and its wellhead is provided with a protective cover 10.

[0055] See appendix Figure 4 and 5 When the bedrock is buried deep, a detection well is set up; a directional gyroscope is used to make a directional deep well in soil layer 12, ensuring that there is an open area of ​​not less than 15m around the wellhead and the width of the open area is not less than 3m.

[0056] The bottom elevation of the well is the surface of bedrock 5 buried in the ground (judgment criterion: soil layer with shear wave velocity greater than 500 m / s. For special monitoring requirements, soil layer with shear wave velocity greater than 800 m / s is identified as bedrock layer).

[0057] After the exploration well is completed, cementing is carried out. The cementing material between the casing and the well wall is cement mortar with a strength grade of not less than 7.5 MPa.

[0058] When constructing a dry well-type deep well, the bottom of the well is sealed with impermeable cement mortar with a strength of not less than 7.5MPa, and the sealing thickness is greater than 1m to serve as an impermeable layer 13. Before sealing, the water in the well is pumped out and the pipe wall and the residue at the bottom of the well are cleaned. After sealing, the ground sensor 1 is installed.

[0059] The exploration well is protected by seamless steel pipe 11, with an inner diameter of not less than 136mm and a wall thickness of not less than 5mm. A protective cover 10 is installed at the wellhead.

[0060] When deploying the well-ground joint monitoring network provided by the present invention, the high-incidence area of ​​mine earthquakes to be monitored, the tunneling position and direction of different roadways in the mine area, the maximum length and width distance and coverage of the mine area are first determined by the mine area boundary 14, the mine area 15 and the high-incidence area of ​​mine earthquakes 16.

[0061] Then, the comprehensive index method was used to score different key factors, and then the optimal solution was calculated for different site selection sets to obtain the risk level of mine earthquake in the area. The monitoring area was selected, and the underground monitoring system 19 was deployed. The distribution location of bedrock 5 on the ground was determined and the ground monitoring system 17 was deployed.

[0062] The construction of observation pier 3 first involves determining the location of bedrock 5, then casting observation pier 3 onto bedrock 5 according to the set dimensions, reserving filling material 4 on both sides of observation pier 3, using loose material for filling, and then laying moisture-proof layer 9, cushion layer 8, leveling layer 7 and ground 6 on both sides of filling material 4 in sequence, and finally installing gasket 2 on observation pier 3, and installing ground sensor 1 on gasket 2.

[0063] During the construction of the exploration well, the location of bedrock 5 is first determined, and it is confirmed whether there are any obvious signs of water seepage around the exploration well, such as water stains, moist soil, or sludge. Seamless steel pipe 11 is used for well cementing, the pipe wall is cleaned and the well is flushed, the well water is pumped out and the pipe wall and residue at the bottom of the well are cleaned, and the bottom of the well is sealed with impermeable cement mortar with a strength of not less than 7.5MPa as an impermeable layer 13. After the sealing is completed, the ground sensor 1 is installed, and finally the protective cover 10 is fastened for protection.

[0064] The method for deploying a joint mine seismic monitoring network provided by this invention, while meeting the monitoring requirements for the coal and rock attachment status in different underground areas, utilizes a ground monitoring network to monitor the entire mining area. Based on the actual ground conditions, ground observation piers or ground detection wells are constructed to achieve accurate monitoring of mine seismic waves by ground stations, thereby increasing the monitoring range of coal and rock dynamic disasters, enhancing monitoring capabilities, and enabling early warning.

[0065] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0066] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for deploying a joint monitoring network for mine seismic activity, characterized in that, Includes the following steps: Step 1: Determine the area and boundary conditions of the mining area to be monitored; Step Two: Delineate key underground areas based on geological and mining technology factors; use the thickness of the coal seam, geological structure, roof and floor conditions, coal mine gas storage, coal mine gas pressure, ground pressure, geothermal energy, and groundwater distribution in the mining area as geological factors, and the location, direction, mining technology, mining sequence, and mining history of different roadways as mining technology factors, and combine the two to determine the key underground areas within the monitored area of ​​the mining area; Step 3: Establish an underground monitoring system; Establish an underground monitoring system on the ground and underground along the direction of the spread of key underground areas in the goaf or roadway. The underground monitoring system includes underground sensors, a signal amplification module, an underground signal transmission module, and an underground signal processing module. The underground sensors are electrically connected to the signal amplification module, and the underground information is aggregated to the underground signal processing module through the underground signal transmission module. The spatial range for the deployment of underground sensors in an area with a tunnel or goaf length of A is B; relevant mining technology factors and geological factors are queried from the basic data of the initially planned site selection spatial range B, and a set of key factors C is established; Step 4: Based on the effective monitoring coverage of the ground microseismic sensors, the distribution of underground goaf areas, and the direction of coal mining and tunneling, key areas for ground monitoring are divided; the key factors are scored using the comprehensive index method, and the optimal solution is calculated for the set of key factors C for different locations to obtain the hazard level of mine seismic events in the area, which serves as the evaluation standard for necessary areas for mine seismic monitoring. Step 5: Explore the bedrock in the ground monitoring area and determine the distribution location of bedrock within the ground monitoring area; soil layers with shear wave velocities greater than 500 m / s are identified as bedrock; Step Six: Select the intact and solid bedrock from Step Five to establish a ground monitoring system; the ground monitoring system includes observation piers, probe wells, a surface signal transmission module, and a surface information processing module. The data monitored by the observation piers and probe wells are aggregated to the surface information processing module through the surface signal transmission module; the observation piers are set at the bedrock at the top of the ground; the probe wells are set at the bedrock buried underground.

2. The method for deploying a joint mine seismic monitoring network according to claim 1, characterized in that, In step one, the key monitoring areas of the mining area are determined according to the areas with high incidence of mining earthquakes.

3. The method for deploying a joint mine seismic monitoring network according to claim 1, characterized in that, The downhole sensor is one or more of the following: microseismic monitoring sensor, electromagnetic monitoring sensor, stress monitoring sensor, strain monitoring sensor, gas concentration sensor, temperature sensor, and humidity sensor.

4. The method for deploying a joint mine seismic monitoring network according to claim 1, characterized in that, The observation pier is equipped with a ground sensor fixed on its top surface. The sensor is 0.4m long and 0.4m wide. The observation pier is surrounded by a vibration isolation groove. The bottom of the vibration isolation groove is equipped with a moisture-proof layer, and the cavity inside the vibration isolation groove is filled with a filling material.

5. The method for deploying a joint mine seismic monitoring network according to claim 4, characterized in that, The exploration well is oriented deep using a gyro-direction instrument. The bottom of the well is located on the top surface of the bedrock within the ground and is equipped with an anti-seepage layer. The ground sensor is fixed on the top surface of the anti-seepage layer. The exploration well is enclosed by seamless steel pipes or plastic pipes, and its wellhead is equipped with a protective cover.

6. A method for deploying a mine seismic monitoring network according to any one of claims 1 to 5, characterized in that, It also includes a data processing system, whose acquisition and conversion circuit is placed in the acquisition cabinet, and transmits the data monitored by the well-ground joint monitoring network to a computer for display, recording and storage.

7. The method for deploying a joint mine seismic monitoring network according to claim 6, characterized in that, It also includes an early warning system. The well-ground joint monitoring network is equipped with a safety threshold. When the data transmitted to the computer exceeds the safety threshold, an alarm will be triggered.

Images