A deep rock dynamic disaster energy situation assessment and early warning device and a use method thereof

Abstract

This invention relates to a device and method for assessing and warning the energy status of deep rock strata dynamic disasters, belonging to the field of mine dynamic disaster monitoring and early warning technology. The device includes a stress-displacement monitoring module, a scanning inversion module, an energy analysis module, an assessment and early warning module, an intervention decision-making module, and a comprehensive interactive module. The stress-displacement monitoring module and the scanning inversion module are connected to the energy analysis module, which in turn is connected to the assessment and early warning module and the intervention decision-making module. The assessment and early warning module and the intervention decision-making module are connected to the comprehensive interactive module. This invention enables scientific assessment and comprehensive early warning of the current state and future development trend of deep rock strata dynamic disasters, and automatically makes decisions on the degree, method, and parameters of intervention technologies for deep rock strata dynamic disasters, providing a guarantee for precise and intelligent prevention and control of deep rock strata dynamic disasters.

Description

Technical Field

[0001] This invention relates to a device for assessing and warning the energy status of dynamic disasters in deep rock strata and its usage method, belonging to the field of monitoring and warning technology for dynamic disasters in mines. Background Technology

[0002] Deep rock strata dynamic disasters, due to their instantaneous, complex, highly destructive, and unpredictable nature, have become one of the main bottlenecks restricting the safe and efficient mining of deep coal. Sudden large deformations of the sidewalls, rapid roof subsidence, and asymmetric floor heaves are all macroscopic results of energy release within the surrounding rock. Obtaining the characteristics of energy release within the surrounding rock is of great significance for the probability assessment and dynamic early warning of deep rock strata dynamic disasters.

[0003] Existing methods for obtaining the energy release characteristics of surrounding rock under actual engineering conditions can be roughly divided into two categories. One category uses numerical simulation methods to obtain the energy release process of surrounding rock. For example, Chinese patent document CN106383172A discloses a method for predicting surrounding rock damage based on the energy release coefficient, which includes the following steps: Step 1: Arrange multiple acoustic detection holes on a circular tunnel; Step 2: Use a tunnel excavation analysis model established by the finite difference method to simulate the energy release process induced by tunnel excavation; Step 3: Plot the strain energy density release process curves of the surrounding rock at different distances from the excavation boundary; Step 4: Define the energy release coefficient LERCi; Step 5: Use the least squares method to fit and establish the relationship between the energy release coefficient LERC and the measured wave velocity drop η; Step 6: Calculate the damage coefficient D of the surrounding rock at that location; Step 7: Determine whether the surrounding rock has been damaged. The model established by this method is a simplified model based on actual conditions and cannot truly reflect the energy release characteristics of the surrounding rock under actual engineering conditions. Furthermore, it cannot achieve dynamic monitoring of the energy released by the surrounding rock in engineering projects.

[0004] Another type utilizes microseismic monitoring technology to obtain the energy release process of surrounding rock. For example, Chinese patent document CN120315025A discloses a method and system for comprehensive monitoring and coordinated near-field and dynamic / static far-field early warning of rockburst. The early warning method includes: based on the generation and propagation mechanism of dynamic stress waves in the far field, determining key monitoring areas and stress wave types in the mining area, delineating high-stress zones in the surrounding rock of the working face, and analyzing the structural characteristics of the rock strata. Microseismic sensors are installed in the key far-field areas to obtain parameters such as the source fracture size, energy, and magnitude through waveform inversion; an acoustic-electric system is deployed in the high-stress near-field areas to dynamically monitor coal and rock fracture characteristics and quantitatively analyze the static energy storage state of the surrounding rock. However, this method obtains energy based on the inversion of wave signals generated by coal and rock fracture, which cannot objectively reflect the mechanical essence of energy as the ability of matter to do work. Furthermore, it can only monitor far-field rock strata and cannot obtain real-time energy release characteristics of the near-field surrounding rock, the main body of deep rock dynamic disasters. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a device and method for assessing and warning the energy status of deep rock dynamic disasters. It obtains the energy release characteristics of surrounding rock movement and surface deformation at different depths, enabling scientific assessment and comprehensive early warning of the current state and future development trend of deep rock dynamic disasters. It also automatically makes decisions on the degree, method, and parameters of intervention technologies for deep rock dynamic disasters, providing a guarantee for precise and intelligent prevention and control of deep rock dynamic disasters.

[0006] The technical solution of the present invention is as follows:

[0007] A device for assessing and warning the energy status of dynamic disasters in deep rock strata includes a stress-displacement monitoring module, a scanning inversion module, an energy analysis module, an assessment and warning module, an intervention decision module, and a comprehensive interactive module. The stress-displacement monitoring module and the scanning inversion module are connected to the energy analysis module. The energy analysis module is sequentially connected to the assessment and warning module and the intervention decision module. The assessment and warning module and the intervention decision module are connected to the comprehensive interactive module.

[0008] The stress-displacement monitoring module is used to acquire the stress state and displacement changes of the coal and rock mass at a certain location inside the surrounding rock of the roadway;

[0009] The scanning inversion module is used to obtain the deformation of the surrounding rock and the stress characteristics of the anchor bolts and cables within the tunnel cross section;

[0010] The energy analysis module, based on the mechanical principles of energy calculation and combined with monitoring data from the stress-displacement monitoring module and the scanning inversion module, quantitatively characterizes the dynamic release process of energy inside and on the surface of the surrounding rock in the roadway.

[0011] The assessment and early warning module is used to assess the status and development trend of deep rock dynamic disasters and provide dynamic early warnings.

[0012] The intervention decision-making module is used to automatically recommend intervention techniques and intervention levels for deep rock dynamic disasters;

[0013] The integrated interactive module is used for information visualization and command control of the deep rock strata dynamic disaster energy status assessment and early warning device.

[0014] According to a preferred embodiment of the present invention, the stress-displacement monitoring module includes a stress sensor, a transmission cable, a wedge-shaped anchor, a transmission cable, a displacement sensor, and a data acquisition instrument. The wedge-shaped anchor is disposed within the surrounding rock and is connected to a transmission cable. The displacement sensor is provided with multiple transmission cables and wedge-shaped anchors.

[0015] Stress sensors are installed in multiple boreholes at different depths to obtain the stress state of the surrounding rock at different depths. The borehole depth can be determined according to the fixing depth of the wedge-shaped anchors. That is, the depth of different boreholes corresponds to the fixing depth of multiple wedge-shaped anchors, thereby obtaining the stress and displacement of the surrounding rock at the same depth.

[0016] Both the stress sensor and the displacement sensor are connected to a data acquisition device. The stress sensor senses the stress state of the surrounding rock at its location and transmits it to the data acquisition device via a transmission cable. The displacement is transmitted to the displacement sensor via a transmission cable connected to the wedge-shaped anchor claw, and then transmitted to the data acquisition device.

[0017] According to a further preferred embodiment of the present invention, the borehole spacing is 1m to 3m.

[0018] According to a preferred embodiment of the present invention, the scanning inversion module is a three-dimensional laser scanner with explosion-proof characteristics.

[0019] According to a preferred embodiment of the present invention, the integrated interactive module includes a downhole visualization operation unit, a downhole ring network switch, a ground server, and a central visualization operation unit. The data acquisition instrument is connected to the downhole visualization operation unit, and the downhole visualization operation unit is connected to the central visualization operation unit through the downhole ring network switch and the ground server.

[0020] The steps for using the aforementioned deep rock strata dynamic disaster energy situation assessment and early warning device are as follows:

[0021] (1) Select monitoring locations and obtain geological and mining technology information of the monitoring locations based on geological specifications, mining operation procedures, etc.;

[0022] (2) Install the stress-displacement monitoring module, the scanning inversion module and the integrated interactive module at the monitoring location, set the sampling frequency of the stress-displacement monitoring module and the scanning inversion module to keep the sampling rates of the two modules consistent and start collecting data;

[0023] (3) The collected monitoring data is transmitted to the energy analysis module through the data acquisition instrument. The energy analysis module performs fitting integration based on the stress, displacement and deformation of the surrounding rock surface at different depths and the axial force of the anchor bolts and anchor cables to obtain the energy release characteristics of the surrounding rock at different depths and surfaces.

[0024] (4) A calculation model is established using discrete element simulation software such as 3DEC and PFC3D to simulate the energy release process of the surrounding rock in the mining roadway. Combined with the energy release characteristics of the dynamic disasters that have occurred in adjacent mines, the critical threshold for energy assessment and early warning is determined. Based on the critical threshold, the assessment and early warning module assesses and warns of the current state and future development trend of the rock dynamic disasters.

[0025] (5) Based on the early warning results, the intervention decision module determines the degree of implementation, specific methods and implementation parameters of rock dynamic disaster intervention technology;

[0026] (6) While obtaining energy release characteristics, assessing early warning results and rock dynamic disaster intervention technology solutions, the central visualization operation unit transmits information to the downhole visualization operation unit through the ground server and downhole ring network switch.

[0027] According to a preferred embodiment of the present invention, in step (2), the scanning inversion module obtains the deformation of the surrounding rock and the deformation of the anchor bolt / cable tray on the roadway surface by scanning the cross-section of the mining roadway, and obtains the stress characteristics of the anchor bolt / cable based on the relationship between the tray deformation and the axial force of the anchor bolt / cable. The deformation of the i-th tray is s. i With the axial force F of the i-th anchor bolt and cable ia The relationship between them is:

[0028]

[0029] In the formula, R and r are the outer and inner diameters of the pallet, respectively, d is the pallet thickness, η is the pallet type correction factor, v is the Poisson's ratio of the pallet material, and ker(s) i ) is about the deformation amount s of the pallet i Kelvin function;

[0030] The axial force F of the anchor bolts and cables in the entire mining roadway cross section a for

[0031]

[0032] In the formula, m represents the number of anchor bolts and cables within the cross-section of the mining roadway.

[0033] According to a preferred embodiment of the present invention, the specific working method of the energy analysis module in step (3) is as follows:

[0034] First, nonlinear fitting is performed on stress and displacement monitoring data at the same depth within the surrounding rock to obtain the stress-displacement mechanical relationship at different depths. Then, integration is performed on the displacements that have occurred at different depths to obtain the energy released by the movement of the surrounding rock at different depths. Simultaneously, nonlinear fitting and integration are performed on the axial force of the anchor bolts and cables with the deformation of the surrounding rock to obtain the energy released by the deformation of the surrounding rock surface.

[0035]

[0036]

[0037] In the formula, a and b represent the width and height of the monitored tunnel, and E Ii w iLet σ represent the energy released by the surrounding rock at the i-th depth and the displacement already generated. i (w) represents the stress-displacement mechanical relationship obtained by nonlinear fitting with the surrounding rock displacement at the i-th depth as the independent variable and the surrounding rock stress at the i-th depth as the dependent variable. S The energy released by the surrounding rock on the surface of the tunnel, w S F represents the deformation occurring on the surface of the tunnel. a (w) is the mechanical relationship between anchor bolt and anchor cable axial force and surrounding rock surface deformation obtained by nonlinear fitting with the deformation of the surrounding rock surface as the independent variable and the axial force of the anchor bolt and anchor cable as the dependent variable.

[0038] Energy E released inside the surrounding rock of the mining roadway I for:

[0039]

[0040] In the formula, n is the number of depths at which the internal stress and displacement of the surrounding rock are monitored.

[0041] According to a preferred embodiment of the present invention, in step (4), the specific working method of the evaluation and early warning module is as follows:

[0042] The internal cumulative energy release value, internal energy release rate, boundary cumulative energy release value, and boundary energy release rate are used as indicators for energy status assessment and early warning of deep rock strata dynamic disasters. The internal cumulative energy release value E... CI and boundary cumulative energy release value E CS The energy E released by the surrounding rock from time 0 to t I E S The internal energy release rate R is obtained by accumulation. I and boundary energy release rate R S By increasing the internal cumulative energy release value E CI and boundary cumulative energy release value E CS Taking the first derivative with respect to time yields:

[0043]

[0044]

[0045] Based on the actual engineering geological mining conditions at the monitoring site, discrete element numerical simulation software such as PFC3D and 3DEC were used to simulate and obtain the energy release characteristics of the surrounding rock of the mining roadway during the occurrence of deep rock dynamic disasters under these engineering conditions, and to obtain the internal cumulative energy release value E. CI1 Boundary cumulative energy release value E CS1 Internal energy release rate R I1 Boundary energy release rate R S1The maximum value is then determined, and then the internal cumulative energy release value E when a rock dynamic disaster has occurred in an adjacent mine in the same mining area is determined. CI2 Boundary cumulative energy release value E CS2 Internal energy release rate R I2 and boundary energy release rate R S2 Then, the internal cumulative energy release value, boundary cumulative energy release value, internal energy release rate, and boundary energy release rate obtained using the two methods are compared, and the maximum value is taken as the internal cumulative energy release value E of the monitoring location. CI Boundary cumulative energy release value E CS Internal energy release rate R I and boundary energy release rate R S The critical threshold, i.e.:

[0046]

[0047] In the formula, E CI R I E CS R S For E CI R I E CS R S The critical threshold;

[0048] Based on the mechanism and contribution of energy released from the interior and surface of the surrounding rock in the occurrence of dynamic disasters in deep rock strata, an assessment index for the current state of dynamic disasters in deep rock strata is established, namely K. P :

[0049]

[0050] In the formula, E CI R I E CS R S This information is obtained in real time at the monitoring location.

[0051] The assessment threshold K for the current state of deep rock dynamic disasters P for:

[0052]

[0053] According to K P and K P The relationship between these factors is used to assess the current state of dynamic hazards in rock strata, namely:

[0054]

[0055] Based on energy release data from monitoring locations over the past week, the energy release process of the surrounding rock in the mining roadway is quantitatively characterized.

[0056]

[0057]

[0058]

[0059]

[0060] In the formula, E CI '、R I '、E CS '、R S 'This is an assessment result of the energy release process;'

[0061] Then, the development trend of dynamic rock strata hazards is assessed, namely:

[0062]

[0063] When K D When K = 0 / 1, the likelihood of a dynamic rock strata disaster progressing from its current state to the next state is low; D When K = 2, the trend of rock strata dynamic disasters developing from the current state to the next state is of medium probability; D When the value is 3 / 4, the dynamic disaster of the rock strata is highly likely to develop from the current state to the next state.

[0064] The warning level for rock strata dynamic hazards that are currently in the gestation stage and have a development trend of low probability, medium probability, and high probability is set to blue level of concern. The warning level for rock strata dynamic hazards that are currently in the nascent stage and have a development trend of low probability is set to blue level of concern.

[0065] The warning level for rock strata dynamic hazards that are currently in the nascent stage and have a medium or high probability of development is set to yellow alert level; the warning level for rock strata dynamic hazards that are currently in the critical stage and have a low probability of development is set to yellow alert level.

[0066] The warning level for rock strata dynamic disasters that are currently in a critical state and have a development trend of medium or high probability is set to the red danger level; the warning level for rock strata dynamic disasters that are currently in an activated state and have a development trend of low, medium or high probability is set to the red danger level.

[0067] According to a preferred embodiment of the present invention, the specific working method of the intervention decision module in step (5) is as follows:

[0068] Based on the early warning level of deep rock strata dynamic hazards, the degree of technical intervention is determined. Specifically, when the early warning level is blue (attention level), local conventional weakening technology is used; when the early warning level is yellow (warning level), local intensive weakening technology and regional conventional modification technology are used; and when the early warning level is red (danger level), local intensive weakening technology and regional intensive modification technology are used. Local weakening technology involves using large-diameter boreholes and loosening blasting in the sidewalls of the mining roadway to weaken the coal seam structure and reduce the energy concentration of the surrounding rock. Regional modification technology involves using hydraulic fracturing and deep-hole blasting to disrupt the integrity of the roof strata and change the overburden structure.

[0069] Then, based on the geological and mining conditions of the monitoring site and the level of the prevention and control team, specific measures and implementation parameters for local weakening and regional modification technologies are determined. If the coal and rock mass strength at the monitoring site is low and the rock strata integrity is good, large-diameter borehole decompression and hydraulic fracturing technologies can be used. If the coal and rock mass strength at the monitoring site is high and the internal fractures of the rock strata are well developed, loosening blasting and deep-hole blasting technologies need to be used respectively. For local weakening technologies such as large-diameter boreholes and loosening blasting, the parameters such as borehole depth, borehole layout, and borehole diameter can be determined according to the parameters already implemented in adjacent mines in the same mining area, while the borehole spacing is determined according to the warning level. The implementation parameters for regional weakening technologies such as hydraulic fracturing and deep-hole blasting need to be divided into borehole parameters and fracturing parameters. The parameters such as borehole depth and borehole angle need to be determined according to the geological conditions and the level of the prevention and control team, the borehole spacing is determined according to the warning level, and the fracturing parameters such as water injection pressure and charge amount can be determined by referring to successful cases already implemented in adjacent mines in the same mining area.

[0070] The beneficial effects of this invention are as follows:

[0071] 1. This invention integrates borehole stress gauges, multi-point displacement gauges, and three-dimensional laser scanners to achieve integrated monitoring of stress and displacement of the surrounding rock inside and on the surface of the tunnel. Based on the monitoring data, fitting and integrating are performed to obtain the energy release characteristics of the movement of the surrounding rock at different depths and the deformation of the surface surrounding rock, thus achieving the purpose of monitoring the energy nature of dynamic disasters in deep rock strata.

[0072] 2. Based on the internal cumulative energy release value, internal energy release rate, boundary cumulative energy release value, and boundary energy release rate, this invention establishes an assessment index K for the current state and future development trend of deep rock strata dynamic disasters. P and K D It can provide scientific and comprehensive early warning of dynamic disasters in deep rock strata.

[0073] 3. This invention constructs a deep rock strata dynamic disaster intervention technology system that includes local weakening and regional modification. It can automatically determine the degree of intervention, intervention method and intervention parameters of the technology based on the early warning level, and realize intelligent decision-making of deep rock strata dynamic disaster intervention technology measures.

[0074] 4. This invention uses energy release characteristics as a unified measure of monitoring results, which solves the engineering problem of difficulty in comparing multi-source data in conventional mine pressure observation. It can provide an objective and quantifiable standard basis for evaluating the effectiveness of subsequent intervention technologies. Attached Figure Description

[0075] Figure 1 This is a three-dimensional schematic diagram of the device according to an embodiment of the present invention;

[0076] Figure 2 This is a plan view of the device according to an embodiment of the present invention;

[0077] Figure 3 This is a schematic diagram of the device architecture according to an embodiment of the present invention;

[0078] Figure 4 This is a schematic diagram of the energy release analysis of the surrounding rock in an embodiment of the present invention;

[0079] Figure 5 This is a schematic diagram illustrating the intervention technology decision-making process according to an embodiment of the present invention;

[0080] In the diagram, 1. Mining roadway, 2. Anchor bolt, 3. Anchor cable, 4. Stress sensor, 5. Transmission cable, 6. Wedge-shaped anchor claw, 7. Transfer cable, 8. Displacement sensor, 9. Data acquisition instrument, 10. 3D laser scanner, 11. Underground visualization operation unit, 12. Underground ring network switch, 13. Ground server, 14. Central visualization operation unit, 15. Working face, 16. Goaf, 17. Coal seam, 18. Siltstone, 19. Fine sandstone, 20. Medium-grained sandstone. Detailed Implementation

[0081] The present invention will be further described below with reference to the embodiments and accompanying drawings, but is not limited thereto.

[0082] Example 1:

[0083] like Figure 1-5 As shown, this embodiment provides a deep rock strata dynamic disaster energy situation assessment and early warning device, including a stress-displacement monitoring module, a scanning inversion module, an energy analysis module, an assessment and early warning module, an intervention decision module, and a comprehensive interaction module. The stress-displacement monitoring module and the scanning inversion module are connected to the energy analysis module. The energy analysis module is sequentially connected to the assessment and early warning module and the intervention decision module. The assessment and early warning module and the intervention decision module are connected to the comprehensive interaction module.

[0084] The stress-displacement monitoring module is used to acquire the stress state and displacement changes of the coal and rock mass at a certain location inside the surrounding rock of the roadway;

[0085] The scanning inversion module is used to obtain the deformation of the surrounding rock and the stress characteristics of the anchor bolts and cables within the tunnel cross section;

[0086] The energy analysis module, based on the mechanical principles of energy calculation and combined with monitoring data from the stress-displacement monitoring module and the scanning inversion module, quantitatively characterizes the dynamic release process of energy inside and on the surface of the surrounding rock in the roadway.

[0087] The assessment and early warning module is used to assess the status and development trend of deep rock dynamic disasters and provide dynamic early warnings.

[0088] The intervention decision-making module is used to automatically recommend intervention techniques and intervention levels for deep rock dynamic disasters;

[0089] The integrated interactive module is used for information visualization and command control of the deep rock strata dynamic disaster energy status assessment and early warning device.

[0090] The stress-displacement monitoring module includes a stress sensor 4, a transmission cable 5, a wedge-shaped anchor 6, a transmission cable 7, a displacement sensor 8, and a data acquisition instrument 9. The wedge-shaped anchor 6 is set in the surrounding rock and is connected to the transmission cable 7. The displacement sensor 8 is equipped with 4 transmission cables and wedge-shaped anchors to obtain the displacement of the surrounding rock at depths of 4m, 8m, 12m, and 16m, respectively.

[0091] Stress sensor 4 was placed in different boreholes with depths of 4m, 8m, 12m and 16m to obtain the stress state of the surrounding rock at different depths, with a borehole spacing of 1.5m.

[0092] Both stress sensor 4 and displacement sensor 8 are connected to data acquisition instrument 9. The stress sensor senses the stress state of the surrounding rock at its location and transmits it to the data acquisition instrument through the transmission cable. The displacement is transmitted to the displacement sensor through the transmission cable connected to the wedge-shaped anchor claw, and then transmitted to the data acquisition instrument.

[0093] The scanning inversion module is a 3D laser scanner 10 with explosion-proof characteristics.

[0094] The integrated interactive module includes a downhole visualization operation unit 11, a downhole ring network switch 12, a ground server 13, and a central visualization operation unit 14. The data acquisition instrument 9 is connected to the downhole visualization operation unit 11, and the downhole visualization operation unit 11 is connected to the central visualization operation unit 14 through the downhole ring network switch 12 and the ground server 13.

[0095] The above-mentioned method for assessing and warning of the energy status of deep rock strata dynamic disasters was applied in a mine site. The roof and floor lithology of coal seam 17 consists of siltstone 18, fine sandstone 19, and medium-grained sandstone 20. When working face 15 is being mined, the mining roadway 1 is affected by the movement of the overlying strata and accumulates a lot of energy, often exhibiting characteristics of rock strata dynamic disasters such as rapid large deformation of the sidewalls and asymmetric floor heave, which seriously restricts the safe and efficient mining of the working face.

[0096] The implementation steps are as follows:

[0097] (1) Select monitoring locations and obtain geological and mining technology information of the monitoring locations based on geological specifications, mining operation procedures, etc.;

[0098] (2) Install stress-displacement monitoring module, scanning inversion module and integrated interactive module at the monitoring location, set the sampling frequency of stress-displacement monitoring module and scanning inversion module to 16.7 mHz, that is, collect data once every 1 min, so that the sampling rate of the two modules is consistent and start collecting data;

[0099] The scanning inversion module obtains the deformation of the surrounding rock and the deformation of the anchor bolt / cable trays on the roadway surface by scanning the cross-section of the mining roadway. Based on the relationship between the tray deformation and the axial force of the anchor bolt / cable, it inverts the stress characteristics of the anchor bolt / cable, where the i-th tray deformation s is... i With the axial force F of the i-th anchor bolt and cable ia The relationship between them is:

[0100]

[0101] In the formula, R and r are the outer and inner diameters of the pallet, respectively, d is the pallet thickness, η is the pallet type correction factor, v is the Poisson's ratio of the pallet material, and ker(s) i ) is about the deformation amount s of the pallet i Kelvin function;

[0102] The axial force F of the anchor bolts and cables in the entire mining roadway cross section a for

[0103]

[0104] In the formula, m represents the number of anchor bolts and cables within the cross-section of the mining roadway.

[0105] (3) The collected monitoring data is transmitted to the energy analysis module through the data acquisition instrument. The energy analysis module performs fitting integration based on the stress, displacement and deformation of the surrounding rock surface at different depths and the axial force of the anchor bolts and anchor cables to obtain the energy release characteristics of the surrounding rock at different depths and surfaces.

[0106] The specific working method of the energy analysis module is as follows:

[0107] First, nonlinear fitting is performed on stress and displacement monitoring data at the same depth within the surrounding rock to obtain the stress-displacement mechanical relationship at different depths. Then, integration is performed on the displacements that have occurred at different depths to obtain the energy released by the movement of the surrounding rock at different depths. Simultaneously, nonlinear fitting and integration are performed on the axial force of the anchor bolts and cables with the deformation of the surrounding rock to obtain the energy released by the deformation of the surrounding rock surface.

[0108]

[0109]

[0110] In the formula, a and b represent the width and height of the monitored tunnel, and E Ii w i Let σ represent the energy released by the surrounding rock at the i-th depth and the displacement already generated. i (w) represents the stress-displacement mechanical relationship obtained by nonlinear fitting with the surrounding rock displacement at the i-th depth as the independent variable and the surrounding rock stress at the i-th depth as the dependent variable. S The energy released by the surrounding rock on the surface of the tunnel, w S F represents the deformation occurring on the surface of the tunnel. a (w) is the mechanical relationship between anchor bolt and anchor cable axial force and surrounding rock surface deformation obtained by nonlinear fitting with the deformation of the surrounding rock surface as the independent variable and the axial force of the anchor bolt and anchor cable as the dependent variable.

[0111] Energy E released inside the surrounding rock of the mining roadway I for:

[0112]

[0113] In the formula, n is the number of depths at which the internal stress and displacement of the surrounding rock are monitored.

[0114] (4) A calculation model is established using discrete element simulation software such as 3DEC and PFC3D to simulate the energy release process of the surrounding rock in the mining roadway. Combined with the energy release characteristics of the dynamic disasters that have occurred in adjacent mines, the critical threshold for energy assessment and early warning is determined. Based on the critical threshold, the assessment and early warning module assesses and warns of the current state and future development trend of the rock dynamic disasters.

[0115] The specific working method of the assessment and early warning module is as follows:

[0116] The internal cumulative energy release value, internal energy release rate, boundary cumulative energy release value, and boundary energy release rate are used as indicators for energy status assessment and early warning of deep rock strata dynamic disasters. The internal cumulative energy release value E... CI and boundary cumulative energy release value E CS The energy E released by the surrounding rock from time 0 to tI E S The internal energy release rate R is obtained by accumulation. I and boundary energy release rate R S By increasing the internal cumulative energy release value E CI and boundary cumulative energy release value E CS Taking the first derivative with respect to time yields:

[0117]

[0118]

[0119] Based on the actual engineering geological mining conditions at the monitoring site, discrete element numerical simulation software such as PFC3D and 3DEC were used to simulate and obtain the energy release characteristics of the surrounding rock of the mining roadway during the occurrence of deep rock dynamic disasters under these engineering conditions, and to obtain the internal cumulative energy release value E. CI1 Boundary cumulative energy release value E CS1 Internal energy release rate R I1 Boundary energy release rate R S1 The maximum value is then determined, and then the internal cumulative energy release value E when a rock dynamic disaster has occurred in an adjacent mine in the same mining area is determined. CI2 Boundary cumulative energy release value E CS2 Internal energy release rate R I2 and boundary energy release rate R S2 Then, the internal cumulative energy release value, boundary cumulative energy release value, internal energy release rate, and boundary energy release rate obtained using the two methods are compared, and the maximum value is taken as the internal cumulative energy release value E of the monitoring location. CI Boundary cumulative energy release value E CS Internal energy release rate R I and boundary energy release rate R S The critical threshold, i.e.:

[0120]

[0121] In the formula, E CI R I E CS R S For E CI R I E CS R S The critical threshold;

[0122] Based on the mechanism and contribution of energy released from the interior and surface of the surrounding rock in the occurrence of dynamic disasters in deep rock strata, an assessment index for the current state of dynamic disasters in deep rock strata is established, namely K. P :

[0123]

[0124] In the formula, E CI R I E CS R S This information is obtained in real time at the monitoring location.

[0125] The assessment threshold K for the current state of deep rock dynamic disasters P for:

[0126]

[0127] According to K P and K P The relationship between these factors is used to assess the current state of dynamic hazards in rock strata, namely:

[0128]

[0129] Based on energy release data from monitoring locations over the past week, the energy release process of the surrounding rock in the mining roadway is quantitatively characterized.

[0130]

[0131]

[0132]

[0133]

[0134] In the formula, E CI '、R I '、E CS '、R S 'This is an assessment result of the energy release process;'

[0135] Then, the development trend of dynamic rock strata hazards is assessed, namely:

[0136]

[0137] When K D When K = 0 / 1, the likelihood of a dynamic rock strata disaster progressing from its current state to the next state is low; D When K = 2, the trend of rock strata dynamic disasters developing from the current state to the next state is of medium probability;D When the value is 3 / 4, the dynamic disaster of the rock strata is highly likely to develop from the current state to the next state.

[0138] Based on the current status and development trend, early warning levels are established for dynamic disasters in deep rock strata (see Table 1).

[0139] Table 1: Early Warning Classification of Dynamic Disasters in Deep Rock Strata

[0140]

[0141] (5) Based on the early warning results, the intervention decision module determines the degree of implementation, specific methods and implementation parameters of rock dynamic disaster intervention technology;

[0142] The specific working method of the intervention decision-making module is as follows:

[0143] Based on the early warning level of deep rock strata dynamic hazards, the degree of technical intervention is determined. Specifically, when the early warning level is blue (attention level), local conventional weakening technology is used; when the early warning level is yellow (warning level), local intensive weakening technology and regional conventional modification technology are used; and when the early warning level is red (danger level), local intensive weakening technology and regional intensive modification technology are used. Local weakening technology involves using large-diameter boreholes and loosening blasting in the sidewalls of the mining roadway to weaken the coal seam structure and reduce the energy concentration of the surrounding rock. Regional modification technology involves using hydraulic fracturing and deep-hole blasting to disrupt the integrity of the roof strata and change the overburden structure.

[0144] Then, based on the geological and mining conditions of the monitoring site and the level of the prevention and control team, specific measures and implementation parameters for local weakening and regional modification technologies are determined. If the coal and rock mass strength at the monitoring site is low and the rock strata integrity is good, large-diameter borehole decompression and hydraulic fracturing technologies can be used. If the coal and rock mass strength at the monitoring site is high and the internal fractures of the rock strata are well developed, loosening blasting and deep-hole blasting technologies need to be used respectively. For local weakening technologies such as large-diameter boreholes and loosening blasting, the parameters such as borehole depth, borehole layout, and borehole diameter can be determined according to the parameters already implemented in adjacent mines in the same mining area, while the borehole spacing is determined according to the warning level. The implementation parameters for regional weakening technologies such as hydraulic fracturing and deep-hole blasting need to be divided into borehole parameters and fracturing parameters. The parameters such as borehole depth and borehole angle need to be determined according to the geological conditions and the level of the prevention and control team, the borehole spacing is determined according to the warning level, and the fracturing parameters such as water injection pressure and charge amount can be determined by referring to successful cases already implemented in adjacent mines in the same mining area.

[0145] (6) While obtaining energy release characteristics, assessing early warning results and rock dynamic disaster intervention technology solutions, the central visualization operation unit transmits information to the downhole visualization operation unit through the ground server and downhole ring network switch.

[0146] In this embodiment, the internal cumulative energy release value E CI The threshold is 2.5 × 10 5 J, Boundary cumulative energy release value E CS The threshold is 1.8 × 10 4 J, Internal energy release rate R I The threshold is 5.2 × 10 4 J / d, boundary energy release rate R S The threshold is 3.7 × 10 3 J / d. When the working face is mined for 15 days, the internal cumulative energy release value is 1.6 × 10⁻⁶. 5 J, the cumulative energy release at the boundary is 1.2 × 10⁻⁶. 4 J, the internal energy release rate is 3.4 × 10 4 J / d, the boundary energy release rate is 2.8 × 10 3 J / d. Then K p =0.64K p The rock strata dynamic disaster is currently in a critical state. Simultaneously, the internal accumulated energy, internal energy release rate, and boundary energy release rate are showing continuous and significant increases or surges. D =3, indicating a high probability of rock strata dynamic disasters developing from a critical state to an initiation state. Under this condition, the early warning level for deep rock strata dynamic disasters is red danger level, which is consistent with the phenomena observed on site, such as severe bulging of the rock face, large-scale tearing of the anchor mesh, and breakage of anchor cables.

[0147] To ensure safe mining operations, the mine implemented large-diameter borehole decompression technology on the No. 1 sidewall of the longwall roadway and hydraulic fracturing technology on the overburden. The large-diameter boreholes had a spacing of 2m, a diameter of 150mm, and a length of 20m. The hydraulic fracturing boreholes had a spacing of 6m, a length of 42m, a borehole inclination angle of 52°, and an injection pressure of 30MPa.

[0148] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be within the protection scope of the present invention.

Claims

1. A device for assessing and warning the energy status of dynamic disasters in deep rock strata, characterized in that, It includes a stress-displacement monitoring module, a scanning inversion module, an energy analysis module, an assessment and early warning module, an intervention and decision-making module, and a comprehensive interactive module. The stress-displacement monitoring module and the scanning inversion module are connected to the energy analysis module. The energy analysis module is connected to the assessment and early warning module and the intervention and decision-making module in turn. The assessment and early warning module and the intervention and decision-making module are connected to the comprehensive interactive module. The stress-displacement monitoring module is used to acquire the stress state and displacement changes of the coal and rock mass inside the surrounding rock of the roadway; The scanning inversion module is used to obtain the deformation of the surrounding rock and the stress characteristics of the anchor bolts and cables within the tunnel cross section; The energy analysis module, based on the mechanical principles of energy calculation and combined with monitoring data from the stress-displacement monitoring module and the scanning inversion module, quantitatively characterizes the dynamic release process of energy inside and on the surface of the surrounding rock in the roadway. The assessment and early warning module is used to assess the status and development trend of deep rock dynamic disasters and provide dynamic early warnings. The intervention decision-making module is used to automatically recommend intervention techniques and intervention levels for deep rock dynamic disasters; The integrated interactive module is used for information visualization and command control of the deep rock strata dynamic disaster energy status assessment and early warning device.

2. The deep rock strata dynamic disaster energy situation assessment and early warning device as described in claim 1, characterized in that, The stress-displacement monitoring module includes a stress sensor, a transmission cable, a wedge-shaped anchor, a transmission cable, a displacement sensor, and a data acquisition instrument. The wedge-shaped anchor is installed in the surrounding rock and is connected to the transmission cable. The displacement sensor is equipped with multiple transmission cables and wedge-shaped anchors. Stress sensors are installed in boreholes at different depths to obtain the stress state of the surrounding rock at different depths; Both the stress sensor and the displacement sensor are connected to a data acquisition device.

3. The deep rock strata dynamic disaster energy situation assessment and early warning device as described in claim 2, characterized in that, The drilling spacing is 1m to 3m.

4. The deep rock strata dynamic disaster energy situation assessment and early warning device as described in claim 3, characterized in that, The scanning inversion module is a 3D laser scanner.

5. The deep rock strata dynamic disaster energy situation assessment and early warning device as described in claim 4, characterized in that, The integrated interactive module includes a downhole visualization operation unit, a downhole ring network switch, a ground server, and a central visualization operation unit. The data acquisition instrument is connected to the downhole visualization operation unit, and the downhole visualization operation unit is connected to the central visualization operation unit through the downhole ring network switch and the ground server.

6. The method of using the deep rock strata dynamic disaster energy situation assessment and early warning device as described in claim 5, characterized in that, The steps are as follows: (1) Select monitoring locations and obtain geological and mining technology information for the monitoring locations; (2) Install the stress-displacement monitoring module, the scanning inversion module and the integrated interactive module at the monitoring location, set the sampling frequency of the stress-displacement monitoring module and the scanning inversion module to keep the sampling rates of the two modules consistent and start collecting data; (3) The collected monitoring data is transmitted to the energy analysis module through the data acquisition instrument. The energy analysis module performs fitting integration based on the stress, displacement and deformation of the surrounding rock surface at different depths and the axial force of the anchor bolts and anchor cables to obtain the energy release characteristics of the surrounding rock at different depths and surfaces. (4) A calculation model is established using discrete element simulation software to simulate the energy release process of the surrounding rock in the mining roadway. Combined with the energy release characteristics of the dynamic disasters that have occurred in adjacent mines, the critical threshold for energy assessment and early warning is determined. Based on the critical threshold, the assessment and early warning module assesses and warns of the current state and future development trend of the dynamic disasters in the rock strata. (5) Based on the early warning results, the intervention decision module determines the degree of implementation, specific methods and implementation parameters of rock dynamic disaster intervention technology; (6) While obtaining energy release characteristics, assessing early warning results and rock dynamic disaster intervention technology solutions, the central visualization operation unit transmits information to the downhole visualization operation unit through the ground server and downhole ring network switch.

7. The method of using the deep rock strata dynamic disaster energy situation assessment and early warning device as described in claim 6, characterized in that, In step (2), the scanning inversion module obtains the deformation of the surrounding rock and the deformation of the anchor bolt / cable tray by scanning the cross-section of the mining roadway. Based on the relationship between the tray deformation and the axial force of the anchor bolt / cable, the stress characteristics of the anchor bolt / cable are obtained. The deformation of the i-th tray is s. i With the axial force F of the i-th anchor bolt and cable ia The relationship between them is: In the formula, R and r are the outer and inner diameters of the pallet, respectively, d is the pallet thickness, η is the pallet type correction factor, v is the Poisson's ratio of the pallet material, and ker(s) i ) is about the deformation amount s of the pallet i Kelvin function; The axial force F of the anchor bolts and cables in the entire mining roadway cross section a for In the formula, m represents the number of anchor bolts and cables within the cross-section of the mining roadway.

8. The method of using the deep rock strata dynamic disaster energy situation assessment and early warning device as described in claim 7, characterized in that, In step (3), the specific working method of the energy analysis module is as follows: First, nonlinear fitting is performed on stress and displacement monitoring data at the same depth within the surrounding rock to obtain the stress-displacement mechanical relationship at different depths. Then, integration is performed on the displacements that have occurred at different depths to obtain the energy released by the movement of the surrounding rock at different depths. Simultaneously, nonlinear fitting and integration are performed on the axial force of the anchor bolts and cables with the deformation of the surrounding rock to obtain the energy released by the deformation of the surrounding rock surface. In the formula, a and b represent the width and height of the monitored tunnel, and E Ii w i Let σ represent the energy released by the surrounding rock at the i-th depth and the displacement already generated. i (w) represents the stress-displacement mechanical relationship obtained by nonlinear fitting with the surrounding rock displacement at the i-th depth as the independent variable and the surrounding rock stress at the i-th depth as the dependent variable. S The energy released by the surrounding rock on the surface of the tunnel, w S F represents the deformation occurring on the surface of the tunnel. a (w) is the mechanical relationship between anchor bolt and anchor cable axial force and surrounding rock surface deformation obtained by nonlinear fitting with the deformation of the surrounding rock surface of the roadway as the independent variable and the axial force of the anchor bolt and anchor cable as the dependent variable; Energy E released inside the surrounding rock of the mining roadway I for: In the formula, n is the number of depths at which the internal stress and displacement of the surrounding rock are monitored.

9. The method of using the deep rock strata dynamic disaster energy situation assessment and early warning device as described in claim 8, characterized in that, In step (4), the specific working method of the assessment and early warning module is as follows: The internal cumulative energy release value, internal energy release rate, boundary cumulative energy release value, and boundary energy release rate are used as indicators for energy status assessment and early warning of deep rock strata dynamic disasters. The internal cumulative energy release value E... CI and boundary cumulative energy release value E CS The energy E released by the surrounding rock from time 0 to t I E S The internal energy release rate R is obtained by accumulation. I and boundary energy release rate R S By increasing the internal cumulative energy release value E CI and boundary cumulative energy release value E CS Taking the first derivative with respect to time yields: Based on the actual engineering geological mining conditions at the monitoring site, discrete element numerical simulation software was used to simulate and obtain the energy release characteristics of the surrounding rock of the mining roadway during the occurrence of deep rock dynamic disasters under these engineering conditions, and to obtain the internal cumulative energy release value E. CI1 Boundary cumulative energy release value E CS1 Internal energy release rate R I1 Boundary energy release rate R S1 The maximum value is then determined, and then the internal cumulative energy release value E when a rock dynamic disaster has occurred in an adjacent mine in the same mining area is determined. CI2 Boundary cumulative energy release value E CS2 Internal energy release rate R I2 and boundary energy release rate R S2 Then, the internal cumulative energy release value, boundary cumulative energy release value, internal energy release rate, and boundary energy release rate obtained using the two methods are compared, and the maximum value is taken as the internal cumulative energy release value E of the monitoring location. CI Boundary cumulative energy release value E CS Internal energy release rate R I and boundary energy release rate R S The critical threshold, i.e.: In the formula, E CI R I E CS R S For E CI R I E CS R S The critical threshold; Based on the mechanism and contribution of energy released from the interior and surface of the surrounding rock in the occurrence of dynamic disasters in deep rock strata, an assessment index for the current state of dynamic disasters in deep rock strata is established, namely K. P : In the formula, E CI R I E CS R S This information is obtained in real time at the monitoring location. The assessment threshold K for the current state of deep rock dynamic disasters P for: According to K P and K P The relationship between these factors is used to assess the current state of dynamic hazards in rock strata, namely: Based on energy release data from monitoring locations over the past week, the energy release process of the surrounding rock in the mining roadway is quantitatively characterized. In the formula, E CI '、R I '、E CS '、R S 'This is an assessment result of the energy release process;' Then, the development trend of dynamic rock strata hazards is assessed, namely: When K D When K = 0 / 1, the likelihood of a dynamic rock strata disaster progressing from its current state to the next state is low; D When K = 2, the trend of rock strata dynamic disasters developing from the current state to the next state is of medium probability; D When the value is 3 / 4, the dynamic disaster of the rock strata is highly likely to develop from the current state to the next state. The warning level for rock strata dynamic hazards that are currently in the gestation stage and have a development trend of low probability, medium probability, and high probability is set to blue level of concern. The warning level for rock strata dynamic hazards that are currently in the nascent stage and have a development trend of low probability is set to blue level of concern. The warning level for rock strata dynamic hazards that are currently in the nascent stage and have a medium or high probability of development is set to yellow alert level; the warning level for rock strata dynamic hazards that are currently in the critical stage and have a low probability of development is set to yellow alert level. The warning level for rock strata dynamic disasters that are currently in a critical state and have a development trend of medium or high probability is set to the red danger level; the warning level for rock strata dynamic disasters that are currently in an activated state and have a development trend of low, medium or high probability is set to the red danger level.

10. The method of using the deep rock strata dynamic disaster energy situation assessment and early warning device as described in claim 9, characterized in that, In step (5), the specific working method of the intervention decision module is as follows: Based on the early warning level of deep rock strata dynamic hazards, the degree of technical intervention is determined. Specifically, when the early warning level is blue (attention level), local conventional weakening technology is used; when the early warning level is yellow (warning level), local intensive weakening technology and regional conventional modification technology are used; and when the early warning level is red (danger level), local intensive weakening technology and regional intensive modification technology are used. Local weakening technology involves using large-diameter boreholes and loosening blasting in the sidewalls of the mining roadway to weaken the coal seam structure and reduce the energy concentration of the surrounding rock. Regional modification technology involves using hydraulic fracturing and deep-hole blasting to disrupt the integrity of the roof strata and change the overburden structure. Then, based on the geological and mining conditions of the monitoring site and the level of the prevention and control team, the specific measures and implementation parameters for local weakening technology and regional modification technology are determined. If the coal and rock mass strength at the monitoring site is low and the rock strata integrity is good, large-diameter borehole decompression and hydraulic fracturing technology can be used. If the coal and rock mass strength at the monitoring site is high and the internal fractures of the rock strata are well developed, loosening blasting and deep-hole blasting technologies need to be used respectively. For local weakening technologies such as large-diameter boreholes and loosening blasting, the borehole depth, borehole layout, and borehole diameter are determined according to the parameters already implemented in adjacent mines in the same mining area, while the borehole spacing is determined according to the warning level. The implementation parameters for regional weakening technology need to be divided into borehole parameters and fracturing parameters. The borehole depth and borehole angle need to be determined according to the geological conditions and the level of the prevention and control team, the borehole spacing is determined according to the warning level, and the water injection pressure and charge amount are determined with reference to successful cases already implemented in adjacent mines in the same mining area.

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