Construction method suitable for comprehensive prevention and control of coal rock dynamic disasters

Abstract

The invention discloses a construction method suitable for comprehensive prevention and control of coal rock dynamic disasters, and relates to the technical field of coal mining. The < 11 > N construction method suitable for comprehensive prevention and control of coal rock dynamic disasters comprises the following steps that S1, the position of a to-be-presplit coal rock layer is determined; s2, determining the position of a drill site; s3, determining a drilling position and a plurality of corresponding pre-splitting paths of the drilled hole in the coal rock layer to be pre-split; s4, directional long drilling construction is carried out, and horizontal long drilling is carried out on the to-be-presplit coal rock layer; s5, horizontal long drilling directional cutting operation is carried out; s6, retreating type segmented presplitting is carried out; and S7, the step S4 to the step S6 are repeated, and pre-splitting operation of the multiple pre-splitting paths in the to-be-pre-split coal rock layer is completed. According to the < 11 > N construction method suitable for comprehensive prevention and control of coal rock dynamic disasters, all-directional comprehensive treatment of coal rock layers can be achieved, large-range presplitting operation is carried out, the pressure relief and anti-reflection effects of presplitting cracks are guaranteed, and safe production of coal mine operation is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of coal mining, and in particular to a method suitable for comprehensive prevention and control of coal-rock dynamic disasters. Background Art

[0002] Before mining, the coal and rock masses underground are in a relatively balanced original rock stress state. With the mining of coal seams, the initial balanced state of original rock stress is broken, resulting in local stress concentration. Under the superimposed influence of dynamic load disturbance stress, the coal and rock masses that exceed the limit suddenly break on a large scale, which means there is a risk of inducing dynamic disaster accidents. With the continuous increase in coal mining depth and the continuous increase in mining intensity, coal and rock dynamic disasters become more and more obvious, and coal and rock dynamic disaster accidents continue to occur.

[0003] Relevant technologies often adopt a multi-technique coordination approach, such as deep hole blasting technology, hydraulic fracturing technology, top cutting pressure relief technology and other technologies in roof management; large diameter drilling pressure relief technology, coal seam jet grooving technology, coal body blasting technology and other technologies in coal seam management; bottom coal retaining drilling pressure relief technology, bottom breaking blasting technology, bottom plate grooving technology and other technologies are adopted in floor management.

[0004] However, the following problems exist during the construction process: the scope of treatment is small. Affected by the applicability of the technology and the process equipment, the vertical depth of the roof corresponding to the roof treatment technology generally does not exceed 30 to 50 meters, the vertical depth of the floor corresponding to the floor treatment technology generally does not exceed 30 meters, and the horizontal extension of the coal seam treatment technology generally does not exceed 150 meters; the treatment effect is single, and only targeted treatment is carried out on the local roof, coal seam or floor. The effect on local danger relief is more obvious, but the effect on large-scale stress regulation and structural optimization is weak; the timing of treatment is limited, generally as the working face is mined more than 300 meters from the front working face, or it is delayed by 30 to 50 meters, and is often affected by cross-operations; the construction efficiency is low. In order to achieve better treatment effects, a single-section multi-technology fan-shaped operation layout is often adopted, with high labor intensity and low engineering efficiency, and there are also high safety hazards during the construction process. Summary of the invention

[0005] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0006] To this end, the embodiment of the present invention proposes a "11N" method suitable for comprehensive prevention and control of coal-rock dynamic disasters. The "11N" method suitable for comprehensive prevention and control of coal-rock dynamic disasters can achieve all-round comprehensive management of high-level thick hard rock layers, medium-level thick hard rock layers, low-level thick hard rock layers, deep mining area surrounding rocks and hard coal seams, hard bottom plates, etc. overlying coal seams, carry out large-scale pre-cracking operations, ensure the pressure relief and permeability enhancement effects of pre-cracking fissures, realize safe mining of coal seams at the source, avoid the occurrence of dynamic disasters such as rock burst, coal and gas outbursts, and ensure safe production of coal mine operations.

[0007] The "11N" method for comprehensive prevention and control of coal-rock dynamic disasters according to an embodiment of the present invention includes the following steps:

[0008] S1: Determine the location of the coal stratum to be pre-splitting;

[0009] S2: Determine the drilling site location;

[0010] S3: placing a high-pressure pump group, determining the drilling position and multiple pre-splitting paths corresponding to the drilling in the coal and rock formation to be pre-splitting;

[0011] S4: Construction is carried out by directional long drilling technology, and horizontal long boreholes are drilled along the pre-splitting path in the coal and rock layer to be pre-splitting;

[0012] S5: performing directional cutting operation on the horizontal long borehole in the position of the coal and rock layer to be pre-splitting, and forming a plurality of cutting points in the horizontal long borehole;

[0013] S6: After the drilling of the horizontal long borehole is completed, the pre-splitting is performed by using a backward segmented pre-splitting method, and the pre-splitting segment is aligned with the cutting point. After the entire pre-splitting of the horizontal long borehole is completed, the drill is withdrawn;

[0014] S7: Repeat steps S4 to S6 to complete the pre-splitting operation of multiple pre-splitting paths in the coal rock layer to be pre-splitting.

[0015] The "11N" method suitable for comprehensive prevention and control of coal-rock dynamic disasters in the embodiment of the present invention can achieve all-round comprehensive management of high-level thick hard rock layers, medium-level thick hard rock layers, low-level thick hard rock layers, deep mining area surrounding rocks and hard coal seams, hard bottom plates, etc. overlying coal seams, carry out large-scale pre-cracking operations, ensure the pressure relief and permeability enhancement effects of pre-cracking fissures, realize safe mining of coal seams at the source, avoid the occurrence of dynamic disasters such as rock burst, coal and gas outbursts, and ensure safe production of coal mine operations.

[0016] In some embodiments, in step S2, the drilling site is set to one of the following locations: a horizontal main tunnel, a mining area main tunnel, a mining face tunnel, an excavation face tunnel, a special measures tunnel, a special chamber, and an area corresponding to the ground.

[0017] In some embodiments, a drilling site is set up on the ground, and pre-splitting operations are performed on at least one coal rock formation to be pre-splitting through a single borehole, and horizontal long boreholes are drilled and pre-splitting along multiple pre-splitting paths in the single coal rock formation to be pre-splitting.

[0018] In some embodiments, the drilling site is set up in a horizontal main tunnel. In step S4, drilling is performed on multiple mining areas for pre-cracked holes, and drilling is performed in an inclined upward direction to the coal and rock layer to be pre-cracked. When the working face is perpendicular to the horizontal main tunnel for mining operations, directional long boreholes are constructed in the corresponding pre-cracked rock layer along the extension direction of the working face. When the working face is parallel to the horizontal main tunnel for mining operations, the long boreholes simultaneously pass through the rock layers corresponding to the cutting eyes, square areas, stop mining lines, and abnormal structural areas of multiple working faces.

[0019] In some embodiments, the drilling site is set up in the main tunnel of the mining area. In step S4, multiple mining areas are pre-cracked by drilling, and the drilling is carried out in an inclined upward direction to the coal rock layer to be pre-cracked. In the rock layer corresponding to the mining area, a directional long drill hole is constructed along the extension direction of the working face.

[0020] In some embodiments, the drilling site is set in the tunnel of the excavation working face or in the tunnel of the mining working face. In step S4, multiple working faces are pre-cracked by drilling, and the drilling is carried out in an inclined upward direction to the coal and rock layer to be pre-cracked. Corresponding to the adjacent working face, directional long drill holes are arranged in the coal and rock layer to be pre-cracked in a direction perpendicular to the extension direction of the working face or in a direction parallel to the extension direction of the working face.

[0021] In some embodiments, the drilling site is set up in a special measures tunnel. In step S4, multiple working faces are pre-cracked by drilling, and the coal rock layer to be pre-cracked is drilled in an inclined upward direction. Corresponding to the adjacent working face, a directional long drill hole is constructed along the extension direction of the working face.

[0022] In some embodiments, the drilling site is set in a chamber. In step S4, with the chamber as the center, the coal and rock layers to be pre-cracked corresponding to the working face cut, the two leading drifts, and the stop-mining line within a radius of 100 to 1500m are pre-cracked.

[0023] In some embodiments, when arranging drilling holes, a judgment is made on the coal rock strata to be pre-cracked. If the coal seam is pre-cracked and permeability-increasing and directional cutting operations are performed, for coal seams with a Pusch firmness coefficient f value of more than 1.6, a directional long drill hole can be directly constructed in the coal seam, and directional cutting and high-pressure pre-crack operations can be carried out in the designed section. For coal seams with a Pusch firmness coefficient f value of less than 1.5, a directional long drill hole can be constructed in the roof of the coal seam at a close distance, and perforations can be shot downward to carry out volume fracturing. If dense pre-crack and crushing operations are performed in interlayers of gangue and collapse columns, directional long drill holes can be directly constructed in the interlayers of gangue or collapse columns, and backward dense pre-cracks can be carried out. If pre-crack and pressure-relief and directional cutting operations are performed in the top and bottom plate rock strata, rock strata with a single layer thickness of more than 5m and a uniaxial compressive strength of more than 40MPa are selected for drilling construction operations.

[0024] In some embodiments, in step S5, the directional cutting operation adopts a high-pressure jet cutting method, using clean water or sand-mixing liquid with a pressure of not less than 60 MPa as a power medium, and ejected at high speed through a nozzle, and using a high-pressure drill pipe to drive the jet cutter to rotate, thereby completing the jet cutting operation;

[0025] Alternatively, the directional cutting operation adopts a mechanical push cutting method, and a movable push rod is built into the drill pipe. After reaching a predetermined position, the tool is slowly opened under the pushing action, and the high-pressure drill pipe is used to drive the cutting tool to rotate to complete the mechanical cutting operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a layout diagram of drilling holes in a drilling site set up on the ground in the "11N" method suitable for comprehensive prevention and control of coal and rock dynamic disasters in an embodiment of the present invention.

[0027] Figure 2 It is a cross-sectional view of the arrangement of drilling holes in a drilling site set up on the ground in the "11N" method suitable for comprehensive prevention and control of coal-rock dynamic disasters in an embodiment of the present invention.

[0028] Figure 3 It is a drilling arrangement diagram for setting up a drilling site in a horizontal main tunnel in the "11N" method suitable for comprehensive prevention and control of coal-rock dynamic disasters in an embodiment of the present invention.

[0029] Figure 4 It is a drilling arrangement diagram for setting up a drilling site in a main tunnel of a mining area in the "11N" method suitable for comprehensive prevention and control of coal and rock dynamic disasters in an embodiment of the present invention.

[0030] Figure 5 It is a drilling arrangement diagram for setting up a drilling site in a tunnel of an excavation working face in the "11N" method suitable for comprehensive prevention and control of coal-rock dynamic disasters in an embodiment of the present invention.

[0031] Figure 6It is a drilling arrangement diagram for setting up a drilling site in a mining face tunnel in the "11N" method suitable for comprehensive prevention and control of coal and rock dynamic disasters in an embodiment of the present invention.

[0032] Figure 7 It is a cross-sectional view of the arrangement of drilling holes along the inclination of the working face in the "11N" method suitable for comprehensive prevention and control of coal and rock dynamic disasters in an embodiment of the present invention.

[0033] Figure 8 It is a cross-sectional view of the arrangement of drilling holes along the working face in the "11N" method suitable for comprehensive prevention and control of coal and rock dynamic disasters in an embodiment of the present invention.

[0034] Fig. 9 It is a drilling arrangement diagram for setting up a drilling site in a special measures tunnel in the "11N" method suitable for comprehensive prevention and control of coal and rock dynamic disasters in an embodiment of the present invention.

[0035] Fig.10 It is a drilling arrangement diagram for setting up a drilling site in a special chamber in the "11N" method suitable for comprehensive prevention and control of coal and rock dynamic disasters in an embodiment of the present invention.

[0036] Fig.11 It is a cross-sectional schematic diagram of directional long drilling construction in a coal seam in the "11N" method suitable for comprehensive prevention and control of coal-rock dynamic disasters in an embodiment of the present invention.

[0037] Reference numerals:

[0038] Pre-splitting path 1; ground 2; horizontal main tunnel 3; mining area main tunnel 4; excavation working face tunnel 5; mining working face tunnel 6; special measures tunnel 7; special chamber 8. DETAILED DESCRIPTION

[0039] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0040] like Figures 1 to 10 As shown, the "11N" method applicable to the comprehensive prevention and control of coal-rock dynamic disasters in an embodiment of the present invention includes the following steps:

[0041] S1: Determine the location of the coal and rock strata to be pre-cracked, and determine the target stratum according to the comprehensive expected effect, the coal and rock occurrence status in the area to be treated, etc. Generally, hard coal seams with poor natural fracture development, thick interlayers, collapse columns, thick hard rock strata, etc. are selected as target strata, among which the thick hard rock strata are strata with a single layer thickness of more than 5m and a uniaxial compressive strength of more than 40MPa.

[0042] S2: Determine the location of Drilling Site 1. The location of Drilling Site 1 shall be determined comprehensively based on the development layout of the mining area, the succession of tunnel mining, the conditions of the construction site, the target layer, the technical parameters of the directional drilling unit, etc. Drilling Site 1 shall meet the requirements of directional drilling and mud pump placement, and have the conditions for building a sedimentation tank. It shall also focus on avoiding the impact of cross-operations, so as to achieve the operational requirements of one Drilling Site 1 taking into account multiple areas, one tunnel taking into account multiple working faces, and one tunnel taking into account multiple mining areas.

[0043] S3: Install the high-pressure pump group. The high-pressure pump group installation area should not be far from the drilling site 1, generally not more than 300m, determine the drilling position and the multiple pre-splitting paths corresponding to the drilling in the coal and rock layer to be pre-splitting. Preferably, the high-pressure pump group installation area is within 50m from the drilling site 1 to ensure that the setting of pipelines is reduced.

[0044] S4: The construction is carried out through directional long drilling technology. Horizontal long boreholes are drilled along the pre-splitting path in the coal and rock layer to be pre-splitting. Directional drilling of long boreholes is carried out along the preset path. The borehole length is generally 100 to 1500m, and the borehole diameter is generally 94 to 153mm.

[0045] S5: In the location of the coal stratum to be pre-splitting, a directional cutting operation is performed on the horizontal long borehole, and a plurality of cutting points are formed in the horizontal long borehole.

[0046] S6: After the drilling of the horizontal long borehole is completed, the pre-splitting is performed by using a backward segmented pre-splitting method, and the pre-splitting segment is aligned with the cutting point. After the entire pre-splitting of the horizontal long borehole is completed, the drill is withdrawn.

[0047] S7: Repeat steps S4 to S6 to complete the pre-splitting operation of multiple pre-splitting paths in the coal rock layer to be pre-splitting.

[0048] The "11N" method suitable for comprehensive prevention and control of coal-rock dynamic disasters in the embodiment of the present invention can achieve all-round comprehensive management of high-level thick hard rock layers, medium-level thick hard rock layers, low-level thick hard rock layers, deep mining area surrounding rocks and hard coal seams, and hard bottom plates overlying coal seams, and carry out large-scale pre-cracking operations to ensure the pressure relief and permeability enhancement effects of pre-cracking fissures. At the same time, it can be used for pumping operations in water-rich layers to achieve safe mining of coal seams at the source, avoid the occurrence of dynamic disasters such as rock burst, coal and gas outbursts, and ensure safe production of coal mine operations.

[0049] In the "11N" method applicable to the comprehensive prevention and control of coal-rock dynamic disasters in the embodiment of the present invention, the first "1" refers to a tunnel or an area, that is, it can be one of the horizontal large tunnel 3, the mining area large tunnel 4, the mining working face tunnel 6, and the excavation working face tunnel 5, or it can be a special measure tunnel 7 or a special chamber 8, or an area corresponding to the ground 2; the second "1" refers to a set of process technologies, namely, long-distance and large-scale segmented pre-splitting process technologies, including long-hole directional drilling methods, multi-parameter downhole detection methods, and directional drilling. The pre-splitting method includes forward perforation pre-splitting method, backward segmented pre-splitting method, flow control induced pre-splitting method, transient electromagnetic pre-splitting effect inspection method, micro-vibration monitoring filtering and self-positioning method, and mine pressure monitoring method; "N" refers to the selection of drilling site 1 in a tunnel or an area, which can realize all-round comprehensive management of high-level thick hard rock layers, medium-level thick hard rock layers, low-level thick hard rock layers, deep mining area surrounding rocks, hard coal seams, hard bottom plates, and multiple working faces or multiple mining areas in the same horizontal coal and rock layers, and carry out large-scale pre-splitting operations.

[0050] The long-hole directional drilling method is implemented based on the directional drilling assembly, which includes a kilometer-long directional drilling vehicle, a high-strength cable drill rod, a flexible screw motor assembly and a high-strength drill bit. The kilometer-long directional drilling vehicle is placed in the drilling site, and the flexible screw motor assembly is driven by the high-strength cable drill rod to achieve directional drilling. The flexible screw motor assembly includes an upper joint, a motor assembly, an adjustable bending housing and a transmission assembly. When the flexible screw motor assembly is working: the rotor and the stator are meshed with each other, and a spiral sealing line is formed through the lead difference between the two, and a sealing cavity is formed at the same time. As the rotor rotates in the stator, the sealing cavity moves along the axial direction, continuously generates and disappears, and completes its energy conversion. A safety release is set between the transmission assembly and the high-strength cable drill rod. When the flexible screw motor assembly and the high-strength drill bit components are stuck due to accidents such as hole collapse and dislocation, it ensures that the high-strength cable drill rod and the flexible screw motor assembly are smoothly disengaged to reduce losses.

[0051] The multi-parameter downhole detection method is implemented based on strain gauges, inclinometers, thrust sensors, torque sensors, speed sensors, displacement sensors and high-definition AI cameras. The strain gauges, inclinometers and inclinometers are placed behind the drill bit and enter the hole through the drill rod. Multiple sensors and cameras are used to monitor the bottom hole stress environment and drilling parameters in real time during the drilling process.

[0052] The directional perforating pre-splitting method is implemented by a directional perforator, which is placed between the front end centralizer and the rear end centralizer, and the distance between the front end centralizer and the rear end centralizer is adjusted by a connecting rod. The outer wall of the directional perforator is evenly distributed with injection ports, and a liquid gravity directional perforator is used. When the directional perforator is working, under the action of the cut-off pressure, the directional inner cylinder is pushed to move, and the direction is guided by the gravity positioning ball to achieve rotation positioning along the designed direction.

[0053] The backward staged pre-splitting method is implemented through a multi-combination pre-splitting assembly, which includes a ball head, a check valve, a front-end centralizer, a front-end packer, a fracturing device, a rear-end packer, a rear-end centralizer, and a safety release. After the drilling operation is completed according to the design, when pre-splitting, the multi-combination pre-splitting assembly is pushed into the borehole through a high-strength pressure-resistant push rod, and the backward staged pre-splitting starts from the bottom of the borehole. The length of a single section is generally 10 to 30 meters.

[0054] The flow control induced pre-fracture method is achieved through hydraulic fracturing, that is, using a high-pressure pump group to inject a certain viscosity of fracturing fluid into the coal rock layer through the borehole. When the injection flow exceeds the absorption capacity of the coal rock layer, the coal rock layer near the bottom of the well will be under tremendous pressure. When the pressure exceeds the tensile strength of the rock, the coal rock layer will break and form cracks. These cracks will then expand with the continuous injection of fracturing fluid, thereby increasing the permeability and conductivity of the coal rock layer. During the fracturing process, the range of the rock pre-fracture network is increased by changing the fracturing pressure and increasing the flow rate, thereby improving the hydraulic fracturing effect.

[0055] The transient electromagnetic pre-splitting effect inspection method is implemented based on the law of electromagnetic induction. It uses an ungrounded return line or a grounded line source to emit a pulse magnetic field underground. During the interval of a pulse magnetic field, a coil or a grounding electrode is used to observe the secondary induced eddy current field caused in the underground medium, thereby detecting the medium resistivity. By measuring the time variation of the secondary field in each time period after power failure, the geoelectric characteristics of different depths are obtained, and then the pre-splitting effect of the rock formation is inspected. During construction, a mining intrinsically safe transient electromagnetic instrument, such as the YCS580 model transient electromagnetic instrument, can be used, and it is not limited to this model, and the pre-splitting effect is specifically analyzed through the apparent resistivity imaging results.

[0056] The microvibration monitoring filtering method is an existing technology and a key link in the processing of microseismic data. It is mainly used to improve the signal-to-noise ratio and reduce the interference of noise on the effective signal. Among them, the filtering method is one of high-pass filtering, low-pass filtering, band-pass filtering and band-stop filtering. The microvibration monitoring self-positioning method refers to the technology of automatically determining the source location through microseismic monitoring data, including the double difference positioning method based on geometric positioning; the inversion positioning based on the waveform characteristics of microseismic waves; the multi-wave joint identification and positioning using multi-channel waveforms, amplitudes, arrival time differences, etc. Joint comparison and identification, select reasonable waveforms for positioning. In the microvibration monitoring self-positioning method, the automatic, rapid and high-precision positioning of microseismic events is achieved by automatically picking up the arrival time and the combined positioning means of the monitoring points.

[0057] The mine pressure monitoring method can adopt at least one of the force sensor method, the deformation meter method, the mining influence zone prediction method and the stress sensing technology. The force sensor method measures the magnitude and direction of the mine pressure by the force sensor, the stretching amount of the conversion rope, chain or rod. The deformation meter method includes two types: the line-of-sight deformation meter and the strain gauge. The line-of-sight deformation meter can measure the surface height and horizontal displacement of the rock formation, providing intuitive rock formation deformation data for mining workers. The strain gauge can measure the strain change inside the rock formation and have a deeper understanding of the stress of the rock formation. The mining influence zone prediction method is a numerical simulation method based on the rock medium mechanics theory and empirical laws. It realizes mine pressure monitoring by analyzing the mechanism of the mine rock mass and predicting the scope of the mining influence zone. Stress sensing technology is one of the core technologies for mine pressure monitoring. The stress of materials such as mine rock and gas is monitored by strain sensors to obtain information about pressure changes. Commonly used stress sensors include strain gauges, pressure sensors, etc. These sensors can be installed in places such as mine tunnels and mines to monitor the pressure changes inside the mine in real time. The application of stress sensing technology makes mine pressure monitoring more accurate and reliable.

[0058] Data acquisition and processing technology is responsible for collecting and storing data transmitted by sensors and sending it to data processors for analysis and processing. Through advanced data processing algorithms and software technologies, the collected data can be quickly analyzed, processed, stored and displayed, providing a more convenient and efficient data processing method to better understand the pressure changes in the mine.

[0059] In some embodiments, in step S2, one of the seven options, namely, horizontal main tunnel 3, mining area main tunnel 4, mining face tunnel 6, excavation face tunnel 5, special measures tunnel 7, special chamber 8, and an area corresponding to the ground 2, can be selected as the setting location of the drilling site 1 to ensure efficient and stable drilling pre-cracking work.

[0060] In some embodiments, Figure 1 and Figure 2 As shown, a drilling site 1 is set on the ground 2, and pre-splitting operations are performed on one or more coal rock layers to be pre-splitting through a single borehole, and horizontal long boreholes are drilled and pre-splitting along multiple pre-splitting paths in a single coal rock layer to be pre-splitting.

[0061] Specifically, a drilling site 1 is set on the ground 2, and extends downward to the coal and rock layer to be pre-cracked through a vertical long borehole according to the drilling position. In the coal and rock layer to be pre-cracked, horizontal section boreholes are drilled along multiple pre-crack paths, and rock formation pre-cracks are performed through multiple horizontal section boreholes, thereby realizing large-area pre-crack operations of multiple pre-crack paths under single well conditions, and according to the rock formation conditions, the pre-crack operations of multiple coal seams can be taken into account by extending a single borehole downward.

[0062] In some embodiments, Figure 3 As shown, the drilling site 1 is set in the horizontal main tunnel 3. In step S4, pre-crack drilling is performed on multiple mining areas, and the drilling is carried out in an inclined upward direction to the coal rock layer to be pre-cracked. When the working face is perpendicular to the horizontal main tunnel 3 for mining operations, a directional long drill hole is constructed in the corresponding pre-cracked rock layer along the extension direction of the working face. The pre-crack operation of the entire area can be completed during the preparation of the working face, which can effectively avoid the influence of cross-operation, enable the tunnel to be excavated in a low-stress environment, and ensure the excavation speed and size of the tunnel; when the working face is parallel to the horizontal main tunnel 3 for mining operations, the long drill hole simultaneously passes through the rock layers corresponding to the cut eyes, square areas, stop mining lines, and abnormal structural areas of multiple working faces, and centralized pre-crack and advance pretreatment are carried out to optimize the regional stress distribution state.

[0063] In some embodiments, Figure 4 As shown, the drilling site 1 is arranged in the main tunnel 4 of the mining area. The drilling site 1 can meet the rock pre-splitting operation requirements of one or two mining areas at the same time. In step S4, drilling pre-splitting is performed on multiple mining areas, and drilling is performed in an inclined upward direction to the coal and rock layer to be pre-splitting. In the rock layer corresponding to the mining area, a directional long borehole is constructed along the extension direction of the working face to ensure the pre-splitting effect of the entire coal and rock layer to be pre-splitting, ensure the pressure relief and permeability enhancement effect of the pre-splitting fissure, realize the safe mining of the coal seam at the source, avoid the occurrence of dynamic disasters such as rock burst, coal and gas outburst, and ensure the safe production of coal mine operations.

[0064] In some embodiments, Figure 5 , Figure 6 , Figure 7 and Figure 8 As shown, when the drilling site 1 is set in the tunnel 5 of the excavation working face, the drilling site 1 can meet the rock pre-splitting operation requirements of 2 or 3 working faces at the same time. When the drilling site 1 is set in the tunnel 6 of the mining working face, the drilling site 1 can meet the rock pre-splitting operation requirements of 2 or 3 working faces at the same time. In step S4, the drilling pre-splitting is performed on multiple working faces, and the coal and rock layers to be pre-splitting are drilled in the inclined upward direction. Corresponding to the adjacent working face, a directional long borehole is arranged in the direction perpendicular to the extension direction of the working face or a directional long borehole is arranged in the direction parallel to the extension direction of the working face in the coal and rock layers to be pre-splitting. When drilling pre-splitting for multiple working faces, directional long boreholes are arranged along the inclination, and the pre-splitting operation is completed by taking into account multiple working faces, which can avoid cross-operation during mining; directional long boreholes are arranged along the strike, taking into account the pre-splitting operation of the corresponding working face and the adjacent next section working face, which can avoid cross-operation during mining, and the construction is convenient.

[0065] In some embodiments, Fig. 9As shown, the drilling site 1 is arranged in the special measures tunnel 7, and the drilling site 1 can meet the rock pre-splitting operation requirements of one or two working faces at the same time. In step S4, drilling pre-splitting is performed on multiple working faces, and drilling is performed in an inclined upward direction to the coal rock layer to be pre-splitting. Corresponding to the adjacent working face, a directional long borehole is constructed along the extension direction of the working face.

[0066] In some embodiments, Fig.10 As shown, the drilling site 1 is set in the chamber. In step S4, with the chamber as the center, the coal and rock layers to be pre-cracked corresponding to the working face cut, the two leading drifts, and the stop line within a radius of 100 to 1500m are pre-cracked to ensure the pre-crack effect of the entire coal and rock layer to be pre-cracked and ensure the safe production of coal mine operations.

[0067] In some embodiments, when arranging the drilling holes, the pre-cracked coal and rock formations are judged. If the coal seam pre-cracked permeability enhancement and directional cutting operations are performed, for the coal seam with a Pusch firmness coefficient f value of more than 1.6, such as Fig.11 As shown, long directional boreholes can be directly constructed in the coal seam, and directional cutting and high-pressure pre-cracking operations can be carried out in the designed section. For coal seams with a Pugh strength coefficient f value of less than 1.5, long directional boreholes can be constructed in the roof of the coal seam at a close distance, and perforations can be shot downward to carry out volume fracturing; if dense pre-cracking and crushing operations are performed in interlayers of gangue and subsidence columns, long directional boreholes can be directly constructed in interlayers of gangue or subsidence columns to carry out backward dense pre-cracking; if pre-cracking and pressure relief and directional cutting operations are performed in the top and bottom plate rock strata, rock strata with a single layer thickness of more than 5m and a uniaxial compressive strength of more than 40MPa are selected for drilling construction operations, and the vertical height of the borehole is controlled not to exceed 200m. Preferably, the vertical height of the borehole is between 30 and 60m.

[0068] In some embodiments, in step S5, the directional cutting operation adopts a high-pressure jet cutting method, using clean water or mixed sand liquid with a pressure of not less than 60MPa as the power medium, and ejected at high speed through the nozzle, and using a high-pressure drill pipe to drive the jet cutter to rotate to complete the jet cutting operation. The structure is simple and easy to operate, and the rapid advancement of the directional cutting operation can be ensured during the construction process.

[0069] In some embodiments, in step S5, the directional cutting operation adopts a mechanical pushing cutting method. A movable push rod is built into the drill rod. After reaching the predetermined position, the tool is slowly opened under the pushing action, and the high-pressure drill rod is used to drive the cutting tool to rotate to complete the mechanical cutting operation. The directional cutting operation is performed by the cutting tool, which is convenient for controlling the accuracy and cutting length of the directional cutting operation.

[0070] The "11N" method for comprehensive prevention and control of coal-rock dynamic disasters according to the embodiment of the present invention has the following beneficial effects:

[0071] 1) Through a tunnel and long-distance and large-scale segmented pre-cracking technology, the coal seam and the overlying high-level thick hard rock layer can be pre-cracking to complete the weakening management, exchanging space for time and having little impact on the mining operation.

[0072] For newly built mines, during the mine construction period, the long-distance and large-scale segmented pre-splitting technology can be used in the central tunnel to weaken the roof and coal seams in the adjacent planned mining area. This can not only reduce the stress environment in the main tunnel area of ​​the construction mining area, but also greatly shorten the preparation time for the first mining working face. For new mining areas, as long as a return mining tunnel is excavated in the mining area, the long-distance and large-scale segmented pre-splitting technology can be used to weaken the thick hard rock layers and coal seams in the roof of the upper and lower working faces to be mined, so that the entire mining area is in a weak roof structure and low-stress mining environment.

[0073] 2) After taking comprehensive measures to control high-level overburden, the cracks in the key layers are fully developed, playing a role similar to that of an elastic cushion. The load transfer range of the overburden is wider, and the dynamic and static loads applied to the coal seam are reduced, thereby reducing the hazard level of coal seam impact and the number of warnings. This provides a good prerequisite for reducing the pre-decompression, emergency relief and other engineering workloads of the surrounding rock in the coal seam mining area.

[0074] 3) The essence of comprehensive pre-treatment of high-level overburden is to pre-crack the key layer to reduce its "frame" effect in the stratum, so as to achieve more uniform and gentle stress transfer in the spatial structure of the overburden, and achieve the purpose of reducing the stress level of the coal body in the area to be mined in advance. Comprehensive treatment of high-level overburden is in line with the anti-shock strategy of "regional first, local follow-up", and can be used as a new type of regional anti-shock measure, which is an important supplement to local anti-shock measures.

[0075] 4) Comprehensive management of high-position overburden strata can reduce the strength and density of tunnel support during excavation and improve excavation efficiency by weakening the roof structure in advance and reducing the basic stress of the coal body. It can ensure the stability of the tunnel during mining and reduce the workload of tunnel maintenance and reinforcement support. It can reduce the stress level of the coal body in the mining area, achieve low-stress mining, and increase the mining speed of the working face.

[0076] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0077] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0078] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0079] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0080] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0081] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A method suitable for comprehensive prevention and control of coal and rock dynamic disasters, characterized in that: The following steps are involved: S1: Determine the location of the coal stratum to be pre-splitting; S2: Determine the drilling site location; S3: placing a high-pressure pump group, determining the drilling position and multiple pre-splitting paths corresponding to the drilling in the coal and rock formation to be pre-splitting; S4: Construction is carried out by directional long drilling technology, and horizontal long boreholes are drilled along the pre-splitting path in the coal and rock layer to be pre-splitting; S5: performing directional cutting operation on the horizontal long borehole in the position of the coal and rock layer to be pre-splitting, and forming a plurality of cutting points in the horizontal long borehole; S6: After the drilling of the horizontal long borehole is completed, the pre-splitting is performed by using a backward segmented pre-splitting method, and the pre-splitting segment is aligned with the cutting point. After the entire pre-splitting of the horizontal long borehole is completed, the drill is withdrawn; S7: Repeat steps S4 to S6 to complete the pre-splitting operation of multiple pre-splitting paths in the coal rock layer to be pre-splitting.

2. The method for comprehensive prevention and control of coal-rock dynamic disasters according to claim 1 is characterized in that: In step S2, the drilling site is set to one of the following positions: a horizontal main tunnel, a mining area main tunnel, a mining face tunnel, an excavation face tunnel, a special measures tunnel, a special chamber, and an area corresponding to the ground.

3. The method for comprehensive prevention and control of coal-rock dynamic disasters according to claim 2 is characterized in that: The drilling site is set up on the ground, and pre-splitting operations are performed on at least one coal rock layer to be pre-splitting through a single borehole, and horizontal long boreholes are drilled and pre-splitting is performed along multiple pre-splitting paths in the single coal rock layer to be pre-splitting.

4. The method for comprehensive prevention and control of coal-rock dynamic disasters according to claim 2 is characterized in that: The drilling site is set up in the horizontal main tunnel. In step S4, multiple mining areas are pre-cracked by drilling holes, and the drilling is carried out in an inclined upward direction to the coal and rock layer to be pre-cracked. When the working face is perpendicular to the horizontal main tunnel for mining operations, a directional long drill hole is constructed in the corresponding pre-cracked rock layer along the extension direction of the working face. When the working face is parallel to the horizontal main tunnel for mining operations, the long drill hole simultaneously passes through the rock layers corresponding to the cutting eyes, square areas, stop mining lines, and abnormal structural areas of multiple working faces.

5. The method for comprehensive prevention and control of coal-rock dynamic disasters according to claim 2 is characterized in that: The drilling site is set up in the main tunnel of the mining area. In step S4, multiple mining areas are pre-split by drilling holes, and the drilling is carried out in an inclined upward direction to the coal rock layer to be pre-split. In the rock layer corresponding to the mining area, a directional long borehole is constructed along the extension direction of the working face.

6. The method for comprehensive prevention and control of coal-rock dynamic disasters according to claim 2 is characterized in that: The drilling site is set in the tunnel of the excavation working face or in the tunnel of the mining working face. In step S4, multiple working faces are pre-cracked by drilling, and the drilling is carried out in an inclined upward direction to the coal and rock layer to be pre-cracked. Corresponding to the adjacent working face, directional long drill holes are arranged in the coal and rock layer to be pre-cracked in a direction perpendicular to the extension direction of the working face or in a direction parallel to the extension direction of the working face.

7. The method for comprehensive prevention and control of coal-rock dynamic disasters according to claim 2 is characterized in that: The drilling site is set up in a special measures tunnel. In step S4, multiple working faces are pre-split by drilling, and the coal and rock layers to be pre-split are drilled in an inclined upward direction. Corresponding to the adjacent working faces, directional long boreholes are constructed along the extension direction of the working faces.

8. The method for comprehensive prevention and control of coal-rock dynamic disasters according to claim 2 is characterized in that: The drilling site is set in the chamber. In step S4, with the chamber as the center, the coal and rock layers to be pre-cracked corresponding to the working face cut, the two leading drifts and the stop line within a radius of 100 to 1500m are pre-cracked.

9. The method for comprehensive prevention and control of coal-rock dynamic disasters according to claim 1, characterized in that: When arranging drilling holes, a judgment shall be made on the pre-cracked coal and rock strata. If the coal seam pre-crack permeability enhancement and directional cutting operations are to be carried out, for coal seams with a Pusch firmness coefficient f value of more than 1.6, a directional long drill hole can be directly constructed in the coal seam, and directional cutting and high-pressure pre-crack operations can be carried out in the designed section. For coal seams with a Pusch firmness coefficient f value of less than 1.5, a directional long drill hole can be constructed in the roof of the coal seam at a close distance, and perforations can be shot downward to carry out volume fracturing. If the pre-crack and crushing operations are to be carried out in the interlayer of gangue or the collapse column, a directional long drill hole can be directly constructed in the interlayer of gangue or the collapse column, and backward intensive pre-crack can be carried out. If the top and bottom plate rock strata are to be pre-cracked for pressure relief and directional cutting operations, rock strata with a single layer thickness of more than 5m and a uniaxial compressive strength of more than 40MPa are selected for drilling operations.

10. The method for comprehensive prevention and control of coal-rock dynamic disasters according to claim 1, characterized in that: In step S5, the directional cutting operation adopts a high-pressure jet cutting method, using clean water or sand-mixing liquid with a pressure of not less than 60 MPa as the power medium, and ejected at high speed through the nozzle, and using the high-pressure drill pipe to drive the jet cutter to rotate, completing the jet cutting operation; Alternatively, the directional cutting operation adopts a mechanical push cutting method, and a movable push rod is built into the drill pipe. After reaching a predetermined position, the tool is slowly opened under the pushing action, and the high-pressure drill pipe is used to drive the cutting tool to rotate to complete the mechanical cutting operation.

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