XYZ precise three-dimensional pressure relief method

Abstract

The invention relates to the technical field of coal mining, and discloses an XYZ precise three-dimensional pressure relief method which comprises the following steps: performing top cutting pressure relief on a top plate of a roadway in a first direction; drilling and pressure relief are conducted on the two sides of the roadway, and the first stress peak position in the second direction is transferred to the direction away from the two sides of the roadway; and drilling and pressure relief are conducted on the bottom plate of the roadway, and the second stress peak position in the first direction is transferred to the direction away from the bottom plate of the roadway. According to the three-dimensional pressure relief system, the three-dimensional pressure relief system for conducting roof cutting pressure relief on the roadway in the first direction, conducting pressure relief on the two sides of the roadway in the second direction and conducting floor heave treatment on the roadway in the first direction is constructed, the limitation of traditional single-dimensional pressure relief is broken through, stress concentration areas of the top plate, the two sides and the bottom plate of the roadway can be covered in an all-dimensional mode, and the pressure relief efficiency is improved. Cooperative regulation and control of stress are achieved, and the surrounding rock damage risk is fundamentally reduced.

Description

Technical Field

[0001] This application relates to the field of coal mining technology, specifically to an XYZ precise three-dimensional pressure relief method. Background Technology

[0002] Coal mines with complex geological structures, well-developed faults and folds, and mineable coal seams that are mostly close-range outburst coal seam groups are characterized by high gas content, small coal seam spacing, and high mining difficulty. Due to repeated mining of coal seam groups, roof pressure is frequent, and the roadways of the rock-gate system are subjected to repeated mining stress for a long time, which easily leads to problems such as roadway deformation, support failure, and cross-sectional reduction, which in turn can cause safety hazards such as roof collapse and gas accumulation. Moreover, the amount of roadway disrepair is high, requiring a large investment of manpower, material resources, and financial resources for repair.

[0003] In related technologies, existing pressure relief methods are mostly single-dimensional operations, such as simply cutting the top or local drilling for pressure relief. These methods have problems such as limited pressure relief range, incomplete stress transfer, and poor parameter matching. They are difficult to adapt to the complex laws of stress transmission in three-dimensional space and cannot fundamentally solve the problem of surrounding rock damage caused by high stress concentration. Summary of the Invention

[0004] This application provides a precise XYZ three-dimensional pressure relief method to solve or improve problems such as limited pressure relief range, incomplete stress transfer, and poor parameter matching.

[0005] This application provides a precise XYZ three-dimensional decompression method, including the following steps:

[0006] The roof of the tunnel is cut and pressure is relieved along the first direction;

[0007] Drilling holes on both sides of the tunnel to relieve pressure and shift the position of the first stress peak along the second direction away from the two sides of the tunnel.

[0008] Drilling holes in the floor of the tunnel to relieve pressure will shift the second stress peak position along the first direction away from the floor of the tunnel.

[0009] In one optional embodiment, the step of cutting and depressurizing the roof of the roadway along the first direction includes:

[0010] The top plate is drilled with a first hole along the first direction;

[0011] Install a drilled casing into the first borehole, and inject grout between the inner wall of the first borehole and the outer wall of the drilled casing;

[0012] Explosive material is loaded into the drilled casing, and blasting is carried out.

[0013] In one optional embodiment, the step of drilling a first hole in the top plate along the first direction includes:

[0014] The first borehole shall be drilled to a depth of at least 2 / 3 of the thickness of the critical rock strata in the top plate.

[0015] And / or, the diameter of the first borehole shall not be less than 50 mm;

[0016] And / or, the distance between two adjacent first boreholes along a third direction during construction shall not exceed 2m.

[0017] In one optional embodiment, the step of cutting and depressurizing the roof of the roadway along the first direction further includes:

[0018] Before drilling the first hole in the roof of the roadway along the first direction, the actual roadway roof-cutting drilling should be carried out at least 100m ahead of the coal mining face.

[0019] In one optional embodiment, the step of drilling holes to relieve pressure on both sides of the tunnel, and shifting the position of the first stress peak along the second direction away from the sides of the tunnel, includes:

[0020] Obtain a first initial position of the first stress peak position along the second direction, and preset a first target position to which the first stress peak position needs to be transferred;

[0021] Based on the first initial position and the first target position, second boreholes are drilled along the second direction on both sides of the tunnel.

[0022] During the second borehole drilling process, the first real-time position of the first stress peak position is obtained;

[0023] When the first real-time position is detected to have reached or exceeded the first target position, the second drilling operation is stopped.

[0024] In one optional implementation, the steps of performing second drilling operations along the second direction on both sides of the roadway based on the first initial position and the first target position, and obtaining the first real-time position of the first stress peak position during the second drilling operation, include:

[0025] Multiple second boreholes are drilled at intervals along a third direction, the diameter of the second borehole is set as the first borehole diameter, and the distance between adjacent second boreholes is set as the first spacing.

[0026] Real-time determination of whether the shift in the position of the first stress peak exceeds a threshold;

[0027] If so, the adjacent second borehole continues to be constructed with the first borehole diameter and the first spacing;

[0028] If not, adjust the distance between adjacent second boreholes to a second spacing, where the second spacing is less than the first spacing.

[0029] In an optional implementation, the step of performing second drilling operations along the second direction on both sides of the roadway based on the first initial position and the first target position, and the step of obtaining the first real-time position of the first stress peak position during the second drilling operation, further includes:

[0030] If the second borehole collapses during construction, the diameter of the second borehole will be set as a third diameter, which is smaller than the first diameter.

[0031] And / or, if the second borehole collapses during construction, the distance between adjacent second boreholes is adjusted to a third spacing, and the third spacing is greater than the first spacing.

[0032] In one optional embodiment, the first diameter of the second borehole is set to 130mm to 160mm, and the first distance between adjacent second boreholes is set to 2m to 2.2m;

[0033] And / or, the second spacing between adjacent second boreholes is set to 1.7m to 1.9m;

[0034] And / or, the third diameter of the second borehole is set to 90mm to 100mm, and the third spacing between adjacent second boreholes is set to 2.5m to 3m.

[0035] In one optional embodiment, the step of drilling holes in the floor of the tunnel to relieve pressure and shift the second stress peak position along the first direction away from the floor of the tunnel includes:

[0036] Obtain a second initial position of the second stress peak position along the first direction, and preset a second target position to which the second stress peak position needs to be transferred;

[0037] Based on the second initial position and the second target position, a third borehole is drilled in the bottom plate of the tunnel along the first direction;

[0038] During the third borehole construction process, the second real-time position of the second stress peak position is obtained;

[0039] When the second real-time position is detected to reach or exceed the second target position, the third drilling operation is stopped.

[0040] In one optional implementation, the step of drilling a third hole in the floor of the tunnel along the first direction based on the second initial position and the second target position includes:

[0041] The third borehole is set at the connection between the two sides of the tunnel and the bottom plate of the tunnel, and the drilling direction of the third borehole is set at an angle to the extension direction of the first direction.

[0042] Alternatively, the third borehole can be located in the middle of the bottom plate of the tunnel, with the drilling direction of the third borehole parallel to the extension direction of the first direction.

[0043] This application constructs a three-dimensional stress relief system that performs roof cutting and stress relief along the first direction, stress relief on the sides of the roadway along the second direction, and floor heave treatment along the first direction. This system breaks through the limitations of traditional single-dimensional stress relief and can comprehensively cover the stress concentration areas of the roof, sides, and floor of the roadway, achieving coordinated stress control and fundamentally reducing the risk of surrounding rock damage.

[0044] Furthermore, by adopting a construction sequence of first cutting the roof and then releasing the pressure, the stress transmission path is cut off by cutting the roof, and the stress peak is transferred by large-diameter boreholes, forming a synergistic effect of cutting off, transferring and weakening, which significantly shortens the roof overhang length, reduces the stress concentration, reduces the amount of roadway deformation, and extends the roadway service life. Attached Figure Description

[0045] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0046] Figure 1 This is a three-dimensional structural diagram of the tunnel according to an embodiment of this application;

[0047] Figure 2 This is a schematic diagram showing the arrangement of the first and second boreholes according to an embodiment of this application;

[0048] Figure 3 This is a schematic diagram illustrating the stress transfer principle in the two sides and the tunnel excavation direction of an embodiment of this application.

[0049] Figure 4 This is a schematic diagram of the first initial position and the first target position in an embodiment of this application;

[0050] Figure 5This is a schematic diagram showing the arrangement of the boreholes in the coal mining face according to an embodiment of this application;

[0051] Figure 6 This is a schematic diagram showing the arrangement of the first and second boreholes in the return airway of the coal mining face according to an embodiment of this application.

[0052] Figure 7 This is a schematic diagram showing the arrangement of the second borehole in the coal mining face transport roadway according to an embodiment of this application.

[0053] Explanation of reference numerals in the attached figures:

[0054] Z, first direction; Y, second direction; X, third direction;

[0055] 100, First initial position; 200, First target position; 300, Third initial position; 400, Third target position;

[0056] 1. Tunnel; 101. Roof; 102. Sidewalls; 103. Floor;

[0057] 2. First borehole; 3. Key strata of the roof; 4. Coal face; 5. Second borehole; 6. Third borehole; 7. Lower adjacent coal seam; 8. Key strata of the floor; 9. This coal seam; 10. Fourth borehole; 11. Overlying coal seam; 12. Pre-mined coal seam; 13. Transport roadway; 14. Return airway; 15. Goaf. Detailed Implementation

[0058] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0059] The following is combined with Figures 1 to 7 This describes an embodiment of the present application.

[0060] According to embodiments of this application, a precise XYZ three-dimensional decompression method is provided. Firstly, it should be noted that... Figure 2 As shown, in a coal mine, along the first direction Z from bottom to top are the adjacent lower coal seam 7, the key floor stratum 8, the main coal seam 9, the key roof stratum 3, and the overlying coal seam 11. Since roadway 1 is excavated within the rock mass and mostly located within the main coal seam 9, a stress redistribution zone is formed around it, including the roof 101, sidewalls 102, and floor 103. The original stress peak position is usually close to the surface of roadway 1, easily leading to surrounding rock fracturing and deformation. For example... Figure 1As shown, in this embodiment, the first direction Z refers to the height direction of tunnel 1, the second direction Y refers to the width direction of tunnel 1, and the third direction X refers to the excavation direction of tunnel 1. Of course, those skilled in the art can adjust the specific directions referred to by the first direction Z, the second direction Y, and the third direction X according to actual needs.

[0061] The precise three-dimensional decompression method provided in this application specifically includes the following steps: First, the roof 101 of the roadway 1 is cut and decompressed along the first direction Z. The main purpose of this step is to cut off the key rock layer 3 of the roof and block the stress transmission path.

[0062] Subsequently, boreholes can be drilled on both sides 102 of the roadway 1 to relieve pressure, thereby shifting the first stress peak position along the second direction Y to the side 102 of the roadway 1 away from the roadway 1. This step can shift the first stress peak position from the area close to the side 102 of the roadway 1 to the area away from the side 102, effectively alleviating the stress concentration phenomenon on the side 102.

[0063] Furthermore, the floor 103 of the tunnel 1 can be drilled to relieve pressure, thereby shifting the second stress peak position along the first direction Z to a direction away from the floor 103 of the tunnel 1. This step can shift the second stress peak position from the area close to the floor 103 of the tunnel 1 to the area away from the floor 103, thereby significantly reducing the heave pressure of the floor 103 and effectively preventing floor heave.

[0064] Typically, the above-described implementation method is used to construct a three-dimensional stress relief system. This system involves roof cutting and stress relief along the first direction Z of the tunnel 1, stress relief on the two sidewalls 102 of the tunnel 1 along the second direction Y, and floor heave treatment along the first direction Z of the tunnel 1. This system overcomes the limitations of traditional single-dimensional stress relief and can comprehensively cover the stress concentration areas of the roof 101, sidewalls 102, and floor 103 of the tunnel 1, achieving synergistic stress control and fundamentally reducing the risk of surrounding rock failure. Furthermore, by adopting a construction sequence of roof cutting followed by stress relief, the stress transmission path is cut off by roof cutting, and the stress peak is transferred through large-diameter boreholes, forming a synergistic effect of cutting off, transferring, and weakening. This significantly shortens the overhang length of the roof 101, reduces the degree of stress concentration, reduces the deformation of the tunnel 1, and extends the service life of the tunnel 1.

[0065] Understandably, the construction steps described above can be followed: first, depressurize the top; then, depressurize the two side panels (102); and finally, depressurize the bottom plate (103). Of course, the construction sequence can be adjusted according to actual needs.

[0066] In one embodiment, such as Figure 2 , Figure 6As shown, the steps for cutting and depressurizing the roof 101 of the roadway 1 along the first direction Z include: firstly, drilling a first hole 2 in the roof 101 along the first direction Z. The inclination angle of the first hole 2 relative to the first direction Z can be set to 75°. Compared with the traditional 90° inclination angle, this setting method can improve the effect of cutting and depressurizing the roof.

[0067] Subsequently, a drilled casing is installed into the first borehole 2, and grout is injected between the inner wall of the first borehole 2 and the outer wall of the drilled casing. Polyurethane-based grouting material can be used to fix the drilled casing to the inner wall of the first borehole 2, ensuring blasting stability.

[0068] Finally, explosive materials are loaded into the borehole casing, and blasting is carried out. Specifically, during the blasting operation, the process of "Technical Conditions for Controlled Pre-splitting Blasting in Deep Holes of Coal Mines" (MT1036-2007) can be adopted to cut off the key rock layer 3 of the roof through deep hole pre-splitting blasting, thereby shortening the overhang length.

[0069] In one embodiment, such as Figure 2 As shown, the steps for constructing the first borehole 2 along the first direction Z of the roof 101 include: the depth of the first borehole 2 is at least 2 / 3 of the thickness of the key rock stratum 3 in the roof, thereby ensuring that the first borehole 2 can fully penetrate and disturb the key rock stratum 3 in the roof 101. The diameter of the first borehole 2 is not less than 50 mm, and this lower limit ensures that the first borehole 2 has sufficient initial space and resistance to deformation. Specifically, during the stress adjustment process after the excavation of the tunnel 1, the surrounding rock will deform and converge. By setting the diameter of the first borehole 2 to not less than 50 mm, it is possible to resist the local closure of the first borehole 2 caused by rock stratum deformation for a certain period of time, maintaining the effectiveness and durability of the pressure relief channel. The spacing between two adjacent first boreholes 2 along the third direction X is not greater than 2 m. This upper limit ensures that the arrangement of the first boreholes 2 along the third direction X of the tunnel 1 has sufficient density, and the relatively dense first boreholes 2 can form a continuous and uniform weakening zone in the rock strata of the roof 101.

[0070] In one embodiment, such as Figure 3 As shown, the step of cutting and depressurizing the roof 101 of the roadway 1 along the first direction Z also includes that before the construction of the first borehole 2 of the roof 101 of the roadway 1 along the first direction Z, the construction of the roof cutting borehole of the solid roadway 1 is at least 100m ahead of the coal mining face 4, and the tunneling face adopts the cyclic depressurization and advance method.

[0071] In this embodiment, as Figure 5 , Figure 6 , Figure 7As shown, when roadway 1 is a pre-formed roadway serving mining operations, such as transport roadway 13 or return airway 14 of coal face 4, the construction of the first borehole 2 on its roof 101 must be sufficiently advanced in both space and time. Specifically, the construction position of the first borehole 2 should be at least 100 meters ahead of the corresponding coal face 4. This provides the necessary period for the redistribution of rock stress due to roof cutting and pressure relief, allowing the stress peak to be stably transferred to deeper parts outside the roadway 1 outline. When roadway 1 is in the tunneling construction stage, since the tunneling face continues to advance, it is impossible to complete long-distance advance pressure relief in one go. Therefore, a dynamic construction mode of cyclic pressure relief and advancement that matches the tunneling cycle can be adopted.

[0072] Furthermore, such as Figure 5 As shown, in this coal seam 9, on the third direction X along the roadway 1, one side of the coal mining face 4 is set as the coal mining advance direction, which is the pre-mined coal seam 12, and the other side is the goaf 15. On the coal mining advance direction, a fourth borehole 10 can also be constructed. The construction of the fourth borehole 10 can transfer the third stress peak position on the third direction X to the depth of the roadway 1, which is convenient for coal seam mining.

[0073] Furthermore, during the construction of the fourth borehole 10 in the coal mining advance direction of roadway 1, the third initial position 300 of the third stress peak position along the third direction X is obtained, and the third target position 400 to which the third stress peak position needs to be transferred is preset. Then, the construction of the fourth borehole 10 is carried out, and its construction method is roughly the same as that of the second borehole 5.

[0074] In one embodiment, such as Figure 3 , Figure 4 As shown, the steps of drilling and decompression on the two sides 102 of roadway 1 to transfer the first stress peak position along the second direction Y to the two sides 102 away from roadway 1 include: obtaining the first initial position 100 of the first stress peak position along the second direction Y, and presetting the first target position 200 to which the first stress peak position needs to be transferred. The first initial position 100 refers to the depth of the maximum horizontal concentrated stress in the surrounding rock of the two sides 102 of roadway 1 under the influence of the original or mining along the second direction Y before any decompression work is carried out. The first target position 200 refers to the depth to which the first stress peak is expected to be transferred according to the support design of roadway 1, the stability requirements of the surrounding rock, and engineering experience.

[0075] Based on the first initial position 100 and the first target position 200, the two sides 102 of the roadway 1 are drilled with second boreholes 5 along the second direction Y. During the construction of the second boreholes 5, the first real-time position of the first stress peak position is obtained. When the first real-time position is detected to reach or exceed the first target position 200, the construction of the second boreholes 5 is stopped.

[0076] Optionally, the first real-time position of the first stress peak can be determined in real time using the drill cuttings method, and a stress detection unit can be set up to monitor stress changes around the second borehole 2. The stress detection unit can be a pressure sensor and a compatible data transmission module. In this way, the arrangement parameters of the second borehole 5 can be dynamically adjusted based on the measured first real-time position.

[0077] Specifically, based on the first initial position 100 and the first target position 200, the two sides 102 of the tunnel 1 are respectively drilled with second boreholes 5 along the second direction Y. The step of obtaining the first real-time position of the first stress peak position during the construction of the second boreholes 5 includes drilling multiple second boreholes 5 at intervals along the third direction X. The diameter of the second boreholes 5 is set as the first diameter, and the distance between adjacent second boreholes 5 is set as the first spacing. It is also determined in real time whether the transfer of the first stress peak position exceeds a threshold, which can be the transfer speed or the transfer distance of the first stress peak position.

[0078] For example, when a preset number of second boreholes 5 are drilled or a preset distance is arranged along a third direction X, if so, that is, the transfer distance of the first stress peak position meets the expectation, the adjacent second boreholes 5 continue to be constructed with the first borehole diameter and the first spacing; if not, that is, the transfer distance of the first stress peak position does not meet the expectation, the distance between adjacent second boreholes 5 is adjusted to the second spacing, and the second spacing is less than the first spacing, so as to dynamically adjust the borehole diameter of the second borehole 5 and the spacing between adjacent second boreholes 5 according to the first real-time position of the first stress peak position to meet the construction requirements.

[0079] In one embodiment, the steps of constructing second boreholes 5 along the second direction Y on both sides 102 of the roadway 1 based on the first initial position 100 and the first target position 200, and obtaining the first real-time position of the first stress peak position during the construction of the second boreholes 5, further include: if the second borehole 5 collapses during the construction process, setting the diameter of the second borehole 5 to a third diameter, the third diameter being smaller than the first diameter; and / or, if the second borehole 5 collapses during the construction process, adjusting the distance between adjacent second boreholes 5 to a third spacing, the third spacing being greater than the first spacing.

[0080] In one embodiment, the first diameter of the second borehole 5 is set to 130mm to 160mm, and the first spacing between adjacent second boreholes 5 is set to 2m to 2.2m; and / or, the second spacing between adjacent second boreholes 5 is set to 1.7m to 1.9m; ​​and / or, the third diameter of the second borehole 5 is set to 90mm to 100mm, and the third spacing between adjacent second boreholes 5 is set to 2.5m to 3m.

[0081] In this embodiment, the diameter of the second borehole 5 and the spacing between adjacent second boreholes 5 can be adaptively adjusted according to actual construction. For example, during initial construction, the diameter of the second borehole 5 is set to a first diameter, which can be 153mm, and the spacing between adjacent second boreholes 5 is set to a first spacing, which can be 2m. During the construction of the second borehole 5, if local stress concentration is found to be unrelieved, the diameter of the second borehole 5 and the spacing between adjacent second boreholes 5 can be corrected by adjusting the parameters. For example, the spacing between adjacent second boreholes 5 can be corrected to a second spacing, which can be 1.8m. Similarly, if severe borehole collapse occurs during the construction of the second borehole 5, the diameter of the second borehole 5 can be reduced to a third diameter, which can be 94mm, or the spacing between adjacent second boreholes 5 can be increased to a third spacing, which can be 2.6m. By dynamically adjusting the parameters of the second borehole 5 as described above, the pressure relief effect of the second borehole 5 construction is ensured.

[0082] In one embodiment, the step of drilling a hole in the floor 103 of the tunnel 1 to relieve pressure and transfer the second stress peak position along the first direction Z to a direction away from the floor 103 of the tunnel 1 includes: obtaining a second initial position of the second stress peak position along the first direction Z, and presetting a second target position to which the second stress peak position needs to be transferred; based on the second initial position and the second target position, constructing a third hole 6 in the floor 103 of the tunnel 1 along the first direction Z; during the construction of the third hole 6, obtaining a second real-time position of the second stress peak position; and stopping the construction of the third hole 6 when the second real-time position is detected to have reached or exceeded the second target position.

[0083] In this embodiment, the construction method of drilling holes to relieve pressure on the bottom plate 103 of the tunnel 1 is roughly the same as the construction method of drilling holes to relieve pressure on the two sides 102 of the tunnel 1. The difference between the two is that the second hole 5 and the third hole 6 are oriented differently.

[0084] Optionally, the XYZ precise three-dimensional decompression method also includes a precise positioning and monitoring module. The precise positioning and monitoring module may specifically include a micro-vibration monitoring device, a displacement sensor, and a stress sensor. The micro-vibration monitoring device is used to be arranged on both sides 102 of the roadway 1. The displacement sensor is used to be fixed to the roof 101 and the floor 103 of the roadway 1. The stress sensor is installed in conjunction with the second borehole 5 and the third borehole 6. That is, the stress sensor can be installed in the second borehole 5 and the third borehole 6. All data can be integrated to the control terminal through a wireless transmission module to generate stress distribution cloud maps and displacement change curves in real time.

[0085] It should be noted that the aforementioned precise positioning monitoring module is only one method for monitoring stress distribution and displacement changes. Those skilled in the art can determine the specific monitoring method according to actual needs to meet usage requirements.

[0086] This embodiment emphasizes the function of pressure-relieving boreholes. Boreholes of appropriate diameter are drilled into the coal (rock) seam, penetrating 3-5 meters into the stress peak zone of the surrounding rock to relieve pressure. The greater the mine pressure, the greater the deformation of roadway 1. When a standard borehole collapses, the borehole diameter is appropriately reduced, and the borehole spacing is appropriately increased. The elastic deformation of the "ridge" formed by the coal (rock) mass between boreholes is utilized to create an "artificial strong spring." Furthermore, using the principle of W=FS and the law of conservation of energy, the small deformation of the borehole absorbs a large amount of energy. After the pressure-relieving borehole construction is completed, another borehole is drilled in the middle of the "ridge" to inspect the borehole, proving that the original stress peak zone is relatively fragmented.

[0087] Furthermore, through drill cuttings analysis, it was found that the stress peak shifted deeper into the coal (rock) mass, and the pressure outside the original peak zone also decreased. Practice has proven that roadway 1 no longer deforms. In summary, the precise three-dimensional stress relief method involves all-round stress relief along the strike and dip of the coal (seam), including the roof 101, sidewalls 102, and floor 103 of roadway 1. Depending on the actual site conditions, the stress relief technology can be flexibly and varied. Moreover, the precise three-dimensional stress relief method emphasizes proactive action on mine pressure, reducing the stress in the surrounding rock of roadway 1 by blocking stress transmission and transferring stress peaks. It has low construction costs and significant effects.

[0088] In one embodiment, the step of drilling a third hole 6 in the bottom plate 103 of the tunnel 1 along the first direction Z based on the second initial position and the second target position includes: setting the third hole 6 at the connection between the two sides 102 of the tunnel 1 and the bottom plate 103 of the tunnel 1, and the drilling direction of the third hole 6 is set at an angle to the extension direction of the first direction Z; or, setting the third hole 6 at the middle position of the bottom plate 103 of the tunnel 1, and the drilling direction of the third hole 6 is parallel to the extension direction of the first direction Z.

[0089] To further describe this application, the following description is provided by way of specific embodiments.

[0090] Step 1: System Exploration and Scheme Design. A special team led by the mine's chief engineer was formed to investigate the geological conditions of the track gate through geological drilling, identify the No. 18 coal seam roof as the main key layer for stress transmission, and formulate a stress relief scheme based on the initial data from the precise positioning monitoring module.

[0091] Specifically, for the roof of the No. 18 coal seam in the Shanjiaoshu Mine track gate, the thickness of the key stratum 3 of the roof is 4.7m~7.56m. The depth of the first borehole 2 for cutting the roof in the first direction Z is set to 5m, so that the depth of the first borehole 2 exceeds 2 / 3 of the thickness of the key stratum 3 of the roof. The borehole spacing between the two roadways along the 226 track gate is set to 1.8m, where the two roadways refer to the return airway 14 and the transport roadway 13. The spacing of the inclined boreholes along the stop line of the 221812 working face is set to 7m. Polyurethane grouting material is used. The Φ50mm borehole casing is fixed to the inner wall of the first borehole 2 to ensure the stability of the first borehole 2 during the blasting process. The blasting execution unit uses coal mine special deep hole blasting equipment. The amount of explosive is adjusted according to the depth of the first borehole 2 and the hardness of the stratum. The blasting is carried out in strict accordance with the MT1036-2007 standard to cut off the key stratum 101 hard siltstone of the roof of the No. 18 coal seam and shorten the overhang length.

[0092] The diameter of the second borehole 5 is set to 153mm. Based on the stress peak value determined by the drill cuttings method in the direction of the 221812 working face, which is located in front of the working face, the depth of the second borehole 5 is set to 30m to penetrate the stress peak area. The spacing between the second boreholes 5 is set to 2.0m. The positions of the second boreholes 5 are adjusted according to the adaptive design of the 221812 stop-mining line. The pressure sensor of the stress monitoring unit is embedded in the inner wall of the second borehole 5, collecting stress data in real time and transmitting it to the control terminal to dynamically provide feedback on the pressure relief effect.

[0093] The diameter of the third borehole 6 is set to 130mm, and it is arranged obliquely along the bottom plate 103 of the tunnel 1. The depth is set to 15m to penetrate the stress concentration area of ​​the bottom plate 103. The spacing of the third borehole 6 is set to 2.0m. By weakening the rock mass strength of the bottom plate 103, the stress peak is transferred to the depth, thus solving the bottom heave problem.

[0094] Step 2: Conduct the first direction Z-cut roof decompression construction. Drill the first borehole 2 within the working face 221812 ahead of the 226 track stone gate. After fixing the borehole casing with polyurethane grouting material, carry out deep hole pre-splitting blasting to cut off the key roof strata 3 of the No. 18 coal seam.

[0095] Step 3: Perform pressure relief construction in the second direction (Y) and the first direction (Z). 72 hours after the blasting is completed, initiate pressure relief construction in the second direction (Y) and drill the second borehole 5 into both side walls 102. Simultaneously initiate pressure relief construction in the first direction (Z), or initiate pressure relief construction in the first direction (Z) after the second direction (Y) is completed, and drill the third borehole 6 into the bottom plate 103. During the construction process, the parameters of the second borehole 5 and the third borehole 6 are adjusted in real time through the stress monitoring unit.

[0096] Step 4: Dynamic monitoring and parameter optimization. The control terminal analyzes microseismic signals and stress data in real time. When local stress concentration is found to be unrelieved, the parameters of the pressure relief borehole are adjusted by modifying the parameters, and the distance between the adjacent second borehole 5 is adjusted to 1.8m.

[0097] Step 5: Effect Evaluation and Summary. After the construction was completed, monitoring data showed that the displacement of the surrounding rock of the 226 track gate was controlled within 50mm, the stress peak shifted to the deeper part of the coal and rock mass by ~5m, the protective coal pillar of the 221812 working face was reduced from the original design to 7.4m, an additional 42,750t of raw coal was mined, and no deformation or damage occurred in roadway 1, demonstrating a significant pressure relief effect.

[0098] Although embodiments of this application have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of this application, and all such modifications and variations fall within the scope defined by the appended claims.

Claims

1. A precise XYZ three-dimensional pressure relief method, characterized in that, Includes the following steps: The roof (101) of the roadway (1) is cut and depressurized along the first direction (Z); Drill holes (102) on both sides of the roadway (1) to relieve pressure and shift the first stress peak position along the second direction (Y) away from the two sides (102) of the roadway (1); Drilling is performed on the bottom plate (103) of the roadway (1) to relieve pressure, and the second stress peak position along the first direction (Z) is moved away from the bottom plate (103) of the roadway (1).

2. The XYZ precise three-dimensional pressure relief method according to claim 1, characterized in that, The step of cutting and relieving pressure on the roof (101) of the roadway (1) along the first direction (Z) includes: The top plate (101) is drilled with a first hole (2) along the first direction (Z); Install a drilling sleeve into the first borehole (2) and inject grout between the inner wall of the first borehole (2) and the outer wall of the drilling sleeve; Explosive material is filled into the drilled casing, and blasting is carried out.

3. The XYZ precise three-dimensional pressure relief method according to claim 2, characterized in that, The step of drilling (2) the top plate (101) along the first direction (Z) includes: The depth of the first borehole (2) shall be at least 2 / 3 of the thickness of the critical rock stratum (3) in the top plate; And / or, the diameter of the first borehole (2) is not less than 50 mm; And / or, the distance between two adjacent first boreholes (2) along the third direction (X) during construction is no greater than 2m.

4. The XYZ precise three-dimensional pressure relief method according to claim 1, characterized in that, The step of cutting and relieving pressure on the roof (101) of the roadway (1) along the first direction (Z) further includes: Before the first borehole (2) is drilled in the first direction (Z) of the roof (101) of the roadway (1), the actual roadway (1) roof cutting borehole construction is carried out at a distance of not less than 100m ahead of the coal mining face (4).

5. The XYZ precise three-dimensional pressure relief method according to any one of claims 1-4, characterized in that, The step of drilling and decompression on both sides (102) of the roadway (1) to shift the first stress peak position along the second direction (Y) away from the two sides (102) of the roadway (1) includes: Obtain the first initial position (100) of the first stress peak position along the second direction (Y), and preset the first target position (200) to which the first stress peak position needs to be transferred. Based on the first initial position (100) and the first target position (200), second boreholes (5) are drilled on both sides (102) of the tunnel (1) along the second direction (Y); During the construction of the second borehole (5), the first real-time position of the first stress peak position is obtained; When the first real-time position is detected to reach or exceed the first target position (200), the second drilling (5) construction is stopped.

6. The XYZ precise three-dimensional pressure relief method according to claim 5, characterized in that, The steps of constructing second boreholes (5) along the second direction (Y) on both sides (102) of the roadway (1) based on the first initial position (100) and the first target position (200), and obtaining the first real-time position of the first stress peak position during the construction of the second boreholes (5) include: Multiple second boreholes (5) are constructed at intervals along a third direction (X), the diameter of the second boreholes (5) is set as a first diameter, and the distance between adjacent second boreholes (5) is set as a first spacing; Real-time determination of whether the shift in the position of the first stress peak exceeds a threshold; If so, the adjacent second borehole (5) continues to be constructed with the first borehole diameter and the first spacing; If not, adjust the distance between adjacent second boreholes (5) to a second spacing, and the second spacing is less than the first spacing.

7. The XYZ precise three-dimensional pressure relief method according to claim 6, characterized in that, The step of constructing second boreholes (5) along the second direction (Y) on both sides (102) of the roadway (1) based on the first initial position (100) and the first target position (200), and the step of obtaining the first real-time position of the first stress peak position during the construction of the second boreholes (5) further includes: If the second borehole (5) collapses during construction, the diameter of the second borehole (5) shall be set as the third diameter, which shall be smaller than the first diameter. And / or, if the second borehole (5) collapses during construction, the distance between adjacent second boreholes (5) is adjusted to a third spacing, and the third spacing is greater than the first spacing.

8. The XYZ precise three-dimensional pressure relief method according to claim 7, characterized in that, The first diameter of the second borehole (5) is set to 130mm to 160mm, and the first distance between adjacent second boreholes (5) is set to 2m to 2.2m; And / or, the second spacing between adjacent second boreholes (5) is set to 1.7m to 1.9m; And / or, the third diameter of the second borehole (5) is set to 90mm to 100mm, and the third spacing between adjacent second boreholes (5) is set to 2.5m to 3m.

9. The XYZ precise three-dimensional pressure relief method according to any one of claims 1-4, characterized in that, The step of drilling and decompressing the floor slab (103) of the tunnel (1) to transfer the second stress peak position along the first direction (Z) to a direction away from the floor slab (103) of the tunnel (1) includes: Obtain the second initial position of the second stress peak position along the first direction (Z), and preset the second target position to which the second stress peak position needs to be transferred; Based on the second initial position and the second target position, a third borehole (6) is drilled in the bottom plate (103) of the tunnel (1) along the first direction (Z); During the construction of the third borehole (6), the second real-time position of the second stress peak position is obtained; When the second real-time position is detected to reach or exceed the second target position, the construction of the third borehole (6) is stopped.

10. The XYZ precise three-dimensional pressure relief method according to claim 9, characterized in that, The step of drilling a third hole (6) in the bottom plate (103) of the tunnel (1) along the first direction (Z) based on the second initial position and the second target position includes: The third borehole (6) is set at the connection between the two sides (102) of the tunnel (1) and the bottom plate (103) of the tunnel (1), and the drilling direction of the third borehole (6) is set at an angle to the extension direction of the first direction (Z). Alternatively, the third borehole (6) may be located in the middle of the bottom plate (103) of the tunnel (1), with the drilling direction of the third borehole (6) being parallel to the extension direction of the first direction (Z).

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