Coal mine tunnel fracturing tunneling method

Abstract

The invention provides a coal mine roadway fracturing tunneling method. The coal mine roadway fracturing tunneling method comprises the steps that rock stratum information of a target rock stratum in a roadway advance area is obtained; according to the rock stratum information, fracturing parameters are determined, and fracturing holes and pressure relief holes are constructed in the roadway working face; a plurality of separation grooves are constructed in the fracturing hole, and the straight line where the grooving direction of the separation grooves is located is staggered with the axis of the roadway; according to the fracturing parameters and the separation grooves, fracturing sections are determined, all the fracturing sections in the fracturing holes are fractured one by one, and when liquid flows out of the pressure relief holes, fracturing of the fracturing sections is stopped; and the fracturing work of all the fracturing holes is completed. According to the coal mine tunnel fracturing tunneling method, the tunneling efficiency can be improved, and the tunneling cost is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of coal mining, and in particular to a coal mine tunnel fracturing excavation method. Background Art

[0002] In the process of coal mining, when encountering some relatively hard rocks, the excavation equipment is very susceptible to rock wear during long-term and high-intensity operations, resulting in rapid wear and tear of parts and increased replacement frequency, such as picks. This not only increases the mining cost, but also seriously affects the continuity and stability of mining operations. In addition, due to the difficulty of excavating hard rocks, the labor intensity of workers also increases. Working under high-intensity physical labor for a long time will not only reduce the work efficiency of workers, but may also affect the safety of operations. Summary of the invention

[0003] The present invention is based on the inventor's discovery and understanding of the following facts and problems:

[0004] In coal mine excavation, for relatively hard rock layers, the rock breaking operation is currently mainly carried out by blasting and tunneling machines. However, both methods have significant technical limitations and operational difficulties in practical applications.

[0005] First, although the blasting method can effectively break hard rocks to a certain extent, it consumes a large amount of explosives, which not only increases the mining cost, but also poses a potential risk of environmental pollution. Moreover, due to the uncontrollability of the explosion of explosives, the safety factor of blasting operations is relatively low, which is easy to cause safety accidents and pose a threat to the lives of workers.

[0006] The use of a multi-purpose excavator can improve the mechanization level of excavation operations to a certain extent. However, when facing hard rocks, due to the high hardness of the rocks, the picks of the multi-purpose excavator are very easy to wear or even break during long-term, high-intensity cutting operations, which not only increases the equipment maintenance cost, but also shortens the service life of the multi-purpose excavator.

[0007] In summary, both the blasting method and the comprehensive excavation machine have obvious limitations in the process of coal mine excavation, and cannot meet the requirements of efficient, safe and low-cost excavation. To this end, an embodiment of the present invention provides a coal mine tunnel fracturing excavation method, which includes the following steps:

[0008] S10, obtaining rock formation information of the target rock formation in the advance area of ​​the tunnel;

[0009] S20, determining fracturing parameters according to the rock formation information, and constructing fracturing holes and pressure relief holes on the tunnel working surface;

[0010] S30, constructing a plurality of separation grooves on the fracturing hole, wherein the straight line where the groove directions of the separation grooves are located intersects with the axis of the roadway;

[0011] S40, determining the fracturing section according to the fracturing parameters and the separation groove, and fracturing all the fracturing sections in the fracturing hole one by one, wherein when liquid flows out of the pressure relief hole, the fracturing of the fracturing section is stopped;

[0012] Step S40 is repeated until the fracturing work of all the fracturing holes is completed.

[0013] In summary, the coal mine tunnel fracturing excavation method provided by the embodiment of the present invention provides a scientific basis for determining the fracturing parameters by comprehensively acquiring and analyzing the rock formation information of the target rock formation in the advance area of ​​the tunnel; by accurately constructing fracturing holes and pressure relief holes, and cleverly designing separation grooves, accurate control of the crack propagation direction is achieved; by orderly implementing fracturing operations and closely monitoring the dynamic changes of the pressure relief holes, the fracturing effect is ensured while avoiding unnecessary damage and potential threats to the tunnel structure, thereby improving excavation efficiency, reducing excavation costs, and effectively ensuring the stability and support strength of the tunnel structure, providing strong support for the sustainable development of coal mining.

[0014] In some embodiments, the step S20, determining fracturing parameters according to rock formation information, and constructing fracturing holes and pressure relief holes on the tunnel working surface, includes the following steps:

[0015] Determine the drilling parameters of the fracturing holes and the pressure relief holes according to the rock formation information, the drilling parameters at least including the position, quantity, drilling depth and hole spacing, wherein the drilling depth between two adjacent fracturing holes is set in a stepped manner;

[0016] Based on the drilling parameters, fracturing holes and pressure relief holes are drilled on the tunnel working face.

[0017] In some embodiments, the drilling depths of two adjacent fracturing holes are at least 1 meter apart;

[0018] And / or, the distance from at least part of the pressure relief holes to the two sides of the tunnel is greater than or equal to 0.5 meters, and the distance from at least part of the pressure relief holes to the top plate of the tunnel is greater than or equal to 0.4 meters.

[0019] In some embodiments, the step S30, constructing a plurality of separation grooves on the fracturing hole, wherein the straight line where the cutting direction of the separation grooves is located intersects with the axis of the roadway, comprises the steps of:

[0020] Determine the number, spacing and depth of the separation grooves according to the drilling depth and hole spacing of the fracturing holes;

[0021] Based on the spacing and groove depth of the dividing grooves, the dividing grooves are constructed in the fracturing hole, wherein the straight line where the groove direction of the dividing grooves is located intersects with the axis of the roadway.

[0022] In some embodiments, the distance between two adjacent separation grooves is set to 1 meter to 1.5 meters.

[0023] In some embodiments, the rock formation information includes at least rock formation strength and rock formation structure; the step S10 of obtaining the rock formation information of the target rock formation in the tunnel advance area includes the following steps:

[0024] Opening a detection hole in the advance area of ​​the tunnel excavation working face;

[0025] Install a peep instrument and a strength tester in the detection hole to obtain the rock structure and rock strength in the advance area;

[0026] The target rock formation is determined based on the rock formation structure and rock formation strength.

[0027] In some embodiments, the S20 determines fracturing parameters according to the rock formation information, and constructs fracturing holes and pressure relief holes on the tunnel working surface, wherein a plurality of fracturing holes are provided, and the plurality of fracturing holes are arranged at intervals around the detection hole.

[0028] In some embodiments, the S40, according to the fracturing parameters and the separation grooves, determines the fracturing section, and fracturifies all the fracturing sections in the fracturing hole one by one, wherein when liquid flows out of the pressure relief hole, the fracturing of the fracturing section is stopped, including the steps of:

[0029] Determine each fracturing section in the fracturing hole according to the fracturing parameters and the separation grooves;

[0030] The plugging device is loaded into the fracturing hole to form a fracturing space in the fracturing section;

[0031] When the pressure in the fracturing space reaches the preset pressure, the pressure in the fracturing space is maintained at the preset pressure for a preset time to complete the fracturing of the fracturing section.

[0032] In some embodiments, the preset pressure is set to 30 MPa to 50 MPa.

[0033] In some embodiments, the coal mine tunnel fracturing excavation method further includes the steps of:

[0034] After the fracturing of the fracturing hole is completed, the fracturing hole is sealed, and the sealing depth is greater than or equal to 1 meter. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic diagram of the process of the coal mine tunnel fracturing excavation method provided by an embodiment of the present invention.

[0036] Figure 2 It is a schematic diagram of the arrangement of fracturing holes and pressure relief holes on the working surface of a coal mine tunnel in the fracturing excavation method provided by an embodiment of the present invention.

[0037] Figure 3 It is a schematic diagram of the layout of fracturing holes, pressure relief holes, separation grooves and fracturing sections in the coal mine tunnel fracturing excavation method provided by an embodiment of the present invention.

[0038] Reference numerals:

[0039] 10. Detection hole;

[0040] 21. First fracturing hole; 22. Second fracturing hole; 23. Third fracturing hole; 24. Separation groove;

[0041] 31. First pressure relief hole; 32. Second pressure relief hole; 33. Third pressure relief hole;

[0042] 41. The left side of the tunnel; 42. The right side of the tunnel; 43. The roof of the tunnel. DETAILED DESCRIPTION

[0043] The 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.

[0044] refer to Figure 1 , is a schematic diagram of a flow chart of a coal mine tunnel hydraulic fracturing and excavation method provided by an embodiment of the present invention. The coal mine tunnel hydraulic fracturing and excavation method provided by an embodiment of the present invention comprises the following steps:

[0045] S10, obtaining rock formation information of the target rock formation in the tunnel advance area, wherein the rock formation information at least includes rock formation strength, rock formation structure and aquifer information, the rock formation strength can be divided into compressive strength, tensile strength and other information, and the rock formation structure can include rock formation thickness, bedding and joints and other information.

[0046] S20, according to the rock formation information, determine the fracturing parameters, and construct fracturing holes and pressure relief holes on the working surface of the tunnel. Among them, the fracturing parameters include at least parameters such as fracturing pressure, fracturing spacing, and single fracturing time. That is to say, according to the rock formation information obtained in step S10, the fracturing parameters that best suit the current rock formation characteristics can be calculated. And according to the physical and mechanical properties of the rock formation, determine the drilling parameters of the fracturing holes and pressure relief holes, such as drilling diameter, drilling depth, drilling angle, etc., and perform drilling operations accordingly. It should be noted that the fracturing holes are used to inject high-pressure fluids to generate cracks in the advance area of ​​the tunnel, while the pressure relief holes are used to monitor crack propagation and release excess pressure. The two work together to achieve the expected fracturing effect.

[0047] S30, construct multiple separation grooves on the fracturing hole, and the straight line where the groove direction of the separation grooves is located intersects with the axis of the roadway. The separation grooves can effectively divide the fracturing hole into multiple independent sections, which can achieve precise control of the crack propagation direction, ensure that the crack propagates along the expected path, and avoid unnecessary damage.

[0048] S40, determine the fracturing section according to the fracturing parameters and the dividing groove, and perform fracturing on the fracturing sections in the fracturing hole one by one, wherein when liquid flows out of the pressure relief hole, the fracturing of the fracturing section is stopped. That is to say, in the axial direction of the fracturing hole, it can be divided into multiple fracturing sections. Then, in the order from the distal end to the proximal end of the fracturing hole, the fracturing operation is performed on each fracturing section one by one. During the fracturing process, always pay attention to the pressure relief hole. If liquid flows out of the pressure relief hole, it means that the crack has successfully extended to this position. At this time, further fracturing of the fracturing section should be stopped immediately to prevent the crack from excessively extending to the tunnel support area, thereby maintaining the stability and support strength of the tunnel structure.

[0049] Repeat step S40 until the fracturing work of the fracturing hole is completed, thereby completing the fracturing operation and ensuring that the entire target rock formation is effectively transformed, facilitating subsequent excavation operations.

[0050] In summary, the coal mine tunnel fracturing excavation method provided by the embodiment of the present invention provides a scientific basis for determining the fracturing parameters by comprehensively acquiring and analyzing the rock formation information of the target rock formation in the advance area of ​​the tunnel; by accurately constructing fracturing holes and pressure relief holes, and cleverly designing separation grooves, accurate control of the crack propagation direction is achieved; by orderly implementing fracturing operations and closely monitoring the dynamic changes of the pressure relief holes, the fracturing effect is ensured while avoiding unnecessary damage and potential threats to the tunnel structure, thereby improving excavation efficiency, reducing excavation costs, and effectively ensuring the stability and support strength of the tunnel structure, providing strong support for the sustainable development of coal mining.

[0051] In some embodiments, the step S20, determining fracturing parameters according to rock formation information, and constructing fracturing holes and pressure relief holes on the tunnel working surface, includes the following steps:

[0052] Determine the drilling parameters of the fracturing holes and the pressure relief holes according to the rock formation information, wherein the drilling parameters at least include the position, quantity, drilling depth and hole spacing, wherein the drilling depth between two adjacent fracturing holes is set in a stepped manner;

[0053] Based on the drilling parameters, fracturing holes and pressure relief holes are drilled on the tunnel working face.

[0054] Specifically, the drilling depth between two adjacent fracturing holes is set in a stepped manner, which can form fracturing holes of different depths, and can form a more complex and intertwined crack network in the advance area, thereby more effectively releasing the stress inside the rock formation and improving the fracturing effect. In addition, the stepped drilling depth can also reduce the direct impact of the fracturing operation on the tunnel structure to a certain extent, and enhance the stability of the tunnel structure.

[0055] Optionally, the drilling depths of two adjacent fracturing holes are at least 1 meter apart. When high-pressure fluid is injected into the fracturing holes, due to the different drilling depths of adjacent holes, the cracks will encounter rock layers of different thicknesses during the expansion process, thereby changing their expansion paths. This differential expansion path helps to form a more complex and intertwined crack network, further releasing the stress inside the rock formation and improving the fracturing effect.

[0056] In some embodiments, at least part of the pressure relief holes are located at the junction of the supporting rock mass and the excavation rock mass, wherein the distance from at least part of the pressure relief holes to the two sides of the tunnel is greater than or equal to 0.5 meters, and the distance from at least part of the pressure relief holes to the top plate of the tunnel is greater than or equal to 0.4 meters.

[0057] Specifically, the rock formation in front of the tunnel working face can be divided into supporting rock mass and excavation rock mass. The pressure relief hole is set at the junction of the supporting rock mass and the excavation rock mass. When the liquid in the pressure relief hole flows out, it means that the crack has extended to the edge of the excavation rock mass, which means that the stress inside the excavation rock mass has been effectively released. At the same time, it also indicates that the supporting rock mass is about to face the minimum stress influence from the excavation rock mass. Stopping fracturing at this time can ensure the stability of the supporting rock mass, effectively maintain the overall structural safety of the tunnel, and reduce the risk of tunnel deformation and collapse.

[0058] In some embodiments, the separation groove effectively guides the expansion of the crack without causing unnecessary damage to the tunnel structure. S30 constructs a plurality of separation grooves on the fracturing hole, and the straight line where the cutting direction of the separation grooves is located intersects with the tunnel axis, including the steps of:

[0059] Determine the number, spacing and depth of the separation grooves according to the drilling depth and hole spacing of the fracturing holes;

[0060] Based on the spacing and groove depth of the dividing grooves, the dividing grooves are constructed in the fracturing hole, wherein the straight line where the groove direction of the dividing grooves is located intersects with the axis of the roadway.

[0061] In other words, according to the drilling depth and hole spacing of the fracturing holes, the number, spacing and groove depth of the separation grooves are reasonably set, which can guide the direction of crack propagation and more effectively release the stress inside the rock formation.

[0062] Optionally, the straight line where the grooving direction of the dividing groove is located can be perpendicular to the axis of the tunnel, which not only facilitates the processing of the dividing groove, but also helps to control the expansion direction of the crack, avoid its direct impact on the key parts of the tunnel structure, and help reduce the risk of tunnel deformation and collapse.

[0063] Furthermore, the spacing between two adjacent separation grooves can be set to 1 meter to 1.5 meters. Among them, a spacing that is too large may cause energy dissipation during crack expansion and affect the fracturing effect; while a spacing that is too small may increase the difficulty of construction and even cause unnecessary damage to the tunnel structure. Therefore, a spacing range of 1 meter to 1.5 meters can ensure sufficient expansion of the cracks while avoiding excessive impact on the tunnel structure.

[0064] In some embodiments, the rock formation information includes at least rock formation strength and rock formation structure. The step S10 of acquiring rock formation information of the target rock formation in the tunnel advance area includes the following steps:

[0065] Opening a detection hole in the advance area of ​​the tunnel excavation working face;

[0066] Install a peep instrument and a strength tester in the detection hole to obtain the rock structure and rock strength in the advance area;

[0067] The target rock formation is determined based on the rock formation structure and rock formation strength.

[0068] In this embodiment, first, a detection hole is opened in the advance area of ​​the tunnel excavation working face based on the previous geological exploration data and the specific needs of the excavation operation. Then, a peep instrument and a strength tester are installed in the detection hole. The peep instrument has high-definition imaging and remote transmission functions, which can capture and transmit the rock structure image in the detection hole in real time, and can intuitively observe the bedding, joints, cracks and other characteristics of the rock formation. The strength tester can accurately measure the key mechanical parameters of the rock formation such as the compressive strength and tensile strength, providing an important basis for evaluating the stability of the rock formation and the effect of the fracturing operation.

[0069] After obtaining the rock structure and strength information in the advance area, the target rock layer is determined in combination with geological exploration data, specific requirements of tunneling operations and previous construction experience. This process not only takes into account the physical and mechanical properties of the rock layer, but also fully considers the relationship between the rock layer and the tunneling direction, the interaction between the rock layers, and possible geological structures.

[0070] It should be noted that in the process of determining the target rock layer, multiple detection and testing may be required to ensure the accuracy and completeness of the information obtained. At the same time, it is also necessary to pay close attention to the changes in geological conditions and the progress of excavation operations, and timely adjust the location, number and depth of the detection holes, as well as the test parameters of the peep instrument and strength tester to adapt to the changing construction environment.

[0071] In some embodiments, the S20 determines fracturing parameters according to the rock formation information, and constructs fracturing holes and pressure relief holes on the tunnel working surface, wherein a plurality of fracturing holes are provided, and the plurality of fracturing holes are arranged at intervals around the detection hole.

[0072] Among them, the fracturing holes are arranged at intervals around the detection holes, which can ensure that the fracturing operation fully covers the target rock formation, realize the effective expansion of cracks and the full release of stress.

[0073] In some embodiments, the S40, according to the fracturing parameters and the separation grooves, determines the fracturing section, and fracturifies all the fracturing sections in the fracturing hole one by one, wherein when liquid flows out of the pressure relief hole, the fracturing of the fracturing section is stopped, including the steps of:

[0074] Determine each fracturing section in the fracturing hole according to the fracturing parameters and the separation grooves;

[0075] The plugging device is loaded into the fracturing hole to form a fracturing space in the fracturing section;

[0076] When the pressure in the fracturing space reaches the preset pressure, the pressure in the fracturing space is maintained at the preset pressure for a preset time to complete the fracturing of the fracturing section.

[0077] In this embodiment, first, each fracturing section in the fracturing hole is calculated and determined according to the fracturing parameters and the position of the dividing groove. Then, the plugger is loaded into the fracturing hole to form a closed fracturing space in a specific fracturing section, and high-pressure liquid is injected into the fracturing space through the injection equipment. The high-pressure liquid can act on the target rock formation to form cracks in the target rock formation. And when the pressure in the fracturing space reaches the preset pressure, the pressure value is maintained within a preset time to ensure that the crack can fully cover the entire fracturing section, thereby achieving complete fracturing of the fracturing section.

[0078] Optionally, the preset pressure is set to 30 MPa to 50 MPa. The size of the preset pressure directly affects the effect of the fracturing operation. Too low a pressure may not fully stimulate the crack expansion capacity of the rock formation, while too high a pressure may cause excessive damage to the rock formation and even cause a safety accident. The preset pressure range of 30 MPa to 50 MPa can achieve effective crack expansion and full stress release under the premise of ensuring safety, thereby achieving the best fracturing effect.

[0079] In some embodiments, the coal mine tunnel hydraulic fracturing excavation method further comprises the steps of:

[0080] After the fracturing of the fracturing hole is completed, the fracturing hole is sealed, and the sealing depth is greater than or equal to 1 meter.

[0081] Among them, after the fracturing operation is completed in the fracturing hole, the fracturing hole is sealed to prevent the fracturing fluid in the fracturing hole from leaking out, and to prevent gravel, dust and other debris generated during the tunnel excavation process from entering the fracturing hole, thereby ensuring the cleanliness and safety of the tunnel.

[0082] Moreover, the sealing operation can not only prevent the leakage of fracturing fluid and the entry of debris, but also improve the stability of the tunnel to a certain extent. By setting the sealing depth reasonably, we can ensure that the rock formation around the fracturing hole is effectively supported, thereby avoiding deformation or collapse of the tunnel caused by rock formation instability.

[0083] In addition, it should be noted that Figure 1 The flow chart of the coal mine tunnel fracturing excavation method shown in the figure is a flow chart of the coal mine tunnel fracturing excavation method, and the sequence of its steps is only based on the logical sequence provided by one of the many embodiments of the present invention. This sequence is intended to clearly illustrate the execution process of the method in a specific application scenario. However, in actual applications, the flexibility and scalability of the present invention allow technicians to adjust the sequence of the above steps according to different actual needs and environmental conditions, such as the existence of parallel or parallel relationships between some steps, etc., which will not be repeated here.

[0084] like Figure 2 and Figure 3 As shown, during the implementation of the coal mine tunnel fracturing excavation method provided in this embodiment, first, at the head section of the tunnel working face, a detection hole is constructed using a water exploration and drainage drill. The drilling direction of the detection hole is perpendicular to the head section, and the drilling direction of the detection hole is parallel to the tunnel axis. The drilling depth of the detection hole can be set to 30m, and the diameter of the detection hole can be set to 60mm. During the drilling of the detection hole, the lithology in the advance area can be inferred by the drilled slag. After the drilling of the detection hole is completed, the lithology in the detection hole can be tested in sections using a strength tester. The length of each section can be set to 1m, and the strength of the rock formation in the advance area can be obtained. Then, a peep instrument is used to perform a panoramic peep on the rock formation in the detection hole, and the rock formation structure in the advance area can be obtained.

[0085] Subsequently, the target rock layer is determined according to the lithology and rock layer structure, and a relationship diagram between lithology and strength in the advanced area is constructed. Then, according to the relationship diagram between lithology and strength, the arrangement of the fracturing holes, the distance between the fracturing sections, the time of a single fracturing, the fracturing pressure, the location of the pressure relief holes and other information are determined to ensure that the fracturing range can cover the hard rock layers in the advanced area. The fracturing holes are then constructed according to the above information, and after the construction of the fracturing holes is completed, the wall of the fracturing holes is processed with a groove cutting drill according to the distribution of the strength of each section of rock in the fracturing holes. The groove direction of the groove is perpendicular to the axis of the fracturing holes and the roadway. The spacing between two adjacent grooves can be set to 1.5 meters. For areas where the rock strength exceeds 70MPa, the spacing between two adjacent grooves can be set to 1 meter.

[0086] Among them, at least three fracturing holes parallel to the tunnel axis are constructed on the front section, the drilling depth of each fracturing hole differs by 1 meter, and the fracturing section spacing of each fracturing hole can be set to 1.5 meters. For areas with rock formation strength exceeding 70MPa, the fracturing section spacing can be set to 1 meter.

[0087] Then, according to the layout information of the fracturing holes, the location of the pressure relief holes is determined and the pressure relief holes are constructed. Among them, at least one pressure relief hole is constructed near the two sides and the top plate of the tunnel, so as to prevent the fracturing cracks from further spreading to the supporting rock mass outside the excavation rock body and ensure the stability of the supporting rock mass.

[0088] After the construction of the fracturing holes and the pressure relief holes is completed, the fracturing holes are fractured one by one, that is, after each fracturing of a fracturing hole is completed, the fracturing operation of the next fracturing hole is carried out. During the fracturing process, a water exploration and release drilling rig can be used to push the plugger composed of two sealing capsules and the high-pressure water injection steel pipe to the bottom of the fracturing hole. The high-pressure hose and the water pressure system are connected to the end of the high-pressure water injection steel pipe. The high-pressure hose is connected to the high-pressure water outlet section of the fracturing pump. In addition, in order to prevent the sealing capsule and the high-pressure water injection steel pipe from jumping out and injuring people or damaging equipment during fracturing and pressure relief, an anti-collapse chain must be used at the mouth of the fracturing hole to fix the high-pressure water injection steel pipe to the top plate of the tunnel and the anchor rods on both sides of the tunnel. After the above equipment is connected, the personnel evacuate to a range of 30m away from the front, and set up a warning to prohibit personnel from entering the area.

[0089] Turn on the fracturing pump, first inject water and pressurize the two sealing bags to expand the sealing bags and seal the fracturing section. After the sealing bags are sealed, further adjust the water outlet pressure of the fracturing pump to 30-50MPa, and observe the water outlet of the pressure relief hole and the adjacent borehole. If a large amount of water is discharged from the adjacent fracturing hole or the pressure relief hole, and the pressure in the fracturing space is significantly reduced, it proves that the fracturing crack has penetrated and is connected. At this time, fracturing can be stopped, and the fracturing pump pressure is lowered to zero. The pressure inside the sealing bag and the fracturing borehole is released, and the high-pressure water injection steel pipe and the connected fracturing tool string are dragged backward to the next split section, and the above steps are repeated to perform the next segment fracturing operation.

[0090] After the fracturing operation of a fracturing hole is completed, the plugger and related pipelines are removed, and the borehole is plugged with sealing materials. The sealing depth is not less than 1m, and then the construction is carried out. After the fracturing operation of all fracturing holes is completed, the comprehensive excavation machine is started for excavation. During the excavation operation, the statistics and monitoring of the consumption of pick teeth, excavation speed, and the frequency of blasting operations are used to comprehensively evaluate the effect of the advanced hydraulic fracturing weakening treatment in hard rock tunnel excavation.

[0091] It should be noted that Figure 1The flowchart of the coal supply and demand scheduling optimization method shown in the figure is a flowchart of the method of supply and demand scheduling optimization, and the sequence of its steps is only based on the logical sequence provided by one of the many embodiments of the present invention. This sequence is intended to clearly illustrate the execution process of the method in a specific application scenario. However, in actual applications, the flexibility and scalability of the present invention allow technicians to adjust the sequence of the above steps according to different actual needs and environmental conditions, such as the existence of parallel or parallel relationships between some steps, etc., which will not be repeated here.

[0092] refer to Figure 2 and Figure 3 It can be seen that the width of the tunnel is set to A, which can be set to 5 meters. The height of the tunnel is set to H, which can be set to 3.2 meters. The length of the advance area of ​​the tunnel working face is L, which can be set to 30 meters. Figure 3 The inner arrow indicates the excavation direction of the tunnel working face. A total of three fracturing holes are constructed on the front section of the tunnel excavation, namely the first fracturing hole 21, the second fracturing hole 22 and the third fracturing hole 23. The first fracturing hole 21 and the second fracturing hole 22 can be located on the same horizontal plane as the detection hole 10, and the first fracturing hole 21 and the second second fracturing hole 22 are symmetrically arranged on both sides of the detection hole 10, the distance between the first fracturing hole 21 and the detection hole 10 is set to 1 meter, and the distance between the second fracturing hole 22 and the detection hole 10 is set to 1 meter. The third fracturing hole 23 is arranged directly above the detection hole 10, and the distance from the third fracturing hole 23 to the detection hole 10 is set to 1 meter.

[0093] The drilling depth of the first fracturing hole 21 can be set to 29 meters, the drilling depth of the second fracturing hole 22 can be set to 28 meters, the drilling depth of the third fracturing hole 23 can be set to 30 meters, and the distance between two adjacent separation grooves 24 can be set to 1.5 meters.

[0094] There are three pressure relief holes, namely the first pressure relief hole 31, the second pressure relief hole 32 and the third pressure relief hole 33. The first pressure relief hole 31 and the second pressure relief hole 32 are located on the same horizontal plane as the detection hole 10. The first pressure relief hole 31 is located between the first fracturing hole 21 and the left side of the tunnel 41. The distance between the first pressure relief hole 31 and the first fracturing hole 21 is set to 1 meter, and the distance between the first pressure relief hole 31 and the left side of the tunnel 41 is set to 0.5 meters. The second pressure relief hole 32 is located between the second fracturing hole 22 and the right side of the tunnel 42. The distance between the second pressure relief hole 32 and the second fracturing hole 22 is set to 1 meter, and the distance between the second pressure relief hole 32 and the right side of the tunnel 42 is set to 0.5 meters. The third pressure relief hole 33 is located directly above the third fracturing hole 23. The distance between the third pressure relief hole 33 and the third fracturing hole 23 is set to 0.8 meters, and the distance from the third pressure relief hole 33 to the tunnel roof 43 is set to 0.4 meters.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] 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.

[0099] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean 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 described specific features, structures, materials or characteristics 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.

[0100] 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 coal mine tunnel fracturing excavation method, characterized in that: The steps include: S10, obtaining rock formation information of the target rock formation in the advance area of ​​the tunnel; S20, determining fracturing parameters according to the rock formation information, and constructing fracturing holes and pressure relief holes on the tunnel working surface; S30, constructing a plurality of separation grooves on the fracturing hole, wherein the straight line where the groove directions of the separation grooves are located intersects with the axis of the roadway; S40, determining a fracturing section according to the fracturing parameters and the dividing groove, and fracturing all the fracturing sections in the fracturing hole one by one, wherein when liquid flows out of the pressure relief hole, the fracturing of the fracturing section is stopped; Step S40 is repeated until the fracturing work of all the fracturing holes is completed.

2. The coal mine tunnel fracturing excavation method according to claim 1, characterized in that: The S20, determining the fracturing parameters according to the rock formation information, and constructing fracturing holes and pressure relief holes on the tunnel working surface, includes the following steps: Determine drilling parameters of the fracturing holes and the pressure relief holes according to the rock formation information, wherein the drilling parameters at least include position, quantity, drilling depth and hole spacing, wherein the drilling depth between two adjacent fracturing holes is set in a stepped manner; Based on the drilling parameters, fracturing holes and pressure relief holes are drilled on the tunnel working surface.

3. The coal mine tunnel fracturing excavation method according to claim 2, characterized in that: The drilling depths of two adjacent fracturing holes should be at least 1 meter apart; And / or, the distance from at least part of the pressure relief holes to the two sides of the tunnel is greater than or equal to 0.5 meters, and the distance from at least part of the pressure relief holes to the top plate of the tunnel is greater than or equal to 0.4 meters.

4. The coal mine tunnel fracturing excavation method according to claim 2, characterized in that: The step S30, constructing a plurality of separation grooves on the fracturing hole, wherein the straight line where the cutting direction of the separation grooves is located intersects with the axis of the roadway, comprises the steps of: Determining the number, spacing and slot depth of the separation slots according to the drilling depth and hole spacing of the fracturing holes; Based on the spacing and groove depth of the dividing grooves, the dividing grooves are constructed in the fracturing hole, wherein the straight line where the groove directions of the dividing grooves are located intersects with the axis of the roadway.

5. The coal mine tunnel fracturing excavation method according to claim 4, characterized in that: The distance between two adjacent dividing grooves is set to 1 meter to 1.5 meters.

6. The coal mine tunnel fracturing excavation method according to claim 1, characterized in that: The rock formation information at least includes rock formation strength and rock formation structure; the step S10 of obtaining rock formation information of the target rock formation in the tunnel advance area includes the following steps: Opening a detection hole in the advance area of ​​the tunnel excavation working face; Installing a peep instrument and a strength tester in the detection hole to obtain the rock structure and rock strength in the advance area; A target rock formation is determined based on the rock formation structure and the rock formation strength.

7. The coal mine tunnel fracturing excavation method according to claim 6, characterized in that: In S20, fracturing parameters are determined according to the rock formation information, and fracturing holes and pressure relief holes are constructed on the working surface of the tunnel, wherein a plurality of fracturing holes are provided, and the plurality of fracturing holes are arranged at intervals around the detection hole.

8. The coal mine tunnel fracturing excavation method according to claim 1, characterized in that: The step S40, determining the fracturing section according to the fracturing parameters and the dividing groove, and fracturing all the fracturing sections in the fracturing hole one by one, wherein when liquid flows out of the pressure relief hole, the fracturing of the fracturing section is stopped, comprising the steps of: Determining each fracturing section in the fracturing hole according to the fracturing parameters and the dividing grooves; Filling the plugger into the fracturing hole to form a fracturing space in the fracturing section; When the pressure in the fracturing space reaches a preset pressure, the pressure in the fracturing space is maintained at the preset pressure for a preset time to complete the fracturing of the fracturing section.

9. The coal mine tunnel fracturing excavation method according to claim 8, characterized in that: The preset pressure is set to 30 MPa to 50 MPa.

10. The coal mine tunnel fracturing excavation method according to claim 1, characterized in that: The coal mine tunnel fracturing excavation method also includes the steps of: After the fracturing of the fracturing hole is completed, the fracturing hole is sealed, and the sealing depth is greater than or equal to 1 meter.

Images