Pressure relief and impact prevention method for protection of main roadway in final mining of working face

Abstract

A pressure relief and impact prevention method for protection of a main roadway in final mining of a working face, comprising: forming fracturing holes (2) in a roof rock stratum (1), wherein at least parts of the fracturing holes are located above a main roadway area (3), and applying pressure to the roof rock stratum by means of the fracturing holes to cause cracks in the portion of the roof rock stratum located above the main roadway area; and forming blasting holes (4) in the roof rock stratum, wherein in a horizontal projection plane, the projections of the blasting holes are located on the side of the projection of the main roadway area facing a coal mining working face (8), and carrying out blasting by means of the blasting holes to cause a gap in the portion of the roof rock stratum located between the main roadway area and the coal mining working face.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based upon and claims priority to Chinese Patent Application No. 202310186958.3, filed February 21, 2023, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0002] The present disclosure relates to the technical field of coal mining, and more particularly to a pressure-relief and anti-impact method for roadway protection at end-of-mining of a working face. BACKGROUND

[0003] Rock burst is a sudden and violent release of elastic deformation energy accumulated in rock mass under certain conditions, causing a phenomenon of rock to burst and eject, which may easily cause casualties and damages to roadways and equipment. In order to avoid the rock burst during coal mining, pressure-relief methods for the rock burst for different locations or environments such as coal seams, surrounding rocks, liberation layers and coal seam group mining conditions are provided respectively in the related art. However, a roadway area of the coal mine is arranged with a plurality of roadways, and an inter-roadway coal pillar has a high internal stress. At an end of working face mining, the roadway area is affected by a superposition of a working face advance support stress and a dynamic load disturbance and is easily to occur the rock burst. Therefore, the roadway area is a key area easily to occur the rock burst, and there is no pressure-relief and anti-impact method for roadway protection at end-of-mining of a working face in the related art. SUMMARY

[0004] The present disclosure aims to solve one of the technical problems existing in the related art to at least some extent. To this end, embodiments of the present disclosure provide a pressure-relief and anti-impact method for roadway protection at end-of-mining of a working face. The pressure-relief and anti-impact method for roadway protection at end-of-mining of the working face arranges a fracturing hole and a blasting hole in a roof rock layer. The fracturing hole is used to generate cracks in an area of the roof rock layer located above a roadway area, and the blasting hole is used to generate a gap in an area of the roof rock layer located between the roadway area and a coal mining working face, thereby playing a role in relieving pressure for the roadway area and avoiding a generation of rock burst in the roadway area.

[0005] A pressure-relief and anti-impact method for roadway protection at end-of- mining of a working face according to embodiments of the present disclosure includes: arranging a fracturing hole in a roof rock layer, where at least part of the fracturing hole is located above a roadway area, and pressure is applied to the roof rock layer through the fracturing hole to generate cracks in part of the roof rock layer located above the roadway area; and arranging a blasting hole in the roof rock layer, where in a horizontal projection plane, a projection of the blasting hole is located at a side of a projection of the roadway area facing a coal mining working face, and blasting is performed through the blasting hole to generate a gap in part of the roof rock layer located between the roadway area and the coal mining working face.

[0006] The pressure-relief and anti-impact method for roadway protection at end-of- mining of the working face according to embodiments of the present disclosure arranges the fracturing hole and the blasting hole in the roof rock layer. The fracturing hole is used to generate the cracks in part of the roof rock layer located above the roadway area to cut off a relation between the working face and the roadway area in a vertical direction. The blasting hole is used to generate the gap in part of the roof rock layer located between the roadway area and the coal mining working face to cut off a relation between the working face and the roadway area in a horizontal direction, thereby playing a role in relieving the pressure and protecting for the roadway area and avoiding a generation of rock burst in the roadway area.

[0007] In some embodiments, there are a plurality of roadways in the roadway area, the plurality of roadways are arranged at intervals in a left-right direction, and there is an interroadway coal pillar between two adjacent roadways, there is an inter-roadway coal pillar at such a side of the roadway closest to the coal mining working face that faces the coal mining working face, and the roadways and the inter-roadway coal pillars both extend in a front-back direction.

[0008] In some embodiments, arranging the fracturing hole in the roof rock layer specifically includes: arranging a chamber in a coal seam, where the chamber is located at a side of the roadway area in an extension direction of the roadway, and drilling the fracturing hole from the chamber into the roof rock layer, where at least part of the fracturing hole is located above an inter- roadway coal pillar in the roadway area.

[0009] In some embodiments, the fracturing hole is a hydraulic fracturing hole. Applying the pressure to the roof rock layer through the fracturing hole includes: supplying pressurized water into the fracturing hole in the chamber. The fracturing hole applies the pressure to the roof rock layer using a staged hydraulic fracturing process.

[0010] In some embodiments, multiple sub-holes of the fracturing hole located at a middle part in a left-right direction are arranged on a horizontal section, and multiple sub-holes of the fracturing hole located at an end part in the left-right direction are arranged on a horizontal section and a curved section.

[0011] In some embodiments, in the horizontal projection plane, a projection of the fracturing hole is arranged along an extension direction of a roadway. There are a plurality of fracturing holes, and the plurality of fracturing holes are arranged in sequence along a direction orthogonal to the extension direction of the roadway.

[0012] In some embodiments, the roadway extends in a front-back direction, the fracturing hole extends in the front-back direction, the plurality of fracturing holes are arranged in sequence in a left-right direction, and two adjacent fracturing holes are communicated or overlapped in an area of the roof rock layer where cracks are generated.

[0013] In some embodiments, arranging the blasting hole in the roof rock layer specifically includes: arranging a pressure-relief measure roadway in a coal seam. The pressure-relief measure roadway is located at a side of the roadway area facing the coal mining working face, and the blasting hole is drilled upward from the pressure-relief measure roadway.

[0014] In some embodiments, the blasting hole extends upward from the pressure-relief measure roadway and is inclined in a direction toward the roadway area.

[0015] In some embodiments, an angle between an extension direction of the blasting hole and a vertical direction is 40° to 75°.

[0016] In some embodiments, the angle between the extension direction of the blasting hole and the vertical direction is 40° to 50°.

[0017] In some embodiments, the roof rock layer includes a mudstone layer, a first fine sandstone layer, a siltstone layer, and a second fine sandstone layer arranged in sequence from bottom to top. The blasting hole penetrates the mudstone layer, the first fine sandstone layer and the siltstone layer in sequence from bottom to top, and extends into the second fine sandstone layer, and part of the blasting hole in the first fine sandstone layer, the siltstone layer and the second fine sandstone layer is a charging section. At least part of the fracturing hole is located in the second fine sandstone layer.

[0018] In some embodiments, the roof rock layer further includes another mudstone layer located above the second fine sandstone layer.

[0019] In some embodiments, a horizontal section of the fracturing hole and an end of a curved section of part of the fracturing hole are located in a middle part of the second fine sandstone layer in an up-down direction.

[0020] In some embodiments, the pressure-relief measure roadway is arranged along an extension direction of a roadway, there are a plurality of blasting holes, and the plurality of blasting holes are arranged at intervals along an extension direction of the pressure-relief measure roadway. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] FIG. 1 is a schematic diagram of a plane structure of a mine in embodiments of the present disclosure.

[0022] FIG. 2 is a front cross-sectional view of a mine in embodiments of the present disclosure.

[0023] Reference numerals:

[0024] 1. roof rock layer; 11. mudstone layer; 12. first fine sandstone layer; 13. siltstone layer; 14. second fine sandstone layer; 2. fracturing hole; 3. roadway area; 31. roadway; 4. blasting hole; 41. charging section; 42. sealing section; 5. coal seam; 6. chamber; 7. pressure relief measure roadway; 8. coal mining working face; and 81. stop mining line. DETAILED DESCRIPTION

[0025] Embodiments of the present disclosure will be described in detail below, and examples of embodiments are illustrated in the drawings. Embodiments described below with reference to the drawings are illustrative, are intended to explain the present disclosure, and cannot be construed to limit the present disclosure.

[0026] A pressure-relief and anti-impact method for roadway protection at end-of- mining of a working face according to embodiments of the present disclosure describes below with reference to drawing 1 to drawing 2.

[0027] As shown in FIG. 1 to FIG. 2, a pressure-relief and anti-impact method for roadway protection at end-of-mining of a working face according to embodiments of the present disclosure includes arranging a fracturing hole 2 in a roof rock layer 1, where at least part of the fracturing hole 2 is located above a roadway area 3, and pressure is applied to the roof rock layer 1 through the fracturing hole 2 to generate cracks in part of the roof rock layer 1 located above the roadway area 3; and arranging a blasting hole 4 in the roof rock layer 1, where in a horizontal projection plane, a projection of the blasting hole 4 is located at a side of a projection of the roadway area 3 facing a coal mining working face 8, and blasting is performed through the blasting hole 4 to generate a gap in part of the roof rock layer 1 located between the roadway area 3 and the coal mining working face 8.

[0028] As shown in FIG. 2, a mine includes a roof rock layer 1 and a coal seam 5, and the roof rock layer 1 is located above the coal seam 5. As shown in FIG. 1, the mine has a roadway area 3 and a coal mining working face 8 arranged at intervals in a left-right direction, and the coal mining working face 8 is located at a left side of the roadway area 3. A right end of the coal mining working face 8 is a stop mining line 81. There are a plurality of roadways 31, for example, five roadways 31 in the roadway area 3. The five roadways 31 are arranged at intervals in the left-right direction, and there is an inter-roadway coal pillar between two adjacent roadways 31. There is an inter-roadway coal pillar at such a side of the roadway 31 closest to the coal mining working face 8 that faces the coal mining working face 8. In FIG. 1, a left side of the roadway 31 at a far left end has an inter-roadway coal pillar, and the roadways 31 and the inter-roadway coal pillars both extend in a front-back direction.

[0029] Before mining the coal mining working face 8, the fracturing hole 2 is arranged in part of the roof rock layer 1 located above the roadway area 3, and the blasting hole 4 is arranged in part of the roof rock layer 1 located between the roadway area 3 and the coal mining working face 8, and then the pressure is applied to the roof rock layer 1 through the fracturing hole 2 to generate the cracks in part of the roof rock layer 1 located above the roadway area 3, and the blasting is performed through the blasting hole 4 to generate the cracks in part of the roof rock layer 1 located between the roadway area 3 and the coal mining working face 8.

[0030] The pressure-relief and anti-impact method for roadway protection at end-of- mining of the working face according to embodiments of the present disclosure arranges the fracturing hole and the blasting hole in the roof rock layer. The fracturing hole is used to generate the cracks in part of the roof rock layer located above the roadway area to cut off a relation between the working face and the roadway area in a vertical direction. The blasting hole is used to generate the gap in part of the roof rock layer located between the roadway area and the coal mining working face to cut off a relation between the working face and the roadway area in a horizontal direction, thereby playing a role in relieving the pressure and protecting for the roadway area. When the coal mining working face is mined, a disturbance of a mining operation to the roadway is significantly weakened, reducing dynamic and static load sources in the roadway area, thereby avoiding a generation of rock burst in the roadway area.

[0031] In some embodiments, in the horizontal projection plane, a projection of the fracturing hole 2 is arranged along an extension direction of a roadway 31. There are a plurality of fracturing holes 2, and the plurality of fracturing holes 2 are arranged in sequence along a direction orthogonal to the extension direction of the roadway 31.

[0032] As shown in FIG. 1 and FIG. 2, the roadway 31 extends in a front-back direction, the fracturing hole 2 extends in the front-back direction. There are the plurality of fracturing holes 2, the plurality of fracturing holes 2 are arranged in sequence in a left-right direction, and two adjacent fracturing holes 2 are communicated or overlapped in an area of the roof rock layer 1 where cracks are generated.

[0033] In some embodiments, arranging the fracturing hole 2 in the roof rock layer 1 specifically includes arranging a chamber 6 in a coal seam 5, where the chamber 6 is located at a side of the roadway area 3 in an extension direction of the roadway 31, and drilling the fracturing hole 2 from the chamber 6 into the roof rock layer 1, where at least part of the fracturing hole 2 is located above an inter-roadway coal pillar in the roadway area 3.

[0034] As shown in FIG. 1 and FIG. 2, before mining the coal mining working face 8, the chamber 6 is arranged in part of the coal seam 5 located in front of the roadway area 3, and one roadway 31 extends forward to outside of the roadway area 3 and is communicated to the chamber 6, preferably communicating one roadway 31 located at a middle part in a left-right direction among the plurality of roadways 31. The fracturing hole 2 is drilled from the chamber 6 into the roof rock layer 1, and the fracturing hole 2 includes a horizontal section and a curved section. The horizontal section is located at an end of a corresponding curved section, and the horizontal section is located above a corresponding inter-roadway coal pillar in the roadway area 3. The horizontal section extends straightly in the front-back direction, and the curved section communicates the chamber 6 and a corresponding horizontal section. As shown in FIG. 2, a circular part of the fracturing hole 2 in FIG. 2 is a cross-sectional shape of the horizontal section in a front cross-sectional view, and a curved part of the fracturing hole 2 in FIG. 2 is a projection of a center line of the curved section in the front cross-sectional view.

[0035] Since the pressure-relief method for the rock burst according to embodiments of the present disclosure is used in the roadway area, a manner of drilling the fracturing hole from the chamber may avoid a safety impact of ground fracturing on the roadway compared to a manner of drilling the fracturing hole from the ground well in the related art.

[0036] In some embodiments, the fracturing hole 2 is a hydraulic fracturing hole 2. Applying the pressure to the roof rock layer 1 through the fracturing hole 2 includes supplying pressurized water into the fracturing hole 2 in the chamber 6. The fracturing hole 2 applies the pressure to the roof rock layer 1 using a staged hydraulic fracturing process.

[0037] As shown in FIG. 1, the fracturing hole 2 is the hydraulic fracturing hole 2. The pressurized water is supplied into the fracturing hole 2 in the chamber 6, so that the fracturing hole 2 applies the pressure to the roof rock layer 1 using the staged hydraulic fracturing process. The fracturing hole 2 has multiple sub-holes, and multiple sub-holes are arranged in sequence from back to front, and multiple sub-holes apply the pressure to the roof rock layer 1 in sequence from back to front. Since the plurality of fracturing holes 2 are arranged at different positions in the left-right direction compared to the chamber 6, among the plurality of fracturing holes 2, multiple sub-holes of the fracturing hole 2 located at a middle part in a left-right direction are arranged on a horizontal section, and multiple sub-holes of the fracturing hole 2 located at an end part in the left-right direction are arranged on a horizontal section and a curved section.

[0038] It may be understood that the fracturing hole is not limited to being the hydraulic fracturing hole. In other embodiments, high-pressure gas is supplied into the fracturing hole, so that the fracturing hole applies the pressure to the roof rock layer.

[0039] In some embodiments, arranging the blasting hole 4 in the roof rock layer 1 specifically includes arranging a pressure-relief measure roadway 7 in a coal seam 5. The pressure-relief measure roadway 7 is located at a side of the roadway area 3 facing the coal mining working face 8, and the blasting hole 4 is drilled upward from the pressure-relief measure roadway 7.

[0040] As shown in FIG. 1 and FIG. 2, before mining the coal mining working face 8, the pressure-relief measure roadway 7 is arranged in part of the coal seam 5 located at a left side of the roadway area 3, and the blasting hole 4 is drilled upward from the pressure-relief measure roadway 7.

[0041] It may be understood that the pressure-relief measure roadway is not limited to being arranged separately before mining the coal mining working face. In other embodiments, the pressure-relief measure roadway may be other existing roadways.

[0042] In some embodiments, the pressure-relief measure roadway 7 is arranged along an extension direction of a roadway 31, there are a plurality of blasting holes 4, and the plurality of blasting holes 4 arranged at intervals along an extension direction of the pressure-relief measure roadway 7.

[0043] As shown in FIG. 1, the pressure-relief measure roadway 7 extends in the front- back direction, and there are the plurality of blasting holes 4. The plurality of blasting holes 4 are arranged at intervals along the extension direction of the pressure-relief measure roadway 7, and a crack area formed by two adjacent blasting holes 4 are communicated or overlapped.

[0044] It may be understood that a center line of the pressure-relief measure roadway is not limited to being parallel to a center line of the roadway. In other embodiments, there is an acute angle between the center line of the pressure-relief measure roadway and the center line of the roadway.

[0045] In some embodiments, the blasting hole 4 extends upward from the pressure relief measure roadway 7 and is inclined in a direction toward the roadway area 3.

[0046] As shown in FIG. 2, the blasting hole 4 extends upward from the pressure-relief measure roadway 7 and is inclined to the right. In some embodiments, an angle between an extension direction of the blasting hole 4 and a vertical direction is 40° to 75°. In some embodiments, the angle between the extension direction of the blasting hole 4 and the vertical direction is 40° to 50°, for example, 40°, 50°, or 45°.

[0047] It may be understood that the blasting hole is not limited to being inclined. In other embodiments, the blasting hole extends along an arrangement direction.

[0048] In some embodiments, the roof rock layer 1 includes a mudstone layer 11, a first fine sandstone layer 12, a siltstone layer 13 and a second fine sandstone layer 14 arranged in sequence from bottom to top.

[0049] The blasting hole 4 penetrates the mudstone layer 11, the first fine sandstone layer 12 and the siltstone layer 13 in sequence from bottom to top, and extends into the second fine sandstone layer 14, and part of the blasting hole 4 in the first fine sandstone layer 12, the siltstone layer 13 and the second fine sandstone layer 14 is a charging section 41.

[0050] At least part of the fracturing hole 2 is located in the second fine sandstone layer 14.

[0051] As shown in FIG. 2, the roof rock layer 1 includes the mudstone layer 11, the first fine sandstone layer 12, the siltstone layer 13 and the second fine sandstone layer 14 arranged in sequence from bottom to top.

[0052] In some embodiments, the roof rock layer 1 further includes another mudstone layer 11 located above the second fine sandstone layer 14.

[0053] A horizontal section of the fracturing hole 2 is located in the second fine sandstone layer 14, and an end of a curved section of part of the fracturing hole 2 is also located in the second fine sandstone layer 14. In some embodiments, the horizontal section of the fracturing hole 2 and the end of the curved section of part of the fracturing hole 2 are located in a middle part of the second fine sandstone layer 14 in an up-down direction.

[0054] The blasting hole 4 penetrates the mudstone layer 11, the first fine sandstone layer 12 and the siltstone layer 13 in sequence from bottom to top, and extends into the second fine sandstone layer 14. In some embodiments, a top of the blasting hole 4 is not lower than the horizontal section of the fracturing hole 2. The blasting hole 4 includes the charging section 41 and a sealing section 42. Part of the blasting hole 4 in the first fine sandstone layer 12, the siltstone layer 13 and the second fine sandstone layer 14 is the charging section 41, and the charging section 41 is filled with explosives or gunpowder. Part of the blasting hole 4 in the mudstone layer 11 and the coal seam 5 is the sealing section 42, and the sealing section 42 is used to seal the explosives or gunpowder in the charging section 41.

[0055] In the description of the present disclosure, it is necessary to understand that terms such as “center”, “longitudinal”, “lateral”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, and “outside”, indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for convenience of describing the present disclosure and simplifying the description, rather than indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present disclosure.

[0056] In addition, terms such as “first” and “second” are used herein for distinction only and should not be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Thus, the feature limited with “first” and “second” may explicitly or implicitly include at least one of the features. In the description of the present disclosure, “a plurality of” means at least two, for example, two, three, etc., unless otherwise clearly and specifically limited.

[0057] In the present disclosure, unless otherwise clearly specified and limited, a first feature being “on” or “below” a second feature may mean that the first feature is in direct contact with the second feature, or that the first and second features are in indirect contact via an intermediate medium. Furthermore, a first feature “on”, “above” and “on top of” a second feature may mean that the first feature is right above or obliquely above the second feature, or simply means that the first feature is at a higher horizontal height than the second feature. A first feature being “below”, “under” and “on bottom of” a second feature may mean that the first feature is right below or obliquely below the second feature, or simply means that the first feature is at a smaller horizontal height than the second feature.

[0058] In the present disclosure, terms such as “one embodiment”, “some embodiments”, “an example”, “a specific example”, or “some examples” mean that a specific feature, structure, material or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present disclosure. In the present specification, schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. In addition, those skilled in the art may combine and associate different embodiments or examples and features of different embodiments or examples described in the present specification without mutually inconsistent.

[0059] Although the above embodiments have been shown and described, it is to be understood that the above embodiments are illustrative and are not to be construed as limitations on the present disclosure, and changes, modifications, alternatives and variations of the above embodiments by those ordinary skilled in the art are all within the scope of protection of the present disclosure.

Claims

1. A pressure-relief and anti-impact method for roadway protection at end-of-mining of a working face, comprising:arranging a fracturing hole (2) in a roof rock layer (1), wherein at least part of the fracturing hole (2) is located above a roadway area (3), and pressure is applied to the roof rock layer (1) through the fracturing hole (2) to generate cracks in part of the roof rock layer (1) located above the roadway area (3); andarranging a blasting hole (4) in the roof rock layer (1), wherein in a horizontal projection plane, a projection of the blasting hole (4) is located at a side of a projection of the roadway area (3) facing a coal mining working face (8), and blasting is performed through the blasting hole (4) to generate a gap in part of the roof rock layer (1) located between the roadway area (3) and the coal mining working face (8).

2. The pressure-relief and anti-impact method for roadway protection at end-of-mining of the working face according to claim 1, wherein there are a plurality of roadways (31) in the roadway area (3), the plurality of roadways (31) are arranged at intervals in a left-right direction, and there is an inter-roadway coal pillar between two adjacent roadways (31), there is an interroadway coal pillar at such a side of the roadway (31) closest to the coal mining working face (8) that faces the coal mining working face (8), and the roadways (31) and the inter-roadway coal pillars both extend in a front-back direction.

3. The pressure-relief and anti-impact method for roadway protection at end-of-mining of the working face according to claim 1, wherein arranging the fracturing hole (2) in the roof rock layer (1) comprises:arranging a chamber (6) in a coal seam (5), wherein the chamber (6) is located at a side of the roadway area (3) in an extension direction of the roadway (31), anddrilling the fracturing hole (2) from the chamber (6) into the roof rock layer (1), wherein at least part of the fracturing hole (2) is located above an inter-roadway coal pillar in the roadway area (3).

4. The pressure-relief and anti-impact method for roadway protection at end-of-mining of the working face according to claim 3, wherein the fracturing hole (2) is a hydraulic fracturing hole (2); andapplying the pressure to the roof rock layer (1) through the fracturing hole (2) comprises: supplying pressurized water into the fracturing hole (2) in the chamber (6), wherein thefracturing hole (2) applies the pressure to the roof rock layer (1) using a staged hydraulic fracturing process.

5. The pressure-relief and anti-impact method for roadway protection at end-of-mining of the working face according to claim 4, wherein multiple sub-holes of the fracturing hole (2) located at a middle part in a left-right direction are arranged on a horizontal section, and multiple sub-holes of the fracturing hole (2) located at an end part in the left-right direction are arranged on a horizontal section and a curved section.

6. The pressure-relief and anti-impact method for roadway protection at end-of-mining of the working face according to claim 1, wherein in the horizontal projection plane, a projection of the fracturing hole (2) is arranged along an extension direction of a roadway (31); andthere are a plurality of fracturing holes (2), and the plurality of fracturing holes (2) are arranged in sequence along a direction orthogonal to the extension direction of the roadway (31).

7. The pressure-relief and anti-impact method for roadway protection at end-of-mining of the working face according to claim 6, wherein the roadway (31) extends in a front-back direction, the fracturing hole (2) extends in the front-back direction, the plurality of fracturing holes (2) are arranged in sequence in a left-right direction, and two adjacent fracturing holes (2) are communicated or overlapped in an area of the roof rock layer (1) where cracks are generated.

8. The pressure-relief and anti-impact method for roadway protection at end-of-mining of the working face according to claim 1, wherein arranging the blasting hole (4) in the roof rock layer (1) comprises:arranging a pressure-relief measure roadway (7) in a coal seam (5), wherein the pressurerelief measure roadway (7) is located at a side of the roadway area (3) facing the coal mining working face (8), and the blasting hole (4) is drilled upward from the pressure-relief measure roadway (7).

9. The pressure-relief and anti-impact method for roadway protection at end-of-mining of the working face according to claim 8, wherein the blasting hole (4) extends upward from the pressure-relief measure roadway (7) and is inclined in a direction toward the roadway area (3).

10. The pressure-relief and anti-impact method for roadway protection at end-of-mining of the working face according to claim 9, wherein an angle between an extension direction of the blasting hole (4) and a vertical direction is 40° to 75°.

11. The pressure-relief and anti-impact method for roadway protection at end-of-mining of the working face according to claim 10, wherein the angle between the extension directionof the blasting hole (4) and the vertical direction is 40° to 50°.

12. The pressure-relief and anti-impact method for roadway protection at end-of-mining of the working face according to claim 9, wherein the roof rock layer (1) comprises a mudstone layer (11), a first fine sandstone layer (12), a siltstone layer (13) and a second fine sandstone layer (14) arranged in sequence from bottom to top;the blasting hole (4) penetrates the mudstone layer (11), the first fine sandstone layer (12) and the siltstone layer (13) in sequence from bottom to top, and extends into the second fine sandstone layer (14), and part of the blasting hole (4) in the first fine sandstone layer (12), the siltstone layer (13) and the second fine sandstone layer (14) is a charging section (41); andat least part of the fracturing hole (2) is located in the second fine sandstone layer (14).

13. The pressure-relief and anti-impact method for roadway protection at end-of-mining of the working face according to claim 10, wherein the roof rock layer (1) further comprises another mudstone layer located above the second fine sandstone layer (14).

14. The pressure-relief and anti-impact method for roadway protection at end-of-mining of the working face according to claim 10, a horizontal section of the fracturing hole (2) and an end of a curved section of part of the fracturing hole (2) are located in a middle part of the second fine sandstone layer (14) in an up-down direction.

15. The pressure-relief and anti-impact method for roadway protection at end-of-mining of the working face according to claim 8, wherein the pressure-relief measure roadway (7) is arranged along an extension direction of a roadway (31), there are a plurality of blasting holes (4), and the plurality of blasting holes (4) are arranged at intervals along an extension direction of the pressure-relief measure roadway (7).

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