A prevention and control method for rock burst during the driving and breakthrough of a small coal pillar adjacent to an airway

Abstract

The present invention discloses a method for preventing and controlling rock burst during the driving and breakthrough of a small coal pillar adjacent to an air roadway. The breakthrough form of the working face is determined, and the distance between the driving heading of the driving and breakthrough roadway and the breakthrough point is monitored. If the distance between the driving heading and the breakthrough point is between the starting distance of penetration and the connection distance, coal seam borehole pressure relief is carried out on the breakthrough area and the production rib area at the breakthrough point. If the distance between the driving heading and the breakthrough point is between the connection distance and the end distance of breakthrough, short-distance coal seam borehole pressure relief is carried out by constructing a heading hole, a side-front hole in front of the driving heading, and a rib hole at the rear production rib at the driving heading. Continue driving. When the driving distance reaches the maximum driving distance, repeat the short-distance coal seam borehole pressure relief by constructing a heading hole, a side-front hole, and a rib hole at the rear production rib at the driving heading to form a short driving, short support, and short pressure relief mode. If the distance between the driving heading and the breakthrough point is less than the end distance of breakthrough, a heading penetration hole is constructed at the driving heading before each driving until the driving and breakthrough are completed.

Description

Technical Field

[0001] The present invention belongs to the technical field of coal mine safety mining methods, and particularly relates to a method for preventing and controlling rock bursts during the driving and connection of gob-side small coal pillar roadway. Background Technique

[0002] Rock burst has gradually become one of the main disasters restricting the high-yield and high-efficiency production of medium and deep mines. In recent years, from the perspectives of reducing the abutment pressure during the excavation of gob-side roadway and saving coal resources, the gob-side small coal pillar roadway driving has been gradually widely promoted in the Inner Mongolia-Shaanxi region. During the driving of gob-side roadway, there are phenomena such as difficult driving, rib spalling, and frequent coal bumps. Under the influence of factors such as goaf and advanced abutment pressure, a high stress concentration is likely to form in the connection area. When the stress-bearing limit is reached, it is extremely easy to cause rock bursts in the driving face.

[0003] In order to reduce the risk of rock bursts, the key lies in how to reduce the stress concentration degree in the connection area and transfer the stress to the deep part of the coal body, so as to ensure that the working face is in a low stress level during driving. The present invention comprehensively considers influencing factors such as gob-side small coal pillar driving technology, pressure relief efficiency, and pressure relief effect, and proposes a method for preventing and controlling rock bursts during the driving and connection of gob-side small coal pillar roadway, which has important significance for the safe and efficient production of the working face. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for preventing and controlling rock bursts during the driving and connection of gob-side small coal pillar roadway, forming a fixed driving and connection mode for gob-side roadway, which can effectively solve the problem of preventing and controlling rock bursts during the driving and connection of gob-side roadway.

[0005] The technical solution adopted by the present invention is as follows: A method for preventing and controlling rock bursts during the driving and connection of gob-side small coal pillar roadway, and the specific operation steps are as follows:

[0006] Combined with the gob-side driving method of the working face, determine the connection form of the working face, and real-time monitor the distance between the driving heading of the driving and connecting roadway and the connection point;

[0007] If it is monitored that the distance between the driving heading and the connection point is between the starting distance of penetration and the connection distance, carry out coal seam borehole pressure relief on the heading area and the rib area of the production side at the connection point;

[0008] If it is monitored that the distance between the driving heading and the connection point is between the connection distance and the end distance of penetration, carry out short-distance coal seam borehole pressure relief by constructing heading holes, side front holes in front of the driving heading and rear rib holes in the production side at the driving heading;

[0009] Continue driving, and timely support. When the driving distance reaches the maximum driving distance, repeat to carry out short-distance coal seam borehole pressure relief by constructing heading holes, side front holes and rear rib holes in the production side at the driving heading, forming a "short driving - short support - short pressure relief" mode;

[0010] If it is monitored that the distance between the driving face and the breakthrough point is less than the distance to the end of the breakthrough, a breakthrough hole shall be constructed at the driving face before each driving until the breakthrough is achieved.

[0011] The features of the present invention also lie in that

[0012] According to the driving method of the gob-side entry retaining roadway and the location of the breakthrough point, the breakthrough form is determined, mainly including two forms: linear breakthrough and broken-line breakthrough.

[0013] If linear breakthrough is adopted, a face hole and a side-front hole shall be constructed at the breakthrough point face, and a rib hole shall be constructed at the production rib behind the breakthrough point; if broken-line breakthrough is adopted, a face hole shall be constructed at the breakthrough point face, and a rib hole shall be constructed at the production rib of the broken-line roadway.

[0014] The starting distance of the breakthrough is 150 - 200 m, and the connection distance is 70 - 100 m; at least 5 breakthrough point face holes shall be constructed in the area of the breakthrough point face; if linear breakthrough is adopted, 3 - 5 breakthrough point side-front holes shall be constructed at the breakthrough point face in the area of the breakthrough point rib, and rib holes shall be constructed within 50 m of the production rib from the breakthrough point; if broken-line breakthrough is adopted, rib holes shall be constructed within 50 m of the production rib of the broken-line roadway from the breakthrough point, and the pressure relief range is controlled within 1 - 2 m outside the support design area of the breakthrough roadway.

[0015] The depth of the breakthrough point face hole constructed at the breakthrough point face is 40 - 50 m, along the axis direction of the roadway; if linear breakthrough is adopted, the depth of the breakthrough point side-front hole is 25 - 30 m, with an angle of 20° - 40° with the axis direction of the roadway, and the depth of the production rib hole is 15 - 20 m, perpendicular to the axis direction of the roadway; if broken-line breakthrough is adopted, the depth of the production rib hole of the broken-line roadway is 20 - 40 m, perpendicular to the axis direction of the broken-line roadway.

[0016] The distance to the end of the breakthrough is 30 - 40 m. At least 3 driving face holes and 1 - 3 driving face side-front holes shall be constructed at the driving face, and rib holes shall be constructed within 50 m of the production rib from the driving face.

[0017] The depth of the driving face hole at the driving face is 25 - 30 m, along the axis direction of the roadway, the depth of the driving face side-front hole is 20 - 25 m, with an angle of 20° - 40° with the axis direction of the roadway, and the depth of the production rib hole behind the driving face is 15 - 20 m, perpendicular to the axis direction of the roadway.

[0018] The maximum driving distance is less than 5 - 10 m of the depth of the driving face hole.

[0019] For the pressure relief of the coal seam borehole, the large-diameter borehole adopted has a diameter of 150 - 200 mm, a spacing of 1 - 2 m, and a distance of 1 - 2 m from the roadway floor.

[0020] The beneficial effects of the present invention are as follows: A method for preventing and controlling rock bursts during the driving and breakthrough of a small coal pillar adjacent to an airway. By determining the construction timing of large-diameter boreholes in the coal seam and the driving mode according to the breakthrough form in the driving and breakthrough area, the stress concentration degree in the driving and breakthrough area is reduced in advance, and the stress is transferred to the deep part of the coal body, which is beneficial to alleviating the problem of high static load. Compared with the prior art, using the method of the present invention significantly improves the driving and breakthrough efficiency and ensures the personal safety of personnel during driving. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic flow chart of the prevention and control method of the present invention;

[0022] Figure 2(a) is a schematic diagram of the straight-through breakthrough of the working face of the present invention;

[0023] Figure 2(b) is a schematic diagram of the T-shaped broken-line breakthrough of the working face of the present invention;

[0024] Figure 2(c) is a schematic diagram of the L-shaped broken-line breakthrough of the working face of the present invention;

[0025] Figure 3(a) is a schematic plan view of the layout of pressure relief holes at the breakthrough point of the straight-through breakthrough of the working face of the present invention;

[0026] Figure 3(b) is a schematic plan view of the layout of pressure relief holes at the breakthrough point of the T-shaped broken-line breakthrough of the working face of the present invention;

[0027] Figure 3(c) is a schematic plan view of the layout of pressure relief holes at the breakthrough point of the L-shaped broken-line breakthrough of the working face of the present invention;

[0028] Figure 4(a) is a schematic diagram of the regular three-flower arrangement of the face holes at the breakthrough point of the present invention;

[0029] Figure 4(b) is a schematic diagram of the inverted three-flower arrangement of the face holes at the breakthrough point of the present invention;

[0030] Figure 5 It is a schematic plan view of the layout of pressure relief holes at the driving face of the working face of the present invention;

[0031] Figure 6(a) is a schematic diagram of the regular three-flower arrangement of the face holes at the driving face of the present invention;

[0032] Figure 6(b) is a schematic diagram of the inverted three-flower arrangement of the face holes at the driving face of the present invention;

[0033] In the figure: 1 - coal mining face; 2 - goaf; 3 - solid coal roadway of the mined - out working face; 4 - sectional small coal pillar; 5 - gob - side entry; 6 - breakthrough point; 7 - tunneling heading; 8 - broken - line roadway; 9 - heading hole at the breakthrough point; 10 - side - front hole at the breakthrough point; 11 - production rib hole behind the breakthrough point; 12 - production rib hole of the broken - line roadway; 13 - heading hole at the tunneling heading; 14 - side - front hole at the tunneling heading; 15 - production rib hole behind the tunneling heading; S1 - breakthrough area of the breakthrough point; S2 - rib area of the breakthrough point; HD1 - hole depth of the heading hole at the breakthrough point; HD2 - hole depth of the side - front hole; HD3 - hole depth of the rib hole; HD4 - hole depth of the rib hole of the broken - line roadway; HD5 - hole depth of the heading hole at the tunneling heading. Detailed implementation manners

[0034] In order to enable those skilled in the art of this technology to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0035] The present invention will be further described in detail below with reference to the accompanying drawings:

[0036] According to Figure 1 As shown, the flow chart of the prevention and control method of the present invention includes the following steps:

[0037] Step 101: Combine the gob - side tunneling method of the working face to determine the breakthrough form of the working face, and continuously monitor the distance L between the tunneling heading of the tunneling breakthrough roadway and the breakthrough point in real - time.

[0038] Specifically, according to the tunneling method of the small - coal - pillar gob - side entry and the position of the breakthrough point, the breakthrough form is determined, mainly including two forms: linear breakthrough (as shown in Fig. 2(a)) and broken - line breakthrough (as Figure 2(b) - Figure 2(c) shown). The whole process of the tunneling breakthrough of the present invention occurs in the gob - side entry 5 of the working face to be mined, manifested as the tunneling heading 7 continuously approaching the breakthrough point 6. If the broken - line breakthrough is adopted, there is a broken - line roadway 8; 2 is the goaf of the mined - out working face, 3 is the solid - coal roadway of the mined - out working face, 4 is the sectional small coal pillar between the mined - out working face and the working face to be mined, 6 is the breakthrough point designed for the gob - side entry, and 7 is the position of the tunneling heading of the gob - side entry under construction.

[0039] Step 102: If it is monitored that the distance L between the tunneling heading and the breakthrough point is between the starting breakthrough distance L1 and the connection distance L2, perform coal - seam borehole pressure relief on the heading area S1 and the production rib area S2 at the breakthrough point.

[0040] Specifically, the through - starting distance L1 is 150 - 200 m, and the connecting distance L2 is 70 - 100 m.

[0041] Specifically, according to Figure 3(a) - Figure 3(c) As shown, in the heading area S1 of the breakthrough point, at least 5 breakthrough - point heading holes 9 need to be constructed at the heading of the breakthrough point. The depth HD1 of the breakthrough - point heading hole is 40 - 50 m along the axis direction of the roadway. As Figure 4(a) - Figure 4(b) shown, according to the cross - section size of the adjacent - to - air roadway 5, the breakthrough - point heading holes 9 can be arranged in a regular triangular pattern / inverted triangular pattern, and evenly arranged between 1 - 2 m from the roadway floor.

[0042] Specifically, if a linear breakthrough is adopted, in the side area S2 of the breakthrough point, 3 - 5 breakthrough - point side - front holes 10 need to be constructed at the heading of the breakthrough point. The depth HD2 of the breakthrough - point side - front hole is 25 - 30 m, and the angle with the axis direction of the roadway is 20° - 40°. In the production side within 50 m from the breakthrough point, a breakthrough - point rear production - side - help hole 11 needs to be constructed. The depth HD3 of the side - help hole is 15 - 20 m, perpendicular to the axis direction of the roadway.

[0043] Specifically, if a zigzag breakthrough is adopted, in the production side of the zigzag roadway within 50 m from the breakthrough point in the side area S2 of the breakthrough point, a zigzag - roadway production - side - help hole 12 needs to be constructed. The depth HD4 of the zigzag - roadway side - help hole is 20 - 40 m, perpendicular to the axis direction of the zigzag roadway. The pressure - relief range is controlled within 1 - 2 m outside the support design area of the breakthrough roadway. Example: When the support range of the production side of the adjacent - to - air roadway reaches 4 m, the side - help hole starts to be constructed at 5 - 6 m from the breakthrough point on the production side of the zigzag roadway, and the designed support area is not pressure - relieved.

[0044] Step 103, if it is monitored that the distance L between the driving heading and the breakthrough point is between the connecting distance L2 and the breakthrough - end distance L3, according to Figure 5 shown, at the driving heading, a driving - heading heading hole 13, a driving - heading side - front hole 14, and a driving - heading rear production - side - help hole 5 are constructed for short - distance coal - seam borehole pressure - relief.

[0045] Specifically, the breakthrough - end distance is 30 - 40 m. At least 3 driving - heading heading holes 13 and 1 - 3 driving - heading side - front holes 14 are constructed at the driving heading, and a side - help hole 15 is constructed in the production side within 50 m from the driving heading.

[0046] Specifically, the depth HD5 of the driving - heading heading hole is 25 - 30 m along the axis direction of the roadway. The depth HD2 of the side - front hole of the driving - heading side - front hole 14 is 20 - 25 m, and the angle with the axis direction of the roadway is 20° - 40°. The depth HD3 of the driving - heading rear production - side - help hole 15 is 15 - 20 m, perpendicular to the axis direction of the roadway.

[0047] Specifically, as Figure 6(a) - Figure 6(b)As shown in the figure, according to the cross-sectional dimensions of the airway 5 in the goaf, the heading holes 13 at the heading face can be arranged in a regular or inverted equilateral triangle pattern, and evenly arranged between 1 and 2 m from the roadway floor.

[0048] Step 104: Continue tunneling and timely support. When the tunneling distance reaches the maximum tunneling distance, repeat the previous step to form a "short tunneling, short support, and short pressure relief" mode.

[0049] Specifically, the maximum tunneling distance is less than the hole depth of the heading holes at the heading face by 5 - 10 m. The "short tunneling, short support, and short pressure relief" mode is as follows: First, tunnel a maximum of 15 - 20 m and support in a timely manner, and then relieve pressure for 25 - 30 m.

[0050] Step 105: If it is monitored that the distance L between the heading face of the tunneling airway and the breakthrough point is less than the distance L4 at the end of the breakthrough, construct heading through holes at the heading face before each tunneling until the tunneling is completed.

[0051] In addition, the large-diameter boreholes used for coal seam borehole pressure relief have a diameter of 150 - 200 mm, the spacing between the holes on the rib is 1 - 2 m, and the distance from the roadway floor is 1 - 2 m.

[0052] Example 1

[0053] In a certain mine in the Ordos area, the buried depth of the coal seam in the working face is about 600 m, the average thickness of the coal seam is 6 m, the lithology of the coal seam roof is mainly sandy mudstone and siltstone, followed by fine-grained sandstone; the designed width of the goaf airway 5 of the goaf working face 1 is 5.8 m, the height is 3.7 m, and the support depth of the rib is 4.3 m. This working face is in an L-shaped broken-line through form, and the goaf airway breaks through at the position where it intersects with the main withdrawal roadway. Therefore, the main withdrawal roadway is used as the broken-line roadway in this example. During the tunneling and breakthrough of the small coal pillar in the example working face, the stress concentration degree of the coal body is relatively high, the tunneling is difficult and accompanied by frequent coal bump sounds. Therefore, it is necessary to propose a prevention and control method for rock burst during tunneling and breakthrough for this type of small coal pillar working face. The specific implementation parameters are as follows:

[0054] Implement real-time monitoring of the distance L between the heading face of the tunneling and breakthrough roadway and the breakthrough point.

[0055] When the distance L between the heading face of the tunneling and breakthrough roadway in the working face and the breakthrough point is between 80 m and 150 m, construct 5 heading holes 9 at the breakthrough point 6. The hole depth HD1 of the heading holes at the breakthrough point is 50 m. Along the roadway axis direction, arrange them in a regular equilateral triangle pattern. The lower layer of holes is 1.2 m from the roadway floor, and the upper layer of holes is 1.8 m from the roadway floor; construct rib holes 12 on the production rib of the broken-line roadway within a range of 50 m from the breakthrough point in the main withdrawal roadway. The hole depth HD4 of the rib holes of the broken-line roadway adopts two hole depths of 20 m and 40 m. Start constructing the rib holes at a distance of 5 - 6 m from the breakthrough point, and construct 1 40 - m hole every 4 20 - m holes, perpendicular to the axis of the broken-line roadway.

[0056] When the distance L between the driving heading of the driving-through roadway in the working face and the breakthrough point is between 40 m and 80 m, a driving-heading hole 13 is constructed at the driving heading. The depth HD5 of the driving-heading hole is 30 m. Along the axis direction of the roadway, a regular triangular pattern is adopted. The lower layer of holes is 1.2 m away from the roadway floor, and the upper layer of holes is 1.8 m away from the roadway floor; two side-front holes 14 are constructed, with the depth HD2 of 25 m, and the angles with the axis direction of the roadway are 25° and 35° respectively; at the production side within a range of 50 m behind the driving heading, a driving-heading rear production-side rib hole 15 is constructed, with the depth HD3 of the rib hole being 20 m, perpendicular to the axis of the roadway.

[0057] Continue driving and support in a timely manner. When the driving distance reaches the maximum driving distance of 25 m, repeat the pressure relief - driving - support to form a "short driving - short support - short pressure relief" mode.

[0058] When the distance L between the driving heading of the driving-through roadway in the working face and the breakthrough point is less than 40 m, a driving-through hole is constructed at the driving heading before each driving until the driving-through is completed.

[0059] In addition, the large-diameter borehole for coal seam borehole pressure relief has a diameter of 200 mm, the spacing between rib holes is 1 m, and the distance from the roadway floor is 1.5 m.

[0060] In summary, the present invention provides a method for preventing and controlling rock bursts during the driving-through of a small coal pillar adjacent to an air roadway. Through this method, the adjacent air roadway in the embodiment is successfully driven through, effectively reducing the stress concentration degree in the driving-through area, transferring the stress to the deep part of the coal body, ensuring that the working face is in a low-stress level during driving, and having important significance for the safe and efficient production of the working face.

[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: modifications or equivalent replacements can still be made to the specific implementation manners of the present invention, and any modification or equivalent replacement without departing from the spirit and scope of the present invention shall be covered by the protection scope of the claims of the present invention.

Claims

1. A method for preventing and controlling rock burst during the driving and breakthrough of a roadway adjacent to a small coal pillar, characterized in that, It includes the following steps: Step 1: Combine the empty-heading tunneling method of the working face, determine the through-heading form of the working face, and continuously monitor the distance between the tunneling heading of the tunneling roadway and the through-heading point; If it is monitored that the distance between the tunneling heading and the through-heading point is between the starting distance of penetration and the connection distance, perform coal seam borehole pressure relief on the heading area and the production rib area at the through-heading point; If it is monitored that the distance between the tunneling heading and the through-heading point is between the connection distance and the end distance of penetration, construct a heading hole, a side-front hole at the tunneling heading, and a hole at the rear production rib at the tunneling heading for short-distance coal seam borehole pressure relief; Step 2: Continue tunneling and timely support. When the tunneling distance reaches the maximum tunneling distance, repeat the construction of a heading hole, a side-front hole at the tunneling heading, and a hole at the rear production rib at the tunneling heading for short-distance coal seam borehole pressure relief to form a short tunneling, short support, and short pressure relief mode; Step 3: If it is monitored that the distance between the tunneling heading and the through-heading point is less than the end distance of penetration, construct a heading through-hole at the tunneling heading before each tunneling until the tunneling is completed.

2. A method for preventing and controlling rock burst during the driving and penetration of a small coal pillar adjacent to an air roadway according to claim 1, characterized in that In Step 1, according to the tunneling method of the gob-side entry and the position of the through-heading point, determine the through-heading form, which mainly includes two forms: linear through-heading and broken-line through-heading.

3. A method for preventing and controlling rock burst during driving and breakthrough of a small coal pillar adjacent to an air roadway according to claim 2, characterized in that, If linear through-heading is adopted, construct a heading hole and a side-front hole at the through-heading point at the through-heading heading, and construct a rib hole at the rear production rib of the through-heading point; if broken-line through-heading is adopted, construct a heading hole at the through-heading point at the through-heading heading, and construct a rib hole at the production rib of the broken-line roadway.

4. A method for preventing and controlling rock burst during the driving and breakthrough of a small coal pillar adjacent to an air roadway according to claim 3, characterized in that, The starting distance of penetration is 150 - 200 m, and the connection distance is 70 - 100 m; at least 5 heading holes of the through-heading point need to be constructed in the heading area of the through-heading point; if linear through-heading is adopted, 3 - 5 side-front holes of the through-heading point need to be constructed at the through-heading heading of the through-heading point, and rib holes need to be constructed within 50 m of the production rib from the through-heading point; if broken-line through-heading is adopted, rib holes need to be constructed within 50 m of the production rib of the broken-line roadway from the through-heading point, and the pressure relief range is controlled within 1 - 2 m outside the support design area of the through-heading roadway.

5. A method for preventing and controlling rock burst during driving and breakthrough of a small coal pillar adjacent to an air roadway according to claim 4, characterized in that, The depth of the heading hole of the through-heading point at the through-heading heading is 40 - 50 m, along the axis of the roadway; if linear through-heading is adopted, the depth of the side-front hole of the through-heading point is 25 - 30 m, with an angle of 20° - 40° with the axis of the roadway, and the depth of the rib hole at the production rib is 15 - 20 m, perpendicular to the axis of the roadway; if broken-line through-heading is adopted, the depth of the rib hole at the production rib of the broken-line roadway is 20 - 40 m, perpendicular to the axis of the broken-line roadway.

6. The prevention and control method for rock burst during the driving and penetration of a small coal pillar adjacent to the goaf according to claim 1, characterized in that In Step 1, the end distance of penetration is 30 - 40 m, at least 3 heading holes and 1 - 3 side-front holes need to be constructed at the tunneling heading, and rib holes need to be constructed within 50 m of the production rib from the tunneling heading.

7. A method for preventing and controlling rock burst during the driving and penetration of a small coal pillar adjacent to an air roadway according to claim 6, characterized in that, The depth of the heading hole at the tunneling heading is 25 - 30 m, along the axis of the roadway, the depth of the side-front hole at the tunneling heading is 20 - 25 m, with an angle of 20° - 40° with the axis of the roadway, and the depth of the rib hole at the rear production rib of the tunneling heading is 15 - 20 m, perpendicular to the axis of the roadway.

8. A method for preventing and controlling rock burst during the driving and breakthrough of a small coal pillar adjacent to an air roadway according to claim 1, characterized in that, In Step 2, the maximum tunneling distance is 5 - 10 m less than the depth of the heading hole at the tunneling heading.

9. The prevention and control method for rock burst during the driving and breakthrough of a small coal pillar adjacent to an airway according to claim 1, characterized in that, The large-diameter boreholes used for coal seam borehole pressure relief in Step 2 have a borehole diameter of 150 - 200 mm, a spacing of 1 - 2 m, and are 1 - 2 m away from the roadway floor.

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