Double-roadway tunneling narrow coal pillar pressure relief anti-impact supporting structure
The dual-lane coal pillar support structure with large-diameter holes and tension grouting cables addresses the instability of narrow coal pillars by reducing stress concentration and enhancing load-bearing capacity, thereby improving stability and efficiency.
Patent Information
- Application Number
- CN202422555546.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-22
- Publication Date
- 2025-07-15
- Estimated Expiration
- 2034-10-22
AI Technical Summary
The traditional anchor rod and anchor cable support methods have high construction difficulties, heavy engineering volume, long time and limited applicability in narrow coal columns. Especially when the coal column width is too large, the support effect is poor, making it difficult to effectively prevent the occurrence of impact ground pressure.
The large-diameter drilling hole expansion method is adopted, combined with the pulling grouting anchor cable, high stress is released through the large-diameter drilling hole, and the pressure relief space is expanded. The pulling grouting anchor cable is installed in the drilling hole to improve the load-bearing capacity of the coal column and prevent the tunnel from deformation.
Effectively reduce stress concentration, reduce the number of drilling holes, save costs, improve the stability of coal columns, prevent impact ground pressure, and simplify construction processes.
Smart Images
Figure CN223104504U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of pressure relief and impact prevention for narrow coal pillars in coal mines, in particular to a pressure relief and impact prevention support structure for narrow coal pillars in double - lane tunneling. Background Technique
[0002] The existence of high - stress concentration areas in coal pillars is the fundamental cause of induced rock bursts in coal pillars. High - stress concentration accumulates a large amount of elastic strain energy in coal and rock masses, bringing the risk of rock bursts to the working face. Usually, methods of releasing high stress in coal pillars are mostly used to prevent and control rock bursts. In the double - lane layout, the narrow coal pillar needs to bear the influence of two mining movements. During the mining process, the plastic zone of the narrow coal pillar between the two lanes develops and increases, the stress concentration degree is higher, and the bearing capacity of the coal pillar decreases, making the stability requirements of the coal pillar higher. For traditional large - diameter borehole pressure relief, on the one hand, the number of boreholes is large, the pressure - relief space is limited, and the pressure - relief effect is average; on the other hand, large - diameter boreholes further reduce the stability of the coal pillar while having a large amount of engineering work, high investment, and long time consumption. Aiming at the problem of poor coal - pillar stability, the existing methods for enhancing coal - pillar stability mainly include the combined support of bolts and cables, single - bolt support, cable support, combined support of anchor nets and cables, and cable reinforcement combined with shotcreting technology, etc. Among these methods, the combined support of bolts and cables is the most widely used. When implementing bolt and cable support, considering the diversity of mine conditions, bolts and cables with different characteristics need to be selected, such as high - strength and high - prestress bolts, deformed steel bars, fully - grouted cables, etc. On the one hand, these support technologies require the width of the coal pillar to be controlled between 4 and 5 meters to ensure their effectiveness; on the other hand, they have certain limitations in applicability. Especially when the reserved width of the coal pillar is too large, the support effect of these methods may be greatly reduced, thus reducing the stability of the coal pillar. In addition, these support methods generally face problems such as large construction difficulty, heavy engineering work, and long time consumption. Content of the Utility Model
[0003] Aiming at the above problems, the utility model discloses a pressure relief and impact prevention support structure for narrow coal pillars in double - lane tunneling. By adopting the method of large - diameter boreholes and reaming, on the one hand, the surface of the narrow coal pillar is not affected by reaming, and the stability of the coal pillar is high; on the other hand, by adopting the reaming method, the pressure - relief space is large, the number is small, and time is saved. At the same time, a tension - type grouted cable is installed in the large - diameter borehole, which can effectively improve the self - bearing capacity of the coal pillar and prevent further deformation of the roadway.
[0004] A pressure relief and impact prevention support structure for narrow coal pillars in double - lane tunneling proposed according to the purpose of the utility model includes large - diameter boreholes and tension - type grouted cables; the large - diameter boreholes vertically penetrate the narrow coal pillar and a reaming section is arranged in the middle, and the reaming section is coaxially arranged with the large - diameter borehole; the tension - type grouted cables penetrate through the large - diameter boreholes, and both ends extend out of the large - diameter boreholes and are fixed through trays and locks.
[0005] Preferably, the radius of the large-diameter borehole is 50 - 150 mm, and the radius of the reaming section is three times that of the large-diameter borehole.
[0006] Preferably, the length of the reaming section is one-fourth of the width of the narrow coal pillar.
[0007] Preferably, the large-diameter boreholes are arranged in multiple rows and columns, with a row spacing of 2.0 m and a column spacing of 2.0 m. An reaming section and a tension-grouting anchor cable are arranged in each large-diameter borehole.
[0008] Preferably, the distance between the top large-diameter borehole and the roadway roof is 1.0 m, and the distance between the bottom large-diameter borehole and the roadway floor is 1.2 m.
[0009] Compared with the prior art, the advantages of the double-heading narrow coal pillar pressure-relief and impact-prevention support structure disclosed by the present utility model are as follows:
[0010] (1) On the one hand, this support structure uses the method of large-diameter borehole and reaming to release the high stress in the narrow coal pillar, effectively reducing the peak value of the stress concentration area, releasing elastic energy, slowing down the damage to the narrow coal pillar caused by elastic energy, and preventing the occurrence of rock bursts. On the other hand, by installing tension-grouting anchor cables in the large-diameter boreholes, the self-bearing capacity of the coal pillar is improved. While preventing further deformation of the roadway, it is convenient to grout and reinforce the coal body.
[0011] (2) The present utility model completes the pressure-relief, support, and grouting processes in the same borehole, eliminating the need for secondary drilling, reducing waste of resources, and saving costs. BRIEF DESCRIPTION OF THE DRAWINGS
[0012] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.
[0013] Figure 1 It is a schematic diagram of the pressure-relief and impact-prevention support structure.
[0014] In the figure: 1 - tension-grouting anchor cable; 2 - tray; 3 - locking device; 4 - narrow coal pillar; 5 - roadway; 6 - large-diameter borehole; 7 - reaming section. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0015] The following briefly describes the specific implementation manners of the present utility model in conjunction with the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present utility model without creative efforts belong to the scope protected by the present utility model.
[0016] Figure 1 The preferred embodiments of the present utility model are shown and dissected in detail.
[0017] As Figure 1 shown, a double - lane tunneling narrow coal pillar pressure - relief and impact - prevention support structure includes large - diameter boreholes 6 and tension - type grouting anchor cables 1.
[0018] The large - diameter boreholes 6 vertically penetrate the narrow coal pillar 4 and an enlarged - hole section 7 is arranged in the middle. The enlarged - hole section 7 is coaxially arranged with the large - diameter boreholes 6. The radius of the large - diameter boreholes 6 is 100 mm, and the radius of the enlarged - hole section 7 is three times that of the large - diameter boreholes 6. The length of the enlarged - hole section 7 is one - fourth of the width of the narrow coal pillar 4. The large - diameter boreholes 6 are arranged in multiple rows and columns, with a row spacing of 2.0 m and a column spacing of 2.0 m. The distance between the top large - diameter boreholes 6 and the roof of the roadway 5 is 1.0 m, and the distance between the bottom large - diameter boreholes 6 and the floor of the roadway 5 is 1.2 m.
[0019] The tension - type grouting anchor cables 1 penetrate through the large - diameter boreholes 6, and both ends extend out of the large - diameter boreholes 6 and are fixed by trays 2 and locks 3.
[0020] A method for using the above - mentioned structure to carry out pressure - relief and impact - prevention support for the narrow coal pillar 4 includes the following steps:
[0021] Step 1: Use a drill - reaming integrated machine to drill large - diameter boreholes 6 in a direction perpendicular to the narrow coal pillar 4 at a position 1.0 m away from the roof of the roadway 5 on the narrow coal pillar 4;
[0022] Step 2: When the drilling length of the large - diameter boreholes 6 reaches three - eighths of the width of the narrow coal pillar 4, open the cutter wings on both sides of the drill pipe, drill an enlarged - hole section 7 with a length of one - fourth of the width of the narrow coal pillar 4 and a radius three times that of the large - diameter boreholes 6, retract the two - side cutter wings, and continue drilling until the entire narrow coal pillar 4 is penetrated;
[0023] Step 3: Determine the spacing between the large - diameter boreholes 6 and drill in multiple rows;
[0024] Step 4: Install the tension - type grouting anchor cables 1 into each large - diameter borehole 6 and quickly pass through the large - diameter boreholes 6, then install the tray 2 at the tail of the anchor cable and fix it with the lock 3, and pre - tighten the anchor cable;
[0025] Step 5: Grout into the boreholes through the grouting anchor cables.
[0026] The foregoing description of the disclosed embodiments enables those skilled in the art to implement and use the present utility model. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit and scope of the present utility model. Therefore, the present utility model will not be limited to the embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features disclosed herein.
Claims
1. A double-heading tunneling narrow coal pillar pressure relief and impact prevention support structure, characterized in that, It includes large-diameter boreholes (6) and tension-grouting anchor cables (1); the large-diameter boreholes (6) vertically penetrate through the narrow coal pillar (4), and an enlarged borehole section (7) is arranged in the middle, and the enlarged borehole section (7) is coaxially arranged with the large-diameter boreholes (6); the tension-grouting anchor cables (1) penetrate through the large-diameter boreholes (6), and both ends extend out of the large-diameter boreholes (6) and are fixed through trays (2) and locks (3).
2. The double-heading tunneling narrow coal pillar pressure relief and impact prevention support structure according to claim 1, characterized in that, The radius of the large-diameter borehole (6) is 50 - 150 mm, and the radius of the enlarged borehole section (7) is three times the radius of the large-diameter borehole (6).
3. The double-heading tunneling narrow coal pillar pressure-relief and impact prevention support structure according to claim 1, characterized in that The length of the enlarged borehole section (7) is one-fourth of the width of the narrow coal pillar (4).
4. The double-heading narrow coal pillar pressure-relief and impact prevention support structure according to claim 1, characterized in that, The large-diameter boreholes (6) are arranged in multiple rows and columns, the row spacing is 2.0 m, the column spacing is 2.0 m, and an enlarged borehole section (7) and a tension-grouting anchor cable (1) are arranged in each large-diameter borehole (6).
5. The double-heading narrow coal pillar pressure-relief and impact prevention support structure according to claim 4, characterized in that, The distance between the top large-diameter borehole (6) and the roof of the roadway (5) is 1.0 m, and the distance between the bottom large-diameter borehole (6) and the floor of the roadway (5) is 1.2 m.