Mechanical reaming and pressure relief method for elastic area of coal body

Abstract

The invention relates to a mechanical reaming pressure relief method for a coal body elastic area, and belongs to the technical field of rock burst prevention and control. The method comprises the steps that a small-diameter hole is drilled in a plastic zone to penetrate to an elastic zone, the stress monitoring sensor is used for monitoring crustal stress in real time, the reaming device is started at the peak value to conduct large-diameter reaming, and meanwhile pulverized coal is cleaned through the powder discharging system. The method further comprises a planning step before drilling, wherein the distance between adjacent drill holes and the target depth of each drill hole are calculated and determined. The reaming device comprises a guide drill bit unit, a reamer main body, a reaming mechanical arm and a reaming blade, wherein a powder discharging hole is formed in the reamer main body. The method further comprises a real-time monitoring and effect evaluation step to optimize reaming parameters. According to the method, the gradual operation from small-diameter guide drilling to large-diameter mechanical reaming is carried out in the elastic area of the coal body, and real-time ground stress monitoring and powder discharging cleaning are combined, so that the internal stress of the coal body is effectively released, and meanwhile, the damage to a roadway structure is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of rock burst prevention and control, and in particular to a method for mechanical hole enlarging and pressure relief in an elastic zone of a coal body. Background Art

[0002] As the depth of coal mining continues to increase, the stress state of coal and rock mass becomes more complex, and rock burst disasters have become an important problem for coal mine safety production. During deep coal mining, the high stress energy accumulated inside the coal body can be easily released suddenly under certain conditions, causing severe damage to the coal and rock mass around the tunnel, seriously threatening the life safety of mine workers and the efficiency of mine production. Therefore, it is particularly important to study and develop efficient and safe rock burst prevention and control technologies.

[0003] Although the traditional large-diameter drilling pressure relief technology can alleviate the internal stress concentration of the coal body to a certain extent, its operation area is often limited to the plastic zone around the roadway wall. The coal and rock in this area have undergone plastic deformation, and the pressure relief effect may damage the roadway structure, causing the roadway to become fragile after pressure relief. In addition, although the traditional blasting pressure relief method is effective, the strong blasting effect is prone to cause secondary disasters, such as roof collapse and coal dust explosion, which further increases the risk of mining operations. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art and to provide a method for mechanical hole expansion and pressure relief in the elastic zone of a coal body. By performing a progressive small-diameter guided drilling to a large-diameter mechanical hole expansion operation in the elastic zone of the coal body, and combining real-time ground stress monitoring and powder removal and cleaning, accurate and effective stress release is achieved, while avoiding damage to the tunnel structure and improving the safety and efficiency of coal mining operations.

[0005] To achieve the above object, the present invention provides a method for mechanical hole expansion and pressure relief in the elastic zone of coal, comprising the following steps:

[0006] Drilling a hole with a preset first diameter value in the plastic zone to penetrate into the elastic zone;

[0007] Using a stress monitoring sensor disposed between the pilot drill unit and the reamer body to monitor the ground stress around the borehole in real time;

[0008] When the stress monitoring sensor detects that the ground stress reaches a peak value, the hole expansion device is started to expand the hole in the elastic zone with a preset second diameter value;

[0009] The coal powder generated by hole expansion is cleaned through the powder discharge holes arranged on the reamer body.

[0010] Furthermore, the diameter of the small-diameter drill hole is 30-40 cm, and the diameter of the large-diameter expanded hole is 90-120 cm.

[0011] Furthermore, the method also includes a planning step before drilling: calculating and determining the spacing between adjacent boreholes and the target depth of each borehole.

[0012] Furthermore, the hole expanding device comprises:

[0013] A guide drill unit for guiding the drilling direction;

[0014] A reamer body, arranged at the rear end of the guide drill unit;

[0015] A reaming mechanical arm, arranged on the reamer body;

[0016] A reaming blade is arranged at the end of the reaming mechanical arm.

[0017] Furthermore, a powder discharge hole is provided on the reamer body, and the powder discharge hole is used to accommodate the reaming blade when the reaming robot arm is not deployed, and is used to discharge coal powder generated by reaming after the reaming robot arm is deployed.

[0018] Further, the stress monitoring sensor is arranged between the guide drill unit and the reamer body.

[0019] Furthermore, the method also includes a real-time monitoring step: monitoring the hole expansion rate, hole expansion depth, hole size and powder discharge flow parameters.

[0020] Furthermore, the method also includes an effect evaluation step: evaluating the pressure relief effect by monitoring the stress distribution and deformation of the tunnel.

[0021] Furthermore, the hole expansion parameters are optimized and adjusted according to the effect evaluation results.

[0022] Furthermore, when the guide drill unit and the reaming blade are not deployed, the two have the same diameter and a spacing is provided between them to facilitate deployment of the reaming blade, wherein not deployed refers to being in a fully retracted state.

[0023] Furthermore, the reamer body is a cylindrical structure.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] (1) The present invention achieves precise stress release and improves the pressure relief effect by drilling a small diameter hole in the plastic zone to penetrate into the elastic zone and using a stress monitoring sensor to monitor the ground stress around the borehole in real time. When the stress reaches a peak value, the expansion device is started to expand the hole with a large diameter, thereby achieving accurate stress release and improving the pressure relief effect.

[0026] (2) The method of the present invention avoids the damage to the tunnel structure that may be caused by drilling a large diameter hole in the plastic zone by expanding the hole in the elastic zone, thereby maintaining the stability of the tunnel structure.

[0027] (3) The method of the present invention adopts a real-time monitoring step to monitor the hole expansion rate, hole expansion depth, hole diameter and powder discharge flow parameters, thereby realizing the scientific and stable implementation of the drilling process and improving the intelligence and automation level of the operation.

[0028] (4) The present invention cleans the coal powder generated by the expansion of the powder discharge hole, thereby ensuring the cleanliness, safety and efficiency of the drilling environment and reducing the impact of the coal powder on the working environment.

[0029] (5) The method of the present invention also includes an effect evaluation step, which evaluates the pressure relief effect by monitoring the stress distribution and deformation of the tunnel, and optimizes and adjusts the hole expansion parameters based on the evaluation results to improve the pressure relief efficiency.

[0030] (6) Compared with the traditional direct large-diameter drilling pressure relief method, this technology significantly reduces the destructive impact on the tunnel structure and demonstrates higher engineering applicability and safety.

[0031] In summary, the method for mechanical hole expansion and pressure relief in the elastic zone of coal body of the present invention realizes the effective release of internal stress of coal body, while avoiding damage to the tunnel structure, thereby improving the safety and efficiency of coal mining operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A schematic flow chart of a method for mechanical hole expansion and pressure relief in an elastic zone of a coal body provided by an embodiment of the present invention;

[0033] Figure 2 2 is a schematic structural diagram of a mechanical hole enlarging, powder discharging and pressure relief device in an embodiment of the present invention;

[0034] Figure 3 2 is a schematic diagram of a mechanical hole expansion, powder removal and pressure relief device according to an embodiment of the present invention;

[0035] Figure 4 is a schematic diagram of the mechanical hole expansion, powder removal and pressure relief device in another perspective in an embodiment of the present invention;

[0036] Figure 5 2 is a schematic side view of the mechanical hole expansion, powder removal and pressure relief device in an embodiment of the present invention;

[0037] Explanation of reference numerals: 1. first reaming blade; 2. guide drill unit; 3. stress detection sensor; 4. reamer body; 5. reaming mechanical arm; 6. auger rod; 7. powder discharge hole; 8. second reaming blade. DETAILED DESCRIPTION

[0038] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0039] In the description of the present invention, it should be understood that the terms "center", "axial", "lateral", "upper", "lower", "inner", "outer", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0040] In the description of the invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0041] like Figure 1 As shown, an embodiment of the present invention provides a method for mechanical hole expansion and pressure relief in an elastic zone of a coal body, comprising the following steps:

[0042] Drilling a hole with a preset first diameter value in the plastic zone to penetrate into the elastic zone;

[0043] Using a stress monitoring sensor 3 disposed between the pilot drill unit 2 and the reamer body 4 to monitor the ground stress around the borehole in real time;

[0044] When the stress monitoring sensor 3 detects that the ground stress reaches a peak value, the hole expansion device is started to expand the hole in the elastic zone with a preset second diameter value;

[0045] The coal powder generated by hole expansion is cleaned through the powder discharge hole 7 provided on the reamer body 4.

[0046] Specifically, the preset first diameter value is 30 cm to 40 cm, and the preset second diameter value is 90 cm to 120 cm.

[0047] Furthermore, the method for mechanical hole expansion and pressure relief in the elastic zone of coal body also includes a planning step before drilling: calculating and determining the spacing between adjacent boreholes and the target depth of each borehole.

[0048] Specifically, the hole expansion device in the method for mechanical hole expansion and pressure relief in the elastic zone of coal body comprises:

[0049] A guide drill unit 2, used to guide the drilling direction;

[0050] The reamer body 4 is arranged at the rear end of the guide drill unit 2;

[0051] The hole-expanding mechanical arm 5 is arranged on the hole-expanding device body 4, and the hole-expanding mechanical arm 5 is a telescopic structure;

[0052] A first reaming blade 1 is arranged at the end of a reaming mechanical arm 5;

[0053] The second reaming blade 8 is arranged on the reaming robot arm 5 .

[0054] Furthermore, a powder discharge hole 7 is provided on the reamer body 4. The powder discharge hole 7 is used to accommodate the first reaming blade 1 when the reaming robot arm 5 is not deployed, and is used to discharge coal powder generated by reaming after the reaming robot arm 5 is deployed.

[0055] Specifically, the stress monitoring sensor 3 is disposed between the pilot drill unit 2 and the reamer body 4 .

[0056] Furthermore, the method for mechanical hole expansion and pressure relief in the elastic zone of coal body also includes a real-time monitoring step: monitoring hole expansion rate, hole expansion depth, hole size and powder discharge flow rate parameters.

[0057] Furthermore, the method for mechanical hole expansion and pressure relief in the elastic zone of coal body also includes an effect evaluation step: evaluating the pressure relief effect by monitoring the stress distribution and deformation of the tunnel.

[0058] Specifically, the method for mechanical hole expansion and pressure relief in the elastic zone of coal body also includes optimizing and adjusting hole expansion parameters according to effect evaluation results.

[0059] Specifically, when the guide drill unit 2 and the first reaming blade 1 are not deployed, the diameters of the two are the same, and a distance is provided between the two to facilitate the deployment of the first reaming blade 1.

[0060] Preferably, the reamer body 4 is a cylindrical structure.

[0061] As a specific embodiment, the implementation steps of a method for mechanical hole expansion and pressure relief in the elastic zone of coal are as follows:

[0062] S1: Plan the expansion path, define the spacing between the holes and determine the depth of each hole before drilling in the plastic zone to ensure the accuracy and effectiveness of the operation;

[0063] S2: Detecting the size of ground stress while drilling. The drill bit is equipped with a ground stress monitoring sensor. When the drill bit reaches the elastic area, the sensor 3 can autonomously sense and monitor the changes in the surrounding ground stress with the drill bit as the center;

[0064] S3: Mechanical hole expansion and coal powder discharge. After the local stress monitoring reaches the peak value, the drill starts the hole expansion device to perform drilling expansion and coal powder discharge operations in the elastic zone of the coal body;

[0065] The mechanical reaming, powder removal and pressure relief device comprises a reaming mechanical arm 5, to which a first reaming blade 1 and a second reaming blade 8 are attached, and these two parts together constitute a reaming mechanism. A powder removal hole 7 is provided on the reamer body 4, and the powder removal hole 7 has two functions. When the reaming mechanism is not unfolded, the powder removal hole 7 can be used to place the second reaming blade 8. When the reaming mechanism is unfolded, the main function of the powder removal hole 7 is to use a dust suction device to suck out the coal powder.

[0066] A guide drill unit 2 is used to drill into the coal wall of the tunnel with a small hole diameter to reach the elastic zone. The diameter of the guide drill 2 is the same as the diameter of the first reaming blade 1 when it is not unfolded. A distance is set between the guide drill 2 and the first reaming blade 1 to facilitate the unfolding of the first reaming blade 1.

[0067] The drilling expansion and coal powder discharge operation steps are: use Figure 1 The reaming device performs drilling. When the sensor 3 detects that the stress reaches a peak value, the reaming mechanical arm 5 is unfolded in the elastic zone, and the powder discharge hole 7 is exposed at the same time. As the guide drill bit 2 continues to go deeper, the reaming device can complete the large-diameter drilling operation in the elastic zone, thereby completing the large-diameter drilling and powder discharge pressure relief operation on the coal rock wall without destroying the tunnel structure.

[0068] S4: Strictly control parameters, monitor and control key parameters such as hole expansion speed, depth, diameter and powder discharge flow rate in real time;

[0069] S5: Regularly evaluate the pressure relief effect, evaluate the pressure relief effect through stress monitoring, tunnel deformation observation and other means, and adjust the hole expansion parameters in time to optimize the pressure relief effect and reduce the impact on the tunnel structure.

[0070] Preferably, in step S4, during the hole expansion operation, various parameters need to be strictly monitored, including key indicators such as hole expansion rate, hole expansion depth, hole diameter, and flow rate during powder discharge. By monitoring and regulating these data, the scientific and stable implementation of the drilling process can be achieved.

[0071] Preferably, in step S5, after completing the four consecutive steps S1 to S4, the large-diameter drilling pressure relief operation in the elastic region has been completed. Subsequently, in step S5, the stress distribution and deformation of the tunnel need to be precisely monitored to comprehensively evaluate and verify whether the actual pressure relief effect has achieved the expected goal.

[0072] If the pressure relief effect reaches the expected result and the tunnel structure is stable through stress monitoring and tunnel deformation observation, it means that the pressure relief operation is effective. If the pressure relief effect does not reach the expected result or the tunnel is deformed, it means that the hole expansion parameters need to be further optimized to reduce the impact on the tunnel structure and improve the pressure relief efficiency.

[0073] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0074] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for mechanical hole expansion and pressure relief in the elastic zone of coal, characterized in that: The following steps are involved: Drilling a hole with a preset first diameter value in the plastic zone to penetrate into the elastic zone; Using a stress monitoring sensor (3) disposed between the guide drill unit (2) and the reamer body (4) to monitor the ground stress around the borehole in real time; When the stress monitoring sensor (3) detects that the ground stress has reached a peak value, the hole expansion device is started to expand the hole in the elastic zone at a preset second diameter value; Coal powder generated by hole expansion is cleaned through a powder discharge hole (7) arranged on the hole expander body (4).

2. The method for mechanical hole expansion and pressure relief in the elastic zone of coal according to claim 1, characterized in that: The preset first diameter value is 30 cm to 40 cm, and the preset second diameter value is 90 cm to 120 cm.

3. The method for mechanical hole expansion and pressure relief in the elastic zone of coal according to claim 1, characterized in that: It also includes the planning steps before drilling: calculating and determining the spacing between adjacent drill holes and the target depth of each drill hole.

4. The method for mechanical hole expansion and pressure relief in the elastic zone of coal body according to claim 1, characterized in that: The hole expanding device comprises: A guide drill unit (2) for guiding the drilling direction; A reamer body (4) is arranged at the rear end of the guide drill unit (2); A reaming mechanical arm (5), arranged on the reamer body (4); A first reaming blade (1) is arranged at the end of the reaming mechanical arm (5); A second reaming blade (8) is arranged on the reaming mechanical arm (5).

5. The method for mechanical hole expansion and pressure relief in the elastic zone of coal body according to claim 4, characterized in that: The reamer body (4) is provided with a powder discharge hole (7), which is used to accommodate the first reaming blade (1) when the reaming mechanical arm (5) is not deployed, and is used to discharge coal powder generated by reaming after the reaming mechanical arm (5) is deployed.

6. The method for mechanical hole expansion and pressure relief in the elastic zone of coal body according to claim 4, characterized in that: The stress monitoring sensor (3) is arranged between the guide drill unit (2) and the reamer body (4).

7. The method for mechanical hole expansion and pressure relief in the elastic zone of coal body according to claim 1, characterized in that: The method also includes a real-time monitoring step: monitoring the hole expansion rate, hole expansion depth, hole size and powder discharge flow rate parameters.

8. The method for mechanical hole expansion and pressure relief in the elastic zone of coal body according to claim 1, characterized in that: It also includes an effect evaluation step: evaluating the pressure relief effect by monitoring the stress distribution and deformation in the tunnel.

9. The method for mechanical hole expansion and pressure relief in the elastic zone of coal body according to claim 8, characterized in that: The hole expansion parameters are optimized and adjusted according to the effect evaluation results.

10. The method for mechanical hole expansion and pressure relief in the elastic zone of coal body according to claim 4, characterized in that: When the guide drill unit (2) and the first reaming blade (1) are not deployed, the two have the same diameter, and a spacing is provided between the two to facilitate the deployment of the first reaming blade (1).

Images