Method for dynamically evaluating anti-impact pressure relief effect of large-diameter borehole

Abstract

This invention relates to the field of rockburst prevention technology, specifically to a dynamic evaluation method for the rockburst prevention and pressure relief effect of large-diameter boreholes. The method includes: dividing the large-diameter borehole area into different influence zones based on the distance between the borehole and the coal face; determining the pressure relief effect of different zones based on their influence on the borehole and the degree of deformation; and adjusting mining operations based on the pressure relief effect. This invention's dynamic evaluation method for rockburst prevention and pressure relief can dynamically evaluate the rockburst prevention and pressure relief effect of large-diameter boreholes, improving safety and stability during mining operations.

Description

Technical Field

[0001] This invention relates to the field of rockburst prevention and control technology, specifically to a dynamic evaluation method for the rockburst prevention and pressure relief effect of large-diameter boreholes. Background Technology

[0002] Traditional experience-based prevention and control models are no longer sufficient to meet the needs of precise control under complex geological conditions. Large-diameter pressure relief boreholes, due to their mature technology, high pressure relief strength, and strong adaptability, have become the preferred local pressure relief technology for coal seams prone to rock bursts. However, their application effectiveness has long relied on the experience-based understanding that "implementation is effective," lacking objective and quantifiable means of effectiveness evaluation.

[0003] Existing methods for evaluating the effectiveness of rockburst control are mostly based on macroscopic results. In engineering applications for detecting and evaluating stress relief effects, methods such as borehole stress gauges, drill cuttings analysis, and seismic CT are commonly used. The borehole stress gauge method typically involves two measuring points, one at a shallow depth and one at a deep depth, within a single testing area. This results in limited coal stress data, making it difficult to accurately reflect the peak stress levels and locational changes. The drill cuttings method can obtain the relative changes in coal stress at different depths in the roadway walls, but it is not a continuous monitoring method and requires multiple drilling operations, leading to significant labor intensity. Seismic CT can obtain the regional variation patterns of coal stress before and after stress relief, but its construction process is complex and difficult, and testing requires production shutdowns, impacting mining progress. In summary, current methods for detecting and evaluating borehole stress relief often rely on single technologies and lack effective and easily detectable quantitative indicators, making it difficult to accurately evaluate the effectiveness of borehole stress relief. Summary of the Invention

[0004] The present invention aims to at least partially solve one of the technical problems in the related art.

[0005] Therefore, embodiments of the present invention propose a dynamic evaluation method for the anti-scour and pressure relief effect of large-diameter boreholes, which dynamically evaluates the anti-scour and pressure relief effect of large-diameter boreholes and improves the stability and safety of coal mining.

[0006] The dynamic evaluation method for anti-blowout and pressure relief effect of large-diameter boreholes according to embodiments of the present invention includes: Based on the distance between the large-diameter borehole and the coal mining face, the area of ​​the large-diameter borehole is divided into different influence zones; The pressure relief effect in different areas is determined based on the impact of different influence zones on large-diameter boreholes and the degree of deformation of large-diameter boreholes. Adjustments to mining operations are made based on the pressure relief effect.

[0007] The present invention provides a dynamic evaluation method for the anti-scour and pressure relief effect of large-diameter boreholes, which dynamically evaluates the anti-scour and pressure relief effect of large-diameter boreholes and improves the safety and stability during mining operations.

[0008] In some embodiments, the deformation degree coefficient of the borehole is determined based on the initial aperture of the large-diameter borehole and the observed aperture of the large-diameter borehole; The distance influence coefficient of the large-diameter borehole for the corresponding influence area is determined according to different influence areas; The pressure relief effect index is determined based on the deformation degree coefficient and the distance influence coefficient; Among them, the deformation degree coefficient of the borehole is determined by the following formula. Set the deformation degree coefficient of the large-diameter borehole aperture as D, and , where is the initial aperture of the large-diameter borehole, ; The distance influence coefficient of the large-diameter borehole in different influence areas is . Set the distance between the large-diameter borehole and the coal mining face as L, with the unit of meter and the international unit of m, Satisfy: , The pressure relief effect index is Ei, which is determined by the following formula: Ei = .

[0009] In some embodiments, the borehole state is determined through the pressure relief effect index, and the mining operation is adjusted. Among them, When Ei ≤ 0.1, the borehole deformation degree is not deformed yet, the borehole pressure relief effect is not pressure relieved yet, and the mining operation is adjusted to stop the mining operation and drill additional pressure relief boreholes; When 0.1 < Ei ≤ 0.25, the borehole pressure relief effect is slightly pressure relieved, and the mining operation is adjusted to reduce the mining operation speed and strengthen the stress monitoring of the roadway surrounding rock; When 0.25 < Ei ≤ 0.5, the borehole pressure relief effect is moderately pressure relieved, and the mining operation is adjusted to the normal mining operation speed and strengthen the stress monitoring of the roadway surrounding rock; When Ei > 0.5, the borehole state is fully pressure relieved, and the mining operation is adjusted to the normal mining operation.

[0010] In some embodiments, when Ei ≤ 0.1, bolt support is added to the roadway.

[0011] In some embodiments, the preset observation period for observing the aperture of the large-diameter borehole in different influence areas is set as T, The distance between the large-diameter borehole and the coal mining face is divided into a strong mining influence area within 0 m ≤ L ≤ 50 m, When the pressure relief effect index Ei in the strong mining influence area ≤ 0.1, the observation period is 0.5T; when the pressure relief effect index 0.75 > Ei > 0.1 in the strong mining influence area, the observation period is 0.7T; when the pressure relief effect index Ei in the strong mining influence area ≥ 0.75, the observation period is 1.0T.

[0012] In some embodiments, the spacing between the large-diameter boreholes and the coal mining face is divided into a medium mining influence area where 50m < L ≤ 100m, and a weak mining influence area where 100m < L ≤ 150m. When the pressure relief effect index Ei ≤ 0.1 in the medium mining influence area and the weak mining influence area, the observation period is 0.6T. When the pressure relief effect index in the medium mining influence area and the weak mining influence area satisfies 0.75 > Ei > 0.1, the observation period is 0.75T. When the pressure relief effect index Ei ≥ 0.75 in the medium mining influence area and the weak mining influence area, the observation period is 1.0T.

[0013] In some embodiments, the spacing between the large-diameter boreholes and the coal mining face is divided into a non-mining influence area where 150m < L ≤ 200m; When the pressure relief effect index Ei < 0.75 in the non-mining influence area, the observation period is 0.8T. When the pressure relief effect index Ei ≥ 0.75 in the non-mining influence area, the observation period is T.

[0014] In some embodiments, the spacing of the large-diameter boreholes is 0.8 - 1.5m.

[0015] In some embodiments, the radial dimension of the large-diameter boreholes is 80mm - 100mm.

[0016] In some embodiments, when 0.1 < Ei ≤ 0.25, spray support is applied to the roof. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic diagram of the coal mining face in an embodiment of the present invention.

[0018] Figure 2 is a schematic diagram of different influence areas in an embodiment of the present invention.

[0019] Figure 3 is a flowchart of the dynamic evaluation method for the pressure relief effect based on large-diameter boreholes in an embodiment of the present invention.

[0020] REFERENCE SIGNS: Coal mining face 1, cutting face 11, Large-diameter borehole 2, Roadway 3, goaf 4. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings. The embodiments described below by referring to the drawings are exemplary and are intended to explain the present invention, and should not be construed as a limitation to the present invention.

[0022] The dynamic evaluation method for the anti-impact and pressure relief effect of large-diameter borehole 2 according to the present invention includes: S100: dividing the area of ​​large-diameter borehole 2 into different influence areas according to the distance between large-diameter borehole 2 and coal mining face 1; S200: determining the pressure relief effect of different areas according to the influence of different influence areas on large-diameter borehole 2 and the degree of deformation of large-diameter borehole 2; S300: adjusting the mining operation according to the pressure relief effect.

[0023] The present invention provides a dynamic evaluation method for the anti-impact and pressure relief effect of large-diameter borehole 2, which dynamically evaluates the pressure relief and anti-impact effect of large-diameter borehole 2 and improves the safety and stability during mining operations.

[0024] Understandably, the large-diameter borehole 2 is drilled from the side of the roadway towards the coal seam in order to achieve the effect of borehole pressure relief. Figure 1 The diagram for "large-diameter borehole 2" is a schematic representation of the location of a large-diameter borehole in the roadway and does not indicate the direction of its extension. Based on the distance between the large-diameter borehole 2 and the coal face 1, the area where the large-diameter borehole 2 is located is divided into different influence zones. The stress relief effect of each influence zone is determined based on the degree of deformation of the large-diameter borehole 2 within each influence zone and the influence of each influence zone on the large-diameter borehole 2. For example, L represents the distance between the large-diameter borehole 2 and the coal face 1. This distance can be understood as the distance between the cutting surface 11 of the coal face 1 and the large-diameter borehole 2, or as the distance between the mining face of the coal seam and the large-diameter borehole 2. When 50m < L ≤ 100m, this influence zone is a strong mining influence zone. The stress relief effect of the strong mining influence zone is determined by the degree of deformation of the large-diameter borehole 2 within the strong mining influence zone and the influence of the strong mining influence zone on the large-diameter borehole 2. Then, adjustments are made to the mining operations and support operations in different affected areas based on the pressure relief effect. For example, the coal mining speed is reduced and the support is strengthened. Existing support operations are carried out on the roof of roadway 3, such as spraying or anchoring. The roadway is an existing transport roadway or return airway.

[0025] The dynamic evaluation method for the anti-rockburst and pressure relief effect of large-diameter borehole 2 in embodiments of the present invention divides the distance between the coal face 1 and the large-diameter borehole 2 into multiple influence zones and combines the deformation degree of the boreholes in the corresponding zones. This allows for dynamic evaluation of the pressure relief and anti-rockburst effect of the large-diameter borehole 2, making the pressure relief effect closer to the actual pressure relief effect and improving the stability and safety of coal mining. By dividing the influence zones and evaluating the pressure relief effect in conjunction with the deformation degree of the large-diameter borehole 2 in the corresponding influence zones, and by dynamically adjusting mining and support operations, this method provides strong technical support for anti-rockburst and pressure relief in coal mining operations, effectively reducing the risk of rockbursts and ensuring the safety and stability of coal mining operations.

[0026] In some embodiments, the deformation coefficient of the borehole is determined based on the initial borehole diameter of the large-diameter borehole 2 and the observed borehole diameter of the large-diameter borehole 2; The distance influence coefficient of the large-diameter borehole 2 in the corresponding influence area is determined according to the different influence areas; The pressure relief effect index is determined based on the deformation degree coefficient and the distance influence coefficient. The deformation coefficient of the borehole is determined by the following formula, where the deformation coefficient of the large-diameter borehole is set to D, and... ,in, The initial hole diameter for large-diameter borehole 2, ; The distance influence coefficient of large-diameter borehole 2 in different influence areas is: Let L be the distance between the large-diameter borehole 2 and the coal face 1, in meters (m). satisfy: , The pressure relief effect index, Ei, is determined by the following formula: Ei = .

[0027] Specifically, the initial diameter of the large-diameter borehole 2 is the diameter formed when the large-diameter borehole 2 is first drilled, and the borehole diameter during observation is the actual diameter of the large-diameter borehole 2 measured within a preset time or during the inspection time.

[0028] The distance between different affected areas and the cutting face 11 of the coal mining face 1 also has a certain impact on the pressure relief effect of the borehole. For example, during the coal mining process, the distance between the coal mining face 1 and the large-diameter borehole 2 gradually changes, and the pressure relief effect is affected accordingly. Different distance influence coefficients are applied based on the distance to evaluate the pressure relief effect in different affected areas. This facilitates the optimization of support operations based on the evaluation results, enhancing the stability of key components such as the roof of the roadway 3. This effectively reduces the impact of rockburst on miners' lives and the mine's safety.

[0029] The deformation degree of large-diameter borehole 2 is calculated using the average deformation degree coefficient of large-diameter borehole 2 within the same influence area, with one maximum and one minimum value removed. This is to avoid excessive error in the final deformation degree coefficient of large-diameter borehole 2, thereby improving the stability of the pressure relief effect evaluation and making it more consistent with the actual pressure relief effect. Below are the borehole diameter deformation degree grading table and the pressure relief effect index grading table.

[0030] Classification table of borehole diameter deformation

[0031] That is, by assessing the pressure relief effect, the borehole condition is determined, and adjustments are made to the mining operations. When Ei ≤ 0.1, the degree of borehole deformation is not deformed, the borehole pressure relief effect is not relieved, the mining operation is adjusted to stop the mining operation, and pressure relief boreholes are additionally drilled. When 0.1 < Ei ≤ 0.25, the borehole pressure relief effect is slightly relieved, and the mining operation is adjusted to reduce the mining operation speed and strengthen the stress monitoring of the surrounding rock of roadway 3. When 0.25 < Ei ≤ 0.5, the borehole pressure relief effect is moderately relieved, and the mining operation is adjusted to the normal mining operation speed and strengthen the stress monitoring of the surrounding rock of roadway 3. When Ei > 0.5, the borehole state is fully relieved, and the mining operation is adjusted to the normal mining operation.

[0032] By grading the pressure relief effect index, the pressure relief effect of the large-diameter borehole 2 during the coal mining process is determined, and according to the different grading of the unloading coefficient under different pressure relief effects, the pressure relief effect of the borehole is quantitatively evaluated, and the mining operation and support operation in the influence area corresponding to the pressure relief effect in different states are adjusted.

[0033] The dynamic evaluation method for the impact prevention and pressure relief effect of the large-diameter borehole 2 in the embodiment of the present invention divides the influence range into multiple influence areas according to the spacing of the coal mining face 1, determines the pressure relief effect index Ei according to the deformation degree of the borehole in the influence area, and finally grades the pressure relief effect index Ei to quantitatively grade the pressure relief effect of the large-diameter borehole 2 for evaluation, so as to quantify the pressure relief state of the borehole with a more intuitive digital grading. This not only facilitates accurately obtaining the pressure relief state of the borehole, but also facilitates the understanding and operation of underground mining personnel, improving the safety and convenience of mining operations. And different support operations and coal mining operations can be adopted according to different pressure relief effect indexes, improving the stability and safety of coal mining, avoiding excessive support that increases costs and affects the coal mining speed, and improving the coal mining efficiency. By dynamically adjusting the mining and support plans, the risk of rock burst can be effectively reduced and the safety of coal mining can be improved.

[0034] In some embodiments, when Ei ≤ 0.1, bolt support is additionally provided for roadway 3. For example, bolts are additionally drilled on the basis of the original bolt support of roadway 3 to improve the support strength.

[0035] In some embodiments, a preset observation period T for observing the aperture of the large-diameter borehole 2 in different influence areas is set. The spacing between the large-diameter borehole 2 and the coal mining face 1 within the range of 0 m ≤ L ≤ 50 m is divided into a strong mining influence area. When the pressure relief effect index Ei ≤ 0.1 in the strong mining influence area, the observation period is 0.5T; when the pressure relief effect index in the strong mining influence area satisfies 0.75 > Ei > 0.1, the observation period is 0.7T; when the pressure relief effect index Ei ≥ 0.75 in the strong mining influence area, the observation period is 1.0T.

[0036] For example, a preset observation period of T can be set, which can be one day or 8 hours, etc., and the specific period is determined by the on-site personnel based on the coal mining progress and actual site conditions. For ease of description, this application uses 10 hours as an example. For instance, the preset observation period for large-diameter borehole 2 is 10 hours, that is, the radial dimension at the opening of large-diameter borehole 2 is measured every 10 hours. When the pressure relief effect index Ei ≤ 0.1 in the area affected by strong mining is not yet relieved and the pressure relief effect is generally poor, the observation period is adjusted to 0.5T = 5 hours. When the pressure relief effect index Ei > 0.1 in the area affected by strong mining is 0.7T = 7.0 hours. When the pressure relief effect index Ei ≥ 0.75 in the area affected by strong mining is moderately or slightly relieved, the observation period is adjusted to 1.0T. By adjusting the preset observation period of the large-diameter borehole 2 in different affected areas according to the pressure relief effect, and dynamically adjusting the observation period according to the pressure relief effect index Ei of the strongly mined area, potential risks can be detected in time and corresponding measures can be taken to improve coal mining safety. At the same time, the risk of rock bursts can be reduced and the stability of coal mining can be improved by dynamically adjusting mining and support operations.

[0037] Furthermore, the distance between the large-diameter borehole 2 and the coal face 1 is 50m < L ≤ 100m, which is divided into the medium mining impact zone. The distance between the large-diameter borehole 2 and the coal face 1 is 100m < L ≤ 150m, which is divided into the weak mining impact zone. When the pressure relief effect index Ei ≤ 0.1 in the medium and weak mining impact zones, the observation period is 0.6T. When the pressure relief effect index in the medium and weak mining impact zones satisfies 0.75 > Ei > 0.1, the observation period is 0.75T.

[0038] When the pressure relief effect index \(E_i\leq0.1\) in the moderately mined - affected area and the weakly mined - affected area, the surrounding rock is not yet pressure - relieved, and the pressure relief effect is average. Adjust the observation period to \(0.6T\). When the pressure relief effect index in the moderately mined - affected area and the weakly mined - affected area satisfies \(0.75>E_i>0.1\), the observation period is \(0.75T\). The surrounding rock is moderately or slightly pressure - relieved, and the observation period is adjusted to \(0.75T\). By adjusting the preset observation period of the large - diameter borehole 2 aperture in different affected areas according to the pressure relief effect, and dynamically adjusting the observation period according to the pressure relief effect index \(E_i\) in the strongly mined - affected area, potential risks can be discovered in time and corresponding measures can be taken to improve the safety of coal mining. At the same time, the risk of rock burst can be reduced by dynamically adjusting the mining and support operations, and the stability of coal mining can be improved. By setting the preset observation period of the large - diameter borehole 2 aperture in different affected areas and dynamically adjusting the observation period according to the pressure relief effect index \(E_i\) in the strongly mined - affected area, potential risks can be discovered in time and corresponding measures can be taken to improve the safety of coal mining. At the same time, the risk of rock burst can be reduced by dynamically adjusting the mining and support operations, and the stability of coal mining can be improved.

[0039] In some embodiments, the distance \(L\) between the large - diameter borehole 2 and the coal - mining face 1 is divided into the area without mining influence when \(150m < L\leq200m\); when the pressure relief effect index \(E_i<0.75\) in the area without mining influence, the observation period is \(0.8T\), and when the pressure relief effect index \(E_i\geq0.75\) in the area without mining influence, the observation period is \(T\). By setting the preset observation period of the large - diameter borehole 2 aperture in different affected areas and dynamically adjusting the observation period according to the pressure relief effect index \(E_i\) in the strongly mined - affected area, potential risks can be discovered in time and corresponding measures can be taken to improve the safety of coal mining. At the same time, the risk of rock burst can be reduced by dynamically adjusting the mining and support operations, and the stability of coal mining can be improved.

[0040] In some embodiments, the spacing of the large - diameter boreholes 2 is \(0.8 - 1.5m\). The radial dimension of the large - diameter borehole 2 is \(80mm - 100mm\). The spacing of the large - diameter boreholes 2 being \(0.8 - 1.5m\) can ensure the minimization of the interaction between the boreholes. It can not only ensure sufficient pressure relief effect but also avoid resource waste caused by overly dense boreholes. The radial dimension of the large - diameter borehole 2 being \(80mm\) to \(100mm\) can achieve effective pressure relief while considering the drilling construction efficiency. Through reasonable borehole size and spacing, the stress level of the surrounding rock can be effectively reduced, and the stability of the surrounding rock can be enhanced.

[0041] In some embodiments, when \(0.1 < E_i\leq0.25\), spray support is carried out on the roof. Since the pressure relief effect index indicates a poor pressure relief effect and there may be subsequent rock bursts and similar micro - seismic events, spraying is carried out on the roof to prevent flying gangue, or a certain degree of backfilling is carried out on the goaf 4 so that the filling material covers at least the roof of the goaf 4 to improve the stability of coal mining. In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0042] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0043] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0044] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0045] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative 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 one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0046] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A dynamic evaluation method for the anti-blowout and pressure relief effect of large-diameter boreholes, characterized in that, Including: Dividing the large-diameter borehole area into different influence areas according to the distance between the large-diameter borehole and the coal mining face; Determining the pressure relief effects of different areas according to the influence of different influence areas on the large-diameter borehole and the deformation degree of the large-diameter borehole; Adjusting the mining and excavation operations according to the pressure relief effects.

2. The dynamic evaluation method for anti-blowout and pressure relief effect of large-diameter boreholes according to claim 1, characterized in that, Including: Determining the deformation degree coefficient of the borehole according to the initial aperture of the large-diameter borehole and the observed aperture of the large-diameter borehole; Determining the distance influence coefficient of the large-diameter borehole for the corresponding influence area according to different influence areas; Determining the pressure relief effect index according to the deformation degree coefficient and the distance influence coefficient; The deformation coefficient of the borehole is determined by the following formula, where the deformation coefficient for large-diameter boreholes is set as D, and... ,in, The initial borehole diameter for large-diameter drilling. ; The distance influence coefficient of large-diameter boreholes in different influence areas is: Let L be the distance between the large-diameter borehole and the coal face, in meters (m). satisfy: , The pressure relief effect index, Ei, is determined by the following formula: Ei = .

3. The dynamic evaluation method for the impact prevention and pressure relief effect of large-diameter boreholes according to claim 2, characterized in that Determining the borehole state through the pressure relief effect index and adjusting the mining and excavation operations, wherein When Ei≤0.1, the borehole deformation degree is not deformed, the borehole pressure relief effect is not pressure relieved, and the mining and excavation operations are adjusted to stop the mining and excavation operations and drill additional pressure relief boreholes; When 0.1<Ei≤0.25, the borehole pressure relief effect is slightly pressure relieved, and the mining and excavation operations are adjusted to reduce the mining and excavation operation speed and strengthen the stress monitoring of the roadway surrounding rock; When 0.25<Ei≤0.5, the borehole pressure relief effect is moderately pressure relieved, and the mining and excavation operations are adjusted to the normal mining and excavation operation speed and strengthen the stress monitoring of the roadway surrounding rock; When Ei>0.5, the borehole state is fully pressure relieved, and the mining and excavation operations are adjusted to normal mining and excavation operations.

4. The dynamic evaluation method for anti-blowout and pressure relief effect of large-diameter boreholes according to claim 2, characterized in that, When Ei≤0.1, bolt support is drilled for the roadway.

5. The dynamic evaluation method for anti-blowout and pressure relief effect of large-diameter boreholes according to claim 2, characterized in that, Setting the preset observation period for observing the aperture of the large-diameter borehole in different influence areas as T, Dividing the distance between the large-diameter borehole and the coal mining face within 0m≤L≤50m into a strong mining influence area, When the pressure relief effect index Ei≤0.1 in the strong mining influence area, the observation period is 0.5T; when 0.75>Ei>0.1 in the strong mining influence area, the observation period is 0.7T; when Ei≥0.75 in the strong mining influence area, the observation period is 1.0T.

6. The dynamic evaluation method for anti-blowout and pressure relief effect of large-diameter boreholes according to claim 5, characterized in that, Dividing the distance between the large-diameter borehole and the coal mining face within 50m<L≤100m into a medium mining influence area, and dividing the distance between the large-diameter borehole and the coal mining face within 100m<L≤150m into a weak mining influence area, When the pressure relief effect index Ei≤0.1 in the medium mining influence area and the weak mining influence area, the observation period is 0.6T; when 0.75>Ei>0.1 is satisfied in the medium mining influence area and the weak mining influence area, the observation period is 0.75T; when Ei≥0.75 in the medium mining influence area and the weak mining influence area, the observation period is 1.0T.

7. The dynamic evaluation method for the impact prevention and pressure relief effect of large-diameter boreholes according to claim 5, characterized in that Dividing the distance between the large-diameter borehole and the coal mining face within 150m<L≤200m into a non-mining influence area; When the pressure relief effect index Ei<0.75 in the non-mining influence area, the observation period is 0.8T; when Ei≥0.75 in the non-mining influence area, the observation period is T.

8. The dynamic evaluation method for anti-blowout and pressure relief effect of large-diameter boreholes according to claim 1, characterized in that, The spacing of large-diameter boreholes is 0.8 - 1.5 m.

9. The dynamic evaluation method for anti-blowout and pressure relief effect of large-diameter boreholes according to claim 1, characterized in that, The radial dimension of the large-diameter boreholes is 80 mm - 100 mm.

10. The dynamic evaluation method for anti-blowout and pressure relief effect of large-diameter boreholes according to any one of claims 2-7, characterized in that, When 0.1 < Ei ≤ 0.25, spray support is carried out on the roof.

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