Evaluation method of pressure relief effect based on large diameter drilling

Abstract

The present invention relates to the technical field of rock burst prevention and control, and specifically to a method for evaluating the effect of pressure relief based on large-diameter drilling, the method comprising: setting an air bag in a borehole of a tunnel, monitoring the amount of air in and out of the air bag, determining the tunnel impact hazard level of the tunnel surrounding rock under the influence of geological conditions and the tunnel impact hazard level under the influence of mining technical conditions, evaluating the drilling pressure relief effect based on the amount of air in and out of the air bag, the tunnel impact hazard level under the influence of geological conditions and the tunnel impact hazard level under the influence of mining technical conditions, and adjusting the mining operation according to the pressure relief effect. The method for evaluating the effect of pressure relief based on large-diameter drilling according to the embodiment of the present invention can evaluate the pressure relief effect, making it easier to adjust the mining operation according to the effect.

Description

Technical Field

[0001] The present invention relates to the technical field of rock burst prevention and control, and in particular to a method for evaluating the pressure relief effect based on large-diameter drilling. Background Art

[0002] Large-diameter pressure-relief drilling is one of the most commonly used pressure-relief prevention methods in rockburst mines. Due to its simplicity, adaptability, and low cost, its use rate in rockburst mines exceeds 90%. However, due to regulations such as advanced pre-pressure relief, large-diameter drilling is often carried out beyond 200 meters of the working face. After completion, the borehole itself experiences creep and disturbances, leading to collapse, deformation, closure, and even compaction. Often, the large-diameter borehole closes and compacts before the working face reaches the borehole area, rendering it ineffective in preventing rockbursts. While it is often assumed on-site that the pressure-relief effect is fully realized upon completion of the large-diameter borehole, deformation and pressure-relief take time to develop. Furthermore, after the borehole's free space is compacted, the pressure-relief effect gradually weakens until it fails. Therefore, large-diameter borehole pressure relief has a limited onset time and limited capacity. To reveal the working state and ultimate pressure-relief effect of large-diameter boreholes, a pressure-relief evaluation method is urgently needed. Summary of the Invention

[0003] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0004] To this end, an embodiment of the present invention proposes a method for evaluating the pressure relief effect based on large-diameter drilling, which can evaluate the pressure relief effect and facilitate adjustment of mining operations based on the effect.

[0005] The method for evaluating the pressure relief effect based on large-diameter drilling according to an embodiment of the present invention includes:

[0006] An air bag is installed in the drilled hole of the tunnel and the amount of air in and out of the air bag is monitored;

[0007] Determine the tunnel impact hazard level of tunnel surrounding rock under the influence of geological conditions and the tunnel impact hazard level under the influence of mining technical conditions;

[0008] The drilling pressure relief effect is evaluated by the amount of air in and out of the airbag, the tunnel impact hazard level under the influence of geological conditions, and the tunnel impact hazard level under the influence of mining technical conditions;

[0009] Adjusting the mining operation according to the pressure relief effect: The method for evaluating the pressure relief effect of large-diameter drilling according to the embodiment of the present invention can evaluate the pressure relief effect, making it easier to adjust the mining operation according to the effect.

[0010] In some embodiments, the tunnel impact hazard level under the combined influence of geological conditions and mining technology conditions is determined.

[0011] The unloading coefficient of the borehole is determined by the tunnel impact hazard level under the influence of geological conditions, the tunnel impact hazard level under the influence of mining technical conditions, the tunnel impact hazard level under the comprehensive influence and the amount of air in and out of the air bag.

[0012] The unloading coefficient is used to evaluate the pressure relief effect and determine the state of the borehole. The unloading coefficient of the borehole is determined by the following formula:

[0013] , ,

[0014] in, N D is the tunnel impact hazard level index under the influence of geological conditions, N K is the tunnel impact hazard level index under the influence of mining technical conditions, N Z is the tunnel impact hazard level index under comprehensive influence, W t1 for t The amount of gas discharged by the flexible airbag at 1 moment, W t0 is the total air intake of the flexible airbag under the pressure-maintaining state at the initial moment, W Z1 for t Drilling unloading coefficient at moment 1.

[0015] In some embodiments, the drilling status is determined by the unloading coefficient and the mining operation is adjusted, wherein:

[0016] When W Z1 ≤0.25, the drilling state is in the drilling deformation and compaction stage, the mining operation is adjusted to stop mining operation, and additional pressure relief drilling is carried out;

[0017] When 0.25 <W Z1 ≤0.5, the drilling state is in the drilling deformation adjustment stage, and the mining operation is adjusted to reduce the mining operation speed and strengthen the tunnel surrounding rock stress monitoring;

[0018] When 0.5 <W Z1 ≤0.75, the drilling state is in the stage of borehole fracture expansion and development, the mining operation is adjusted to the normal mining operation speed and the tunnel surrounding rock stress monitoring is strengthened;

[0019] When 0.75 <W Z1 The drilling status is in the drilling balance and stable stage, and the mining operation is adjusted to normal mining operation.

[0020] In some embodiments, the distance between the airbag in the tunnel and the opening of the tunnel drilling hole is 12 to 20 meters.

[0021] In some embodiments, when W Z1 ≤0.5, strengthen the support of the tunnel.

[0022] In some embodiments, a foam block bonded to the airbag is provided on the outer peripheral surface of the airbag.

[0023] In some embodiments, the number of the airbags is multiple, and the multiple airbags are arranged in the drilled holes of the tunnel and connected in sequence.

[0024] In some embodiments, the airbag is made of rubber.

[0025] In some embodiments, the airbag is spherical, hemispherical, or cylindrical in shape.

[0026] In some embodiments, a reflective strip is provided on the airbag. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram of drilling in a method for evaluating pressure relief effects of large-diameter drilling according to an embodiment of the present invention.

[0028] Figure 2 Schematic diagram of drilling and airbag in the method for evaluating pressure relief effect of large-diameter drilling according to an embodiment of the present invention.

[0029] Figure 3 This is a flow chart of a method for evaluating the pressure relief effect of large-diameter drilling according to an embodiment of the present invention.

[0030] Reference numerals:

[0031] Air bag 1, tunnel 2, tunnel surrounding rock 3, drill hole 4, air supply component 5, air collecting component 6. DETAILED DESCRIPTION

[0032] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0033] The method for evaluating the pressure relief effect of a large-diameter borehole according to an embodiment of the present invention includes the following steps: S100: installing an airbag 1 in a borehole of a tunnel 2 and monitoring the amount of air flowing in and out of the airbag 1. S200: determining the impact hazard level of the tunnel 2 under the influence of geological conditions and the impact hazard level of the tunnel 2 under the influence of mining technical conditions for the tunnel surrounding rock 3. S300: evaluating the pressure relief effect of the borehole based on the amount of air flowing in and out of the airbag 1, the impact hazard level of the tunnel 2 under the influence of geological conditions, and the impact hazard level of the tunnel 2 under the influence of mining technical conditions. S400: adjusting mining operations based on the pressure relief effect.

[0034] Specifically, an airbag 1 is set in the drilled hole of the tunnel 2, and the amount of air in and out of the airbag 1 is monitored. For example, an air supply component 5 and an air collecting component 6 are set for the airbag 1. The air supply component 5 supplies air to the airbag 1 and records the total air intake of the airbag 1 under the set pressure. The air collecting component 6 is used to collect the amount of gas discharged by the airbag 1 when the airbag 1 changes.

[0035] The impact hazard level of tunnel 2 under the influence of geological conditions and the impact hazard level of tunnel 2 under the influence of mining technical conditions are determined, and then the tunnel surrounding rock 3 is analyzed.

[0036] The drilling pressure relief effect is evaluated by the amount of air in and out of the airbag 1, the impact hazard level of tunnel 2 under the influence of geological conditions, and the impact hazard level of tunnel 2 under the influence of mining technical conditions. Different methods are used to adjust the mining operation according to different pressure relief effects.

[0037] An air bag 1 is set in the borehole of the tunnel 2, and the stress state and deformation of the tunnel surrounding rock 3 are reflected by monitoring the air inlet and outlet of the air bag 1. When the tunnel surrounding rock 3 is under pressure, the borehole changes and the air bag 1 is compressed and deformed, causing the internal gas to be compressed and discharged. At the same time, geological conditions and mining conditions will affect the drilling pressure relief effect. Geological factors and mining technical conditions have a certain impact on the effect of drilling pressure relief. During the drilling pressure relief process, it is necessary to consider the role of these factors and take corresponding measures to optimize the drilling pressure relief plan. For example, in areas with complex geological conditions, the number and location of pressure relief boreholes can be increased, and more effective support methods can be adopted in areas with high mining intensity. The pressure relief effect of large-diameter boreholes is determined by monitoring the air inlet and outlet of the air bag 1 and the impact of geological conditions and mining conditions on the tunnel surrounding rock 3, and the mining operation is adjusted according to the drilling pressure relief effect.

[0038] The embodiment of the present invention is based on a method for evaluating the pressure relief effect of large-diameter drilling. This application sets an airbag 1 to monitor the degree of change in the spatial structure of the surrounding rock of the drilling in real time throughout the entire process. At the same time, according to the impact hazard level of tunnel 2 under the influence of geological conditions and the impact hazard level of tunnel 2 under the influence of mining technical conditions, the pressure relief effect of large-diameter drilling can be monitored more comprehensively. At the same time, the mining operation can be adjusted according to the drilling pressure relief effect to improve the safety of the mining operation.

[0039] In some embodiments, the impact hazard level of the tunnel 2 under the combined influence of geological conditions and mining technical conditions is determined to determine the impact hazard level of the tunnel 2 under the combined influence.

[0040] The unloading coefficient of the borehole is determined by the impact hazard level of tunnel 2 under the influence of geological conditions, the impact hazard level of tunnel 2 under the influence of mining technical conditions, the impact hazard level of tunnel 2 under the comprehensive influence and the amount of air in and out of airbag 1.

[0041] The unloading coefficient is used to evaluate the pressure relief effect and determine the state of the borehole. The unloading coefficient of the borehole is determined by the following formula:

[0042] , ,

[0043] in, N D is the impact hazard level index of tunnel 2 under the influence of geological conditions, N K is the impact hazard level index of tunnel 2 under the influence of mining technical conditions, N Z is the impact hazard level index of tunnel 2 under comprehensive influence, W t1 for t The amount of gas discharged from the flexible airbag 1 at one moment, W t0 is the total air intake of the flexible airbag 1 under the pressure-maintaining state at the initial moment, W Z1 for t Drilling unloading coefficient at moment 1. W Z1 、 N D 、N K 、 N Z are all constants.

[0044] Specifically, the unloading coefficient uses a comprehensive index, a multi-factor coupled rock burst hazard assessment method, and monitoring of the inflow and outflow of airbag 1 to comprehensively evaluate the borehole's pressure relief effect. This not only takes into account the changes in the borehole itself that affect the pressure relief effect, but also derives the unloading coefficient from geological conditions and mining conditions. The unloading coefficient is used to comprehensively evaluate the unloading effect and classify the unloading coefficient, thereby more reasonably determining the borehole's status and improving the accuracy of the borehole's pressure relief effect and the unloading coefficient. The following is a decomposition of the unloading coefficient, along with adjustments to the corresponding borehole status and mining work, and a system for evaluating the unloading and anti-rock burst performance established in conjunction with the unloading index.

[0045]

[0046] That is, the unloading coefficient is used to determine the drilling status and adjust the mining operation, among which,

[0047] When W Z1 ≤0.25, the drilling state is in the drilling deformation and compaction stage, the mining operation is adjusted to stop mining operation, and additional pressure relief drilling is carried out;

[0048] When 0.25 <W Z1 ≤0.5, the drilling state is in the drilling deformation adjustment stage, and the mining operation is adjusted to reduce the mining operation speed and strengthen the stress monitoring of the tunnel surrounding rock 3;

[0049] When 0.5 <W Z1 ≤0.75, the drilling state is in the stage of borehole fracture expansion and development, the mining operation is adjusted to the normal mining operation speed and the tunnel surrounding rock stress monitoring is strengthened;

[0050] When 0.75 <W Z1 The drilling status is in the drilling balance and stable stage, and the mining operation is adjusted to normal mining operation.

[0051] By grading the unloading coefficient, the time it takes for the borehole to exert its pressure relief effect can be determined based on the different grading conditions, allowing for a quantitative assessment of the drilling status. Furthermore, based on the different grading conditions of the unloading coefficient, adjustments can be made to the drilling operation under different conditions.

[0052] For example, when a borehole fails, a pressure relief borehole can be drilled in time, or the mining operation can be adjusted to strengthen support or drill additional boreholes.

[0053] The embodiment of the present invention is based on a method for evaluating the decompression effect of large-diameter drilling. This application sets an airbag 1 to monitor the degree of change in the spatial structure of the surrounding rock of the borehole in real time throughout the entire process. At the same time, according to the impact hazard level of tunnel 2 under the influence of geological conditions and the impact hazard level of tunnel 2 under the influence of mining technical conditions, the decompression state of the borehole is quantitatively graded for evaluation. The decompression state of the borehole is quantified with a more intuitive digital grade, which not only facilitates the accurate acquisition of the decompression state of the borehole, but also facilitates underground mining personnel to understand the load operation, thereby improving the safety and convenience of mining operations.

[0054] In some embodiments, the distance between the airbag in the tunnel and the tunnel borehole opening is 12-20 meters. After tunnel excavation, the stress equilibrium state is disrupted by mining disturbances, the surrounding rock deformation is partitioned, and stress is redistributed, forming plastic zones, elastic zones, and in-situ stress zones in the tunnel surrounding rock. Placing the airbag 11 in the tunnel surrounding rock plastic zone provides better monitoring results. Existing technology has determined that the plastic zone ranges from 12-20 meters. Therefore, the airbag 11 should be placed within 12-20 meters of the tunnel borehole opening to improve monitoring accuracy.

[0055] In some embodiments, when W Z1 ≤0.5, strengthen the support of Tunnel 2. For example, add anchor support or single column support to improve the stability and safety of Tunnel 2.

[0056] In some embodiments, a foam block is bonded to the outer circumference of the airbag 1. This facilitates positioning of the airbag 1 by applying a certain degree of compression to the airbag 1 within the borehole to limit its position. This prevents movement of the airbag 1 during mining or due to stress changes in the geological conditions and surrounding rock 3 of the tunnel. This improves the accuracy of the unloading coefficient calculation, minimizes errors, and enhances the stability and safety of monitoring the borehole's pressure relief effect.

[0057] In some embodiments, the airbags 1 are provided in multiple numbers, each of which is arranged in a sequentially connected sequence within the borehole of the tunnel 2. This allows for comprehensive monitoring of the tunnel 12m to 20m adjacent to the borehole, improving the stability and safety of monitoring the borehole's pressure relief effect. Furthermore, the airbags 1 are made of rubber. Rubber can withstand a certain amount of pressure during use while maintaining its shape and stability. Furthermore, rubber also exhibits excellent wear resistance, aging resistance, and airtightness, enhancing the stability of the airbags 1 during use.

[0058] In some embodiments, the shape of the airbag 1 can be spherical, hemispherical or cylindrical. Different types of airbags 1 can be selected according to actual use requirements.

[0059] In some embodiments, the airbag 1 is provided with a reflective strip to facilitate the operator to see and operate the airbag 1 when the airbag 1 is installed, thereby improving the convenience of installation.

[0060] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are 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 should not be understood as limiting the present invention.

[0061] 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 the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0062] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0063] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0064] In the present invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples" mean that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification, as well as features of different embodiments or examples, unless they are mutually inconsistent.

[0065] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A method for evaluating the pressure relief effect of large-diameter drilling, characterized in that: include: An air bag is installed in the drilled hole of the tunnel and the amount of air in and out of the air bag is monitored; Determine the tunnel impact hazard level of tunnel surrounding rock under the influence of geological conditions and the tunnel impact hazard level under the influence of mining technical conditions; The drilling pressure relief effect is evaluated by the amount of air in and out of the airbag, the tunnel impact hazard level under the influence of geological conditions, and the tunnel impact hazard level under the influence of mining technical conditions; Adjust mining operations based on pressure relief effects; The tunnel impact hazard level under the combined influence of geological conditions and mining technical conditions is used to determine the tunnel impact hazard level. The unloading coefficient of the borehole is determined by the tunnel impact hazard level under the influence of geological conditions, the tunnel impact hazard level under the influence of mining technical conditions, the tunnel impact hazard level under the comprehensive influence and the amount of air in and out of the air bag. The unloading coefficient is used to evaluate the pressure relief effect and determine the state of the borehole. The unloading coefficient of the borehole is determined by the following formula: ， ， in, N D is the tunnel impact hazard level index under the influence of geological conditions, N K is the tunnel impact hazard level index under the influence of mining technical conditions, N Z is the tunnel impact hazard level index under comprehensive influence, W t1 for t The amount of gas discharged by the flexible airbag at 1 moment, W t0 is the total air intake of the flexible airbag under the pressure-maintaining state at the initial moment, W Z1 for t The drilling unloading coefficient at the moment 1; through the unloading coefficient, the drilling state is determined and the mining operation is adjusted, among which, when W Z1 ≤0.25, the drilling state is in the drilling deformation and compaction stage, the mining operation is adjusted to stop mining operation, and additional pressure relief drilling is carried out; When 0.25< W Z1 ≤0.5, the drilling state is in the drilling deformation adjustment stage, and the mining operation is adjusted to reduce the mining operation speed and strengthen the tunnel surrounding rock stress monitoring; When 0.5< W Z1 ≤0.75, the drilling state is in the stage of borehole fracture expansion and development, the mining operation is adjusted to the normal mining operation speed and the tunnel surrounding rock stress monitoring is strengthened; When 0.75< W Z1 The drilling status is in the drilling balance and stable stage, and the mining operation is adjusted to normal mining operation.

2. The method for evaluating the pressure relief effect based on large-diameter drilling according to claim 1, characterized in that: The distance between the air bag in the tunnel and the opening of the tunnel drilling hole is 12~20m.

3. The method for evaluating the pressure relief effect based on large-diameter drilling according to claim 1, characterized in that: when W Z1 ≤0.5, strengthen the support of the tunnel.

4. The method for evaluating the pressure relief effect based on large-diameter drilling according to claim 1, characterized in that: A foam block adhered to the airbag is provided on the outer peripheral surface of the airbag.

5. The method for evaluating the pressure relief effect based on large-diameter drilling according to claim 1, characterized in that: There are multiple air bags, and the multiple air bags are arranged in the drilled holes of the tunnel and are connected in sequence.

6. The method for evaluating the pressure relief effect based on large-diameter drilling according to claim 1, characterized in that: The material of the airbag is rubber.

7. The method for evaluating the pressure relief effect based on large-diameter drilling according to claim 1, characterized in that: The shape of the airbag is spherical, hemispherical or cylindrical.

8. The method for evaluating the pressure relief effect based on large-diameter drilling according to claim 1, characterized in that: The airbag is provided with a reflective strip.

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