Method for testing influence of coal seam borehole hydraulic cavitation on stress of surrounding coal body
By placing stress testing elements inside the test hole, stress changes during and after the hydraulic cavity creation process in coal seam drilling can be detected in real time. This solves the problem that existing technologies cannot accurately assess the impact of hydraulic cavity creation in coal seam drilling on the stress of the surrounding coal body, and improves the accuracy and safety of the detection.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-18
- Publication Date
- 2026-04-10
AI Technical Summary
Existing technologies cannot accurately detect the stress impact of hydraulic cavity creation in coal seam drilling on the surrounding coal body, resulting in significant safety hazards.
Stress testing elements are placed inside the test hole. Hydraulic cavity creation is performed at the target location of the cavity creation hole. The test results of the stress testing elements are obtained during and after the operation to analyze the impact of hydraulic cavity creation in coal seam drilling on the stress of the surrounding coal body.
It enables rapid and accurate detection of the impact of hydraulic cavity creation in coal seam drilling on the stress of the surrounding coal body, reducing safety hazards.
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Figure CN119777858B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of coal seam mining technology, and in particular to a test method for the effect of hydraulic cavity creation in coal seam drilling on the stress of the surrounding coal body. Background Technology
[0002] Most coal seams in my country are characterized by heterogeneity, high gas content, low permeability, and low gas saturation. Soft, low-permeability coal seams account for a large proportion of mineable coal seams in my country. Soft, low-permeability coal seams often have low permeability, which makes gas extraction difficult, causing an imbalance in the mine's "extraction-excavation-mining" process, creating significant safety hazards, and laying the groundwork for coal mine gas accidents.
[0003] Some related technologies primarily employ hydraulic cavitation through coal seam drilling to improve the permeability and aeration of coal seams. This involves drilling into the coal seam and injecting high-pressure water, which then jets out large amounts of coal, creating cracks and cavities to improve the coal seam structure and provide space for gas seepage and emission. While this effectively increases coal seam permeability, the drilling, cracks, and cavities all have negative impacts on the surrounding coal seam. Currently, the extent of these negative impacts cannot be assessed, posing significant safety hazards and remaining a major technical challenge in coal mine operations.
[0004] Therefore, how to solve the problem of the inability to accurately detect the stress impact of hydraulic cavity creation in coal seam drilling on the surrounding coal body has become an important technical problem to be solved by those skilled in the art. Summary of the Invention
[0005] This invention provides a test method for the effect of hydraulic cavity creation in coal seam drilling on the stress of surrounding coal body, in order to solve the defect in related technologies that cannot accurately detect the stress effect of hydraulic cavity creation in coal seam drilling on surrounding coal body.
[0006] This invention provides a method for testing the impact of hydraulic cavity creation in coal seam drilling on the stress of surrounding coal, comprising:
[0007] Determine the target location of the test hole based on the target location of the cavity-building hole;
[0008] The test hole is machined at the target location of the test hole;
[0009] A stress testing element is placed inside the test hole, and the stress testing element is adapted to detect the stress state around the test hole.
[0010] Perform hydraulic cavity creation operation at the target location of the cavity-creating hole;
[0011] During the hydraulic cavity creation operation and within a target time period after the hydraulic cavity creation operation is completed, the detection results of the stress testing element are obtained.
[0012] According to the coal seam drilling hydraulic cavity forming method for testing the influence of surrounding coal stress, each cavity forming hole in each group is distributed at intervals along the extension direction of the roadway.
[0013] Each cavity forming hole corresponds to a group of test holes, and at least one test hole is arranged corresponding to each adjacent two cavity forming holes.
[0014] According to the coal seam drilling hydraulic cavity forming method for testing the influence of surrounding coal stress, each cavity forming hole in each group is distributed at intervals along the extension direction of the roadway.
[0015] According to the coal seam drilling hydraulic cavity forming method for testing the influence of surrounding coal stress, the height of the cavity forming hole is greater than the height of the test hole, and the distance between the cavity forming hole and the test hole along the height direction of the coal wall is 0.1-0.3 meters.
[0016] The distance between the cavity forming hole and the test hole along the extension direction of the roadway is 1.0-3.5 meters.
[0017] According to the coal seam drilling hydraulic cavity forming method for testing the influence of surrounding coal stress, each group of test holes includes four test holes, and each group of cavity forming holes includes three cavity forming holes.
[0018] The distance between adjacent test holes and cavity forming holes along the extension direction of the roadway is 1 meter, 1.5 meters, 2.0 meters, 2.5 meters and 3 meters, respectively.
[0019] According to the coal seam drilling hydraulic cavity forming method for testing the influence of surrounding coal stress, the cavity forming hole needs to be processed into at least two groups, and each group of cavity forming holes is distributed at intervals along the extension direction of the roadway.
[0020] According to the coal seam drilling hydraulic cavity forming method for testing the influence of surrounding coal stress, the hydraulic cavity forming operation is performed at the target position of the cavity forming hole, which comprises:
[0021] The cavity forming hole is processed at the target position of the cavity forming hole, and the hydraulic cavity is processed at multiple positions in the depth direction of the cavity forming hole.
[0022] Among the hydraulic cavities corresponding to each cavity forming hole, the one closest to the coal wall is called the first hydraulic cavity, and the processing depth of the test hole is greater than or equal to the depth of the first hydraulic cavity.
[0023] According to the coal seam drilling hydraulic hole forming method for testing the influence of the surrounding coal body stress, when each hydraulic hole is processed, the hole forming pressure is adjusted according to a first preset time interval;
[0024] When the total hole forming time of each hydraulic hole reaches a preset time and the coal output of each hydraulic hole reaches a preset coal output, the hydraulic hole forming operation is stopped.
[0025] According to the coal seam drilling hydraulic hole forming method for testing the influence of the surrounding coal body stress, the detection result of the stress testing element is obtained during the hydraulic hole forming operation and within a target time after the hydraulic hole forming operation, and the detection result of the stress testing element includes:
[0026] During the hydraulic hole forming operation, the detection result of the stress testing element is obtained according to a second preset time interval;
[0027] Within the target time after the hydraulic hole forming operation, the detection result of the stress testing element is obtained according to a third preset time interval.
[0028] According to the coal seam drilling hydraulic hole forming method for testing the influence of the surrounding coal body stress, the diameter of the test hole is 40-50 mm.
[0029] In the coal seam drilling hydraulic hole forming method for testing the influence of the surrounding coal body stress, the target position of the test hole is determined according to the target position of the hole forming hole, and then the test hole is processed at the target position of the test hole. The stress testing element in the test hole can detect the stress state around the test hole. The hydraulic hole forming operation is performed at the target position of the hole forming hole, and the detection result of the stress testing element is obtained during the hydraulic hole forming operation and within a target time after the hydraulic hole forming operation. In this way, before the hydraulic hole forming, the test hole is processed around the target position of the hole forming hole, and the stress testing element is placed in the test hole, and then the hydraulic hole forming operation is performed at the target position of the hole forming hole. During the hydraulic hole forming operation and within a certain period of time after the hydraulic hole forming operation, the stress state around the test hole can be detected in real time by the stress testing element. According to the detection result of the stress testing element, the influence of the coal seam drilling hydraulic hole forming on the surrounding coal body stress can be analyzed and determined, and the stress testing element is detected during the construction process of the hydraulic hole forming site, which is fast and accurate, and solves the problem that the influence of the coal seam drilling hydraulic hole forming on the surrounding coal body stress cannot be accurately detected in the related art. BRIEF DESCRIPTION OF DRAWINGS
[0030] In order to more clearly illustrate the technical solutions of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings described below are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort based on these drawings.
[0031] Figure 1 The flow chart of the method for testing the influence of the coal seam drilling hydraulic cavitation on the stress of the surrounding coal body is provided by the present application.
[0032] Figure 2 The schematic diagram of the relative position of the cavitation hole and the test hole in the overhead direction is provided by the present application.
[0033] Figure 3 The schematic diagram of the relative position of the cavitation hole and the test hole on the coal wall is provided by the present application.
[0034] Reference signs:
[0035] 1, cavitation hole; 2, test hole; 3, stress test element; 4, hydraulic cavity; 5, first hydraulic cavity; 6, roadway; 7, coal wall. DETAILED DESCRIPTION
[0036] In order to make the purpose, technical solutions and advantages of the present application more clear, the technical solutions in the present application will be described clearly and completely in the following by combining the drawings in the present application. Obviously, the described embodiments are only some embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative effort belong to the protection scope of the present application.
[0037] In the description of the embodiments of the present application, it should be noted that the orientations or positional relationships indicated by the terms “center”, “longitudinal”, “transverse”, “upper”, “lower”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inner”, “outer” and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the embodiments of the present application. In addition, the terms “first”, “second”, “third” are only for the purpose of description, and cannot be understood as indicating or implying relative importance.
[0038] In the description of the embodiments of the present application, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected", "connected" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.
[0039] In the embodiments of the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature, which can be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature "above", "over" and "on" the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "under" and "under" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.
[0040] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any suitable manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine the different embodiments or examples described in the present application and the features of the different embodiments or examples without contradiction.
[0041] The following will be described in combination with Figures 1 to 3 The present application describes a test method for the influence of coal seam drilling hydraulic cavitation on the stress of the surrounding coal body.
[0042] As Figure 1 and Figure 3 The test method for the influence of coal seam drilling hydraulic cavitation on the stress of the surrounding coal body provided by the embodiments of the present application mainly includes steps 110 to 150.
[0043] Step 110, according to the target position of the cavitation hole, determine the target position of the test hole.
[0044] Step 120, process the test hole at the target position of the test hole.
[0045] Step 130, place a stress test element in the test hole, the stress test element is suitable for detecting the stress state around the test hole.
[0046] Step 140, hydraulic cavitation operation is performed at the target position of the cavitation hole.
[0047] Step 150, during the hydraulic cavitation operation and within a target time after the hydraulic cavitation operation, the detection result of the stress testing element is obtained.
[0048] That is, before the hydraulic cavitation, the test hole 2 is processed around the target position of the cavitation hole 1, and the stress testing element 3 is placed in the test hole 2. Then the hydraulic cavitation operation is performed at the target position of the cavitation hole 1. During the hydraulic cavitation operation and within a certain period of time after the hydraulic cavitation operation, the stress state around the test hole 2 can be detected in real time by the stress testing element 3.
[0049] In this way, according to the detection result of the stress testing element 3, the influence of the coal seam drilling hydraulic cavitation on the surrounding coal stress can be analyzed and determined, and the stress testing element 3 is detected during the construction process of the hydraulic cavitation site, which is fast and accurate, and solves the problem that the influence of the coal seam drilling hydraulic cavitation on the surrounding coal stress cannot be accurately detected in the related art.
[0050] Specifically, the stress testing element 3 described above can be a borehole stress meter.
[0051] In the embodiment of the present application, the cavitation holes 1 are processed in groups, each group of cavitation holes 1 includes a plurality of cavitation holes 1, and each cavitation hole 1 is distributed along the extension direction of the roadway 6. Specifically, the distance between two adjacent cavitation holes 1 along the extension direction of the roadway 6 is 3.5-5.0 meters.
[0052] Each group of cavitation holes 1 corresponds to a group of test holes 2, and at least one test hole 2 is provided corresponding to each adjacent two cavitation holes 1. That is, each test hole 2 is also distributed along the extension direction of the roadway 6 around the cavitation hole 1.
[0053] In this way, by analyzing the detection results of the stress testing elements 3 in each test hole 2, the influence of accidental factors, special positions and other special factors on the accuracy of the stress analysis results can be avoided.
[0054] The diameter of the cavitation hole 1 is generally set to 120 mm, and in the embodiment, the diameter of the test hole 2 is 40-50 mm. Specifically, the diameter of the test hole 2 can be set to 45 mm.
[0055] In a further embodiment, each cavitation hole 1 in each group is distributed with each test hole 2 in each group, that is, one test hole 2 corresponds to any two adjacent cavitation holes 1, and one cavitation hole 1 corresponds to any two adjacent test holes 2.
[0056] The distance between any two adjacent ones of the spaced distribution of the each cavitation hole 1 and the test hole 2 is different. That is, each stress test element 3 is used to detect the stress state at a position with a different distance from the cavitation hole 1, and each stress test element 3 corresponds to a distance. Through the detection of each stress test element 3, the stress state at different distance positions around the cavitation hole 1 is obtained, and the stress influence of the coal seam drilling hydraulic cavitation operation on the coal body at different distance positions around can be determined, which has higher reference value.
[0057] In the embodiment of the present application, the height of the cavitation hole 1 is greater than the height of the test hole 2. The distance between the cavitation hole 1 and the test hole 2 along the height direction of the coal wall 7 is 0.1-0.3 meters.
[0058] The coal wall 7 is located on both sides of the roadway 6 in the extension direction of the roadway 6. Specifically, the test hole 2 can be processed at a position 1.7 meters away from the bottom of the coal wall 7, and the cavitation hole 1 can be processed at a position 2 meters away from the bottom of the coal wall 7, and at this time, the distance between the cavitation hole 1 and the test hole 2 along the height direction of the coal wall 7 is 0.3 meters.
[0059] In the embodiment, when the target position of the test hole 2 is determined according to the target position of the cavitation hole 1, the distance between the cavitation hole 1 and the test hole 2 needs to be ensured. The distance between the cavitation hole 1 and the test hole 2 along the extension direction of the roadway 6 is 1.0-3.5 meters.
[0060] In the specific embodiment, each group of test holes 2 includes four test holes 2, and each group of cavitation holes 1 includes three cavitation holes 1. One cavitation hole 1 is arranged between adjacent two test holes 2, and the distance between the adjacent test hole 2 and the cavitation hole 1 is 1 meter, 1.5 meters, 2.0 meters, 2.5 meters and 3 meters respectively, Figure 2 and Figure 3 In the specific embodiment, the distance between the adjacent test hole 2 and the cavitation hole 1 is 1 meter, 1.5 meters, 2.0 meters, 2.5 meters and 3 meters respectively, Figure 2 only the numerical value of the distance is marked, and the unit of the distance is not marked, and the unit is meter.
[0061] In this way, the distance between the adjacent test hole 2 and the cavitation hole 1 is distributed in equal difference, which can facilitate the statistical analysis of the detection results and improve the statistical analysis efficiency.
[0062] In the embodiment, at least two groups of cavitation holes 1 need to be processed, and each group of cavitation holes 1 is spaced along the extension direction of the roadway 6. The stress influence of different positions in the extension direction of the roadway 6 can be tested to reduce the safety hazard as much as possible.
[0063] In the embodiment of the present application, the hydraulic cavitation operation is performed at the target position of the cavitation hole, which includes steps 141 and 142.
[0064] Step 141, processing the cavitation hole at the target position of the cavitation hole.
[0065] Step 142, machining the hydraulic holes 4 at multiple positions in the depth direction of the hole-making hole.
[0066] That is, in the depth direction of the hole-making hole 1, the multiple hydraulic holes 4 corresponding to each hole-making hole 1 are distributed at intervals.
[0067] The one closest to the coal wall 7 in each hydraulic hole 4 corresponding to each hole-making hole 1 is referred to as the first hydraulic hole 5. In the embodiment, the machining depth of the test hole 2 is also determined according to the distance between the first hydraulic hole 5 and the coal wall 7. Specifically, the machining depth of the test hole 2 can be greater than or equal to the depth at which the first hydraulic hole 5 is located.
[0068] The stress testing element 3 can be placed at the bottom of the test hole 2, which is the end of the test hole 2 away from the coal wall 7.
[0069] The stress testing element 3 can also be placed at a position with a distance of the depth at which the first hydraulic hole 5 is located from the coal wall 7.
[0070] In a specific embodiment, the depth at which the first hydraulic hole 5 is located can be 16 meters, the depth of the hole-making hole 1 can be 100 meters, and each hole-making hole 1 can correspond to 7-10 hydraulic holes 4. During the hydraulic hole-making operation, when the hole-making hole 1 is machined to 16 meters, the first hydraulic hole 5 is machined in the section with a distance of 15-16 meters from the coal wall 7. After the first hydraulic hole 5 is machined, the hole-making hole 1 is continued to be machined, and the next hydraulic hole 4 is machined at the machining position of the next hydraulic hole 4, and so on.
[0071] In the embodiment, during the hydraulic hole-making operation, the hole-making pressure needs to be adjusted according to the first preset time interval when each hydraulic hole 4 is machined; and the hydraulic hole-making operation is stopped when the total machining time of each hydraulic hole 4 reaches the preset time and the coal yield of each hydraulic hole 4 reaches the preset coal yield.
[0072] Specifically, the first preset time interval is 5 minutes, and the hole-making pressure is 5 MPa, 8 MPa, 10 MPa, 12 MPa, and 15 MPa. When each hydraulic hole 4 is machined, the initial hole-making pressure is 5 MPa, the hole-making pressure is adjusted every five minutes, and the hole-making pressure is increased step by step. The above-mentioned preset time is 30 minutes, and the preset coal yield is 1 cubic meter. The total machining time of each hydraulic hole 4 is not less than 30 minutes, and the coal yield of each hydraulic hole 4 is ensured to reach 1 cubic meter, then the hole-making operation of the hydraulic hole 4 can be stopped.
[0073] In the embodiment, the detection results of the stress testing element are obtained within the target time after the hydraulic hole-making operation is completed, including steps 151 and 152.
[0074] Step 151, during the hydraulic cavitation operation, the detection result of the stress testing element is obtained according to a second preset time interval.
[0075] Step 152, within a target time after the hydraulic cavitation operation, the detection result of the stress testing element is obtained according to a third preset time interval.
[0076] The second preset time interval is 1 minute, the third preset time interval is 1 hour, and the target time is 48 hours.
[0077] That is, during the hydraulic cavitation operation, the detection result of the stress testing element 3 is obtained every 1 minute. Within 48 hours after the hydraulic cavitation operation, the detection result of the stress testing element 3 is obtained every 1 hour.
[0078] In summary, the test method for the influence of the coal seam drilling hydraulic cavitation on the stress of the surrounding coal body provided by the embodiment of the present application belongs to a field in-situ test method. In terms of time, the stress change data of the coal body around each cavitation hole 1 during the hydraulic cavitation operation and within 48 hours after the operation is obtained. In terms of space, the stress change data within the range of 1.0-3.5 meters around each cavitation hole 1 is obtained. Through the analysis of the change rules of the data at different times and spaces, the pressure relief radius of the coal seam drilling hydraulic cavitation can be quickly and accurately measured, and the influence of the coal seam drilling hydraulic cavitation construction on the stress of the surrounding coal body can be accurately evaluated.
[0079] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.
Claims
1. A method for testing the influence of hydraulic cavity creation in coal seam drilling on the stress of surrounding coal, characterized in that, include: Based on the target position of the cavitation hole (1), the target position of the test hole (2) is determined. Each group of cavitation holes (1) corresponds to a group of test holes (2), and at least one test hole (2) is set for each two adjacent cavitation holes (1). The test hole (2) is machined at the target position of the test hole (2); A stress testing element (3) is placed inside the test hole (2), and the stress testing element (3) is adapted to detect the stress state around the test hole (2); Hydraulic cavity creation operation is performed at the target location of the cavity creation hole (1); During the hydraulic cavity creation operation and within the target time after the hydraulic cavity creation operation is completed, the detection results of the stress testing element (3) are obtained; The hydraulic cavity-creating operation at the target location of the cavity-creating hole (1) includes: The cavity (1) is machined at the target position of the cavity (1), and hydraulic cavities (4) are machined at multiple positions in the depth direction of the cavity (1). Among the various hydraulic cavities (4) corresponding to each of the cavity-making holes (1), the one closest to the coal wall (7) is called the first hydraulic cavity (5), and the processing depth of the test hole (2) is greater than or equal to the depth of the first hydraulic cavity (5).
2. The test method for the influence of hydraulic cavity creation in coal seam drilling on the stress of surrounding coal seam according to claim 1, characterized in that, The cavity-forming holes (1) are processed in groups, and each cavity-forming hole (1) in each group is distributed at intervals along the extension direction of the roadway (6).
3. The test method for the influence of hydraulic cavity creation in coal seam drilling on the stress of surrounding coal seam according to claim 2, characterized in that, The hole-making holes (1) of each group and the test holes (2) of each group are staggered, and the distances between any two adjacent holes along the extension direction of the tunnel (6) are different.
4. The test method for the influence of hydraulic cavity creation in coal seam drilling on the stress of surrounding coal seam according to claim 3, characterized in that, The height of the cavity-making hole (1) is greater than the height of the test hole (2), and the distance between the cavity-making hole (1) and the test hole (2) along the height direction of the coal wall (7) is 0.1~0.3 meters; The distance between the hole (1) and the test hole (2) along the extension direction of the tunnel (6) is 1.0 to 3.5 meters.
5. The test method for the influence of hydraulic cavity creation in coal seam drilling on the stress of surrounding coal seam according to claim 3, characterized in that, Each group of test holes (2) includes four test holes (2), and each group of cavitation holes (1) includes three cavitation holes (1). One cavitation hole (1) is provided between two adjacent test holes (2). The distances between adjacent test holes (2) and cavity-making holes (1) along the extension direction of the tunnel (6) are 1 meter, 1.5 meters, 2.0 meters, 2.5 meters and 3 meters, respectively.
6. The test method for the influence of hydraulic cavity creation in coal seam drilling on the stress of surrounding coal seam according to any one of claims 2-5, characterized in that, The cavity-forming holes (1) need to be processed in at least two sets, and each set of cavity-forming holes (1) is distributed at intervals along the extension direction of the tunnel (6).
7. The test method for the influence of hydraulic cavity creation in coal seam drilling on the stress of surrounding coal seam according to any one of claims 2-5, characterized in that, When processing each of the hydraulic cavities (4), the cavitation pressure is adjusted according to the first preset time interval; When the total time for creating each hydraulic cavity (4) reaches a preset time and the amount of coal produced by each hydraulic cavity (4) reaches a preset amount of coal produced, the hydraulic cavity creation operation is stopped.
8. The test method for the influence of hydraulic cavity creation in coal seam drilling on the stress of surrounding coal seam according to any one of claims 2-5, characterized in that, The acquisition of the detection results of the stress testing element (3) during the hydraulic cavity creation operation and within the target time after the hydraulic cavity creation operation is completed includes: During the hydraulic cavity creation operation, the detection results of the stress testing element (3) are obtained according to the second preset time interval; Within the target time after the completion of the hydraulic cavity creation operation, the detection results of the stress testing element (3) are obtained according to the third preset time interval.
9. The test method for the influence of hydraulic cavity creation in coal seam drilling on the stress of surrounding coal seam according to any one of claims 2-5, characterized in that, The diameter of the test hole (2) is 40~50 mm.
Citation Information
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