Pressure relief range measuring method for pressure relief drill hole

Abstract

The embodiment of the invention provides a pressure relief range measuring method for a pressure relief drill hole. The method for measuring the pressure relief range of the pressure relief drill hole comprises the following steps: acquiring an initial strain value of a sensing optical fiber, and then acquiring real-time strain values of a plurality of acquisition points of the sensing optical fiber for multiple times so as to obtain a plurality of strain value variations which are acquired at the same time and have stable values; the multiple strain value variations comprise negative segments and non-negative segments which are alternately arranged, the pressure relief radius R of the pressure relief drill hole is calculated according to the formula # imgabs0 #, h is the distance between the center point of the pressure relief drill hole and the sensing optical fiber, and L is the arrangement length of the non-negative segments corresponding to the pressure relief drill hole on the sensing optical fiber. According to the pressure relief range measuring method for the pressure relief drill hole, the pressure relief radius of the pressure relief drill hole can be obtained through calculation, whether the pressure relief effect is qualified or not after the pressure relief drill hole is drilled can be judged through the pressure relief radius of the pressure relief drill hole, and the pressure relief range measuring method can also be used for setting the drilling compactness of the pressure relief drill hole.

Description

Technical Field

[0001] The present invention relates to the field of rock and soil pressure relief, and particularly to a method for measuring the pressure relief range of a pressure relief borehole. Background Art

[0002] During the process of ore mining such as coal mines, rock bursts will pose safety hazards. Drilling pressure relief boreholes is one of the effective measures for pressure relief and danger relief. In the related art, there are problems that it is difficult to determine the pressure relief effect after the pressure relief boreholes are drilled, and it is difficult to determine the compactness during the drilling of the pressure relief boreholes. Summary of the Invention

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

[0004] To this end, an embodiment of the present invention provides a method for measuring the pressure relief range of a pressure relief borehole.

[0005] The method for measuring the pressure relief range of a pressure relief borehole according to the embodiment of the present invention includes:

[0006] Set an optical fiber arrangement hole in the rock mass, and arrange a sensing optical fiber in the optical fiber arrangement hole;

[0007] Seal the optical fiber arrangement hole, and then pour grouting material into the optical fiber arrangement hole;

[0008] Set a pressure relief borehole in the rock mass, and the pressure relief borehole is located below the optical fiber arrangement hole;

[0009] When the grouting material solidifies, collect the initial strain value of the sensing optical fiber through an optical time domain reflectometer;

[0010] Collect the real-time strain values of multiple collection points on the sensing optical fiber through the optical time domain reflectometer, and collect multiple times in sequence. Make a difference between each collected multiple real-time strain values and the initial strain value to obtain multiple strain value changes corresponding to each collection. Stop collecting the real-time strain values when the multiple strain value changes obtained in the same collection are all numerically stable;

[0011] The multiple strain value changes obtained in the same collection and all numerically stable include alternately arranged negative segments and non-negative segments. The negative segments include multiple consecutive negative strain value changes, and the non-negative segments include multiple consecutive non-negative strain value changes. The non-negative segment between the starting negative segment and the ending negative segment corresponds to the pressure relief borehole;

[0012] According to the formula The pressure relief radius R of the pressure relief borehole is calculated, where h is the distance between the center point of the pressure relief borehole and the sensing optical fiber, and L is the arrangement length of the non - negative segment corresponding to the pressure relief borehole on the sensing optical fiber.

[0013] The method for measuring the pressure relief range of the pressure relief borehole in the embodiment of the present invention collects the initial strain value and the real - time strain value of the sensing optical fiber located in the optical fiber arrangement hole through an optical time - domain reflectometer, so as to obtain a plurality of strain value changes that are obtained from the same collection and have stable average values, thereby calculating the pressure relief radius of the pressure relief borehole. The pressure relief radius of the pressure relief borehole can be used to judge whether the pressure relief effect after the pressure relief borehole is drilled is qualified, and can also be used to set the density of the pressure relief borehole drilling.

[0014] In some embodiments, there are at least two pressure relief boreholes, and at least two pressure relief boreholes are arranged at intervals along the length direction of the optical fiber arrangement hole;

[0015] There are at least two non - negative segments between the starting negative segment and the ending negative segment. Along the length direction of the optical fiber arrangement hole, at least two non - negative segments correspond to at least two pressure relief boreholes in sequence;

[0016] According to the formula The pressure relief radius R of each pressure relief borehole is calculated.

[0017] In some embodiments, the apertures of at least two pressure relief boreholes are the same; or

[0018] Among at least two pressure relief boreholes, the apertures of some pressure relief boreholes are the same; or

[0019] Among at least two pressure relief boreholes, the apertures of every two pressure relief boreholes are different.

[0020] In some embodiments, when, among the plurality of strain value changes obtained from the subsequent collection, the numerical change of each strain value change compared with the strain value change of the same collection point obtained from the previous collection is less than or equal to 1%, and each strain value change and the strain value change of the same collection point obtained from the previous collection are both negative numbers or both non - negative numbers, the collection of the real - time strain value is stopped;

[0021] The plurality of strain value changes obtained from the last collection before stopping the collection of the real - time strain value are all stable in average value, and include an alternately arranged negative segment and non - negative segment, thereby obtaining the arrangement length of the non - negative segment corresponding to the pressure relief borehole on the sensing optical fiber.

[0022] In some embodiments, in the vertical projection plane, the distance between the projection of the pressure relief borehole and the projection of the optical fiber arrangement hole is 0.3 m to 0.5 m.

[0023] In some embodiments, a chamber is provided on the roadway sidewall of the rock mass, and the optical fiber arrangement hole is drilled on the wall surface of the chamber. The optical fiber arrangement hole extends parallel to or obliquely along the roadway sidewall, and the distance between the optical fiber arrangement hole and the roadway sidewall is greater than or equal to 2 m.

[0024] In some embodiments, the pressure relief borehole is drilled on the roadway sidewall of the rock mass. In the horizontal projection plane, the projection of the pressure relief borehole intersects the projection of the optical fiber arrangement hole, and the depth of the pressure relief borehole from the roadway sidewall is greater than the maximum distance between the optical fiber arrangement hole and the roadway sidewall.

[0025] In some embodiments, the sensing optical fiber is disposed on a bendable and deformable installation pipe, and the installation pipe is inserted into the optical fiber arrangement hole so that the sensing optical fiber is disposed in the optical fiber arrangement hole, and the sensing optical fiber extends from the opening of the optical fiber arrangement hole to the bottom of the optical fiber arrangement hole.

[0026] In some embodiments, after the installation pipe is inserted into the optical fiber arrangement hole, a grouting pipe is inserted into the optical fiber arrangement hole and arranged side by side with the installation pipe;

[0027] After the optical fiber arrangement hole is sealed, grouting material is poured into the optical fiber arrangement hole through the grouting pipe, and the pouring of the grouting material is stopped when the grouting material is discharged through the installation pipe.

[0028] In some embodiments, the optical time domain reflectometer is connected to the sensing optical fiber through a communication optical fiber to collect the initial strain value and the real-time strain value of the sensing optical fiber; and / or

[0029] The acquisition frequency of the optical time domain reflectometer is less than or equal to 0.1 m. Description of the Drawings

[0030] Figure 1 is a construction schematic diagram of the method for measuring the pressure relief range of the pressure relief borehole according to the embodiment of the present invention;

[0031] Figure 2 is Figure 1 a partial enlarged schematic diagram of

[0032] Figure 3 is a schematic diagram of the relative positions of the optical fiber arrangement hole, the pressure relief borehole and the roadway sidewall in the horizontal projection plane according to the embodiment of the present invention;

[0033] Figure 4 is a schematic diagram of the sensing optical fiber and the installation pipe according to the embodiment of the present invention.

[0034] Reference signs:

[0035] 1, working face; 2, track roadway; 3, return airway; 4, sensing optical fiber; 5, communication optical fiber; 6, flange; 7, air door; 8, optical time domain reflectometer; 9, optical fiber arrangement hole; 10, chamber; 11, roadway side; 12, installation pipe; 13, through hole; 14, binding wire; 15, cable tie; 16, pressure relief borehole. Specific embodiments

[0036] The embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present invention, and should not be construed as limiting the present invention.

[0037] Next, refer to Figures 1-4 to describe a method for measuring the pressure relief range of a pressure relief borehole according to an embodiment of the present invention.

[0038] As Figures 1-4 shown, the method for measuring the pressure relief range of a pressure relief borehole according to an embodiment of the present invention includes:

[0039] Set an optical fiber arrangement hole 9 in the rock mass, and set a sensing optical fiber 4 in the optical fiber arrangement hole 9.

[0040] Seal the optical fiber arrangement hole 9, and then pour grouting material into the optical fiber arrangement hole 9.

[0041] Set a pressure relief borehole 16 in the rock mass, and the pressure relief borehole 16 is located below the optical fiber arrangement hole 9.

[0042] When the grouting material solidifies, collect the initial strain value of the sensing optical fiber 4 through the optical time domain reflectometer 8.

[0043] Collect the real-time strain values of multiple collection points on the sensing optical fiber 4 through the optical time domain reflectometer 8, and collect them multiple times in sequence. Subtract the initial strain value from each of the multiple real-time strain values collected each time to obtain the multiple strain value changes corresponding to each collection. Stop collecting the real-time strain values when the multiple strain value changes obtained in the same collection are all numerically stable.

[0044] Specifically, the multiple collection points are arranged at intervals along the length direction of the sensing optical fiber 4, and the interval distance between adjacent collection points is determined by the collection frequency of the optical time domain reflectometer 8.

[0045] A plurality of strain value variations obtained from the same acquisition and with stable average values include negative segments and non - negative segments arranged alternately. The negative segments include a plurality of consecutive negative strain value variations. In other words, all the plurality of strain value variations in the negative segments are negative. The non - negative segments include a plurality of consecutive non - negative strain value variations. In other words, all the plurality of strain value variations in the non - negative segments are non - negative. The non - negative strain value variations can be positive or zero. The non - negative segment between the starting negative segment and the ending negative segment corresponds to the pressure - relief borehole 16.

[0046] According to the formula The pressure - relief radius R of the pressure - relief borehole 16 is calculated, where h is the distance between the center point of the pressure - relief borehole 16 and the sensing optical fiber 4, and L is the arrangement length of the non - negative segment corresponding to the pressure - relief borehole 16 on the sensing optical fiber 4. In other words, L is the arrangement length of the plurality of acquisition points corresponding to all the plurality of strain value variations in the non - negative segment corresponding to the pressure - relief borehole 16 on the sensing optical fiber 4.

[0047] It should be noted that the length part of the plurality of acquisition points corresponding to all the plurality of strain value variations in the negative segment on the sensing optical fiber 4 does not undergo tensile deformation, while the length part of the plurality of acquisition points corresponding to all the plurality of strain value variations in the non - negative segment on the sensing optical fiber 4 undergoes tensile deformation. Therefore, the arrangement length of the non - negative segment on the sensing optical fiber 4 is used to calculate the pressure - relief radius R of the pressure - relief borehole 16, and the negative segment is used to divide the non - negative segment.

[0048] It should be noted that among the multiple real - time strain value acquisitions, the time interval between two adjacent acquisitions can be the same or different.

[0049] The method for measuring the pressure - relief range of the pressure - relief borehole 16 in the embodiments of the present invention acquires the initial strain value and real - time strain value of the sensing optical fiber located in the optical - fiber arrangement hole through an optical time - domain reflectometer, so as to obtain a plurality of strain value variations obtained from the same acquisition and with stable average values, thereby calculating the pressure - relief radius of the pressure - relief borehole. The pressure - relief radius of the pressure - relief borehole can be used to judge whether the pressure - relief effect after the pressure - relief borehole is drilled is qualified, and can also be used to set the density of the pressure - relief borehole drilling.

[0050] In some embodiments, a chamber 10 is provided on the roadway sidewall 11 of the rock mass, and an optical - fiber arrangement hole 9 is drilled on the wall surface of the chamber 10. The optical - fiber arrangement hole 9 extends parallel to the roadway sidewall 11 or extends obliquely along the roadway sidewall 11, and the distance between the optical - fiber arrangement hole 9 and the roadway sidewall 11 is greater than or equal to 2m.

[0051] Such as Figure 1 and Figure 2As shown, the rock mass is preferably but not limited to a coal seam, the coal seam includes a working face 1 and a roadway, the roadway includes a return airway 3, a chamber 10 is provided on the rib 11 of the return airway 3, and a fiber optic arrangement hole 9 is drilled on the wall surface of the chamber 10. The fiber optic arrangement hole 9 can extend parallel to the rib 11 or obliquely along the rib 11. In other words, the extending direction of the fiber optic arrangement hole 9 can be parallel to the extending direction of the rib 11 or have a certain included angle. Preferably, as Figure 2 shown, the fiber optic arrangement hole 9 extends along the rib 11 and is obliquely arranged in a direction away from the return airway 3, and the included angle between the extending direction of the fiber optic arrangement hole 9 and the extending direction of the rib 11 is 2° to 10°, preferably but not limited to 5°.

[0052] The distance between the fiber optic arrangement hole 9 and the rib 11 is greater than or equal to 2 m. In other words, the distance between any position in the length direction of the fiber optic arrangement hole 9 and the rib 11 is greater than or equal to 2 m.

[0053] Drilling the fiber optic arrangement hole 9 on the wall surface of the chamber 10 is convenient for construction on the one hand and ensures the reliability of the obtained pressure relief radius R value on the other hand. The distance between the fiber optic arrangement hole 9 and the rib 11 being greater than or equal to 2 m also ensures the reliability of the obtained pressure relief radius R value.

[0054] In some embodiments, the sensing optical fiber 4 is arranged on a bendable and deformable installation pipe 12, and the installation pipe 12 is inserted into the fiber optic arrangement hole 9 so that the sensing optical fiber 4 is arranged in the fiber optic arrangement hole 9, and the sensing optical fiber 4 extends from the opening of the fiber optic arrangement hole 9 to the bottom of the fiber optic arrangement hole 9.

[0055] As Figure 1 、 Figure 2 and Figure 4 shown, the sensing optical fiber 4 is arranged on a bendable and deformable installation pipe 12. When changes such as settlement occur on the working face 1, the installation pipe 12 bends and deforms along with the deformation of the fiber optic arrangement hole 9 to drive the sensing optical fiber 4 to bend and deform, so as to be collected by an optical time domain reflectometer 8 and obtain a non-negative strain value variation.

[0056] The worker inserts the installation pipe 12 provided with the sensing optical fiber 4 into the fiber optic arrangement hole 9 and abuts against the bottom of the fiber optic arrangement hole 9 so that the sensing optical fiber 4 is arranged in the fiber optic arrangement hole 9, and the sensing optical fiber 4 extends from the opening of the fiber optic arrangement hole 9 to the bottom of the fiber optic arrangement hole 9. In other words, one end of the sensing optical fiber 4 is located at the bottom of the fiber optic arrangement hole 9, and the other end is located at the opening of the fiber optic arrangement hole 9. Thus, the multiple real-time strain values of the sensing optical fiber 4 collected by the optical time domain reflectometer 8 can fully reflect the deformation of the fiber optic arrangement hole 9.

[0057] It should be noted that one end of the installation pipe 12 and one end of the sensing optical fiber 4 are both located at the bottom of the optical fiber arrangement hole 9. The other end of the installation pipe 12 and the other end of the sensing optical fiber 4 can both be located at the opening of the optical fiber arrangement hole 9, or the other end of the installation pipe 12 can be located inside the opening of the optical fiber arrangement hole 9. In other words, the length of the installation pipe 12 can be the same as the length of the optical fiber arrangement hole 9, or shorter than the length of the optical fiber arrangement hole 9.

[0058] In some embodiments, after the installation pipe 12 is inserted into the optical fiber arrangement hole 9, a grouting pipe is inserted into the optical fiber arrangement hole 9 and arranged side by side with the installation pipe 12. After the optical fiber arrangement hole 9 is sealed, grouting material is poured into the optical fiber arrangement hole 9 through the grouting pipe, and the pouring of the grouting material is stopped when the grouting material is discharged through the installation pipe 12.

[0059] Specifically, after the worker inserts the installation pipe 12 into the optical fiber arrangement hole 9, the grouting pipe is inserted into the optical fiber arrangement hole 9. The grouting pipe and the installation pipe 12 are arranged side by side in the optical fiber arrangement hole 9. During the insertion of the grouting pipe, care should be taken to avoid touching and damaging the sensing optical fiber 4.

[0060] After the grouting pipe is inserted into the optical fiber arrangement hole 9, the optical fiber arrangement hole 9 is sealed. The sealing material is preferably but not limited to polyurethane.

[0061] After the optical fiber arrangement hole 9 is sealed, preferably but not limited to after the polyurethane solidifies, the grouting pump connected to the grouting pipe is started, and grouting material is poured into the optical fiber arrangement hole 9 through the grouting pipe. The grouting pump is closed to stop pouring the grouting material when the grouting material flows back and is discharged through the installation pipe 12. To ensure that the optical fiber arrangement hole 9 is completely filled with the grouting material, so as to ensure that the installation pipe 12 can bend and deform with the deformation of the optical fiber arrangement hole 9 when changes such as settlement occur on the working surface 1.

[0062] The grouting material is preferably but not limited to cement mortar. The specific ratio of the cement mortar is set according to the parameters of the coal seam. Preferably, the elastic modulus of the cement mortar is ±5% of the elastic modulus of the coal seam.

[0063] It can be understood that in some other embodiments, the installation pipe and the grouting pipe can also be inserted into the optical fiber arrangement hole together.

[0064] In some embodiments, the installation pipe 12 is preferably but not limited to a PVC pipe, and the sensing optical fiber 4 is preferably but not limited to being bundled on the outer wall surface of the installation pipe 12, as Figure 4 shown.

[0065] Specifically, the mounting tube 12 includes a tip, an opening section and a closed section connected in sequence along the length direction. The tube cavity of the mounting tube 12 is located at least in the opening section and the closed section, and a tube mouth is formed at the end of the closed section away from the opening section. The tip is closed to facilitate insertion into the optical fiber arrangement hole 9 and fixation at the bottom of the optical fiber arrangement hole 9. The length of the closed section is 5 times or more than the length of the opening section. The tube wall of the opening section is provided with a plurality of penetrating through holes 13, and the through holes 13 are connected to the tube cavity of the mounting tube 12.

[0066] The grouting material poured into the optical fiber arrangement hole 9 by the grouting pipe enters the tube cavity of the installation tube 12 through the through hole 13 , then flows back along the tube cavity of the installation tube 12 and is discharged from the tube opening of the installation tube 12 .

[0067] By setting a through hole 13 in the opening section and sealing the tip, it is possible to ensure that the grouting material enters the lumen of the mounting tube 12 through the through hole 13, and to avoid the situation where the entrance of the grouting material is blocked and the grouting material cannot enter the lumen of the mounting tube 12 due to the tip being inserted into the bottom of the optical fiber arrangement hole 9 when the entrance of the grouting material is set at the tip.

[0068] The sensing optical fiber 4 is bundled on the outer wall surface of the opening section and the closed section. Preferably, a tie wire 14 and a tie band 15 are provided on the opening section to bundle the sensing optical fiber 4. The tie wire 14 and the tie band 15 on the opening section are alternately arranged and arranged at intervals along the length direction of the opening section, and the tie bands 15 arranged at intervals are provided on the closed section to bundle the sensing optical fiber 4. This ensures that the sensing optical fiber 4 is installed stably and avoids damage to the sensing optical fiber 4. It should be noted that the tie band 15 is made of plastic material and the tie wire 14 is made of metal material.

[0069] In some embodiments, the diameter of the sensing optical fiber 4 is preferably but not limited to 5.0±0.2 mm, the strain coefficient is preferably but not limited to not less than 499.8 MHz / %, the maximum breaking force is preferably but not limited to not less than 2350 N, and the sensing optical fiber 4 is preferably but not limited to a metal base.

[0070] In some embodiments, a pressure relief borehole 16 is drilled in the sidewall 11 of the rock mass. In the horizontal projection plane, the projection of the pressure relief borehole 16 intersects with the projection of the optical fiber arrangement hole 9 , and the depth of the pressure relief borehole 16 from the sidewall 11 is greater than the maximum distance between the optical fiber arrangement hole 9 and the sidewall 11 .

[0071] like Figure 2 and Figure 3 As shown, a pressure relief borehole 16 is drilled in the tunnel wall 11 of the rock mass, the pressure relief borehole 16 extends in the front-to-back direction, and the optical fiber arrangement hole 9 extends in the left-to-right direction.

[0072] It should be noted that the pressure relief bore 16 may extend horizontally in the front-to-back direction, or may have a certain inclination angle in the vertical direction and / or the left-to-right direction, and preferably extends in the front-to-back direction.

[0073] The optical fiber arrangement hole 9 can extend horizontally in the left - right direction, or can have a certain inclination angle in the vertical direction and / or the front - back direction. Preferably, it extends in the left - right direction, has an included angle of 5° with the roadway side in the front - back direction, and has an included angle of 1° in the vertical direction.

[0074] In the horizontal projection plane, as Figure 3 shown, the projection of the pressure - relief borehole 16 intersects with the projection of the optical fiber arrangement hole 9. The depth of the pressure - relief borehole 16 from the roadway side 11 is W3. The optical fiber arrangement hole 9 has a minimum distance W1 and a maximum distance W2 from the roadway side 11, and W2 is less than W3 to ensure the reliability of the obtained pressure - relief radius R value.

[0075] In some embodiments, in the vertical projection plane, the distance between the projection of the pressure - relief borehole 16 and the projection of the optical fiber arrangement hole 9 is 0.3 m to 0.5 m. In other words, the highest position of the pressure - relief borehole 16 in the vertical direction is lower than the lowest position of the optical fiber arrangement hole 9 in the vertical direction, and the height difference between the highest position of the pressure - relief borehole 16 in the vertical direction and the lowest position of the optical fiber arrangement hole 9 in the vertical direction is 0.3 m to 0.5 m. Thus, it ensures the reliability of the obtained pressure - relief radius R value.

[0076] In some embodiments, the optical time - domain reflectometer 8 is connected to the sensing optical fiber 4 through the communication optical fiber 5 to collect the initial strain value and the real - time strain value of the sensing optical fiber 4.

[0077] As Figure 1 shown, the optical time - domain reflectometer 8 is connected to the sensing optical fiber 4 through the communication optical fiber 5. Specifically, the connection can be made after the grouting material is poured, or can be made after the installation pipe 12 carrying the sensing optical fiber 4 is inserted into the optical fiber arrangement hole 9. Preferably, the connection is made after the grouting material is poured.

[0078] The communication optical fiber 5 and the sensing optical fiber 4 are preferably but not limited to being assisted by a flange 6. Since the sensing optical fiber 4 is located in the optical fiber arrangement hole 9, the flange 6 is located at the opening of the optical fiber arrangement hole 9.

[0079] The roadway of the coal seam also has a track roadway 2. The optical time - domain reflectometer 8 is preferably but not limited to being installed in the track roadway 2. The communication optical fiber 5 reaches the track roadway 2 from the return airway 3 through the air door 7 and is connected to the optical time - domain reflectometer 8 to transmit the signal of the sensing optical fiber 4 to the optical time - domain reflectometer 8.

[0080] In some embodiments, the acquisition frequency of the optical time - domain reflectometer 8 is less than or equal to 0.1 m, preferably but not limited to 0.1 m. In other words, the distance between adjacent acquisition points is less than or equal to 0.1 m, preferably but not limited to 0.1 m. Thus, it ensures the reliability of the obtained pressure - relief radius R value.

[0081] In some embodiments, there are at least two pressure relief boreholes 16, and the at least two pressure relief boreholes 16 are arranged at intervals along the length direction of the optical fiber arrangement hole 9. Specifically, as Figure 3 shown, preferably but not limited to, there are multiple pressure relief boreholes 16, and the multiple pressure relief boreholes 16 are arranged at intervals in the left-right direction. It can be understood that in some other embodiments, there may be only one pressure relief borehole 16.

[0082] There are at least two non-negative segments between the starting negative segment and the ending negative segment. Along the length direction of the optical fiber arrangement hole 9, the at least two non-negative segments correspond to the at least two pressure relief boreholes 16 in sequence. Specifically, the negative segments and the non-negative segments are arranged alternately along the length direction of the corresponding optical fiber arrangement hole 9. The first negative segment is the starting negative segment, the last negative segment is the ending negative segment, and there are multiple non-negative segments between the starting negative segment and the ending negative segment that correspond to the pressure relief boreholes 16 in sequence. In other words, each pressure relief borehole 16 has a corresponding non-negative segment. There is a corresponding negative segment between adjacent non-negative segments.

[0083] According to the formula the pressure relief radius R of each pressure relief borehole 16 is calculated.

[0084] In some embodiments, the apertures of the at least two pressure relief boreholes 16 are the same. Or among the at least two pressure relief boreholes 16, the apertures of some pressure relief boreholes 16 are the same. Or among the at least two pressure relief boreholes 16, the apertures of every two pressure relief boreholes 16 are different.

[0085] For example, in the example as Figure 3 shown, the multiple pressure relief boreholes 16 have three apertures, such as 65 mm, 90 mm, and 108 mm, and there are at least two pressure relief boreholes 16 with each aperture. Thus, the pressure relief radii R corresponding to the pressure relief boreholes 16 with three apertures can be obtained simultaneously, and there are at least two pressure relief radii R for each aperture of the pressure relief boreholes 16 to corroborate each other.

[0086] Furthermore, the pressure relief boreholes 16 can also be arranged in multiple rows at intervals in the vertical direction.

[0087] In some embodiments, when among the multiple strain value changes obtained in the later acquisition, the numerical change of each strain value change compared with the strain value change of the same acquisition point obtained in the previous acquisition is less than or equal to 1%, and each strain value change and the strain value change of the same acquisition point obtained in the previous acquisition are both negative numbers or both non-negative numbers, it is considered that the multiple strain value changes obtained in the later acquisition are all numerically stable, and the acquisition of real-time strain values is stopped.

[0088] The average values of the multiple amounts of change in strain values obtained from the last acquisition before stopping the acquisition of real-time strain values (in other words, the subsequent acquisition described above) are stable, and include negative segments and non-negative segments arranged alternately, so as to obtain the arrangement length of the non-negative segments corresponding to the pressure relief borehole 16 on the sensing optical fiber 4.

[0089] It can be understood that in some other embodiments, the average values of the multiple amounts of change in strain values obtained from the penultimate acquisition before stopping the acquisition of real-time strain values can also be considered stable, and negative segments and non-negative segments arranged alternately can be obtained therefrom.

[0090] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "length", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0091] In the present invention, unless otherwise clearly specified and limited, the terms "mounted", "connected", "connected to", "fixed" and other terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection, an electrical connection or communication with each other; it can be directly connected, or indirectly connected through an intermediate medium, and can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0092] In the present invention, unless otherwise clearly specified and limited, the first feature being "above" or "below" the second feature can be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "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 first feature is at a higher horizontal height than the second feature. The first feature being "below", "under" and "beneath" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the first feature is at a lower horizontal height than the second feature.

[0093] In the present invention, terms such as "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean 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 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 may be combined in any one or more embodiments or examples in a suitable manner. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0094] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for measuring the pressure relief range of a pressure relief borehole, characterized in that: include: Arrange an optical fiber arrangement hole in the rock mass, and arrange a sensing optical fiber in the optical fiber arrangement hole; The optical fiber arrangement hole is sealed, and then the optical fiber arrangement hole is injected with grouting material; A pressure relief borehole is provided in the rock mass, wherein the pressure relief borehole is located below the optical fiber arrangement hole; When the grouting material solidifies, an initial strain value of the sensing optical fiber is collected by an optical time domain reflectometer; The real-time strain values ​​of multiple collection points on the sensing optical fiber are collected by the optical time domain reflectometer, and the real-time strain values ​​are collected multiple times in sequence, and the difference between the multiple real-time strain values ​​collected each time and the initial strain value is made to obtain multiple strain value changes corresponding to each collection, and the real-time strain value collection is stopped when the multiple strain value changes obtained in the same collection are all stable in value; The multiple strain value changes obtained from the same acquisition and having stable values ​​include alternating negative segments and non-negative segments, the negative segment includes multiple strain value changes that are consecutively negative, the non-negative segment includes multiple strain value changes that are consecutively non-negative, and the non-negative segment between the initial negative segment and the final negative segment corresponds to the pressure relief borehole; According to the formula The pressure relief radius R of the pressure relief borehole is calculated, wherein h is the distance between the center point of the pressure relief borehole and the sensing optical fiber, and L is the arrangement length of the non-negative segment corresponding to the pressure relief borehole on the sensing optical fiber.

2. The method for measuring the pressure relief range of a pressure relief borehole according to claim 1, characterized in that: There are at least two pressure relief drill holes, and the at least two pressure relief drill holes are arranged at intervals along the length direction of the optical fiber arrangement hole; There are at least two non-negative segments between the negative segment at the beginning and the negative segment at the end, and along the length direction of the optical fiber arrangement hole, at least two non-negative segments correspond to at least two pressure relief boreholes in sequence; According to the formula The pressure relief radius R of each pressure relief borehole is obtained by calculation.

3. The method for measuring the pressure relief range of a pressure relief borehole according to claim 2, characterized in that: At least two of the pressure relief boreholes have the same aperture; or Among at least two of the pressure relief boreholes, some of the pressure relief boreholes have the same aperture; or Among the at least two pressure relief boreholes, the hole diameters of each of the two pressure relief boreholes are different.

4. The method for measuring the pressure relief range of a pressure relief borehole according to claim 1, characterized in that: When, among the multiple strain value changes obtained in the next acquisition, the value change of each strain value change compared with the strain value change obtained at the same acquisition point at the previous acquisition is less than or equal to 1%, and each strain value change compared with the strain value change obtained at the same acquisition point at the previous acquisition is negative or non-negative, stop acquiring the real-time strain value; The multiple strain value changes obtained from the last collection before stopping the collection of the real-time strain value are all numerically stable and include alternating negative segments and non-negative segments, thereby obtaining the arrangement length of the non-negative segments corresponding to the pressure relief drilling hole on the sensing optical fiber.

5. The method for measuring the pressure relief range of a pressure relief borehole according to claim 1, characterized in that: In the vertical projection plane, the distance between the projection of the pressure relief borehole and the projection of the optical fiber arrangement hole is 0.3m to 0.5m.

6. The method for measuring the pressure relief range of a pressure relief borehole according to claim 1, characterized in that: A chamber is set in the roadway of the rock mass, and the optical fiber arrangement hole is drilled in the wall of the chamber. The optical fiber arrangement hole extends parallel to the roadway or extends obliquely along the roadway, and the distance between the optical fiber arrangement hole and the roadway is greater than or equal to 2m.

7. The method for measuring the pressure relief range of a pressure relief borehole according to claim 1, characterized in that: The pressure relief borehole is drilled in the lane side of the rock mass, and in the horizontal projection plane, the projection of the pressure relief borehole intersects with the projection of the optical fiber arrangement hole, and the depth of the pressure relief borehole from the lane side is greater than the maximum distance between the optical fiber arrangement hole and the lane side.

8. The method for measuring the pressure relief range of a pressure relief borehole according to claim 1, characterized in that: The sensing optical fiber is arranged on a bendable and deformable mounting tube, and the mounting tube is inserted into the optical fiber arrangement hole so that the sensing optical fiber is arranged in the optical fiber arrangement hole, and the sensing optical fiber extends from the opening of the optical fiber arrangement hole to the bottom of the optical fiber arrangement hole.

9. The method for measuring the pressure relief range of a pressure relief borehole according to claim 8, characterized in that: After the installation tube is inserted into the optical fiber arrangement hole, a grouting tube is inserted into the optical fiber arrangement hole and arranged side by side with the installation tube; After the optical fiber arrangement hole is sealed, grouting material is poured into the optical fiber arrangement hole through the grouting pipe, and the pouring of the grouting material is stopped when the grouting material is discharged through the installation pipe.

10. The method for measuring the pressure relief range of a pressure relief borehole according to claim 1, characterized in that: The optical time domain reflectometer is connected to the sensing optical fiber via a communication optical fiber to collect the initial strain value and the real-time strain value of the sensing optical fiber; and / or The acquisition frequency of the optical time domain reflectometer is less than or equal to 0.1 m.

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