Drilling sound wave testing device and method suitable for fractured rock mass

Abstract

The invention discloses a drilling sound wave testing device and method suitable for fractured rock mass, and the device comprises an outer cylinder which is provided with a mounting cavity in the center; the sound wave emission probe is mounted in the mounting cavity; the sound wave receiving probe is mounted in the mounting cavity; the number of the inflatable sealing discs is two, the two inflatable sealing discs are both installed on the periphery of the outer cylinder and located at the upper end and the lower end of the outer cylinder correspondingly, and the inflatable sealing discs can be inflated so that the periphery can be expanded to make sealing contact with the hole wall; and the inflating and exhausting mechanism is partially arranged in the mounting cavity in a penetrating manner and is used for inflating or exhausting the inflating sealing disc. According to the device disclosed by the invention, the two inflatable sealing discs which are respectively mounted at the upper end and the lower end of the outer cylinder are adopted, after the inflatable sealing discs are inflated through the inflation and exhaust mechanism, the peripheries of the inflatable sealing discs can be uniformly expanded and are tightly attached to irregular hole walls of the fractured rock mass, and a closed test space is formed between the two inflatable sealing discs. Interference of sound wave signals in the propagation process is reduced, and the quality of signal acquisition and the reliability of test results are improved.

Description

Technical Field

[0001] This invention relates to the field of geotechnical engineering testing technology, and in particular, to a device and method for acoustic testing of boreholes in fractured rock masses. Background Technology

[0002] In the field of geotechnical engineering investigation and quality assessment, acoustic testing technology, with its non-destructive and efficient advantages, has become one of the core methods for evaluating rock mass integrity, classifying rock mass quality grades, and assessing foundation stability. The core principle of this technology is to excite elastic waves using an acoustic wave transmitting probe, which then propagate through the rock mass and are captured by a receiving probe. The mechanical properties and structural characteristics of the rock mass are then inverted by analyzing parameters such as the acoustic wave propagation speed and amplitude. Effective coupling of the acoustic waves between the probe and the rock mass is a crucial prerequisite for ensuring testing accuracy.

[0003] However, in engineering scenarios involving fractured bedrock, such as tunnel excavation and slope stabilization, traditional acoustic testing technology faces insurmountable bottlenecks. Fractured rock masses are generally characterized by loose geological structures, well-developed joints and fissures, and high porosity, resulting in highly unstable test borehole walls. This not only prevents effective water storage but also leads to severe seepage and leakage. Traditional acoustic testing devices rely on water as the acoustic coupling medium; the inability to store water in the test borehole directly obstructs acoustic wave propagation between the probe and the borehole wall, causing severe signal attenuation and significantly impacting the quality of acoustic signal acquisition and the reliability of test results. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes an acoustic testing device suitable for drilling in fractured rock masses.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: An acoustic testing device for drilling in fractured rock masses includes: an outer cylinder with a central mounting cavity; an acoustic wave emitting probe mounted in the mounting cavity; an acoustic wave receiving probe mounted in the mounting cavity; two inflatable sealing discs, each mounted on the outer periphery of the outer cylinder, located at the upper and lower ends of the outer cylinder respectively, wherein the inflatable sealing discs can be inflated to expand their outer periphery and seal against the borehole wall; and an inflation / exhaust mechanism, partially extending through the mounting cavity, for inflating or venting the inflatable sealing discs.

[0006] Furthermore, it also includes an auxiliary support structure, which is arranged around the outer cylinder and is located between the two inflatable sealing discs with its upper and lower ends abutting against the two inflatable sealing discs respectively.

[0007] Furthermore, the length of the auxiliary support structure is adjustable.

[0008] Furthermore, the auxiliary support structure can be moved radially along the outer cylinder to adjust its position.

[0009] Furthermore, it also includes two inner sleeve discs; the two inner sleeve discs are slidably sleeved on the outer cylinder and located between the two inflatable sealing discs, and the auxiliary support structure is located between the two inner sleeve discs, with the upper and lower ends of the auxiliary support structure respectively abutting against the two inner sleeve discs.

[0010] Furthermore, a radial track is provided on one side of each of the two inner sleeve discs facing each other, and sliding blocks embedded in the radial track are respectively provided at the upper and lower ends of the auxiliary support structure, and the sliding blocks can slide along the radial track.

[0011] Furthermore, the outer periphery of the upper and lower ends of the outer cylinder is provided with annular grooves, and the inner wall of the annular grooves is provided with two through holes communicating with the mounting cavity. The through holes of the upper and lower annular grooves are circumferentially staggered. The inner periphery of the inflatable sealing plate is embedded in the corresponding annular groove. The inner periphery of the inflatable sealing plate is provided with two connecting pipe heads. The two connecting pipe heads are respectively inserted into the two corresponding through holes. The inflation and deflation mechanism includes two vent pipes. The vent pipe includes a connecting pipe head communicating with the connecting pipe head and an extension pipe extending vertically and communicating with the connecting pipe head. The extension pipe extends out of the mounting cavity.

[0012] Furthermore, it also includes a central mounting cylinder, which is inserted into the center of the mounting cavity. The acoustic wave emitting probe and the acoustic wave receiving probe are both mounted on the central mounting cylinder. The vent pipe is located on the outer periphery of the central mounting cylinder. The outer peripheral wall of the central mounting cylinder contacts the end of the connecting pipe head to prevent the connecting pipe head from being pulled out of the connecting pipe head. The bottom of the central mounting cylinder is provided with an end cap, and the upper end of the end cap is provided with a threaded connection section, which is threaded to the bottom peripheral wall of the mounting cavity. The upper end of the outer cylinder is detachably connected with an axially outer limiting ring, and the bottom surface of the axially outer limiting ring contacts the upper inflatable sealing disc. The outer periphery of the end cap is provided with a limiting cylinder, the upper end surface of which is used to contact the lower inflatable sealing disc. A clearance groove is provided between the threaded connection section and the limiting cylinder for the lower end of the outer cylinder to be embedded.

[0013] Furthermore, the inflatable sealing disc is provided with an elastic skirt on its outer periphery.

[0014] This invention also proposes a method for acoustic testing of boreholes in fractured rock masses, comprising the following steps: drilling a test hole in the test area; inserting an outer cylinder carrying an acoustic wave emitting probe, an acoustic wave receiving probe, and an uninflated inflatable sealing disc into the test hole, such that the lower inflatable sealing disc is at a predetermined depth; inflating the two inflatable sealing discs using an inflation and deflation mechanism to ensure the sealing of the test hole; activating the acoustic wave emitting probe, and the acoustic wave receiving probe acquiring and recording test data; after data acquisition, venting the gas from the two inflatable sealing discs using the inflation and deflation mechanism to restore the discs to their original state, and then removing the device from the test hole.

[0015] The present invention has the following beneficial effects: The device employs two inflatable sealing discs, one mounted at the top and one at the bottom of the outer cylinder. Inflated via an inflation / deflation mechanism, the discs expand uniformly and fit tightly against the irregular borehole walls of the fractured rock mass, creating a closed testing space between them. This ensures the acoustic wave transmitting and receiving probes, installed within the outer cylinder's mounting cavity, remain in a stable coupling environment, reducing interference during signal propagation and improving signal acquisition quality and test result reliability. The device integrates both the transmitting and receiving probes within a central mounting cavity in the outer cylinder, forming a modular, integrated structure. The tight fit between the two inflatable sealing discs and the borehole walls provides robust axial and radial fixation to the outer cylinder. This ensures precise positioning and stable orientation of the transmitting and receiving probes during testing, preventing interference from probe movement and further guaranteeing data accuracy. The inflation and deflation of the sealing discs is easily controlled and responsive via the inflation / deflation mechanism. The air-filled sealing disc can be adjusted to fit the actual shape of the test hole wall in the fractured rock mass, and can be adapted to test holes with different degrees of fracture development and different diameters, thus solving the problem of high requirements for the hole wall conditions of traditional devices.

[0016] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the figures. Attached Figure Description

[0017] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic diagram of the overall structure of one embodiment of the present invention in use; Figure 2 yes Figure 1 Enlarged view of point A; Figure 3 yes Figure 1Sectional view at BB; Figure 4 This is a schematic diagram of the structure of the inflatable sealing disc; Figure 5 This is a schematic diagram of another embodiment of the present invention.

[0018] Legend: Outer cylinder 100, mounting cavity 110, annular groove 120, perforation 121, axial outer limiting ring 130, guide tube auxiliary clamp 140, test hole 101; 200mm acoustic wave emitting probe; 300mm acoustic wave receiving probe; Inflatable sealing disc 400, connecting pipe head 410, elastic skirt 420; Inflation and de-inflation mechanism 500, vent pipe 510, connecting pipe 511, extension pipe 512; Auxiliary support structure 600, sliding block 610, telescopic motor 620; Inner sleeve 700, radial track 710; Center mounting cylinder 800, center cavity 810, end cap 820, threaded connection section 830, limiting cylinder 840, and clearance groove 850. Detailed Implementation

[0019] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0021] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0022] Furthermore, the use of terms such as "first" and "second" in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.

[0023] Please refer to Figure 1 and Figure 2 A preferred embodiment of the present invention provides an acoustic testing device suitable for drilling in fractured rock mass, comprising an outer cylinder 100, an acoustic emitting probe 200, an acoustic receiving probe 300, an inflatable sealing plate 400, and an inflatable and venting mechanism 500.

[0024] An installation cavity 110 is provided at the center of the outer cylinder 100. The acoustic wave transmitting probe 200 is installed in the installation cavity 110. The acoustic wave receiving probe 300 is installed in the installation cavity 110.

[0025] Two inflatable sealing discs 400 are provided. Both inflatable sealing discs 400 are installed on the outer periphery of the outer cylinder 100. The two inflatable sealing discs 400 are located at the upper end and the lower end of the outer cylinder 100, respectively. The inflatable sealing discs 400 can be inflated to expand the outer periphery and make sealing contact with the hole wall.

[0026] The inflation and deflation mechanism 500 is partially inserted into the mounting cavity 110 and is used to inflate or deflate the inflation sealing plate 400.

[0027] This invention provides an acoustic testing device suitable for drilling in fractured rock masses. The device employs two inflatable sealing discs 400, respectively installed at the upper and lower ends of an outer cylinder 100. After being inflated by an inflation and deflation mechanism 500, the outer periphery of the inflatable sealing discs 400 expands uniformly and fits tightly against the irregular borehole wall of the fractured rock mass, forming a closed testing space between the two inflatable sealing discs 400. This ensures that the acoustic wave emitting probe 200 and the acoustic wave receiving probe 300, installed in the mounting cavity 110 of the outer cylinder 100, are always in a stable coupling environment, reducing interference in the acoustic wave signal propagation process and improving the quality of signal acquisition and the reliability of test results. The device integrates the acoustic wave emitting probe 200 and the acoustic wave receiving probe 300 into the mounting cavity 110 at the center of the outer cylinder 100, forming a modular integrated structure. The tight fit between the upper and lower inflatable sealing discs 400 and the borehole wall provides a firm axial and radial fixation to the outer cylinder 100. To ensure the precise positioning and stable attitude of the acoustic wave transmitting probe 200 and acoustic wave receiving probe 300 during testing, interference caused by probe shaking on the acoustic wave propagation path is avoided, further guaranteeing the accuracy of the test data. The inflation and deflation of the inflation sealing plate 400 can be completed through the inflation and deflation mechanism 500, a process that is convenient, controllable, and responsive. The inflation sealing plate 400 can be adjusted to fit the actual morphology of the test hole wall in the fractured rock mass, adapting to test holes with different fracture development levels and different diameters, thus solving the problem of high requirements for hole wall conditions in traditional devices.

[0028] Reference Figure 1 and Figure 2 In some embodiments of the present invention, an auxiliary support structure 600 is also included. The auxiliary support structure 600 is arranged around the outer cylinder 100 and is located between the two inflatable sealing discs 400, with its upper and lower ends respectively abutting against the two inflatable sealing discs 400. The auxiliary support structure 600 provides auxiliary support to the opposing sides of the two inflatable sealing discs 400, preventing excessive deformation or displacement of the inflatable sealing discs 400 due to excessive external pressure. At the same time, the auxiliary support structure 600 can share the pressure on the inflatable sealing discs 400, reducing fatigue wear and extending their service life. It further enhances the overall stability of the outer cylinder 100 within the test hole, providing a more stable working environment for the acoustic wave emitting probe 200 and the acoustic wave receiving probe 300 within the mounting cavity 110.

[0029] In some embodiments of the present invention, the length of the auxiliary support structure 600 is telescopically adjustable. This telescopic adjustment allows the device to flexibly adapt to different spacing requirements between the two inflatable sealing discs 400. By adjusting the length of the auxiliary support structure 600, it can be ensured that it is always in close contact with the two inflatable sealing discs 400, maintaining a stable support effect; this improves the versatility and adaptability of the device, eliminating the need to replace dedicated support components for different testing requirements.

[0030] In some embodiments of the present invention, the auxiliary support structure 600 can be moved radially along the outer cylinder 100 to adjust its position. This radial movement of the auxiliary support structure 600 allows it to be adjusted according to the diameter of the test hole, adapting to different hole diameter requirements.

[0031] Reference Figure 2 In some embodiments of the present invention, two inner sleeves 700 are further included; the two inner sleeves 700 are slidably sleeved on the outer cylinder 100 and located between the two inflatable sealing discs 400, and an auxiliary support structure 600 is disposed between the two inner sleeves 700, with the upper and lower ends of the auxiliary support structure 600 respectively abutting against the two inner sleeves 700. Since the inflatable sealing disc 400 is a flexible structure, it is inconvenient to directly connect with the auxiliary support structure 600 and it is convenient to adjust the position of the auxiliary support structure 600. The inner sleeves 700 enable the supporting force of the auxiliary support structure 600 to be accurately transmitted to the inflatable sealing disc 400.

[0032] Reference Figure 2 In some embodiments of the present invention, a radial track 710 is provided on one side of the two inner sleeves 700 facing each other, and sliding blocks 610 embedded in the radial track 710 are respectively provided at the upper and lower ends of the auxiliary support structure 600. The sliding blocks 610 can slide along the radial track 710. Providing a radial track 710 on one side of the inner sleeves 700 and allowing the sliding blocks 610 at the upper and lower ends of the auxiliary support structure 600 to slide within the radial track 710 provides precise guidance for the radial movement adjustment of the auxiliary support structure 600. The cross-section of the sliding block 610 can be dovetail-shaped or circular, and the radial track 710 can be provided with a dovetail-shaped groove or a spherical groove to accommodate the sliding block 610. Figure 1 As shown, the auxiliary support structure 600 can be driven and adjusted by the telescopic motor 620, or its position can be adjusted before insertion into the test hole, and then the auxiliary support structure 600 and the inner sleeve 700 can be fixed in position after adjustment by fasteners. The auxiliary support structure 600 can be a telescopic motor to achieve electric telescopic drive, or it can include an outer rod and an inner rod, with the inner rod inserted into the outer rod and able to telescopically adjust. After adjustment, its position can be fixed by fasteners, and it can be adjusted and fixed manually. Of course, the inner rod can also be threaded to the outer rod so that its length can be adjusted by screwing the thread. The sliding block 610 can adopt a spherical structure, and the radial track 710 is provided with a spherical groove with a notch at the upper end of the spherical groove.

[0033] Reference Figure 2In some embodiments of the present invention, the outer periphery of the upper and lower ends of the outer cylinder 100 is provided with annular grooves 120, and the inner wall of the annular grooves 120 is provided with two through holes 121 communicating with the mounting cavity 110. The through holes 121 of the upper and lower annular grooves 120 are circumferentially staggered. The inner periphery of the inflation sealing plate 400 is embedded in the corresponding annular grooves 120. The inner periphery of the inflation sealing plate 400 is provided with two connecting pipe heads 410. The two connecting pipe heads 410 are respectively inserted into the corresponding two through holes 121. The inflation and deflation mechanism 500 includes two vent pipes 510. The vent pipe 510 includes a connecting pipe head 511 communicating with the connecting pipe head 410 and an extension pipe 512 extending vertically and communicating with the connecting pipe head 511. The extension pipe 512 extends out of the mounting cavity 110. The annular grooves 120 on the outer periphery of the upper and lower ends of the outer cylinder 100 provide precise installation positioning for the inflatable sealing disc 400, preventing the inflatable sealing disc 400 from rotating circumferentially or shifting axially on the outer periphery of the outer cylinder 100, thus ensuring installation accuracy. The connection tube head 410 embedded in the through hole 121 also plays a certain role in positioning and installation. Since both the inflatable sealing disc 400 and the connection tube head 410 are made of flexible materials, they can withstand a certain degree of deformation during installation. The perforations 121 of the upper and lower annular grooves 120 are staggered circumferentially to avoid mutual interference between the vent pipes 510 in the mounting cavity 110, thus optimizing the internal space layout. The extension pipe 512 extends out of the mounting cavity 110, making it convenient for operators to control the inflation and deflation process from outside the test hole. One of the two vent pipes 510 is responsible for deflation, and the other is responsible for air intake. A one-way valve can be installed in or at the end of the vent pipe 510 to achieve one-way gas flow. The upper ends of the extension pipes 512 of the two vent pipes 510 can be connected to the inflation pump and the deflation pump respectively to achieve automatic inflation and deflation.

[0034] like Figure 3 As shown, a conduit auxiliary clamp 140 can be provided on the inner wall of the installation cavity 110 to clamp the extension tube 512, which has a pre-fixing effect during installation.

[0035] Reference Figure 3 and Figure 5In some embodiments of the present invention, a central mounting cylinder 800 is also included. The central mounting cylinder 800 is inserted into the center of the mounting cavity 110. The acoustic wave emitting probe 200 and the acoustic wave receiving probe 300 are both mounted in the central mounting cylinder 800. The central mounting cylinder 800 has a central cavity 810 for mounting the acoustic wave emitting probe 200 and the acoustic wave receiving probe 300. The vent pipe 510 is located on the outer periphery of the central mounting cylinder 800. The outer periphery of the central mounting cylinder 800 contacts the end of the connecting pipe head 511 to prevent the connecting pipe head 511 from being pulled out of the connecting pipe head 410. The bottom of the central mounting cylinder 800 is provided with an end cap 820. The upper end of the end cap 820 is provided with a threaded connection section 830, which is threaded to the bottom periphery of the mounting cavity 110. The upper end of the outer cylinder 100 is detachably connected with an axial outer limiting ring 130. The bottom surface of the axial outer limiting ring 130 contacts the upper inflation sealing plate 400. The outer periphery of the end cap 820 is provided with a limiting cylinder 840. The upper end surface of the limiting cylinder 840 is used to contact the lower inflation sealing plate 400. A clearance groove 850 is provided between the threaded connection section 830 and the limiting cylinder 840 for the lower end of the outer cylinder 100 to be embedded. The central mounting cylinder 800 is inserted into the center of the mounting cavity 110, integrating the acoustic wave emitting probe 200 and the acoustic wave receiving probe 300. This modular arrangement of the probes facilitates their installation, disassembly, and maintenance. The outer peripheral wall of the central mounting cylinder 800 contacts the ends of the inlet connecting pipe 511 and the outlet connecting pipe 521, effectively limiting the removal of the connecting pipe from the corresponding pipe head and preventing pipe detachment due to pressure fluctuations during the charging and discharging process, thus ensuring the reliability of the charging and discharging system. The threaded connection section 830 of the end cap 820 is threadedly connected to the bottom peripheral wall of the mounting cavity 110, making the central mounting cylinder 800 more securely fixed within the mounting cavity 110. At the same time, the threaded connection facilitates the disassembly and assembly of the central mounting cylinder 800, providing convenience for the maintenance of internal components and further enhancing the practicality of the device. The axial outer limiting ring 130 can axially limit the outer side of the upper inflatable sealing disc 400. The upper end face of the limiting cylinder 840 contacts the lower inflatable sealing disc 400, thus axially limiting the lower inflatable sealing disc 400. Combined with the auxiliary support structure 600 located between the two inflatable sealing discs 400, this ensures stable axial limiting of the inflatable sealing disc 400 and makes the overall shape of the inflatable sealing disc 400 flat, expanding outwards to contact the inner wall of the test hole, ensuring sealing. The clearance groove 850 avoids structural interference.

[0036] Reference Figure 4In some embodiments of the present invention, an elastic skirt 420 is provided on the outer periphery of the inflatable sealing disc 400. The elastic skirt 420, with its excellent flexibility and deformation capability, allows for a tighter fit between the inflatable sealing disc 400 and the irregular hole wall of the fractured rock mass, further improving the sealing effect and preventing air leakage within the sealed test space that could lead to coupling failure. Simultaneously, the elastic skirt 420 buffers friction and impact between the inflatable sealing disc 400 and the hole wall, reducing damage to the inflatable sealing disc 400 from sharp protrusions on the hole wall, extending the service life of the inflatable sealing disc 400, and reducing equipment replacement costs. The inflatable sealing disc 400 can be made of water-swellable rubber material. The elastic skirt 420 can be made of a highly elastic material (such as neoprene rubber or butyl rubber), and the elastic skirt can have a mesh reinforcement design, with its outer layer being a high-strength elastic mesh.

[0037] The present invention also provides a method for acoustic testing in boreholes in fractured rock masses, comprising the following steps: Test holes 101 are formed by drilling within the test area. The uninflated inflatable sealing disc 400 is first inserted into the test hole along with the outer cylinder 100. This prevents the inflatable sealing disc 400 from being damaged by friction against the hole wall during insertion and facilitates precise positioning of the depth of the lower inflatable sealing disc 400. The outer cylinder 100, carrying the acoustic wave emitting probe 200, the acoustic wave receiving probe 300, and the uninflated inflatable sealing disc 400, is then inserted into the test hole 101, ensuring the lower inflatable sealing disc 400 is at a predetermined depth. Inflation is then performed on both inflatable sealing discs 400 through the inflation and deflation mechanism 500 to ensure the sealing of the test hole. This ensures that the acoustic wave emitting probe 200 and the acoustic wave receiving probe 300 operate in a stable environment, guaranteeing the reliability of the test data. Simultaneously, this simplifies the operation process, shortens the test cycle, and improves on-site work efficiency. Start the acoustic wave emitting probe 200, and the acoustic wave receiving probe 300 will obtain and record the test data. After the data acquisition is completed, the gas is released from the two inflatable sealing discs 400 through the inflation and deflation mechanism 500 to restore the discs to their original state. Then the device is removed from the test hole.

[0038] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A sonic testing device suitable for drilling in fractured rock masses, characterized in that, include: The outer cylinder (100) has a central mounting cavity (110). A sound wave emitting probe (200) is installed in the mounting cavity (110); An acoustic wave receiving probe (300) is installed in the mounting cavity (110); Two inflatable sealing discs (400) are provided, both of which are installed on the outer periphery of the outer cylinder (100). The two inflatable sealing discs (400) are located at the upper end and the lower end of the outer cylinder (100) respectively. The inflatable sealing discs (400) can be inflated to expand the outer periphery and seal against the hole wall. An inflation / deflation mechanism (500) is partially installed in the mounting cavity (110) for inflating or deflating the inflation sealing disc (400).

2. The acoustic testing device for drilling in fractured rock mass according to claim 1, characterized in that, It also includes an auxiliary support structure (600), which is arranged around the outer cylinder (100). The auxiliary support structure (600) is located between two inflatable sealing discs (400) and its upper and lower ends abut against the two inflatable sealing discs (400) respectively.

3. The acoustic testing device for drilling in fractured rock mass according to claim 2, characterized in that, The length of the auxiliary support structure (600) is adjustable.

4. The acoustic testing device for drilling in fractured rock mass according to claim 3, characterized in that, The auxiliary support structure (600) can be moved radially along the outer cylinder (100) to adjust its position.

5. The acoustic testing device for drilling in fractured rock mass according to claim 2, characterized in that, It also includes two inner sleeve discs (700); the two inner sleeve discs (700) are slidably sleeved on the outer cylinder (100) and located between the two inflatable sealing discs (400), and the auxiliary support structure (600) is located between the two inner sleeve discs (700), with the upper and lower ends of the auxiliary support structure (600) respectively abutting against the two inner sleeve discs (700).

6. The acoustic testing device for drilling in fractured rock mass according to claim 5, characterized in that, The two inner sleeves (700) are provided with radial rails (710) on opposite sides. The upper and lower ends of the auxiliary support structure (600) are respectively provided with sliding blocks (610) embedded in the radial rails (710). The sliding blocks (610) can slide along the radial rails (710).

7. The acoustic testing device for drilling in fractured rock mass according to claim 1, characterized in that, The outer cylinder (100) has annular grooves (120) on the outer periphery of its upper and lower ends. The inner wall of the annular grooves (120) has two through holes (121) that communicate with the mounting cavity (110). The through holes (121) of the upper and lower annular grooves (120) are staggered in the circumference. The inner periphery of the inflatable sealing disc (400) is embedded in the corresponding annular grooves (120). The inner periphery of the inflatable sealing disc (400) has two connecting pipe heads (410). The two connecting pipe heads (410) are respectively inserted into the corresponding two through holes (121). The inflation and deflation mechanism (500) includes two vent pipes (510). The vent pipe (510) includes a connecting pipe head (511) that communicates with the connecting pipe head (410) and an extension pipe (512) that extends vertically and communicates with the connecting pipe head (511). The extension pipe (512) extends out of the mounting cavity (110).

8. The acoustic testing device for drilling in fractured rock mass according to claim 7, characterized in that, It also includes a central mounting cylinder (800), which is inserted into the center of the mounting cavity (110). The acoustic wave emitting probe (200) and the acoustic wave receiving probe (300) are both mounted on the central mounting cylinder (800). The vent pipe (510) is located on the outer periphery of the central mounting cylinder (800). The outer peripheral wall of the central mounting cylinder (800) contacts the end of the connecting pipe head (511) to restrict the connecting pipe head (511) from being pulled out of the connecting pipe head (410). The bottom of the central mounting cylinder (800) is provided with an end cap (820), and the upper end of the end cap (820) is provided with a screw thread. The threaded connecting section (830) is threaded to the bottom peripheral wall of the mounting cavity (110); the upper end of the outer cylinder (100) is detachably connected to an axial outer limiting ring (130), the bottom surface of the axial outer limiting ring (130) is in contact with the upper inflatable sealing disc (400); the outer periphery of the end cap (820) is provided with a limiting cylinder (840), the upper end surface of the limiting cylinder (840) is used to contact the lower inflatable sealing disc (400), and a relief groove (850) is provided between the threaded connecting section (830) and the limiting cylinder (840) for the lower end of the outer cylinder (100) to be embedded.

9. The acoustic testing device for drilling in fractured rock mass according to claim 1, characterized in that, The inflatable sealing disc (400) has an elastic skirt (420) on its outer periphery.

10. A method for acoustic testing in boreholes in fractured rock masses, characterized in that, Includes the following steps: Drill holes within the test area to form test holes; The outer cylinder (100) with the acoustic wave emitting probe (200), the acoustic wave receiving probe (300) and the inflatable sealing plate (400) in an uninflated state are inserted into the test hole, so that the inflatable sealing plate (400) below is at a predetermined depth; Inflation is performed on the two inflatable sealing discs (400) through the inflation and deflation mechanism (500) to ensure the sealing of the test hole; The acoustic wave transmitting probe (200) is activated, and the acoustic wave receiving probe (300) obtains and records the test data; After data acquisition is completed, the gas is released from the two inflatable sealing discs (400) through the inflation and deflation mechanism (500) to restore the discs to their original state, and then the device is removed from the test hole.

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