Experimental device and method for realizing acoustic emission positioning in fluid-solid coupling confining pressure chamber

Abstract

The present invention relates to a test device and method for realizing acoustic emission positioning in a fluid-solid coupling confined pressure chamber, comprising a confined pressure chamber having a confined pressure chamber, a loading part being arranged on the top of the confined pressure chamber, and a plurality of probes being arranged on the side wall of the confined pressure chamber, wherein one end of the probe is located outside the confined pressure chamber and connected to an acoustic emission device, and the other end of the probe sequentially passes through a fixing part and the side wall of the confined pressure chamber and then extends into the confined pressure chamber, the fixing part is fixed to the side wall of the confined pressure chamber, the probe passes through the side wall of the confined pressure chamber through a probe channel, the probe channel comprises a first channel portion and a second channel portion, an annular boss is arranged on the probe in the second channel portion, an elastic part is arranged between the annular boss and the fixing part, a first balancing channel is arranged between the confined pressure chamber and the second channel to balance the thrust of the probe exerted by the confining pressure medium toward the outside of the confined pressure chamber, and the test device of the present invention can not only accurately locate the crack of the test piece, but also avoid the damage of the acoustic emission device.

Description

Technical Field

[0001] The invention relates to the technical field of rock mechanics tests, and in particular to a test device and method capable of realizing acoustic emission positioning in a fluid-solid coupling confining pressure chamber. Background Art

[0002] The statements herein merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] The triaxial compression tester is one of the most commonly used experimental equipment in the field of rock mechanics, and is mainly used to study the physical and mechanical properties of rock under confining pressure. Due to the loading of confining pressure, the rock sample is in a closed confining pressure cavity, and it is impossible to intuitively and comprehensively obtain the damage and destruction of the sample. Therefore, based on the principle that rock samples will release energy to generate transient elastic waves during the destruction process, people use acoustic emission technology to supplement the information that the tester cannot obtain, such as the generation, expansion and location of cracks. However, acoustic emission technology is easily affected by external interference, resulting in inaccurate test results. At the same time, at least three acoustic emission sensors at different positions are required to locate the crack position of the sample. Therefore, in order to verify the authenticity and effectiveness of acoustic emission technology in collecting signals during triaxial compression tests, many scholars have conducted the following research:

[0004] Invention patent CN105842343B discloses an acoustic emission test device in which an acoustic emission sensor is built into a true triaxial chamber. T-shaped cavities are respectively processed in the rock sample fixtures in three directions in the true triaxial electro-hydraulic servo mutagenesis test system, and the acoustic emission sensors are built into them. The acoustic emission sensor and the rock sample are always kept in close contact through a force transmission mechanism, which can realize the collection of acoustic emission signals and crack location in the true triaxial compression test. However, the true triaxial compression instrument cannot perform seepage tests and conventional triaxial compression tests on the samples.

[0005] Invention patent CN104677994B discloses an integrated acoustic emission test sensor positioning device for rock damage testing, which includes a positioning device frame, an acoustic emission test sensor mounting seat, a fixing assembly for fixing the acoustic emission test sensor in the mounting seat, and a mounting mechanism for mounting the mounting seat on the positioning device frame. The device can realize real-time collection of acoustic emission signals and crack positioning, but the device is only suitable for uniaxial compression tests. If it is used for ordinary triaxial compression tests, the sealing problem of the confining pressure chamber needs to be solved.

[0006] Invention patent CN103323537B discloses a coupling device that can collect acoustic emission signals in a triaxial pressure chamber. The triaxial instrument base of the device is designed as an L-shaped conductive pipe, in which the sensor signal line is placed, and waterproof rubber plugs are installed at both ends of the conductive pipe. The acoustic emission signal line is fixed to a whole by glass glue, and the acoustic emission sensor is mounted on a protective fixed cover, parallel to the surface of the sample, which can monitor the acoustic emission signal generated by the sample rupture in real time. However, the device cannot locate the rupture position.

[0007] The article "Experimental study on loading rate effect of triaxial fracture behavior and energy release of deep coal and rock" published by Xie Jing et al. in the Journal of Central South University (Natural Science Edition) Volume 52, Issue 8, August 2021 disclosed an MTS rock mechanics acoustic emission monitoring system, which can monitor the crack propagation information and positioning in real time during uniaxial and triaxial compression tests. However, the monitoring system is located in a confining pressure chamber, which is complicated to operate and has an adverse effect on the triaxial loading effect. The acoustic emission sensor is easily damaged in a high-pressure environment.

[0008] In summary, acoustic emission and its positioning technology have been widely used in the field of rock mechanics. The main shortcomings are as follows:

[0009] (1) The acoustic emission and its positioning technology of most existing test devices can only be applied to uniaxial or true triaxial compression tests. Due to the sealing problem of the confining pressure chamber, it is rarely used in conventional triaxial compression and seepage tests.

[0010] (2) A small number of test devices can be used for conventional triaxial compression and seepage tests, but crack location cannot be performed due to the limited number of acoustic emission sensors contacting the specimen;

[0011] (3) The acoustic emission sensor of the existing conventional triaxial compression and seepage test equipment is located in the confining pressure chamber, which is complicated to operate and has an adverse effect on the triaxial loading effect. The acoustic emission sensor is easily damaged in a high-pressure environment. Summary of the invention

[0012] The purpose of the present invention is to overcome the shortcomings of the prior art and to provide a test device and method for realizing acoustic emission positioning in a fluid-solid coupling confining pressure chamber. The acoustic emission positioning technology can be used to locate cracks during conventional triaxial compression and seepage tests, and the acoustic emission sensor is not easily damaged.

[0013] To achieve the above purpose, the present invention adopts the following technical solutions

[0014] In the first aspect, an embodiment of the present invention provides a test device that can realize acoustic emission positioning in a fluid-solid coupled confined pressure chamber, including a confined pressure chamber having a confined pressure chamber, a loading part is provided on the top of the confined pressure chamber, and a plurality of probes are provided on the side wall of the confined pressure chamber. One end of the probe is located outside the confined pressure chamber and connected to the acoustic emission equipment, and the other end of the probe passes through the fixing part and the side wall of the confined pressure chamber in sequence and then extends into the confined pressure chamber. The fixing part is fixed to the side wall of the confined pressure chamber, and the probe passes through the side wall of the confined pressure chamber through a probe channel. The probe channel includes a first channel portion and a second channel portion. The probe in the second channel portion is provided with an annular boss, and an elastic part is provided between the annular boss and the fixing part. A first balancing channel is provided between the confining pressure chamber and the second channel to balance the thrust of the confining pressure medium on the probe toward the outside of the confining pressure chamber.

[0015] Optionally, a first sealing ring is provided between the probe and the inner side surface of the first channel, and a second sealing ring is provided between the annular boss and the inner side surface of the second channel.

[0016] Optionally, the probe is also provided with a second balance channel, one end of the second balance channel extends to the outer peripheral surface of the probe between the first sealing ring and the second sealing ring, and the other end extends to the end surface of the probe extending outside the confining pressure chamber, so that the space between the probe part between the first sealing ring and the second sealing ring and the probe channel is connected to the outside.

[0017] Optionally, the fixing member includes a first fixing portion and a second fixing portion coaxially arranged at one end of the first fixing portion, the second fixing portion is threadedly fixed to the side wall of the confining pressure chamber, and the inner end surface of the first fixing portion is in contact with the outer surface of the side wall of the confining pressure chamber.

[0018] Optionally, a third sealing ring is provided between the probe and the second fixing part, and a fourth sealing ring is provided between the inner end surface of the first fixing part and the outer surface of the side wall of the confining pressure chamber.

[0019] Optionally, the bottom cavity wall of the confining pressure chamber is provided with a sample table coaxially arranged with the loading component, the loading component is provided with a seepage inlet channel, and correspondingly, the loading table and the bottom cavity wall of the confining pressure chamber are provided with a seepage outflow channel.

[0020] Optionally, a fifth sealing ring is provided between the loading member and the top cavity wall of the confining pressure chamber.

[0021] Optionally, a sample sleeve fixing platform is provided on the bottom surface of the top cavity wall of the confining pressure chamber, and the loading component passes through the top cavity wall and the sample sleeve fixing platform.

[0022] Optionally, multiple groups of probes are arranged along the circumferential direction of the confining pressure chamber, each group having at least one probe, and when the same group has multiple probes, the multiple probes are arranged along the axial direction of the confining pressure chamber.

[0023] Optionally, the loading member adopts an axial pressure rod, the axial pressure rod is connected to the head of the press, and the confining pressure chamber is arranged on the workbench of the press.

[0024] In a second aspect, an embodiment of the present invention provides a test method for a test device capable of realizing acoustic emission positioning in a fluid-solid coupling confining pressure chamber, comprising the following steps:

[0025] After the specimen is installed in the confining pressure chamber, the probe is passed through the side wall of the confining pressure chamber until the front end of the probe contacts the outer surface of the specimen, or after the specimen wrapped with a latex sleeve is installed in the confining pressure chamber, the probe is passed through the side wall of the confining pressure chamber until the front end of the probe contacts the outer surface of the latex sleeve;

[0026] The elastic member is sleeved on the outer periphery of the probe so that the front end of the elastic member contacts the annular boss of the probe, and the fixing member is passed through the portion of the probe located outside the confining pressure chamber, and the fixing member is fixed to the side wall of the confining pressure chamber, and the probe is fixed by the fixing member;

[0027] Connect the acoustic emission probe to the acoustic emission equipment, start the test and collect data.

[0028] Beneficial effects of the present invention:

[0029] 1. The test device of the present invention can realize the acoustic emission positioning in the fluid-solid coupling confining pressure chamber. Through the setting of the probe, the acoustic emission device can be set outside the confining pressure chamber, and there is no need to set it inside the confining pressure chamber. Through the setting of the second channel, the spring and the first balance channel, the thrust exerted by the confining pressure medium on the probe toward the outside of the confining pressure chamber can be balanced, so that the probe can always be in close contact with the sample under the action of the spring, and at the same time, the deformation of the specimen is not affected, ensuring that the acoustic emission signal generated by the rupture of the sample is transmitted to the outside of the confining pressure chamber through the probe, avoiding the defects of the acoustic emission device being easily damaged due to being located inside the confining pressure chamber, affecting the triaxial loading effect and complicated installation operation, and the acoustic emission device can be reused, saving the test cost.

[0030] 2. The test device of the present invention can realize acoustic emission positioning in a fluid-solid coupling confining pressure chamber. The probe is installed on the side wall of the confining pressure chamber through a probe channel. The probe and the side wall are detachably connected. Different numbers of probes can be installed according to test requirements to realize the positioning of sample cracks.

[0031] 3. The test device of the present invention can realize the acoustic emission positioning in the fluid-solid coupling confining pressure chamber. The loading part is provided with a seepage inflow channel. Correspondingly, the sample table and the bottom cavity wall of the confining pressure chamber are provided with a seepage outflow channel, so that the whole test device can be applied to uniaxial compression, conventional triaxial compression and seepage tests. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The drawings in the specification, which constitute a part of the present application, are used to provide a further understanding of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute a limitation on the present application.

[0033] Figure 1 This is a schematic diagram of the overall structure of Embodiment 1 of the present invention;

[0034] Figure 2 For the present invention Figure 1 A local enlarged view of point A in FIG.

[0035] Figure 3 It is a top view of Embodiment 1 of the present invention;

[0036] Among them, 1-1. Loading part, 1-2. Seepage inflow channel, 1-3. Fifth sealing ring, 1-4. Top cavity wall, 1-5. Upper clamp fixed by latex sleeve, 1-6. Rock sample, 1-7. Confining pressure cavity, 1-8. Latex sleeve, 1-9. Side wall, 1-10. Lower clamp fixed by latex sleeve, 1-11. Seepage outflow channel, 1-12. Sixth sealing ring, 1-13. Sample table, 2-1. First balance channel, 2-2. Probe, 2-3. Second sealing ring, 2-4. Spring, 2-5. Fourth sealing ring, 2-6. Acoustic emission probe seat, 2-7. First sealing ring, 2-8. Second balance channel, 2-9. Third sealing ring, 2-10 Fixing nut. DETAILED DESCRIPTION

[0037] Example 1

[0038] This embodiment provides a test device that can realize acoustic emission positioning in a fluid-solid coupling confining pressure chamber. Figure 1-Figure 3 As shown, it includes a confining pressure chamber, the inner cavity of the confining pressure chamber is the confining pressure chamber 1-7, the confining pressure chamber 1-7 is used to place the rock sample 1-6, and the confining pressure load can be applied to the rock sample 1-6 by injecting the confining pressure medium into the confining pressure chamber 1-7, the top cavity wall of the confining pressure chamber is provided with a loading member 1-1, and the bottom cavity wall is provided with a sample table 1-13, the sample table 1-13 is used to place the rock sample 1-6, the loading member 1-1 is used to apply an axial load to the rock sample 1-6, and a plurality of probes are also provided on the side wall 1-9 of the confining pressure chamber, and the probes are connected to the acoustic emission equipment for obtaining information on the generation, expansion and location of cracks.

[0039] Specifically, the confining pressure chamber includes a top cavity wall 1-4, a bottom cavity wall and a side wall 1-9 arranged between the top cavity wall 1-4 and the bottom cavity wall. The bottom end of the bottom cavity wall and the side wall 1-9 are detachably fixedly connected by bolts, and the top end of the top cavity wall 1-4 and the side wall 1-9 are detachably fixedly connected by bolts. The loader 1-1 is arranged on the top cavity wall, and the sample table 1-13 is arranged on the bottom cavity wall. The loader 1-1 and the sample table 1-13 are coaxially arranged. This arrangement makes it convenient to place the rock sample 1-6 on the sample table 1-13.

[0040] In order to prevent leakage of the confining pressure medium in the confining pressure chamber 1-7, a sixth sealing ring 1-12 is provided between the top chamber wall 1-4 and the side wall 1-9 and between the bottom chamber wall and the side wall 1-9 to seal the gap between the side wall 1-9 and the top chamber wall 1-4 and the bottom chamber wall.

[0041] The loading member 1-1 adopts an axial pressure rod, which is connected to the pressure head part of the press. The confining pressure chamber is placed on the workbench of the press. After the rock sample 1-6 is placed on the sample table 1-13, the axial pressure rod can use the pressure head part of the press to apply axial pressure load to the rock sample.

[0042] The axial pressure rod passes through the top cavity wall through an opening set at the center position of the top cavity wall, and its bottom end extends into the confining pressure cavity 1-7 as a loading end for the rock sample 1-6. In order to prevent the confining pressure medium from leaking between the axial pressure rod and the opening of the top cavity wall, a fifth sealing ring 1-3 is set between the axial pressure rod and the top cavity wall 1-4. Since the axial pressure rod is a moving part, in order to improve the sealing performance, at least two fifth sealing rings 1-3 are set between the axial pressure rod and the top cavity wall.

[0043] By setting the confining pressure chambers 1-7 and the axial pressure rods, uniaxial and conventional triaxial tests can be carried out by the test device of this embodiment.

[0044] The axial pressure rod is provided with a seepage inlet channel 1-2 for introducing seepage medium into the rock sample 1-6. Correspondingly, the sample table 1-13 and the bottom cavity wall of the confining pressure chamber are provided with a seepage outflow channel 1-11 for discharging the seepage medium to the outside of the confining pressure chamber.

[0045] By setting up the seepage inflow channel and the seepage outflow channel, the whole test device can carry out uniaxial, conventional triaxial and seepage tests. When carrying out conventional triaxial and seepage tests, it is necessary to wrap the outer surface of the rock sample 1-6 with a sample sleeve. The sample sleeve in this embodiment is a latex sleeve 1-8. In order to ensure the wrapping effect, the length of the latex sleeve 1-8 is greater than the length of the rock sample 1-6. Both ends of the latex sleeve 1-8 need to be fixed. Therefore, a sample sleeve fixing table is set on the bottom surface at the center of the top cavity wall. In order to facilitate the fixation of the latex sleeve 1-8, the sample sleeve fixing table adopts an inverted cone-shaped table, and its surface The end with a larger area is fixed to the bottom surface of the top cavity wall, and the sample sleeve fixing platform is provided with a through hole for the axial pressure rod to pass through. The axial pressure rod passes through the sample sleeve fixing platform. The part of the rock sample growing out of the top of the latex sleeve is wrapped on the sample sleeve fixing platform and can be wrapped and fixed to the sample sleeve fixing platform through the latex sleeve fixing upper clamp 1-5, and the part of the rock sample growing out of the bottom of the latex sleeve is wrapped and fixed to the sample platform 1-13. Therefore, the sample platform of this embodiment adopts a conical platform, and its end with a larger area is fixed to the bottom cavity wall of the confining pressure chamber, and the part of the rock sample growing out of the bottom of the latex sleeve can be wrapped and fixed to the sample platform through the latex sleeve fixing lower clamp 1-10.

[0046] By setting up the seepage inflow channel 1-2 and the seepage outflow channel 1-11, the entire test device can carry out rock seepage tests.

[0047] A plurality of probes 2-2 are fixed on the side wall of the confining pressure chamber. The ends of the probes 2-2 located outside the confining pressure chamber are connected to the acoustic emission equipment to obtain information such as the generation and expansion position of the cracks.

[0048] In this embodiment, the probe 2-2, the fixing member 2-5 and the acoustic emission device constitute an acoustic emission positioning mechanism.

[0049] A probe channel is provided on the side wall of the confining pressure chamber, and the axis of the probe channel is perpendicular to the side wall 1-9 of the confining pressure chamber. The probe 2-2 extends into the confining pressure chamber 1-7 through the probe channel. One end of the probe 2-2 extends into the confining pressure chamber 1-7 as a contact end with the rock sample 1-6, and the other end extends to the outside of the confining pressure chamber as a connection end with the acoustic emission equipment.

[0050] The probe 2-2 is mounted on the side wall of the confining pressure chamber through a fixing member 2-5. Specifically, the fixing member includes a first fixing portion and a second fixing portion coaxially arranged. The diameter of the first fixing portion is larger than that of the second fixing portion. The first fixing portion and the second fixing portion are coaxially arranged with the probe channel. The second fixing portion is threadedly fixedly connected to the side wall of the confining pressure chamber. The inner end surface of the first fixing portion is in contact with the outer side surface of the side wall of the confining pressure chamber. Therefore, one end of the probe is located outside the confining pressure chamber, and the other end passes through the fixing member in turn, and passes through the side wall of the confining pressure chamber through the probe channel and then extends into the confining pressure chamber.

[0051] Since the fixing is detachably connected by thread, the probe is detachably connected to the side wall of the confining pressure chamber through the probe channel and the fixing, and different numbers of probes can be installed according to test requirements to locate the cracks in the specimen.

[0052] The probe channel includes a first channel portion and a second channel portion. The first channel portion is arranged close to the confining pressure chamber, and the diameter of the first channel portion is smaller than the diameter of the second channel portion. The probe passes through the first fixing portion and the second fixing portion, the second channel, and the first channel in sequence and then extends into the confining pressure chamber.

[0053] The part of the probe located in the second channel portion is provided with an annular boss, and an elastic member is provided between the annular boss and the inner side end face of the second fixing portion of the fixing member. In this embodiment, the elastic member is a spring 2-4, and the spring 2-4 is sleeved on the outer periphery of the probe. One end of the spring 2-4 contacts with the outer end face of the annular boss, and the other end contacts with the inner end face of the second fixing portion.

[0054] Since the diameter of the first channel portion is smaller than that of the second channel portion, a stepped hole is formed, and thus the moving position of the spring-pushed probe can be limited.

[0055] A first balancing channel 2-1 is provided between the second channel and the confining pressure chamber, for balancing the thrust of the confining pressure medium on the probe 2-2 toward the outside of the confining pressure chamber, so that the probe can always be in contact with the rock sample under the action of the elastic force of the spring, thereby ensuring the smooth transmission of the acoustic signal.

[0056] In this embodiment, according to the setting position of the probe channel, the proximity principle is adopted. One end of the first balance channel 2-1 is connected to the second channel, and the other end extends to the top surface or bottom surface of the side wall 1-9 of the confining pressure chamber, and is located on the inner side of the sixth sealing ring 1-12, so that the first balance channel 2-1 is connected to the confining pressure chamber.

[0057] In order to facilitate balancing the outward thrust of the confining pressure medium in the confining pressure chamber on the probe, a first sealing ring 2-7 is provided between the probe 2-2 and the inner side surface of the first channel, and a second sealing ring 2-3 is provided between the annular boss and the inner side surface of the second channel.

[0058] Furthermore, a second balancing channel 2-8 is provided in the probe, and the second balancing channel 2-8 includes a third channel portion and a fourth channel portion which are perpendicular to each other. The third channel portion is coaxially arranged with the probe, and one end extends to the outer end face of the probe and is connected to the external environment space. The other end is provided with a fourth channel portion, and one end of the fourth channel portion is connected to the third channel portion, and the other end extends to the outer axial surface position of the probe between the first sealing ring 2-7 and the second sealing ring 2-3, so that the part of the probe located between the first sealing ring 2-7 and the second sealing ring 2-3 and the space between the probe channel are connected to the external environment space, thereby avoiding the vacuum in the space between the first sealing ring 2-7 and the second sealing ring 2-3, which makes the probe 2-2 unable to move.

[0059] In this embodiment, the end face of the probe 2-2 used to contact the rock sample 1-6 is an arc-shaped face, and the arc of the arc-shaped face is small and approximately equal to the cross-sectional area of ​​the probe. After contacting the rock sample, there is a gap between the probe and the rock sample, so it will be thrusted by the confining pressure medium toward the outside of the confining pressure chamber. The end face area of ​​the annular boss is approximately equal to the cross-sectional area of ​​the probe, because the outward thrust generated on the top of the probe after the confining pressure chamber is pressurized and the pressure on the annular boss in the second channel toward the confining pressure chamber is balanced and offset. In this way, the probe is always in contact with the rock sample under the action of the spring, avoiding the confining pressure medium from separating the probe from the sample, and ensuring the continuity of the signal collected by the acoustic emission equipment.

[0060] In order to prevent the confining pressure medium in the second channel from leaking, a third sealing ring 2-9 is provided between the probe 2-2 and the second fixing part to block the channel between the fixing part and the probe and separate the second channel from the outside.

[0061] A fourth sealing ring 2-5 is provided between the inner end surface of the first fixing part and the side wall of the confining pressure chamber, which is used to block the passage between the fixing part and the confining pressure chamber and separate the second passage from the external environment.

[0062] An acoustic emission probe seat 2-6 is provided at the end of the probe extending out of the confining pressure chamber. The acoustic emission probe seat is connected to the acoustic emission probe, and the acoustic emission probe is connected to the acoustic emission equipment.

[0063] In this embodiment, in order to locate the crack, multiple groups of probes are arranged along the circumferential direction of the confining pressure chamber, each group having at least one probe, and when the same group has multiple probes, the multiple probes are arranged along the axial direction of the confining pressure chamber. Each probe is connected to an acoustic emission device.

[0064] Specifically, four groups of probes are provided to divide the confining pressure chamber into four equal parts, and probe channels are provided at positions of 0°, 90°, 180° and 270°, respectively.

[0065] A probe channel is set at the 0° position, and the distance from the top cavity wall to the center of the probe channel is 80 mm, that is, the probe is located 40 mm below the upper surface of the rock sample.

[0066] Two probe channels are set at the 90° position, and the two probe channels are set along the axial direction of the confining pressure chamber. The distances from the top chamber wall to the centers of the two probe channels are 60 mm and 120 mm, that is, the probes are located 20 mm and 80 mm below the upper surface of the rock sample.

[0067] Two probe channels were set at the 180° position, and the distances from the top cavity wall to the center of the probe channel were 60 mm and 120 mm, respectively, that is, the probes were located 20 mm and 80 mm below the upper surface of the rock sample.

[0068] A probe channel is set at the 270° position, and the distance from the top cavity wall to the center of the probe channel is 100 mm, that is, the probe is located 60 mm below the upper surface of the rock sample.

[0069] Embodiment 2:

[0070] This embodiment provides a method for the test device capable of realizing acoustic emission positioning in a fluid-solid coupling confining pressure chamber as described in Embodiment 1, comprising the following steps:

[0071] Step 1: First, place the rock sample on the sample table according to the test type and assemble the confining pressure chamber. When conducting a seepage test or a triaxial compression test, it is necessary to wrap the outer surface of the rock sample with a latex sleeve. The uniaxial compression test does not require a latex sleeve.

[0072] Step 2: Insert the probe into the confining pressure chamber through the probe channel so that the end of the probe is against the rock sample or the latex sleeve outside the rock sample.

[0073] Step 3: Put the spring around the outer periphery of the probe and place it inside the second channel, with one end of the spring in contact with the annular boss. Thread the fixing piece with the side wall of the confining pressure chamber and in contact with the other end of the spring, and compress the spring to a certain extent so that the probe is always in contact with the rock sample or latex sleeve.

[0074] Step 4: Install the acoustic emission probe holder at the end of the probe extending out of the confining pressure chamber, and connect the probe to the acoustic emission equipment through the acoustic emission probe holder.

[0075] Step 5: Apply axial pressure using a loading device as needed, inject confining pressure medium into the confining pressure cavity to apply confining pressure, and collect data using acoustic emission equipment.

[0076] The device of this embodiment, through the setting of the probe, can make the acoustic emission device be set outside the confining pressure chamber, without being set inside the confining pressure cavity, and through the setting of the second channel, the spring and the first balance channel, the thrust exerted by the confining pressure medium on the probe toward the outside of the confining pressure cavity can be balanced, so that the probe can always be in contact with the sample under the action of the spring, ensuring that the acoustic emission signal is transmitted to the sample, avoiding the defects of the acoustic emission device being easily damaged when it is located inside the confining pressure cavity, affecting the triaxial loading effect and complicated installation operation, etc., and the acoustic emission device can be reused, saving the test cost.

[0077] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the scope of protection of the present invention.

Claims

1. A test device capable of realizing acoustic emission positioning in a fluid-solid coupling confining pressure chamber, characterized in that: The invention comprises a confined pressure chamber having a confined pressure cavity, a loading part is arranged on the top of the confined pressure chamber, a plurality of probes are arranged on the side wall of the confined pressure chamber, one end of the probe is located outside the confined pressure chamber and connected to the acoustic emission device, and the other end of the probe passes through the fixing part and the side wall of the confined pressure chamber in sequence and then extends into the confined pressure cavity, the fixing part is fixed to the side wall of the confined pressure chamber, the probe passes through the side wall of the confined pressure chamber through a probe channel, the probe channel comprises a first channel part and a second channel part, an annular boss is arranged on the probe in the second channel part, an elastic part is arranged between the annular boss and the fixing part, and a first balancing channel is arranged between the confined pressure cavity and the second channel to balance the thrust of the confining pressure medium on the probe toward the outside of the confined pressure cavity; A first sealing ring is arranged between the probe and the inner side surface of the first channel, and a second sealing ring is arranged between the annular boss and the inner side surface of the second channel; The probe is also provided with a second balance channel, one end of which extends to the outer peripheral surface of the probe between the first sealing ring and the second sealing ring, and the other end extends to the end surface outside the confined pressure chamber, so that the space between the probe part between the first sealing ring and the second sealing ring and the probe channel is connected to the outside; The confining pressure chamber includes a top cavity wall, a bottom cavity wall and a side wall arranged between the top cavity wall and the bottom cavity wall. The bottom cavity wall and the bottom end of the side wall are detachably fixedly connected by bolts, and the top cavity wall and the top end of the side wall are detachably fixedly connected by bolts. The loading piece is arranged on the top cavity wall, and the sample table is arranged on the bottom cavity wall. The loading piece and the sample table are coaxially arranged. This arrangement makes it convenient to place the rock sample on the sample table.

2. The test device capable of realizing acoustic emission positioning in a fluid-solid coupling confining pressure chamber according to claim 1, characterized in that: The fixing member includes a first fixing part and a second fixing part coaxially arranged at one end of the first fixing part, the second fixing part is threadedly fixed to the side wall of the confining pressure chamber, the inner end face of the first fixing part is fitted with the outer side face of the side wall of the confining pressure chamber, a third sealing ring is arranged between the probe and the second fixing part, and a fourth sealing ring is arranged between the inner end face of the first fixing part and the outer side face of the side wall of the confining pressure chamber.

3. The test device capable of realizing acoustic emission positioning in a fluid-solid coupling confining pressure chamber according to claim 1, characterized in that: The bottom cavity wall of the confining pressure chamber is provided with a sample table coaxially arranged with the loading component, and the loading component is provided with a seepage inlet channel. Correspondingly, the loading table and the bottom cavity wall of the confining pressure chamber are provided with a seepage outflow channel, and a fifth sealing ring is provided between the loading component and the top cavity wall of the confining pressure chamber.

4. The test device capable of realizing acoustic emission positioning in a fluid-solid coupling confining pressure chamber according to claim 1, characterized in that: A sample sleeve fixing platform is provided on the bottom surface of the top cavity wall of the confining pressure chamber, and a loading component passes through the top cavity wall and the sample sleeve fixing platform. The loading component adopts an axial pressure rod, which is connected to the head of the press, and the confining pressure chamber is arranged on the working table of the press.

5. The test device capable of realizing acoustic emission positioning in a fluid-solid coupling confining pressure chamber according to claim 1, characterized in that: A plurality of groups of probes are arranged along the circumferential direction of the confining pressure chamber, each group having at least one probe. When a group has a plurality of probes, the plurality of probes are arranged along the axial direction of the confining pressure chamber.

6. The test method of the test device capable of realizing acoustic emission positioning in a fluid-solid coupling confining pressure chamber according to any one of claims 1 to 5, comprising the following steps: After the specimen is installed in the confining pressure chamber, the probe is passed through the side wall of the confining pressure chamber until the front end of the probe contacts the outer surface of the specimen, or after the specimen wrapped with a latex sleeve is installed in the confining pressure chamber, the probe is passed through the side wall of the confining pressure chamber until the front end of the probe contacts the outer surface of the latex sleeve; The elastic member is sleeved on the outer periphery of the probe so that the front end of the elastic member contacts the annular boss of the probe, and the fixing member is passed through the portion of the probe located outside the confining pressure chamber, and the fixing member is fixed to the side wall of the confining pressure chamber, and the probe is fixed by the fixing member; Connect the acoustic emission probe to the acoustic emission equipment, start the test and collect data.

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