A triaxial stress under seal hole material performance testing device

Abstract

The application discloses a triaxial stress under hole sealing material performance testing device, relates to the technical field of coal mine gas extraction and mine safety engineering, and comprises a base, a confining pressure testing piece, a sample to be tested, a shaft pressure testing piece and a control panel, the base is fixedly arranged on the ground, the confining pressure testing piece is fixedly arranged on the base, the confining pressure testing piece can simulate an underground stress environment, the sample to be tested is placed at the center of the confining pressure testing piece, the shaft pressure testing piece is slidingly arranged on the base, the shaft pressure testing piece is located directly above the sample to be tested, the shaft pressure testing piece can exert a vertical downward shaft pressure on the sample to be tested, simulates an actual underground stress state, the control panel is fixedly arranged on one side of the base, and the control panel can control the stress size and direction exerted by the confining pressure testing piece and the shaft pressure testing piece on the sample to be tested; and the application has the effect of improving the accuracy of performance data of an underground hole sealing material.

Description

Technical Field

[0001] This application relates to the field of coal mine gas extraction and mine safety engineering technology, and in particular to a device for testing the performance of sealing materials under triaxial stress. Background Technology

[0002] As the depth of coal mining continues to increase, the coal and rock mass is in a high-stress environment for a long time, the closure rate of primary fractures increases significantly, and the permeability generally decreases. This leads to low gas desorption efficiency in deep coal seams, limited transport channels, and increased risk of gas enrichment and outbursts, which seriously threatens the safe production of mines. Therefore, it is necessary to effectively seal the coal seams during the coal mining process, and the performance of borehole sealing materials directly affects the gas extraction efficiency and mine safety.

[0003] One relevant method for testing the performance of borehole sealing materials involves separate testing of uniaxial compressive strength and static permeability. When testing the performance of borehole sealing materials, axial pressure is applied to the material in three directions to simulate the triaxial stress environment in actual mining, and the deformation resistance of the sealing material is determined through experimental data. After the deformation resistance test is completed, a static permeability test is performed to evaluate its gas barrier effect under high stress.

[0004] When using the above method to test the performance of borehole sealing materials, the test environment differs from the actual mining environment because pressure is applied to the sealing material in three directions separately rather than simultaneously. This results in significant deviations between the test data and the actual downhole working conditions. Utility Model Content

[0005] To improve the accuracy of testing data on the performance of downhole sealing materials, this application provides a device for testing the performance of sealing materials under triaxial stress.

[0006] This application provides a device for testing the performance of sealing materials under triaxial stress, which adopts the following technical solution: A device for testing the performance of sealing materials under triaxial stress includes: A base, which is fixedly mounted on the ground; A confining pressure test specimen, which is fixedly mounted on the base, can simulate underground stress environment; The test sample is placed at the center of the confining pressure test piece; An axial compression test piece is slidably disposed on the base and positioned directly above the sample to be tested. The axial compression test piece can apply a vertically downward axial force to the sample to be tested to simulate the actual underground stress state. The control panel is fixedly installed on one side of the base. The control panel can control the magnitude and direction of the stress applied to the sample under test by the confining pressure test piece and the axial pressure test piece.

[0007] By adopting the above technical solution, when performance testing of the sealing material is required, the prepared sealing material sample is placed at the center of the confining pressure test piece. The axial pressure test piece is then activated, moving towards the sample until it contacts the sample and then stopping. After contact, the control panel controls both the confining pressure test piece and the axial pressure test piece to simultaneously apply a predetermined pressure to the sample. The deformation resistance of the sealing material can then be accurately evaluated by reading the experimental data. This method effectively simulates the actual downhole stress environment, greatly improving the accuracy of the test data.

[0008] Optionally, the confining pressure test specimen includes: The lower end cover is fixedly mounted on the base, and a placement hole is vertically provided at the axis of the lower end cover; A rubber sleeve, wherein the rubber sleeve is placed inside the placement hole; An oil inlet pipe, one end of which is fixedly connected to the outer periphery of the lower end cover, and the other end of which is fixedly connected to the oil storage tank; The upper end cover is fixedly disposed directly above the lower end cover, and a mating hole is vertically disposed at the center of the upper end cover.

[0009] By employing the above technical solution, when testing the horizontal deformation resistance of a sample, the sample is placed inside a rubber sleeve. High-pressure oil is injected through the inlet pipe between the lower and upper end caps. Once the high-pressure oil enters the cavity between the lower and upper end caps, it uniformly compresses the rubber sleeve and the sample until the pressure exerted by the high-pressure oil on the rubber sleeve and the sample reaches a predetermined value. At this point, the injection is stopped, and experimental data can be recorded to analyze the deformation of the sample under horizontal pressure. Measuring the horizontal deformation resistance of the sample in this way ensures a uniform pressure distribution in the horizontal direction, accurately simulating the actual downhole stress environment and effectively improving the accuracy of the experimental data.

[0010] Optionally, the axial compression test specimen includes: A fixing plate is fixedly mounted on the base; A first motor is fixedly mounted on the fixed plate; A drive wheel is rotatably mounted on the fixed plate and is fixedly connected to the output shaft of the first motor. The driven wheel is rotatably mounted on the fixed plate. The driven wheel and the driving wheel are located on the same horizontal line, and the driving wheel and the driven wheel are connected by a belt. A threaded rod is rotatably mounted on the fixed plate, and the top end of the threaded rod is fixedly connected to the output shaft of the driven wheel; A pressure rod is sleeved on the outer periphery of the threaded rod, and the pressure rod is fixedly provided with a threaded groove that mates with the threaded rod.

[0011] By employing the above technical solution, when testing the performance of sealing materials under axial stress, the sample to be tested is placed inside a rubber sleeve. The first motor is started, and its rotation drives the driving wheel, which in turn drives the driven wheel via a belt. The driven wheel then drives the threaded rod. Since the pressure rod has a threaded groove that mates with the threaded rod, its rotation moves the pressure rod towards the sample until the bottom of the pressure rod contacts the top of the sample. After the pressure rod contacts the sample, the axial stress value is input to the control panel. Once input, the system controls the first motor to rotate, allowing it to continue moving towards the sample and applying axial pressure until the applied pressure reaches a predetermined value. At this point, the system stops the motor, and experimental data is recorded to analyze the performance of the sealing material under axial stress. This method measures the deformation resistance of the sealing material under axial pressure, ensuring uniform pressure distribution in the axial direction and effectively improving the accuracy of the experimental data.

[0012] Optionally, the upper end cover and the lower end cover are symmetrically provided with sealing elements along the axis of the mating hole, and the sealing elements include: The second motor is provided in two parts, each of which is fixedly installed at the bottom of the lower end cover and the top of the upper end cover. Two drive gears are provided, each drive gear is rotatably disposed inside the upper end cover and the lower end cover, and each drive gear is fixedly connected to the second motor; The circular arc rack has two components, each of which is positioned inside the upper and lower end covers when rotating, and each of the circular arc racks meshes with the drive gear. The upper and lower end covers each have three sealing rods, each of which is rotatably disposed within the upper and lower end covers and engages with the arc-shaped rack.

[0013] By employing the above technical solution, when it is necessary to measure the horizontal deformation resistance of the test sample, the test sample is placed inside the rubber sleeve, and the second motor is started. After starting, the second motor drives the drive gear to rotate, which in turn drives the arc rack to rotate. The arc rack then moves the sealing rod towards the test sample and the rubber sleeve until the sealing rod clamps the test sample and the rubber sleeve, at which point the second motor stops rotating. After the sealing rod clamps the test sample and the rubber sleeve, hydraulic oil can be injected into the cavity between the upper and lower end caps through the oil inlet pipe, thereby testing the horizontal deformation resistance of the test sample. By sealing the test sample using this method, it is ensured that the hydraulic oil will not leak after entering the cavity between the upper and lower end caps, thus ensuring that the test can stably simulate the stress conditions of the test sample in actual applications, effectively improving the reliability of the experimental data.

[0014] Optionally, a pore pressure test piece is fixedly disposed inside the base, the pore pressure test piece comprising: A water inlet block is fixedly installed inside the base, with the top of the water inlet block contacting the bottom of the sample to be tested. A water inlet pipe, one end of which is fixedly connected to the outer periphery of the water inlet block, and the other end of which is fixedly connected to the water tank; The water outlet block is fixedly connected to the pressure rod, and the bottom end of the water outlet block abuts against the top of the sample to be tested.

[0015] By employing the above scheme, when testing the horizontal and vertical deformation resistance of the sample, water is injected into the inlet block through the inlet pipe. As water is continuously injected into the inlet block, it gradually fills the block. Since the top of the inlet block is in contact with the bottom of the sample, excess water flows into the sample's interior after the block is full. Under capillary action, the water gradually moves upwards along the sample's interior. Because the top of the sample is in contact with the bottom of the outlet block, the water enters the outlet block when it reaches the top. By measuring the pressure change during water penetration, the pore pressure data of the sample is accurately calculated. This method effectively improves the comprehensiveness of the test data.

[0016] Optionally, an oil outlet pipe is fixedly provided at the end of the lower end cap away from the oil inlet pipe, and an overflow valve is fixedly provided on the oil outlet pipe.

[0017] By adopting the above technical solution, when testing the horizontal deformation resistance of a sample, the sample is placed inside a rubber sleeve, and hydraulic oil is injected into the cavity between the upper and lower end covers through the oil inlet pipe. Once the hydraulic oil enters the cavity between the upper and lower end covers, it compresses the sample, subjecting it to uniform pressure in the horizontal direction. Injection is stopped when the hydraulic oil pressure reaches a preset value, and test data can then be read. Due to factors such as temperature, the hydraulic oil pressure in the cavity between the upper and lower end covers may change. In this case, the overflow valve can be adjusted to maintain a stable hydraulic oil pressure between the upper and lower end covers, ensuring a constant pressure on the sample during the test and effectively improving the accuracy of the test data.

[0018] Optionally, a buffer pad is fixedly provided on the side of each sealing rod closest to the sample to be tested.

[0019] By adopting the above technical solution, the buffer pad reduces the clamping force on the test sample when the sealing rod clamps the rubber sleeve to the test sample, thus preventing sample damage due to excessive clamping force. The buffer pad effectively improves the stability during the testing process.

[0020] Optionally, the upper cover is made of transparent high-strength glass, and the oil storage tank contains silicone oil.

[0021] By adopting the above technical solution, when the sample is subjected to deformation resistance testing, the deformation of the sample under the action of hydraulic oil can be observed through the transparent upper cap, preventing the sample from deforming or being damaged due to excessive pressure. Furthermore, silicone oil has low sensitivity to temperature changes, preventing pressure instability caused by temperature fluctuations during the test, thus further ensuring the accuracy of the experimental data.

[0022] In summary, this utility model provides a device for testing the performance of sealing materials under triaxial stress, which has at least one of the following beneficial technical effects: 1. When performance testing of sealing materials is required, the prepared sealing material sample is placed at the center of the confining pressure test piece. The axial pressure test piece is then activated. After activation, the axial pressure test piece moves towards the sample until it contacts the sample and then stops moving. Once in contact with the sample, the control panel is used to apply a predetermined pressure to the sample simultaneously using both the confining pressure test piece and the axial pressure test piece. The deformation resistance of the sealing material can then be accurately evaluated by reading the experimental data. Testing the sealing material performance in this way effectively simulates the actual downhole stress environment, greatly improving the accuracy of the test data.

[0023] 2. When testing the horizontal deformation resistance of the sample, place the sample inside a rubber sleeve. Inject high-pressure oil through the inlet pipe between the lower and upper end caps. Once the high-pressure oil enters the cavity between the lower and upper end caps, it evenly compresses the rubber sleeve and the sample until the pressure exerted by the high-pressure oil on the rubber sleeve and the sample reaches the predetermined pressure value. Then stop injecting oil and record the experimental data to analyze the deformation of the sample under horizontal pressure. Measuring the horizontal deformation resistance of the sample using this method ensures that the pressure on the sample is evenly distributed in the horizontal direction, thus accurately simulating the actual downhole stress environment and effectively improving the accuracy of the experimental data.

[0024] 3. When testing the performance of the sealing material under axial stress, place the sample to be tested inside the rubber sleeve, start the first motor, and the rotation of the first motor drives the drive wheel to rotate. The drive wheel then drives the driven wheel to rotate via a belt, which in turn drives the threaded rod to rotate. Since the pressure rod has a threaded groove that mates with the threaded rod, the rotation of the threaded rod drives the pressure rod to move along the threaded rod towards the sample to be tested until the bottom of the pressure rod contacts the top of the sample. Then, stop the first motor. After the pressure rod contacts the sample, input the axial stress value to the control panel. After the stress value is input, the system controls the first motor to rotate. The rotating first motor allows the pressure rod to continue moving towards the sample and applying axial pressure until the applied axial pressure reaches the predetermined value. At this point, the system controls the motor to stop rotating. Experimental data can then be recorded, and the performance of the sealing material under axial stress can be analyzed. Measuring the deformation resistance of the sealing material under axial pressure using this method ensures that the pressure on the sample is uniformly distributed in the axial direction, thus effectively improving the accuracy of the experimental data. Attached Figure Description

[0025] Figure 1 A schematic diagram of a triaxial stress-based test device for the performance of sealing materials is provided in an embodiment of this utility model. Figure 2 A schematic diagram of the confining pressure test piece in a triaxial stress-based hole sealing material performance testing device provided in this embodiment of the utility model; Figure 3 A schematic diagram of the pore pressure test piece in a triaxial stress-based pore sealing material performance testing device provided in this embodiment of the present invention; Figure 4 A schematic diagram of the sealing element structure in a triaxial stress-based test device for the performance of sealing materials is provided in an embodiment of this utility model. Figure 5A schematic diagram of the overflow valve structure in a triaxial stress-based test device for the performance of sealing materials provided in this embodiment of the present invention.

[0026] Explanation of the markings in the image: 1. Base; 11. Sample to be tested; 12. Control panel; 2. Confining pressure test piece; 21. Lower end cover; 22. Upper end cover; 23. Oil inlet pipe; 24. Oil reservoir; 25. Rubber sleeve; 26. Oil inlet pump; 27. Oil outlet pipe; 28. Overflow valve; 3. Axial pressure test piece; 31. Fixing plate; 32. First motor; 33. Drive wheel; 34. Driven wheel; 35. Belt; 36. Threaded rod; 37. Pressure rod; 38. Belt; 4. Pore pressure test piece; 41. Water inlet block; 42. Water inlet pipe; 43. Water tank; 44. Water outlet block; 45. Water outlet pump; 5. Seal; 51. Second motor; 52. Drive gear; 53. Driven gear; 54. Circular arc rack; 55. Sealing rod; 56. Buffer pad. Detailed Implementation

[0027] The following is in conjunction with the appendix Figure 1-5 This application will be described in further detail.

[0028] Combination Figure 1 , Figure 2 and Figure 3 This application discloses a device for testing the performance of sealing materials under triaxial stress, including a base 1, a confining pressure test piece 2, a sample to be tested 11, an axial pressure test piece 3, and a control panel 12. The base 1 is fixedly set on the ground, and the confining pressure test piece 2 is fixedly set on the base 1. The confining pressure test piece 2 can simulate the underground stress environment. The sample to be tested 11 is placed at the center of the confining pressure test piece 2. The axial pressure test piece 3 is slidably set on the base 1 and is located directly above the sample to be tested 11. The axial pressure test piece 3 can apply a vertically downward axial pressure to the sample to be tested 11 to simulate the actual underground stress state. The control panel 12 is fixedly set on one side of the base 1. The control panel 12 can control the magnitude and direction of the stress applied to the sample to be tested by the confining pressure test piece 2 and the axial pressure test piece 3.

[0029] In this embodiment, the base 1 is a rectangular structure and is fixed to the ground by bolts. The test sample 11 is a cylindrical structure and the control panel 12 is a rectangular structure. The control panel 12 can be fixedly connected to the base 1 by integral molding or by welding. No specific limitation is made in this embodiment.

[0030] In practical use, when performance testing of the sample 11 is required, the sample 11 is placed at the center of the confining pressure test piece 2. The axial pressure test piece 3 is then activated, moving towards the sample 11 until its bottom end contacts the top end of the sample 11. After the axial pressure test piece 3 contacts the sample 11, the parameters of the control panel 12 are adjusted to synchronously apply a preset pressure to the sample 11, thus simulating the actual underground stress environment. By reading the experimental data, the performance of the sample 11 under triaxial stress can be analyzed, thereby evaluating the reliability of the sample 11 in practical engineering applications.

[0031] Combination Figure 1 , Figure 2 and Figure 5 In a specific embodiment, the confining pressure test piece 2 includes a lower end cover 21, a rubber sleeve 25, an oil inlet pipe 23, and an upper end cover 22. The lower end cover 21 is fixedly mounted on the base 1, and a placement hole is vertically provided at the center of the lower end cover 21. The rubber sleeve 25 is placed in the placement hole. One end of the oil inlet pipe 23 is fixedly connected to the outer periphery of the lower end cover 21, and the other end of the oil inlet pipe 23 is fixedly connected to the oil storage tank. The upper end cover 22 is fixedly mounted directly above the lower end cover 21, and a mating hole is vertically provided at the center of the upper end cover 22. The axial compression test piece 3 includes a fixed plate 31, a first motor 32, a driving wheel 33, a driven wheel 34, a threaded rod 36, and a pressure rod 37. The fixed plate 31 is fixedly mounted on the base 1. The first motor 32 is fixedly mounted on the fixed plate 31. The driving wheel 33 is rotatably mounted on the fixed plate 31 and is fixedly connected to the output shaft of the first motor 32. The driven wheel 34 is rotatably mounted on the fixed plate 31 and is located on the same horizontal line as the driving wheel 33. The driving wheel 33 and the driven wheel 34 are connected by a belt 35. The threaded rod 36 is rotatably mounted on the fixed plate 31 and its top end is fixedly connected to the output shaft of the driven wheel 34. The pressure rod 37 is sleeved on the outer periphery of the threaded rod 36 and has a threaded groove that mates with the threaded rod 36. A pore pressure test piece 4 is fixedly installed inside the base 1. The pore pressure test piece 4 includes a water inlet block 41, a water inlet pipe 42, and a water outlet block 44. The water inlet block 41 is fixedly installed inside the base 1, with its top end abutting against the bottom of the sample 11 to be tested. One end of the water inlet pipe 42 is fixedly connected to the outer periphery of the water inlet block 41, and the other end of the water inlet pipe 42 is fixedly connected to the water tank 43. The water outlet block 44 is fixedly connected to the pressure rod 37, with its bottom end abutting against the top of the sample 11 to be tested. An oil outlet pipe 27 is fixedly installed at the end of the lower end cover 21 away from the oil inlet pipe 23, and an overflow valve 28 is fixedly installed on the oil outlet pipe 27. The upper end cover 22 is made of transparent high-strength glass, and the oil storage tank contains silicone oil.

[0032] In this embodiment, the lower end cap 21 is cylindrical and is integrally formed and fixedly connected to the base 1. The placement hole is cylindrical, and the specifications of the rubber sleeve 25 match the placement hole, ensuring that the rubber sleeve 25 can be embedded in the placement hole. The upper end is cylindrical, and the upper end cap 22 is fixedly connected to the lower end cap 21 by bolts. The mating hole and the placement hole are on the same axis and have the same specifications. The oil inlet pipe 23 is cylindrical and can be integrally formed and fixedly connected to the lower end cap 21 and the oil tank 24, or it can be connected by welding. In this embodiment, no specific limitation is made. The oil outlet pipe 27 is cylindrical and is integrally formed and fixedly connected to the lower end cap 21. The overflow valve 28 can be integrally formed and fixedly connected to the oil outlet pipe 27, or it can be connected by welding. In this embodiment, no specific limitation is made. The fixing plate 31 has a rectangular structure and is integrally formed and fixedly connected to the base 1. The first motor 32 is fixedly connected to the fixing plate 31 by bolts. The drive wheel 33 is fixedly connected to the output shaft of the first motor 32 by welding. The threaded rod 36 is integrally formed and fixedly connected to the output shaft of the driven wheel 34. The water inlet block 41 is integrally formed and fixedly connected to the base 1. The water inlet pipe 42 has a cylindrical structure and can be integrally formed and fixedly connected to the water inlet block 41 and the water tank 43, or it can be connected by welding. In this embodiment, no specific limitation is made. The water outlet block 44 can be integrally formed and fixedly connected to the pressure rod 37, or it can be connected by welding. In this embodiment, no specific limitation is made. The oil storage tank 24 and the water tank 43 are both rectangular structures and are fixedly installed on the ground by bolts.

[0033] In practical use, when it is necessary to perform performance testing on the sample 11, open the upper cover 22, place the sample 11 inside the rubber sleeve 25, and ensure that the sample 11 is in close contact with the water inlet block 41. Then, fix the upper cover 22 and the lower cover 21 together with bolts. Start the first motor 32. After the first motor 32 rotates, it drives the drive wheel 33 to rotate. After the drive wheel 33 rotates, it drives the driven wheel 34 to rotate through the belt 35. After the driven wheel 34 rotates, it drives the threaded rod 36 to rotate. Since the inner circumference of the pressure rod 37 is fixedly provided with a threaded groove that mates with the threaded rod 36, after the threaded rod 36 rotates, the pressure rod 37 can move along the threaded rod 36 toward the sample 11 until the water outlet block 44 passes through the mating hole and contacts the sample 11. Then, stop rotating the first motor 32. After the water outlet block 44 comes into contact with the test sample 11, a preset pressure value can be input through the control panel 12. After receiving the preset pressure value, the control panel 12 controls the oil pump 26 to start and inject silicone oil through the oil inlet pipe 23 into the gap between the upper end cover 22 and the lower end cover 21. After the silicone oil is injected into the cavity between the upper end cover 22 and the lower end cover 21, pressure is uniformly applied to the rubber sleeve 25 and the test sample 11 until the pressure applied to the test sample 11 by the silicone oil reaches the preset value, at which point the injection of silicone oil can be stopped. The control panel 12 controls the start of the oil pump 26 and the start of the first motor 32 at the same time. After the first motor 32 rotates, it controls the pressure rod 37 to continue moving the water outlet block 44 toward the test sample 11. Since the water outlet block 44 is in close contact with the test sample 11, the water outlet block 44 can uniformly apply pressure to the test sample 11 after the first motor 32 rotates until the axial pressure on the test sample 11 reaches the preset value, at which point the control panel 12 controls the first motor 32 to stop rotating. At this time, the sample 11 to be tested is simultaneously subjected to horizontal pressure from silicone oil and vertical pressure from water outlet block 44, thereby accurately simulating the stress state of the sample 11 to be tested in the actual working environment and ensuring the accuracy and reliability of the test data.

[0034] While applying pressure to the silicone oil and the water outlet block 44, the water pump 45 is started, and water is injected into the water inlet block 41 through the water inlet pipe 42. Since the water inlet block 41 is in close contact with the test sample 11, and as the water volume increases, the water can enter the interior of the test sample 11 through the water inlet block 41. The water permeates to the top of the test sample 11 through capillary action. Since the bottom end of the water outlet block 44 is in close contact with the top end of the test sample 11, the water enters the interior of the water outlet block 44 when it moves to the top end of the test sample 11. The pore pressure value of the test sample 11 in actual application is then tested by the resistance during water permeation.

[0035] During the testing of the sample, changes in external factors such as temperature may cause variations in the temperature of the silicone oil. These temperature changes result in variations in the pressure exerted on the test sample 11. The overflow valve 28 can be used to adjust the silicone oil flow rate in a timely manner, ensuring that the pressure on the test sample 11 remains stable within a preset range. Simultaneously, the transparent upper cap 22 and the transparent silicone oil can be used to observe the morphological changes of the test sample 11 in real time during the test, thus preventing data deviations caused by sample deformation.

[0036] Combination Figure 4 In a specific embodiment, sealing elements 5 are symmetrically arranged on the upper end cover 22 and the lower end cover 21 along the axis of the mating hole. The sealing element 5 includes a second motor 51, a drive gear 52, an arc rack 54, and sealing rods 55. There are two second motors 51, each of which is fixedly installed at the bottom of the lower end cover 21 and the top of the upper end cover 22. There are two drive gears 52, each of which is rotatably installed inside the upper end cover 22 and the lower end cover 21. Each drive gear 52 is fixedly connected to the second motor 51. There are two arc racks 54, each of which is installed inside the upper end cover 22 and the lower end cover 21 when rotating. Each arc rack 54 meshes with the drive gear 52. There are three sealing rods 55 inside the upper end cover 22 and the lower end cover 21, each of which is rotatably installed inside the upper end cover 22 and the lower end cover 21. Each sealing rod 55 meshes with the arc rack 54. Each sealing rod 55 has a buffer pad 56 fixedly installed on the side closest to the test sample 11.

[0037] In this embodiment, the second motor 51 is fixedly connected to the upper end cover 22 and the lower end cover 21 by bolts, and the drive gear 52 is fixedly connected to the output shaft of the second motor 51 by welding. The buffer pad 56 can be made of rubber or silicone, and no specific limitation is made in this embodiment. The buffer pad 56 is fixedly connected to the sealing rod 55 by adhesive.

[0038] In practical use, before injecting silicone oil into the gap between the upper end cover 22 and the lower end cover 21, the second motor 51 must be started first. After the second motor 51 starts, it drives the drive gear 52 to rotate. After the drive gear 52 rotates, it drives the arc rack 54 to rotate. After the arc rack 54 rotates, it drives the sealing rod 55 to move towards the rubber sleeve 25 until the buffer pad 56 clamps the rubber sleeve 25, at which point the second motor 51 can be stopped. After the buffer pad 56 clamps the rubber sleeve 25, silicone oil can be injected into the gap between the upper end cover 22 and the lower end cover 21. After the silicone oil fills the cavity between the upper end cover 22 and the lower end cover 21, the setting of the buffer pad 56 not only ensures that the silicone oil does not leak, avoiding the change in the pressure value of the test sample 11 due to silicone oil leakage during the test, but also reduces the clamping force of the sealing rod 55 on the test sample 11 after clamping the rubber sleeve 25, thereby effectively improving the accuracy of the test data.

[0039] The principle of this embodiment is as follows: When a performance test is required on the sample 11 to be tested, the sample 11 is placed at the center of the confining pressure test piece 2. The axial pressure test piece 3 is then activated, moving towards the sample 11 until its bottom end contacts the top end of the sample 11. After the axial pressure test piece 3 contacts the sample 11, the parameters of the control panel 12 are adjusted so that the confining pressure test piece 2 and the axial pressure test piece 3 apply a preset pressure to the sample 11 simultaneously, thereby simulating the actual underground stress environment. By reading the experimental data obtained, the performance of the sample 11 under triaxial stress can be analyzed, and the reliability of the sample 11 in practical engineering applications can be evaluated.

[0040] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A device for testing the performance of sealing materials under triaxial stress, characterized in that, include: The base (1) is fixedly installed on the ground; The confining pressure test piece (2) is fixedly installed on the base (1) and can simulate the underground stress environment. The test sample (11) is placed at the center of the confining pressure test piece (2); Axial compression test piece (3) is slidably disposed on the base (1). The axial compression test piece (3) is located directly above the sample to be tested (11). The axial compression test piece (3) can apply a vertically downward axial pressure to the sample to be tested (11) to simulate the actual underground stress state. Control panel (12) is fixedly installed on one side of the base (1). The control panel (12) can control the magnitude and direction of the stress applied to the test sample (11) by the confining pressure test piece (2) and the axial pressure test piece (3).

2. The device for testing the performance of sealing materials under triaxial stress according to claim 1, characterized in that, The confining pressure test specimen (2) includes: The lower end cover (21) is fixedly mounted on the base (1), and a placement hole is vertically provided at the axis of the lower end cover (21); A rubber sleeve (25) is placed inside the placement hole; An oil inlet pipe (23) is provided, one end of which is fixedly connected to the outer periphery of the lower end cap (21), and the other end of which is fixedly connected to the oil storage tank. The upper end cover (22) is fixedly disposed directly above the lower end cover (21), and a mating hole is vertically disposed at the center of the upper end cover (22).

3. The device for testing the performance of sealing materials under triaxial stress according to claim 1, characterized in that, The axial compression test piece (3) includes: A fixing plate (31) is fixedly mounted on the base (1); The first motor (32) is fixedly mounted on the fixed plate (31); The drive wheel (33) is rotatably mounted on the fixed plate (31) and is fixedly connected to the output shaft of the first motor (32). Driven wheel (34), the driven wheel (34) is rotatably mounted on the fixed plate (31), the driven wheel (34) and the driving wheel (33) are located on the same horizontal line, the driving wheel (33) and the driven wheel (34) are connected by a belt (35); A threaded rod (36) is rotatably mounted on the fixed plate (31), and the top end of the threaded rod (36) is fixedly connected to the output shaft of the driven wheel (34). A pressure rod (37) is sleeved on the outer periphery of the threaded rod (36), and the pressure rod (37) is fixedly provided with a threaded groove that mates with the threaded rod (36).

4. The device for testing the performance of sealing materials under triaxial stress according to claim 2, characterized in that, The upper end cap (22) and the lower end cap (21) are symmetrically provided with sealing elements (5) along the axis of the mating hole. The sealing element (5) includes: There are two second motors (51), each of which is fixedly installed at the bottom of the lower end cover (21) and the top of the upper end cover (22); Two drive gears (52) are provided. Each drive gear (52) is rotatably disposed inside the upper end cover (22) and the lower end cover (21). Each drive gear (52) is fixedly connected to the second motor (51). Two circular arc racks (54) are provided. Each circular arc rack (54) is located inside the upper end cover (22) and the lower end cover (21) when rotating. Each circular arc rack (54) meshes with the drive gear (52). The upper end cover (22) and the lower end cover (21) are each provided with three sealing rods (55). Each sealing rod (55) is rotatably disposed in the upper end cover (22) and the lower end cover (21). Each sealing rod (55) meshes with the arc rack (54).

5. The device for testing the performance of sealing materials under triaxial stress according to claim 3, characterized in that, A pore pressure test piece (4) is fixedly installed inside the base (1), and the pore pressure test piece (4) includes: Water inlet block (41), the water inlet block (41) is fixedly installed in the base (1), and the top of the water inlet block (41) abuts against the bottom of the sample to be tested (11); Water inlet pipe (42), one end of which is fixedly connected to the outer periphery of the water inlet block (41), and the other end of which is fixedly connected to the water tank (43); Water outlet block (44) is fixedly connected to the pressure rod (37), and the bottom end of the water outlet block (44) abuts against the top of the sample to be tested (11).

6. The device for testing the performance of sealing materials under triaxial stress according to claim 2, characterized in that, An oil outlet pipe (27) is fixedly installed at the end of the lower end cap (21) away from the oil inlet pipe (23), and an overflow valve (28) is fixedly installed on the oil outlet pipe (27).

7. The device for testing the performance of sealing materials under triaxial stress according to claim 4, characterized in that, Each of the sealing rods (55) has a buffer pad (56) fixedly installed on the side near the test sample (11).

8. The device for testing the performance of sealing materials under triaxial stress according to claim 2, characterized in that, The upper cover (22) is made of transparent high-strength glass, and the oil storage tank contains silicone oil.

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