Multi-field coupling triaxial seepage test device

Abstract

The utility model relates to the technical field of rock stratum mechanics tests, in particular to a multi-field coupling triaxial seepage test device which comprises a box body, a counter-force base and a confining pressure chamber are arranged in the box body, a counter-force frame is arranged on the counter-force base, a loading system is arranged on the counter-force frame, and the loading system comprises a top loading shaft. A top loading head is arranged at the lower end of the top loading shaft; a one-way loading platform is arranged at the position, corresponding to the top loading head, of the counter-force base, sliding rails are arranged on the two sides of the one-way loading platform respectively, and the bottom of the confining pressure chamber is in sliding connection with the counter-force base through cooperation with the two sliding rails. And a confining pressure chamber lifting mechanism is further arranged at the top of the counter-force frame, and the confining pressure chamber lifting mechanism is connected with the top of the confining pressure chamber to lift the confining pressure chamber. One-way loading, three-way loading and seepage tests are combined together, the compactness of the structure of the device is improved, the confining pressure chamber lifting mechanism is additionally arranged, the confining pressure chamber barrel can be conveniently and effectively lifted, and the difficulty of the test process is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of rock stratum mechanics tests, in particular to a multi-field coupled triaxial seepage test device. Background Art

[0002] During coal mining, local or overall instability of geological bodies caused by mining disturbance is an important factor in causing mining dynamic disasters and safety accidents. The deformation and failure laws of rocks as natural geological materials are closely related to the use design and construction safety of rock engineering and the occurrence of disasters. Therefore, it is of great significance to explore the strength, deformation, seepage characteristics and failure mode of rocks under different engineering disturbances to reduce the risk of engineering disasters and improve the design and construction level of rock engineering.

[0003] However, at present, most of the indoor tests on the mechanical behavior of rocks under engineering disturbances are based on uniaxial compression test systems, which make it difficult to restore the deformation and failure characteristics of coal-rock media under triaxial stress in the in-situ strata. At the same time, it is difficult to capture the details of the rock fracture process, such as deformation, micro cracking, crack occurrence and development. Patent CN211740856U discloses a shear seepage coupling test device for columnar rocks, including a reaction frame, a confining pressure chamber, a shear force loading shaft of the outer ring of the rock sample, a top loading head, a top force transmission rod, a shear force loading shaft of the inner core of the rock sample, and a base. Although it can perform shear seepage coupling tests on the specimens through confining pressure, it can only perform annular shear tests on the specimens during use, and cannot be used for uniaxial compression tests. In addition, since the cylinder of the confining pressure chamber is too heavy, it is difficult for one person to remove it, and it is very difficult to replace the specimens.

[0004] Based on the above problems, the utility model proposes a multi-field coupled triaxial seepage test device. Utility Model Content

[0005] In order to solve the above technical problems, the utility model provides a multi-field coupled triaxial seepage test device, which aims to solve the problem that the existing device cannot be used for unidirectional loading tests and the cylinder of the confining pressure chamber is too heavy for operators to remove, so as to achieve a more realistic technical effect of simulating the original stress state of coal rock.

[0006] To achieve this technical purpose, the utility model adopts the following scheme:

[0007] A multi-field coupled triaxial seepage test device comprises a box body, a reaction force frame and a confining pressure chamber are arranged inside the box body, a reaction force base is arranged at the lower part of the reaction force frame, a loading system is arranged at the upper part of the reaction force frame, the loading system comprises a top loading shaft, and a top loading head is arranged at the lower end of the top loading shaft;

[0008] A one-way loading platform is arranged on the reaction base at a position corresponding to the top loading head, and slide rails are arranged on both sides of the one-way loading platform. The bottom of the confining pressure chamber can move on the two slide rails to realize sliding connection with the reaction base.

[0009] A confining pressure chamber lifting mechanism is also provided on the top of the reaction force frame, and the confining pressure chamber lifting mechanism lifts the confining pressure chamber by being connected to the top of the confining pressure chamber.

[0010] Compared with the prior art, the beneficial effects of the utility model are:

[0011] The utility model ensures the safety of equipment lifting by adding a confining pressure chamber lifting mechanism to lift the confining pressure chamber, facilitates opening the confining pressure chamber to take and place test pieces, and reduces the labor intensity of operators; and the device can meet the requirements of both unidirectional loading experiments and confining pressure experiments, thereby improving the compactness and applicability of the structure.

[0012] Further, the preferred solution adopted by the utility model is:

[0013] The one-way loading platform is provided with an installation groove at a position corresponding to the top loading head, and a plurality of stacked pads are arranged in the installation groove, and a loading groove is respectively provided at the center of each pad.

[0014] The confining pressure chamber lifting mechanism includes a mounting platform and a driving motor. The driving motor is placed on the mounting platform. A lead screw is arranged at the output end of the driving motor. A connector connected to the top of the confining pressure chamber is arranged at the lower end of the lead screw.

[0015] The bottom of the confining pressure chamber corresponds to the two slide rails on the unidirectional loading platform and is respectively provided with sliding blocks that match therewith, and the cooperation between the sliding blocks and the slide rails realizes the sliding connection between the confining pressure chamber and the reaction force base.

[0016] The confining pressure chamber includes a cylinder and a base, and the base and the cylinder are detachably connected; a specimen pressurizing platform is arranged at the center of the base, a pressurizing shaft is slidably and sealably connected to the top of the cylinder, the upper end of the pressurizing shaft is arranged outside the cylinder and is connected to the top loading head through a flange; a pressurizing block is arranged at the lower end of the pressurizing shaft;

[0017] The side surface of the base is provided with seepage pipelines and confining pressure pipelines along its radial direction.

[0018] The confining pressure chamber comprises an upper cylinder, a lower cylinder and a base, the upper cylinder and the lower cylinder are sealed and connected, and the outer parts of the upper cylinder and the lower cylinder are fixed by a reinforcing ring;

[0019] Seepage pipelines and confining pressure pipelines are arranged on the specimen pressure platform of the base.

[0020] The upper surface of the pressurizing platform and the lower surface of the pressurizing block are respectively provided with test piece grooves. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a three-dimensional schematic diagram of the utility model;

[0022] Figure 2 for Figure 1 A side view of the box, wherein the box is hidden in order to see the internal structure of the box;

[0023] Figure 3 for Figure 1 The front view of the box, in which the box is hidden in order to see the internal structure of the box;

[0024] Figure 4 for Figure 1 A top view of

[0025] Figure 5 It is a structural schematic diagram of a unidirectional loading platform;

[0026] Figure 6 This is a schematic diagram of the internal structure of the confining pressure chamber;

[0027] Figure 7 is a schematic diagram of the structure of the cushion block;

[0028] The markings in the figure are: 1. box body; 2. loading hydraulic cylinder; 3. confining pressure lifting mechanism; 4. reaction force frame; 5. reaction force base; 6. confining pressure chamber; 601. cylinder body; 602. base; 7. cushion block; 701. loading slot; 8. one-way loading platform; 9. mounting slot; 10. slide rail; 11. top loading shaft; 12. top loading head; 13. driving motor; 14. screw; 15. connector; 16. pressurizing shaft; 17. flange; 18. semicircular plate; 19. reinforcement ring; 20. slider; 21. mounting plate; 22. tightening screw; 23. specimen; 24. silicone sleeve; 25. confining pressure pipeline; 26. seepage pipeline; 27. confining pressure discharge port; 28. seepage liquid discharge port; 29. ​​pressurizing block; 30. specimen pressurizing platform. DETAILED DESCRIPTION

[0029] In order to fully understand the purpose, features and effects of the present invention, the following specific implementation methods are provided. Figures 1 to 6 The present invention is described in detail with reference to the accompanying drawings, but the present invention is not limited thereto.

[0030] A multi-field coupled triaxial seepage test device comprises a box body 1 and a reaction force base 5 and a confining pressure chamber 6 arranged inside the box body 1. The confining pressure chamber 6 is used to provide a confining pressure environment for the test.

[0031] The reaction frame 4 is placed above the reaction base 5, and a loading system is arranged on the reaction frame 4. The loading system in this embodiment is a loading hydraulic cylinder 2, and the output end of the loading hydraulic cylinder 2 is connected to the top loading shaft 11. The loading hydraulic cylinder 2 pushes the top loading shaft 11 to perform telescopic movement; in this embodiment, the lower end of the top loading shaft 11 is connected to a top loading head 12.

[0032] A unidirectional loading platform 8 is provided on the upper surface of the reaction base 5 at a position corresponding to the top loading head 12. A mounting groove 9 is provided on the unidirectional loading platform 8 at a position corresponding to the top loading head 12. A plurality of stacked pads 7 are provided in the mounting groove 9. A loading groove 701 for placing the test piece 23 is provided at the center of each pad 7.

[0033] Two slide rails 10 are installed on the front and rear sides and the left and right sides of the unidirectional loading platform 8, and the confining pressure chamber 6 is slidably connected to the slide rails 10. Specifically, a mounting plate 21 is provided at the bottom of the confining pressure chamber 6, and sliders 20 are provided on the front and rear sides of the bottom of the mounting plate 21 respectively corresponding to the two slide rails 10. The mounting plate 21 cooperates with the slide rails 10 through the sliders 20 to achieve a sliding connection with the unidirectional loading platform 8, thereby making the confining pressure chamber 6 slidably connected to the reaction force base 5.

[0034] The confining pressure chamber 6 is composed of a cylinder 601 and a base 602. The base 602 is fixedly mounted on the mounting plate 21. The slider 20 is mounted at the bottom of the mounting plate 21. The base 602 and the cylinder 601 are detachably connected. When the base 602 and the cylinder 601 are connected, the sealing between the two should be ensured. The cavity between the cylinder 601 and the base 602 is the confining pressure chamber. The center of the base 602 is raised upward to form a specimen pressurizing platform 30. The top of the cylinder 601 is slidably sealed and connected with a pressurizing shaft 16. The upper end of the pressurizing shaft 16 is placed outside the cylinder 601 and is provided with a flange 17. The flange 17 can be connected to the top loading head 12. The lower end of the pressurizing shaft 16 is fixedly connected with a pressurizing block 29, which is used to pressurize the specimen 23.

[0035] The specimen pressurizing platform 30 is introduced into the seepage pipeline 26 through the base 602. The seepage pipeline 26 is externally connected to a water pump. The water pump performs a seepage test on the specimen 23 through the seepage pipeline 26. A confining pressure pipeline 25 is also opened along the radial direction on the side surface of the base 602. The confining pressure pipeline 25 is externally connected to a confining pressure pump. The confining pressure pump injects liquid into the confining pressure chamber through the confining pressure pipeline 25 for pressurization.

[0036] In this embodiment, a confining pressure outlet 27 and a seepage liquid outlet 28 are provided above the cylinder 601, and valves are provided at the confining pressure outlet and the seepage liquid outlet, respectively.

[0037] In this embodiment, the cylinder 601 and the base 602 are fixed by two semicircular plates 18, and the outside of the two semicircular plates 18 is tightened and reinforced by a reinforcement ring 19. Specifically, the lower end of the cylinder 601 is provided with an annular protrusion outwardly, and the upper end of the base 602 is also provided with an annular outer edge adapted to the annular protrusion. The inner walls of the two semicircular plates 18 are respectively provided with grooves adapted to the annular protrusion and the annular outer edge. After the annular protrusion and the annular outer edge are aligned, the cylinder 601 and the base 602 are fixed by the two semicircular plates 18; the reinforcement ring 19 is sleeved on the outside of the two semicircular plates 18, and the surface of the reinforcement ring 19 is circumferentially spaced with threaded holes, and each threaded hole is threadedly connected with a tightening screw 22, and the tightening screw 22 tightens the surface of the semicircular plate 18.

[0038] A lifting mechanism for the confining pressure chamber 6 is also installed on the top of the reaction frame 4. The lifting mechanism for the confining pressure chamber 6 is composed of a mounting platform and a driving motor 13. The output end of the driving motor 13 is connected to a lead screw 14, and the driving motor 13 drives the lead screw 14 to move up and down. A connector 15 is fixedly connected to the lower end of the driving lead screw 14, and the connector 15 can be connected to the flange at the top of the cylinder 601 of the confining pressure chamber 6.

[0039] In this embodiment, holes can be opened in the center of the top loading head 12 and the pressure block 29, and acoustic emission detection equipment probes can be installed in the holes to collect crack signals generated during the loading process in real time through the acoustic emission probes.

[0040] When the device performs a unidirectional loading test, the number of pads required is determined according to the height of the specimen 23, the pads 7 are stacked together at one time, and then the specimen 23 is placed in the loading slot 701 of the topmost pad 7, and the loading hydraulic cylinder 2 drives the top loading shaft 11 downward to pressurize the specimen 23 according to the test requirements.

[0041] When the device is conducting a three-dimensional loading test, a silicone sleeve 24 is firstly sheathed on the outside of the cylindrical specimen 23, and the inner diameter of the silicone sleeve 24 matches the cross-sectional diameter of the specimen 23. Then, a displacement sensor is installed on the outside of the silicone, and the two ends of the silicone sleeve 24 extend out of the upper and lower end surfaces of the specimen 23, respectively, so as to ensure that a certain margin is left in the silicone sleeves 24 at both ends of the specimen 23.

[0042] Then, the test piece 23 is placed on the test piece pressurizing platform 30 at the center of the base 602, and then the cylinder 601 of the confining pressure chamber 6 is installed and the sealing between the cylinder 601 and the base 602 is checked;

[0043] Then, the loading hydraulic cylinder 2 is started to pressurize the specimen 23, so that the upper and lower ends of the specimen 23 are in good contact with the pressurizing block 29 and the specimen pressurizing platform 30, respectively, so as to achieve a sealing effect between the two ends of the specimen 23 and the pressurizing block 29 and the specimen pressurizing platform 30, respectively, so that the specimen is not exposed in the confining pressure chamber;

[0044] The confining pressure pump is started to inject liquid into the confining pressure chamber and pressurize it to a specified value, and then axial loading and seepage pressure are applied, and the deformation of the test piece 23 is monitored in real time.

[0045] When the three-way loading test is completed, the connection between the upper end of the confining pressure chamber 6 and the top loading head 12 is removed, and then the confining pressure chamber 6 is moved along the slide rail 10 to the bottom of the confining pressure chamber 6 lifting mechanism, and the flange at the upper end of the confining pressure chamber 6 is aligned with the connecting head 15 at the lower end of the screw 14, and the driving motor 13 drives the connecting head 15 to move down through the screw 14 until it contacts the upper surface of the flange, and the two are connected by bolts; after the pressure relief and confining pressure liquid discharge operations inside the confining pressure chamber are completed, the reinforcing ring 19 and the semicircular plate 18 are removed, and the driving motor 13 is started. The driving motor 13 drives the cylinder 601 to move upward through the screw 14, the confining pressure chamber 6 is opened, and then the test piece 23 is taken out.

[0046] The device combines unidirectional loading and three-directional loading tests together to improve the compactness of the structure of the device. By adding a confining pressure chamber lifting mechanism, the cylinder of the confining pressure chamber can be lifted quickly and effectively, which facilitates the replacement of test pieces and reduces the labor intensity of operators.

[0047] Finally, it should be noted that the above-listed examples are only preferred embodiments of the present invention. Of course, those skilled in the art can make changes and modifications to the present invention. If these modifications and modifications fall within the scope of the claims of the present invention and their equivalent technologies, they should be considered to be within the scope of protection of the present invention.

Claims

1. A multi-field coupled triaxial seepage test device, comprising a box, a reaction force frame and a confining pressure chamber are arranged inside the box, a reaction force base is arranged at the lower part of the reaction force frame, and a loading system is arranged at the upper part of the reaction force frame, characterized in that: The loading system comprises a top loading shaft, and a top loading head is arranged at the lower end of the top loading shaft; A one-way loading platform is arranged on the reaction base at a position corresponding to the top loading head, and slide rails are arranged on both sides of the one-way loading platform. The bottom of the confining pressure chamber can move on the two slide rails to realize sliding connection with the reaction base. A confining pressure chamber lifting mechanism is also provided on the top of the reaction force frame, and the confining pressure chamber lifting mechanism lifts the confining pressure chamber by being connected to the top of the confining pressure chamber.

2. The multi-field coupled triaxial seepage test device according to claim 1, characterized in that: The one-way loading platform is provided with an installation groove at a position corresponding to the top loading head, and a plurality of stacked pads are arranged in the installation groove, and a loading groove is respectively provided at the center of each pad.

3. The multi-field coupled triaxial seepage test device according to claim 1, characterized in that: The confining pressure chamber lifting mechanism includes a mounting platform and a driving motor. The driving motor is placed on the mounting platform. A lead screw is arranged at the output end of the driving motor. A connector connected to the top of the confining pressure chamber is arranged at the lower end of the lead screw.

4. The multi-field coupled triaxial seepage test device according to claim 1, characterized in that: The bottom of the confining pressure chamber corresponds to the two slide rails on the unidirectional loading platform and is respectively provided with sliding blocks that match therewith, and the cooperation between the sliding blocks and the slide rails realizes the sliding connection between the confining pressure chamber and the reaction force base.

5. The multi-field coupled triaxial seepage test device according to claim 1, characterized in that: The confining pressure chamber includes a cylinder and a base, and the base and the cylinder are detachably connected; a specimen pressurizing platform is arranged at the center of the base, a pressurizing shaft is slidably and sealably connected to the top of the cylinder, the upper end of the pressurizing shaft is arranged outside the cylinder and is connected to the top loading head through a flange; a pressurizing block is arranged at the lower end of the pressurizing shaft; The side surface of the base is provided with seepage pipelines and confining pressure pipelines along its radial direction. The confining pressure chamber comprises an upper cylinder, a lower cylinder and a base, the upper cylinder and the lower cylinder are sealed and connected, and the outer parts of the upper cylinder and the lower cylinder are fixed by a reinforcing ring; Seepage pipelines and confining pressure pipelines are arranged on the specimen pressure platform of the base.

6. The multi-field coupled triaxial seepage test device according to claim 5, characterized in that: The upper surface of the pressurizing platform and the lower surface of the pressurizing block are respectively provided with test piece grooves.

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