Size-adjustable rock shear box tooling and test method

Abstract

A size-adjustable rock shear box tool and test method, comprising upper and lower shear boxes, left and right push-pull plates, side connecting column bodies, adjusting discs, adjusting bolts and the like; the right side of the upper shear box abuts against an upper shear pressing seat; the left side of the lower shear box abuts against a lower shear pressing seat; the upper and lower shear pressing seats respectively abut against the left and right push-pull plates, and the left and right push-pull plates are connected through the side connecting column bodies. Through the designed side connecting column bodies and the inner and outer adjusting discs in the upper shear box, the size of the upper shear box can be adjusted; through adjusting the position of the adjusting bolt in the lower shear box connecting block body, the size of the lower shear box is adjusted, so that the accurate matching of the upper and lower shear samples and the shear box size is realized, and the gap between the shear sample and the shear tool box in the size matching process is eliminated, the accuracy of the shear test result is ensured, and it has important significance for the study of the shear mechanical properties of rock.

Description

Technical Field

[0001] This invention belongs to the field of geotechnical engineering testing technology, and particularly relates to a rock shear box fixture with adjustable dimensions and a testing method. Background Technology

[0002] With the continuous development of modern society, simply developing and utilizing above-ground resources can no longer meet the needs of industrial development, making the development of underground space resources an inevitable trend. Rock, as a natural geological material, has deformation and failure patterns that are closely related to the construction safety, service life, and disaster occurrence of rock engineering projects. In the natural environment, rock has relatively high strength, but the strength of rock masses along weak structural planes is very low. The presence of structural planes has an adverse effect on the strength and stability of rock masses. Extensive engineering practice shows that when rock masses fail and become unstable, the root cause is often shear slippage of internal structures along structural planes, without macroscopic damage to the structures themselves. Therefore, the mechanical properties of rock masses largely depend on the mechanical properties of joints, and can even be considered one of the most critical factors controlling the stability of geotechnical engineering. Currently, research on the shear mechanics of rock mass structural planes remains a hot topic in the field of geotechnical engineering.

[0003] Currently, scholars are studying the shear mechanics effects and failure modes of rock mass structural surfaces using various methods. Among these, shear mechanics testing is considered the most important and effective method for testing the shear strength of rocks. However, when conducting shear tests, a shearing fixture box matching the size of each rock specimen needs to be fabricated, resulting in a large number of shearing boxes and complex installation procedures. Furthermore, gaps often appear between the shearing specimen box and the shearing specimen due to insufficient flatness of the shearing specimen, affecting the shear displacement value of the test.

[0004] To address these issues, a rock shear box fixture with adjustable dimensions and a testing method are proposed. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention proposes a rock shearing box fixture with adjustable dimensions and a testing method.

[0006] To achieve the above objectives, the present invention provides a rock shearing box fixture with adjustable dimensions, comprising: an upper shearing fixture, a lower shearing fixture, an upper shearing box, a lower shearing box, and a lower structure; the upper shearing box is fixedly installed inside the upper shearing fixture, the lower shearing box is fixedly installed inside the lower shearing fixture, the upper shearing box and the lower shearing box are correspondingly arranged, and the bottoms of the upper shearing fixture and the lower shearing fixture are slidably connected to the lower structure.

[0007] Preferably, the upper shearing fixture includes an upper shearing box fixing steel block that abuts against the left side of the upper shearing box, and a left push-pull plate fixedly connected to the left side of the upper shearing box fixing steel block; an upper shearing pressure seat that abuts against the right side of the upper shearing box, and a right push-pull plate fixedly connected to the right side of the upper shearing pressure seat; and side connecting columns fixedly connected to the four corners of the inner side of the right push-pull plate, with one end of the side connecting column away from the right push-pull plate passing through the left push-pull plate and slidably connected to the left push-pull plate.

[0008] Preferably, the right push-pull plate is fixedly connected to the side connecting column via a fixed disc; an upper shear box internal adjustment disc is provided on the inner side of the connection between the left push-pull plate and the side connecting column, and the upper shear box internal adjustment disc is slidably sleeved with the side connecting column; an upper shear box external adjustment disc is provided on the outer side of the connection between the left push-pull plate and the side connecting column, and the upper shear box external adjustment disc is slidably sleeved with the side connecting column.

[0009] Preferably, a drag-reducing bearing is provided between the upper shear box and the upper shear box fixing steel block, and between the upper shear box and the upper shear pressure block. The drag-reducing bearing is fixedly connected to the upper shear box fixing steel block and the inner side of the upper shear box, respectively, and the inner side of the drag-reducing bearing abuts against the upper shear box.

[0010] Preferably, the lower shearing fixture includes a lower shearing pressure seat that abuts against the left side of the lower shearing box, and a lower shearing box fixing steel block that abuts against the right side of the lower shearing box. A lower shearing box connecting block abuts against the outer sides of the lower shearing pressure seat and the lower shearing box fixing steel block. An adjusting bolt is provided through the inside of the right side of the lower shearing box connecting block, and one end of the adjusting bolt near the lower shearing box fixing steel block abuts against the lower shearing box fixing steel block. A hydraulic cylinder connecting steel block is fixed to the left side of the lower shearing box connecting block by a steel block fixing bolt.

[0011] Preferably, the upper shear box has lateral connecting plates fixed to its front and rear sides. One end of the lateral connecting plate is fixed to the upper shear box fixing steel block via a first upper shear box fixing bolt, and the other end is fixed to the upper shear pressure seat via the first upper shear box fixing bolt. The lower shear box has lateral connecting plates fixed to its front and rear sides. One end of the lateral connecting plate is fixed to the lower shear pressure seat via a lower shear box fixing bolt, and the other end is fixed to the lower shear box fixing steel block via a lower shear box fixing bolt.

[0012] Preferably, the lower structure includes a bottom pad block, and a plurality of sliding tracks are fixedly connected above the bottom pad block. The sliding tracks located on the inner side are slidably connected to the bottom of the lower shear box connecting block, and the sliding tracks located on the outer side are slidably connected to the bottom sides of the left push-pull plate and the right push-pull plate.

[0013] Preferably, a shearing fixture box pad is fixedly connected to the bottom of the lower shearing box connecting block, and a plurality of shearing fixture box bases are fixedly connected below the shearing fixture box pad, the shearing fixture box bases being slidably connected to the sliding track.

[0014] Preferably, the left push-pull plate and the right push-pull plate extend from the side of the lower shear box connecting block, and push-pull plate pressure pads are fixedly connected to both ends of the bottom of the left push-pull plate and the right push-pull plate pressure pads, respectively. A movable base is fixedly connected to the bottom of the push-pull plate pressure pads, and the movable base is slidably connected to the sliding track.

[0015] A method for testing rock shear boxes with adjustable dimensions, comprising the following steps:

[0016] S1: Install the adjustable-size rock shear box fixture;

[0017] S2: Place the specimen to be sheared in the upper shear box and the lower shear box respectively, and ensure that the upper and lower shear specimens are aligned;

[0018] S3: Adjust the lower shear box fixture to make the lower shear specimen fit tightly against the lower shear box, eliminating the gap between the lower shear specimen and the left and right side components;

[0019] S4: Adjust the upper shearing fixture to make the upper shearing box fit tightly against the upper shearing sample, eliminate the gap between the component and the shearing sample, and then lock the upper shearing fixture.

[0020] S5: Apply a normal load to the upper end of the shear box, and apply shear loads to the sides of the upper and lower shear boxes; during the shear test, keep the shear load of one shear box constant, change the shear load of the other shear box to shear the specimen, form a shear displacement, and complete the shear test according to the test design value.

[0021] S6: Record all experimental data, photograph the experimental process, and end the experiment.

[0022] Compared with the prior art, the present invention has the following advantages and technical effects:

[0023] This invention develops an adjustable-size rock shear box fixture and testing method. This shearing fixture system is easy to install and operate, and has low cost. By changing the position of the adjusting bolts on the connecting block of the lower shear box, various sizes of lower shear specimens can be installed. By adjusting the position of the left push-pull plate and the inner and outer adjusting discs of the upper shear box, the upper shear box can be matched with multiple upper shear specimens of different sizes. Simultaneously, the gaps between the upper and lower shear specimens and the surrounding shearing fixture are eliminated during installation, thereby improving the accuracy of the shear test. This has significant implications for the theoretical research and engineering design of rock mass shear mechanics. Attached Figure Description

[0024] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0025] Figure 1 This is a schematic diagram of the structure of an adjustable-size rock shearing box tooling according to the present invention;

[0026] Figure 2 This is a schematic diagram of the internal structure of an adjustable-size rock shearing box tool according to the present invention.

[0027] Figure 3 This is a schematic diagram of the lower shearing fixture structure of an adjustable-size rock shearing box fixture according to the present invention.

[0028] In the diagram: 1. External adjusting disc of the upper shear box; 2. Left push-pull plate; 3. Upper shear box fixing steel block; 4. Side connecting plate of the upper shear box; 5. Internal adjusting disc of the upper shear box; 6. Side connecting column; 7. Upper shear box; 8. Fixing disc; 9. Right push-pull plate; 10. Drag-reducing bearing; 11. First upper shear box fixing bolt; 12. Lower shear box fixing bolt; 13. Sliding rail; 14. Bottom pad; 15. Side connecting plate of the lower shear box; 16. Moving base; 17. Push-pull plate pressure pad; 18. Lower shear box connecting block; 19. Adjusting bolt; 20. Second upper shear box fixing bolt; 21. Connecting screw; 22. Hydraulic cylinder connecting steel block; 23. Steel block fixing bolt; 24. Lower shear pressure seat; 25. Lower shear box; 26. Lower shear box fixing steel block; 27. Upper shear pressure seat; 28. Shearing tooling box pad; 29. ​​Shearing tooling box base. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] Example 1

[0032] Reference Figure 1-3As shown, this embodiment provides a rock shearing box fixture with adjustable dimensions, including: an upper shearing fixture, a lower shearing fixture, an upper shearing box 7, a lower shearing box 25, and a lower structure; the upper shearing box 7 is fixedly installed in the upper shearing fixture, and the lower shearing box 25 is fixedly installed in the lower shearing fixture. The upper shearing box 7 and the lower shearing box 25 are correspondingly arranged, and the bottoms of the upper shearing fixture and the lower shearing fixture are slidably connected to the lower structure.

[0033] The upper shear box 7 is installed inside the upper shear fixture. The upper shear fixture can be adjusted appropriately according to the size of the upper shear box 7 to install upper shear specimens of various sizes and eliminate the gap between the upper shear fixture and the upper shear specimen. The lower shear box 25 is installed inside the lower shear fixture. The lower shear fixture can be adjusted appropriately according to the size of the lower shear box 25 to install lower shear specimens of various sizes and eliminate the gap between the lower shear fixture and the lower shear specimen. The upper and lower shear fixtures can slide on the lower structure and generate shear displacement during the shear test.

[0034] The scheme is further optimized. The upper shearing fixture includes an upper shearing box fixing steel block 3 that abuts against the left side of the upper shearing box 7. A left push-pull plate 2 is fixedly connected to the left side of the upper shearing box fixing steel block 3. An upper shearing pressure seat 27 abuts against the right side of the upper shearing box 7. A right push-pull plate 9 is fixedly connected to the right side of the upper shearing pressure seat 27. Side connecting columns 6 are fixedly connected to the four corners of the inner side of the right push-pull plate 9. The end of the side connecting column 6 away from the right push-pull plate 9 passes through the left push-pull plate 2 and is slidably connected to the left push-pull plate 2.

[0035] The upper shearing fixture is supported by the lower structure, and the four side connecting columns 6 guide the left push-pull plate 2, allowing the left push-pull plate 2 to move left and right under the guidance of the side connecting columns 6. This adjusts the distance between the upper shearing box 7 and the upper shearing fixture according to the size of the upper shearing box 7, accommodating shearing samples and shearing boxes of different sizes. The left push-pull plate 2 abuts against the upper shearing box fixing steel block 3, the upper shearing box fixing steel block 3 abuts against the left side of the upper shearing box 7, the right side of the upper shearing box 7 abuts against the upper shearing pressure seat 27, and the upper shearing pressure seat 27 abuts against the right push-pull plate 9. Through the abutment and sequential pushing of the left push-pull plate 2, the gap between the upper shearing block and each upper shearing fixture is eliminated.

[0036] In a further optimized design, the right push-pull plate 9 is fixedly connected to the side connecting column 6 via a fixed disc 8; the inner side of the connection between the left push-pull plate 2 and the side connecting column 6 is provided with an upper shear box internal adjustment disc 5, which is slidably sleeved with the side connecting column 6; the outer side of the connection between the left push-pull plate 2 and the side connecting column 6 is provided with an upper shear box external adjustment disc 1, which is slidably sleeved with the side connecting column 6.

[0037] The side connecting column 6 is fixed to the right push-pull plate 9 via a fixed disc 8, guiding the sliding of the left push-pull plate 2. The connection between the left push-pull plate 2 and the side connecting column 6 is limited and fixed on both sides by the internal adjusting disc 5 and the external adjusting disc 1 of the upper shear box. Both the internal adjusting disc 5 and the external adjusting disc 1 of the upper shear box are equipped with fastening bolts for locking and loosening the connection between the internal adjusting disc 5 and the side connecting column 6, and between the external adjusting disc 1 and the side connecting column 6. When the upper shear... When the internal adjusting disc 5 and the side connecting column 6 of the upper shear box are relaxed, and the external adjusting disc 1 and the side connecting column 6 of the upper shear box are relaxed, the left push-pull plate 2 can slide left and right to adjust the size of the upper shear box 7 to match the upper shear sample of different sizes. During the size adjustment process, the upper shear box 7 fixture presses the upper shear box 7 to eliminate the gap between the upper shear box 7 and the upper shear fixture. After adjusting the position of the left push-pull plate 2, the internal adjusting disc 5 and the external adjusting disc 1 of the upper shear box are tightened in the corresponding positions to limit the position of the left push-pull plate 2.

[0038] In a further optimized design, a drag-reducing bearing 10 is provided between the upper shear box 7 and the upper shear box fixing steel block 3, and between the upper shear box 7 and the upper shear pressure block. The drag-reducing bearing 10 is fixed to the upper shear box fixing steel block 3 and the inner side of the upper shear box 7, respectively, and the inner side of the drag-reducing bearing 10 abuts against the upper shear box 7.

[0039] The drag-reducing bearing 10 is composed of a cylindrical roller structure, which can change the friction mode from sliding friction to rolling friction, and play a drag-reducing role when the upper shear box 7 moves up and down due to normal pressure.

[0040] The scheme is further optimized. The lower shearing fixture includes a lower shearing pressure seat 24 that abuts against the left side of the lower shearing box 25, and a lower shearing box 25 fixing steel block that abuts against the right side of the lower shearing box 25. The lower shearing pressure seat 24 and the lower shearing box 25 fixing steel block abut against the outer side of the lower shearing box connecting block 18. An adjusting bolt 19 is installed through the right side of the lower shearing box connecting block 18. The end of the adjusting bolt 19 near the lower shearing box 25 fixing steel block abuts against the lower shearing box 25 fixing steel block. A hydraulic cylinder connecting steel block 22 is fixed to the left side of the lower shearing box connecting block 18 by a steel block fixing bolt 23.

[0041] By tightening or loosening the adjusting bolt 19, the position of the adjusting bolt 19 within the lower shear box connecting block 18 can be changed. The end of the adjusting bolt 19 can be moved to tighten and loosened to move back on the right side of the lower shear box 25, thereby adjusting the size of the lower shear box 25 to accommodate lower shear samples of different sizes. The left side of the lower shear box connecting block 18 is connected to the hydraulic system via a hydraulic cylinder connecting block.

[0042] The scheme is further optimized. The upper shear box 7 is fixed to the front and rear sides with an upper shear box side connecting plate 4. One end of the upper shear box side connecting plate 4 is fixed to the upper shear box 7 fixing steel plate through the first upper shear box fixing bolt 11, and the other end is fixed to the upper shear pressure seat 27 through the first upper shear box fixing bolt 11. The lower shear box 25 is fixed to the front and rear sides with a lower shear box side connecting plate 15. One end of the lower shear box side connecting plate 15 is fixed to the lower shear pressure seat 24 through the lower shear box fixing bolt 12, and the other end is fixed to the lower shear box 25 fixing steel block through the lower shear box fixing bolt 12.

[0043] After adjusting the left and right positions of the upper shear box 7 and the lower shear box 25, the upper shear box side connecting plate 4 and the lower shear box side connecting plate 15 are reinforced and limited on the front and rear sides to form a shear box space, which is convenient, quick and low cost to install.

[0044] Furthermore, the upper shear box 7 and the upper shear pressure seat 27 are fixedly connected by the second upper shear box fixing bolt 20.

[0045] Further optimization of the scheme: the lower structure includes a bottom pad 14, and several sliding rails 13 are fixedly connected above the bottom pad 14. The inner sliding rail 13 is slidably connected to the bottom of the lower shear box connecting block 18, and the outer sliding rail 13 is slidably connected to the bottom sides of the left push-pull plate 2 and the right push-pull plate 9.

[0046] The bottom pad 14 supports the entire shearing box fixture, and several sliding tracks 13 are used for the sliding of the upper shearing fixture and the sliding of the lower shearing fixture, so that the shearing fixture can move accordingly when shear displacement occurs in the shearing experiment.

[0047] In a further optimized design, a shearing fixture box pad 28 is fixedly connected to the bottom of the lower shearing box 25 connecting block, and several shearing fixture box bases 29 are fixedly connected below the shearing fixture box pad 28. The shearing fixture box bases 29 are slidably connected to the sliding rail 13.

[0048] The shearing fixture box pad 28 is used to increase the bearing area and relieve local pressure; the shearing fixture box base 29 is slidably connected to the sliding rail 13 as a slider, so that the lower shearing fixture can slide on the rail.

[0049] The scheme is further optimized by extending the left push-pull plate 2 and the right push-pull plate 9 from the side of the lower shear box connecting block 18. Push-pull plate pressure pads 17 are fixed to the bottom ends of the left push-pull plate 2 and the right push-pull plate 9 respectively. The bottom of the push-pull plate pressure pads 17 is fixed to a movable base 16, and the movable base 16 is slidably connected to the sliding rail 13.

[0050] The push-pull plate bearing pad 17 also serves to relieve local pressure and connects to the movable base 16. The movable base 16 acts as a slider and is slidably connected to the sliding rail 13, allowing the upper shearing fixture to slide on the rail.

[0051] Furthermore, the push-pull plate pressure pad 17 is divided into upper and lower layers, which are connected as a whole by connecting screws 21, further enhancing the pressure-bearing function of the push-pull plate pressure pad 17.

[0052] A method for testing rock shear boxes with adjustable dimensions, comprising the following steps:

[0053] S1: Install the adjustable-size rock shear box fixture;

[0054] S2: Place the specimen to be sheared in the upper shear box 7 and the lower shear box 25 respectively, and ensure that the upper and lower shear specimens are aligned;

[0055] S3: Adjust the lower shear box fixture to make the lower shear specimen fit tightly against the lower shear box 25, eliminating the gap between the lower shear specimen and the left and right side components;

[0056] Adjust the adjusting bolts 19 in the lower shear box connecting block 18 to make the lower shear specimen and the lower shear fixture completely fit together, eliminate the gap between the lower shear specimen and the left and right side components, and install the lower shear box side connecting plate 15.

[0057] S4: Adjust the upper shearing fixture so that the upper shearing box 7 is close to the upper shearing sample to eliminate the gap between the component and the shearing sample, and then lock the upper shearing fixture.

[0058] Adjust the external adjusting disc 1 and the internal adjusting disc 5 of the upper shear box, move the push-pull plate to make the fixed steel block on the left side of the upper shear box 7 and the upper shear pressure seat 27 fit tightly against the upper shear sample, eliminate the gap between the component and the shear sample, then lock the external adjusting disc 1 and the internal adjusting disc 5 of the upper shear box, and install the side connecting plate 4 of the upper shear box.

[0059] S5: Apply a normal load to the upper end of the upper shear box 7, and apply shear loads to the sides of the upper shear box 7 and the lower shear box 25; during the shear test, control the shear load of one shear box to remain constant, change the shear load of the other shear box to shear the specimen, form a shear displacement, and complete the shear test according to the test design value.

[0060] S6: Record all experimental data, photograph the experimental process, and end the experiment.

[0061] Example 2

[0062] To better illustrate the shear test method of this device, a direct shear test of jointed rock under constant normal stress conditions is used as Example 2, including the following test steps:

[0063] S1: Assemble the shearing fixture system, install and debug each component according to the specific implementation method;

[0064] S2: The shear sample is processed into two pieces, which are used as upper and lower shear samples respectively. The cut surfaces interlock to form a shear surface.

[0065] S3: Place the lower shear sample into the lower shear box 25, rotate the adjusting bolt 19 in the lower shear box connecting block 18 to make the lower shear box fixing steel block 26 and the lower shear pressure seat 24 close to the lower shear sample, eliminate the gap between the lower shear sample and the left and right side components, and install the lower shear box side connecting plate 15.

[0066] S4: First, install the upper shear sample. Then, loosen the external adjusting disc 1 and the internal adjusting disc 5 of the upper shear box. Next, push the left push-pull plate 2 so that the upper shear pressure seat 27 is close to the upper shear sample. Then, tighten the external adjusting disc 1 of the upper shear box so that it is close to the left push-pull plate 2, eliminating the gap between the upper shear sample and the upper shear box fixing steel block 3 and the upper shear pressure seat 27. Finally, tighten the internal adjusting disc 5 of the upper shear box and install the side connecting plate 4 of the upper shear box.

[0067] S5: Activate the normal pressure cylinder so that the normal pressure plate presses against the upper end of the upper shear box 7;

[0068] S6: Start the left and right hydraulic cylinders and keep their loading speeds the same, so that the shear load on the upper shear box 7 and the lower shear box 25 reaches the experimental design value and then locks; start the normal cylinder to make the upper shear box 7 and the lower shear box 25 reach the boundary condition of constant normal stress.

[0069] S7: Keep the left shearing hydraulic cylinder locked, start the right shearing cylinder, apply shearing force to the lower shearing box 25, and conduct the test until the test design value is reached;

[0070] S8: Record experimental data, including all loading force and displacement data, and generate a graph.

[0071] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0072] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A rock shearing box fixture with adjustable dimensions, characterized in that, include: The upper shearing fixture, the lower shearing fixture, the upper shearing box (7), the lower shearing box (25), and the lower structure are provided. The upper shearing box (7) is fixedly installed in the upper shearing fixture, and the lower shearing box (25) is fixedly installed in the lower shearing fixture. The upper shearing box (7) and the lower shearing box (25) are provided correspondingly, and the bottom of the upper shearing fixture and the lower shearing fixture are slidably connected to the lower structure. The upper shearing fixture includes an upper shearing box fixing steel block (3) that abuts against the left side of the upper shearing box (7), and a left push-pull plate (2) fixedly connected to the left side of the upper shearing box fixing steel block (3); an upper shearing pressure seat (27) that abuts against the right side of the upper shearing box (7), and a right push-pull plate (9) fixedly connected to the right side of the upper shearing pressure seat (27); and side connecting columns (6) fixedly connected to the four corners of the inner side of the right push-pull plate (9), with one end of the side connecting column (6) away from the right push-pull plate (9) passing through the left push-pull plate (2) and slidingly connected to the left push-pull plate (2). The upper shearing fixture also includes an upper shearing box side connecting plate (4), which is fixed to the front and rear sides of the upper shearing box (7). One end is fixed to the upper shearing box fixing steel block (3) through the first upper shearing box fixing bolt (11), and the other end is fixed to the upper shearing pressure seat (27) through the first upper shearing box fixing bolt (11). The lower shearing fixture includes a lower shearing pressure seat (24) that abuts against the left side of the lower shearing box (25), and a lower shearing box fixing steel block (26) that abuts against the right side of the lower shearing box (25). A lower shearing box connecting block (18) abuts against the outer side of the lower shearing pressure seat (24) and the lower shearing box fixing steel block (26). An adjusting bolt (19) is provided through the inside of the right side of the lower shearing box connecting block (18). One end of the adjusting bolt (19) near the lower shearing box fixing steel block (26) abuts against the lower shearing box fixing steel block (26). A hydraulic cylinder connecting steel block (22) is fixed to the left side of the lower shearing box connecting block (18) by a steel block fixing bolt (23).

2. The adjustable-size rock shearing box fixture according to claim 1, characterized in that: The right push-pull plate (9) is fixed to the side connecting column (6) by a fixed disc (8); the inner side of the left push-pull plate (2) connected to the side connecting column (6) is provided with an upper shear box internal adjustment disc (5), and the upper shear box internal adjustment disc (5) is slidably sleeved to the side connecting column (6); the outer side of the left push-pull plate (2) connected to the side connecting column (6) is provided with an upper shear box external adjustment disc (1), and the upper shear box external adjustment disc (1) is slidably sleeved to the side connecting column (6).

3. The adjustable-size rock shearing box fixture according to claim 1, characterized in that: A drag-reducing bearing (10) is provided between the upper shear box (7) and the upper shear box fixing steel block (3), and between the upper shear box (7) and the upper shear pressure seat (27). The drag-reducing bearing (10) is fixed to the upper shear box fixing steel block (3) and the inner side of the upper shear box (7), respectively, and the inner side of the drag-reducing bearing (10) abuts against the upper shear box (7).

4. The adjustable-size rock shearing box fixture according to claim 1, characterized in that: The upper shear box (7) is fixedly connected to the front and rear sides with an upper shear box side connecting plate (4). One end of the upper shear box side connecting plate (4) is fixedly connected to the upper shear box (7) fixing steel plate by the first upper shear box fixing bolt (11), and the other end is fixedly connected to the upper shear pressure seat (27) by the first upper shear box fixing bolt (11). The lower shear box (25) is fixedly connected to the front and rear sides with a lower shear box side connecting plate (15). One end of the lower shear box side connecting plate (15) is fixedly connected to the lower shear pressure seat (24) by the lower shear box fixing bolt (12), and the other end is fixedly connected to the lower shear box fixing steel block (26) by the lower shear box fixing bolt (12).

5. The adjustable-size rock shearing box fixture according to claim 1, characterized in that: The lower structure includes a bottom pad (14), and several sliding rails (13) are fixedly connected above the bottom pad (14). The inner sliding rail (13) is slidably connected to the bottom of the lower shear box connecting block (18), and the outer sliding rail (13) is slidably connected to the bottom sides of the left push-pull plate (2) and the right push-pull plate (9).

6. The adjustable-size rock shearing box fixture according to claim 5, characterized in that: The bottom of the lower shear box (25) connecting block is fixedly connected to a shearing fixture box pad (28), and several shearing fixture box bases (29) are fixedly connected below the shearing fixture box pad (28). The shearing fixture box bases (29) are slidably connected to the sliding rail (13).

7. The adjustable-size rock shearing box fixture according to claim 5, characterized in that: The left push-pull plate (2) and the right push-pull plate (9) extend from the side of the lower shear box connecting block (18). Push-pull plate pressure pads (17) are fixed at both ends of the bottom of the left push-pull plate (2) and the right push-pull plate (9). A movable base (16) is fixed at the bottom of the push-pull plate pressure pad (17). The movable base (16) is slidably connected to the sliding rail (13).

8. A method for testing a rock shear box with adjustable dimensions, comprising a rock shear box fixture with adjustable dimensions as described in any one of claims 1-7, characterized in that, Includes the following steps: S1: Install the adjustable-size rock shear box fixture; S2: Place the sheared specimens in the upper shear box (7) and the lower shear box (25) respectively, and ensure that the upper and lower sheared specimens are aligned; S3: Adjust the lower shear box fixture to make the lower shear specimen and the lower shear box (25) fit together completely, and eliminate the gap between the lower shear specimen and the left and right side components; S4: Adjust the upper shearing fixture so that the upper shearing box (7) is close to the upper shearing sample, eliminate the gap between the component and the shearing sample, and then lock the upper shearing fixture. S5: Apply a normal load to the upper end of the upper shear box (7), and apply shear loads to the sides of the upper shear box (7) and the lower shear box (25); during the shear test, control the shear load of one shear box to remain constant, change the shear load of the other shear box to shear the specimen, form a shear displacement, and complete the shear test according to the test design value. S6: Record all experimental data, photograph the experimental process, and end the experiment.

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