Rock mass structural surface constant rigidity direct shear test device

Abstract

The invention discloses a rock mass structural surface constant rigidity direct shear test device which comprises a U-shaped support, a placing platform is arranged on the inner side of the U-shaped support, a test rock mass is placed on the placing platform, and fixing plates are arranged on the front side and the rear side, opposite to the U-shaped support, of the upper edge of the placing platform; a lifting plate is installed at the top of the U-shaped support, L-shaped shielding covers are connected to the two sides of the lifting plate, the lower surfaces of the long edges of the L-shaped shielding covers abut against the upper surface of the fixing plate, a protection space is defined by the L-shaped shielding covers on the two sides and the fixing plate, and a cleaning plate is connected to the side, located in the protection space, of the fixing plate. The cleaning plate is provided with a high-pressure spray head used for blowing away chippings, and a collecting drawer is arranged below the containing platform. According to the invention, the problem that broken stones and rock debris are easy to splash during the constant-rigidity direct shear test of the rock mass structural surface in the prior art is solved.

Description

Technical Field

[0001] This invention belongs to the field of experimental equipment technology, specifically relating to a constant stiffness direct shear test device for rock mass structural surfaces. Background Technology

[0002] The shear mechanical properties of rock mass structural surfaces are the core basis for stability evaluation of rock mass engineering such as slope engineering and tunnel engineering, and are also key parameters for geological disaster prediction and prevention. The constant stiffness direct shear test can accurately simulate the stress state of structural surfaces under actual working conditions such as seismic load and underground chamber excavation. Compared with the traditional constant normal stress test, it can better reflect the true mechanical response of rock mass. Therefore, related test devices are widely used in geotechnical engineering research. However, the existing constant stiffness direct shear test device for rock mass structure surfaces does not have a protective structure on the outside. During the shearing process, the rock fragments and rock chips generated by the destruction of the rock mass structure surface are prone to flying at high speed, which may not only damage the surrounding measuring instruments, but also pose a safety hazard to the operators. At the same time, the existing device lacks a design for collecting rock fragments. After the test, a large amount of rock fragments will remain inside the device, requiring staff to clean it frequently by hand, which increases the labor intensity and affects the test efficiency. Summary of the Invention

[0003] The purpose of this invention is to provide a constant stiffness direct shear test device for rock mass structural surfaces, which solves the problem of easy splashing of gravel and rock chips during constant stiffness direct shear tests of rock mass structural surfaces in existing technologies.

[0004] The technical solution adopted in this invention is a constant stiffness direct shear test device for rock mass structure surface, including a U-shaped support, a placement platform is provided on the inner side of the U-shaped support, the test rock mass is placed on the placement platform, and a fixing plate is provided on the upper edge of the placement platform relative to the front and rear sides of the U-shaped support. The top of the U-shaped bracket is equipped with a lifting plate, and L-shaped shields are connected to both sides of the lifting plate. The lower surface of the long side of the L-shaped shield abuts against the upper surface of the fixed plate. The L-shaped shields on both sides and the fixed plate enclose a protective space. A cleaning plate is connected to one side of the fixed plate inside the protective space. The cleaning plate is equipped with a high-pressure nozzle for blowing away debris. A collection drawer is installed below the platform.

[0005] The invention is further characterized in that: The top of each end of the U-shaped bracket is provided with an embedding groove, and a support plate is provided on the outside of the U-shaped bracket. A third hydraulic telescopic rod is vertically connected to the support plate. The output end of the third hydraulic telescopic rod is connected to the corresponding ends of the lifting plate. The extension and retraction of the third hydraulic telescopic rod drives the lifting plate to embed and separate from the embedding groove. Limiting grooves are respectively opened on the left and right side walls of the inner side of the U-shaped bracket along the vertical direction. Limiting sliders are slidably connected inside the limiting grooves, and the limiting sliders are fixedly connected to two L-shaped shields.

[0006] The fixed plate is located inside the protective space and is connected to a movable plate on one side. The movable plate has a hollow structure, and one side of the movable plate forms an air outlet cavity that passes through the fixed plate and connects to the cleaning plate. The cleaning plate also has a hollow structure, and its interior is connected to the inner cavity of the movable plate. The fixed plate has a sliding groove at the position of the air outlet cavity, and the movable plate is movably connected to the fixed plate along the direction of the sliding groove.

[0007] The U-shaped bracket has a through-type equipment installation cavity on one side of the platform. An air pump is installed inside the equipment installation cavity. The air pump's outlet is connected to a T-shaped pipe, and the other two ends of the T-shaped pipe are connected to air delivery hoses. The ends of the air delivery hoses away from the air pump are connected to the interiors of two movable plates.

[0008] A through-type control cavity is provided on the U-shaped bracket opposite to the equipment installation cavity. A pair of sliding plates are provided in the control cavity. The pair of sliding plates are arranged in a straight line. A support rod is fixedly connected to the side of the sliding plate near the placement platform. The other end of the support rod is connected to the movable plate on the corresponding side. A connecting plate is fixed at the port of the U-shaped bracket relative to the control cavity. A drive motor is installed on one end of the connecting plate. The output end of the drive motor passes through the connecting plate and is connected to a control rod. The other end of the control rod is connected to the connecting plate on the other side through a rotating shaft. The control rod is located on the side of the sliding plate away from the support rod, and several extrusion cams are fixedly connected to the outside of the control rod.

[0009] Several guide rods are arranged parallel to the movement direction of the support rod inside the control cavity. The two ends of the guide rods are connected to the U-shaped bracket and pass through the sliding plate and are movably connected to the sliding plate. A return spring is also sleeved on the outside of the guide rod. One end of the return spring abuts against the inner wall of the control cavity near the placement platform, and the other end abuts against the sliding plate.

[0010] A brush plate is installed between the two cleaning plates; The collection drawer is slidably connected to the U-shaped bracket, and several discharge slots are provided on the placement platform, through which debris falls into the collection drawer.

[0011] A first hydraulic telescopic rod is installed on the lifting plate. The telescopic end of the first hydraulic telescopic rod passes through the lifting plate and is connected to a first clamping plate. A roller plate is connected to the bottom of the first clamping plate, and a second clamping plate is connected to the bottom of the roller plate. The test rock mass consists of an upper rock mass and a lower rock mass, with a structural layer between the upper and lower rock masses. The bottom of the second clamping plate is in contact with the upper rock mass. A second hydraulic telescopic rod is installed on one side of the inner side of the U-shaped support. The second hydraulic telescopic rod is located above the placement platform, and the telescopic end is connected to a push plate. The push plate abuts against the side wall of the upper rock mass. Below the second hydraulic telescopic rod, there is a pair of adjusting screws. The lower rock mass is located between the pair of adjusting screws. One end of the adjusting screw is fixed to the U-shaped bracket, and the other end is connected to a fixing component. The fixing component is located on the side opposite to the push plate. The adjusting screw passes through the fixing component and is connected to a locking nut.

[0012] An observation window is integrally formed on one side of the L-shaped shield, and a data display screen and control buttons are also installed on the U-shaped bracket on one side of the observation window.

[0013] The bottom of the U-shaped bracket is fixedly connected with several anti-slip legs.

[0014] The beneficial effects of this invention are: (1) This invention sets up an L-shaped shield on the front and rear sides of the lifting plate and uses a fixed plate to achieve shielding support. At the same time, the sliding cooperation between the limiting vertical groove and the limiting slider ensures the stability of the L-shaped shield during the lifting process. It can form an all-round protective barrier during the constant stiffness direct shear test of the rock mass structure surface, effectively blocking the high-speed splashing of gravel and rock chips generated by shear failure. This not only avoids the damage to the surrounding measuring instruments caused by the impact of gravel, but also completely eliminates the safety hazards caused by the splashing of gravel to the operators, significantly improving the safety and reliability of the test process.

[0015] (2) The present invention provides high-pressure airflow to the high-pressure nozzle through an air pump, a three-way pipe and an air delivery hose. In conjunction with the drive motor, control rod, extrusion cam, sliding plate and support rod, the movable plate moves left and right along the sliding groove, thereby driving the cleaning plate and the high-pressure nozzle to move synchronously. It can perform all-round high-pressure blowing and cleaning of the fine rock debris remaining on the surface of the placement platform and around the test rock mass. The brush plate can also help clean the rock debris that is more firmly attached, ensuring that the inside of the device is thoroughly cleaned and avoiding the impact of residual rock debris on the accuracy of subsequent tests. This further improves the practicality and continuity of the test device.

[0016] In addition, the multiple through-type discharge troughs on the platform and the collection drawers that slide on the inner wall of the U-shaped bracket allow the gravel and rock fragments generated during the test to fall directly into the collection drawers through the discharge troughs, achieving automatic collection of gravel. This eliminates the need for staff to manually clean the residual gravel inside the device frequently after the test, greatly reducing the labor intensity of the staff, saving the tedious cleaning process, shortening the test interval, and effectively improving the overall test efficiency.

[0017] (3) The present invention uses a design with multiple extrusion cams facing different directions to achieve the alternating lateral movement of the two movable plates, so that the cleaning plates on the front and rear sides and the high-pressure nozzles can form a staggered cleaning effect, avoiding the cleaning blind spots that may be generated by the synchronous movement of the two, and making the cleaning coverage inside the device more comprehensive. Whether it is the edge of the placement platform or the gap area left by the test rock, it can be fully cleaned. Moreover, the alternating movement does not require separate drive components for the two movable plates. The bidirectional cleaning action can be achieved by a single drive motor and a set of control rods. This not only simplifies the transmission structure of the equipment and reduces the manufacturing cost, but also reduces the energy consumption and coordination control difficulty when multiple drive sources are running. At the same time, it avoids the problem of reduced cleaning efficiency caused by mutual interference of airflow during synchronous movement, so that the functions of high-pressure blowing and brush cleaning can be fully utilized, further optimizing the cleaning performance and operating economy of the device. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the constant stiffness direct shear test device for rock mass structural surfaces of the present invention. Figure 2 This is a front view structural schematic diagram of the cross-section of the present invention without lifting plate and L-shaped shield; Figure 3 This is a schematic diagram of the overall side view of the U-shaped bracket-free structure of the present invention; Figure 4 This is a side view structural schematic diagram of the cross-section of the present invention without lifting plate and L-shaped shield; Figure 5 This is a schematic diagram of the overall structure of the extrusion cam and sliding plate of the present invention; Figure 6 This is the present invention. Figure 2 Enlarged structural diagram at point A; Figure 7 This is the present invention. Figure 3 A magnified structural diagram at point B in the middle.

[0019] In the diagram: 1. U-shaped support; 2. Placement platform; 3. Test rock mass; 301. Upper rock mass; 302. Lower rock mass; 303. Structural layer; 4. Embedded groove; 5. Lifting plate; 6. L-shaped shield; 7. Fixing plate; 8. Movable plate; 9. Sliding groove; 10. Air outlet chamber; 11. Cleaning plate; 12. High-pressure nozzle; 13. Anti-slip support leg; 14. First hydraulic telescopic rod; 15. First clamping plate; 16. Second hydraulic telescopic rod; 17. Push plate; 18. Support plate; 19. Third hydraulic telescopic rod; 20. Collection drawer; 21. 21. Discharge chute; 22. Equipment mounting cavity; 23. Air pump; 24. T-pipe; 25. Air supply hose; 26. Control cavity; 27. Sliding plate; 28. Support rod; 29. ​​Connecting plate; 30. Drive motor; 31. Control rod; 32. Extrusion cam; 33. Guide rod; 34. Return spring; 35. Observation window; 36. Data display screen; 37. Control button; 38. Brush plate; 39. Limiting vertical groove; 40. Limiting slider; 41. Roller plate; 42. Second clamping plate; 43. Fixing component; 44. Adjusting screw; 45. Locking nut. Detailed Implementation

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

[0021] Example 1 The rock mass structural plane constant stiffness direct shear test device of the present invention includes a U-shaped support 1, as shown in the figure. Figure 1 and Figure 2 As shown, multiple anti-slip legs 13 are fixedly connected to the lower surface of the U-shaped bracket 1; The multiple anti-slip outriggers 13 provide stable support for the entire device. The anti-slip outriggers 13 are evenly distributed, which can evenly transfer the weight of the device itself and the load generated during the test to the ground, avoiding excessive local stress that could cause the device to tilt. At the same time, they can significantly increase the static friction with the ground, effectively suppressing the device displacement caused by the vibration generated by the operation of the loading system and the impact force caused by the shear failure of the rock mass during the test, ensuring the stability of the loading process and improving the safety and reliability of the test.

[0022] The inner sidewall of the U-shaped support 1 is fixedly connected to the lower part of the placement platform 2. The test rock mass 3 is set above the placement platform 2. The upper surface of the U-shaped support 1 is symmetrically provided with embedding grooves 4. The two embedding grooves 4 are jointly provided with lifting plates 5. The front and rear surfaces of the lifting plates 5 are fixedly connected with L-shaped shields 6. The upper surface of the placement platform 2 is fixedly connected with fixing plates 7 at the front and rear. The lower surfaces of the two L-shaped shields 6 are in contact with the upper surfaces of the two fixing plates 7 respectively.

[0023] like Figure 3 and Figure 4 As shown, movable plates 8 are slidably connected inside both fixed plates 7. Through sliding grooves 9 are opened on opposite sides of the interior of both fixed plates 7. Air outlet chambers 10 are fixedly connected to opposite sides of both movable plates 8. The opposite sides of the two air outlet chambers 10 pass through the two sliding grooves 9 respectively and are fixedly connected to cleaning plates 11. Multiple high-pressure nozzles 12 are provided on opposite sides of the two cleaning plates 11. A collection drawer 20 is slidably connected to the inner wall of the U-shaped bracket 1 and below the placement platform 2. Multiple through discharge grooves 21 are opened on the upper surface of the placement platform 2. The test rock mass 3 includes an upper rock mass 301, a lower rock mass 302 is provided below the upper rock mass 301, and a structural layer 303 is provided between the upper rock mass 301 and the lower rock mass 302. During the test, the test rock mass 3, which is a composite rock mass structure consisting of an upper rock mass 301, a lower rock mass 302, and a structural layer 303 between them, is first placed stably on the placement platform 2 below the inner wall of the U-shaped support 1. Then, the lifting plate 5 is embedded into the two symmetrically opened embedding slots 4 on the upper surface of the U-shaped support 1, so that the L-shaped shields 6 fixed on the front and rear surfaces of the lifting plate 5 are in close contact with the upper surfaces of the fixed plates 7 on the front and rear sides of the upper surface of the placement platform 2, respectively. With the cooperation of the L-shaped shields 6 and the fixed plates 7, a sealed protective structure is formed around the test rock mass 3. Then, the test device can be started to carry out the constant stiffness direct shear test. During the test, the gravel and rock debris generated by the structural surface damage of the test rock mass 3 will be effectively blocked by the L-shaped shields 6, avoiding high-speed splashing that could damage the surrounding measuring instruments or cause safety hazards to the operators. After the test, the movable plates 8 inside the two fixed plates 7 and the air outlet 10, together with multiple high-pressure nozzles 12, spray high-pressure airflow to thoroughly remove debris and dust from the surface of the placement platform 2, the residual parts of the test rock 3, and the inside of the device. The blown debris and dust will fall directly into the collection drawer 20 through multiple through-type discharge troughs 21 on the placement platform 2. After the collection drawer 20 has collected a certain amount, it can be pulled out from the U-shaped bracket 1 to achieve centralized cleaning of debris and dust. The L-shaped shield 6 solves the problem of debris splashing caused by the lack of protection on the outside of the traditional test device. At the same time, the synergistic effect of the high-pressure nozzles 12, discharge troughs 21 and collection drawer 20 replaces the traditional method of frequent manual cleaning of debris inside the device. This not only greatly reduces the labor intensity of the staff, but also quickly completes the cleaning of the device, which facilitates the rapid and continuous conduct of subsequent tests, effectively improves the test efficiency, and avoids the adverse effects on the accuracy of subsequent tests caused by incomplete cleaning of residual debris.

[0024] Example 2 This embodiment is based on the above embodiment 1, such as... Figures 1-4 As shown, in this invention, a first hydraulic telescopic rod 14 is fixedly connected to the upper surface of the lifting plate 5, and a first pressing plate 15 is provided below the lifting plate 5. The upper surface of the first pressing plate 15 is fixedly connected to the bottom end of the output shaft of the first hydraulic telescopic rod 14. A roller plate 41 is slidably connected to the lower surface of the first pressing plate 15, and a second pressing plate 42 is slidably connected to the lower surface of the roller plate 41. The lower surface of the second pressing plate 42 is in contact with the upper surface of the upper rock mass 301. The U-shaped bracket 1 is located on the left side inside and on the placement platform 2. A second hydraulic telescopic rod 16 is fixedly connected to the top. A push plate 17 is fixedly connected to the right end of the output shaft of the second hydraulic telescopic rod 16. The right side of the push plate 17 is in contact with the left side of the upper rock mass 301. A fixing part 43 is provided on the right side of the lower rock mass 302. Adjusting screws 44 are symmetrically threaded inside the fixing part 43. The left ends of the two adjusting screws 44 are fixedly connected to the left side of the inside of the U-shaped bracket 1. Locking nuts 45 are threadedly connected to the right side of the fixing part 43 and outside the two adjusting screws 44. During the test, the test rock mass 3, which is a composite rock mass structure consisting of an upper rock mass 301, a lower rock mass 302, and a structural layer 303 between them, is first placed stably on the placement platform 2 to ensure that the lower rock mass 302 is in stable contact with the surface of the placement platform 2. Then, by rotating the locking nut 45 on the outside of the adjusting screw 44, the fixing part 43 is pushed to the left along the adjusting screw 44 until the left side of the fixing part 43 is in close contact with the right side of the lower rock mass 302. Then, the locking nut 45 is tightened to lock the position of the fixing part 43, thereby firmly clamping the test rock mass 3 between the pushing plate 17 and the fixing part 43, providing a stable benchmark for the shear failure of the structural layer 303. Then, the lifting plate 5 is embedded into the two symmetrically opened embedding slots 4 on the upper surface of the U-shaped bracket 1, so that the L-shaped shields 6 fixed on the front and rear surfaces of the lifting plate 5 are in close contact with the upper surfaces of the fixed plates 7 on the front and rear sides of the upper surface of the platform 2, respectively. With the cooperation of the L-shaped shields 6 and the fixed plates 7, a sealed protective structure is formed around the test rock mass 3. Then, the output shaft extension stroke can be flexibly adjusted according to the height of the test rock mass 3 by the first hydraulic telescopic rod 14, which drives the first pressing plate 15 to press down precisely. The pressure is transmitted to the second pressing plate 42 through the roller plate 41, so that the second pressing plate 42 is in close contact with the upper surface of the upper rock mass 301. The setting of the roller plate 41 makes the first pressing plate 15 and the second pressing plate 42 form a sliding fit, which can ensure that the vertical pressure is evenly transmitted to the upper rock mass 301 and eliminate the friction interference between the upper rock mass 301 and the pressing components during the horizontal shearing process. After the upper rock mass 301 is vertically fixed, the push plate 17 is moved by the second hydraulic telescopic rod 16. The second hydraulic telescopic rod 16 outputs horizontal thrust smoothly according to the constant stiffness test requirements, which drives the push plate 17 to apply uniform shear force to the test rock mass 3 on the right. Since the lower rock mass 302 is fixedly limited by the fixing part 43 on the right, the horizontal thrust will be concentrated on the structural layer 303 between the upper rock mass 301 and the lower rock mass 302, causing the structural layer 303 to undergo shear failure.

[0025] Example 3 This embodiment is based on the above embodiment 2, such as Figures 1 to 4 As shown, the left and right sides of the U-shaped bracket 1 of the present invention are fixedly connected to support plates 18. The upper surfaces of the two support plates 18 are fixedly connected to third hydraulic telescopic rods 19. The top ends of the output shafts of the two third hydraulic telescopic rods 19 are fixedly connected to the lower surface of the lifting plate 5. The left and right sides of the inner sidewall of the U-shaped bracket 1 are symmetrically provided with limiting vertical grooves 39. The lower part of the interior of the multiple limiting vertical grooves 39 is slidably connected to limiting sliders 40. The outer sidewalls of the multiple limiting sliders 40 are fixedly connected to the left and right sides of the two L-shaped shields 6 respectively. When the test is ready and protection is required, the third hydraulic telescopic rods 19 on both sides are lowered synchronously, causing the lifting plate 5 to move downward and embed into the embedding groove 4 on the upper surface of the U-shaped bracket 1. At this time, the L-shaped shield 6 is lowered synchronously with the lifting plate 5. During the descent, the limiting sliders 40 fixedly connected to the left and right sides of the L-shaped shield 6 will slide smoothly along the limiting vertical grooves 39 symmetrically opened on the inner sidewall of the U-shaped bracket 1. The cooperation structure between the limiting vertical grooves 39 and the limiting sliders 40 effectively restricts the movement trajectory of the L-shaped shield 6, preventing it from deviating or shaking during the lifting process. This ensures that the lower surfaces of the two L-shaped shields 6 can accurately and tightly contact the upper surface of the fixed plate 7 on the placement platform 2, forming a reliable sealed protection around the test rock mass 3. After the test is completed and the interior is cleaned, the two L-shaped shields 6 can be raised synchronously by extending the two third hydraulic telescopic rods 19, and the test rock mass 3 can be removed for subsequent operations.

[0026] Example 4 This embodiment is based on the above embodiment 3, such as Figure 1 , Figure 2 , Figure 3 and Figure 6 As shown, a through-type equipment mounting cavity 22 is provided on the right side of the front surface of the U-shaped bracket 1 of the present invention. An air pump 23 is fixedly connected to the upper surface inside the equipment mounting cavity 22. A three-way pipe 24 is fixedly connected to the top of the output shaft of the air pump 23. Air supply hoses 25 are fixedly connected to the front and rear ends of the three-way pipe 24. The ends of the two air supply hoses 25 away from the air pump 23 are respectively connected to the interior of the two movable plates 8. The through-type equipment mounting cavity 22 on the right side of the front surface of the U-shaped bracket 1 provides a dedicated installation space for the air pump 23. The air pump 23 serves as a high-pressure gas supply source, and the three-way pipe 24 connected to the top of its output shaft plays a crucial role in airflow diversion. It evenly divides the high-pressure gas generated by the air pump 23 into two paths, which are then delivered to the front and rear air delivery hoses 25 respectively, ensuring consistent airflow pressure and guaranteeing uniformity for subsequent cleaning operations. The air delivery hoses 25, with their excellent flexibility, can freely extend and deform as the movable plate 8 slides, effectively preventing deformation when the movable plate 8 moves. The problem of pipeline damage due to tension; when the test is over and the placement platform 2 needs to be cleaned, the air pump 23 is started. High-pressure gas is diverted through the three-way pipe 24 and delivered to the inside of the movable plate 8 through the air delivery hose 25. Then, the high-pressure nozzle 12 forms a high-speed airflow to thoroughly blow away the residual gravel, rock debris and dust on the surface of the placement platform 2. Thus, the high-pressure cleaning method powered by the air pump 23 is more efficient and thorough than manual cleaning. It can quickly clean the impurities on the placement platform 2 and the inside of the device. With the help of the discharge chute 21 and the collection drawer 20, the impurities are collected in a concentrated manner, which greatly reduces the labor intensity of the staff.

[0027] Example 5 This embodiment is based on embodiment 4 above, such as Figure 1 , Figure 2 , Figure 5 , Figure 6 As shown, a through-type control cavity 26 is provided on the left side of the front surface of the U-shaped bracket 1. Sliding plates 27 are symmetrically slidably connected inside the control cavity 26. Support rods 28 are fixedly connected to the right side of the two sliding plates 27. The right ends of the two support rods 28 are fixedly connected to the left side of the two movable plates 8 respectively. Connecting plates 29 are symmetrically fixedly connected to the upper and lower surfaces inside the control cavity 26. A drive motor 30 is fixedly connected to the front surface of the front connecting plate 29. A control rod 31 is fixedly connected to the rear end of the output shaft of the drive motor 30. The rear end of the control rod 31 is rotatably connected to the front surface of the rear connecting plate 29 through a rotating shaft. Multiple extrusion cams 32 are fixedly connected to the outer wall of the control rod 31. Multiple guide rods 33 are fixedly connected to the left and right sides of the control cavity 26. The outer walls of the multiple guide rods 33 are slidably connected to the interior of the two sliding plates 27. Each outer wall of the multiple guide rods 33 is fitted with a return spring 34. Both ends of the multiple return springs 34 are fixedly connected to the right side of the two sliding plates 27 and the right side of the control cavity 26. When the test is over and the placement platform 2 needs to be cleaned, the air pump 23 is started simultaneously with the drive motor 30. The drive motor 30 rotates the control rod 31 at the rear end of the output shaft. As the control rod 31 rotates, it causes multiple compression cams 32 fixed to its outer wall to rotate synchronously. Because the compression cams 32 on the left side of the two corresponding sliding plates 27 have different orientations, when the control rod 31 rotates, the force exerted by the two compression cams 32 on their respective sliding plates 27 alternates. When the protruding ends of two of the compression cams 32 rotate to contact their corresponding sliding plates 27 and apply a rightward compression force, the other two compression cams... The protruding end of the pressure cam 32 rotates away from its corresponding sliding plate 27; the compressed sliding plate 27 slides to the right along the guide rod 33 in the control cavity 26. The guide rod 33 provides precise guidance for the sliding plate 27, avoiding jamming or deviation during the sliding process. At the same time, the sliding plate 27 compresses the return spring 34 on the outside of its corresponding guide rod 33; while the uncompressed sliding plate 27 returns to the left along the guide rod 33 under the action of the release of the elastic potential energy of its corresponding return spring 34; through the difference in the direction of multiple pressure cams 32 and the elastic return of the return spring 34, the alternating lateral sliding of the two sliding plates 27 is achieved. The two sliding plates 27 transmit power to the corresponding movable plates 8 through the support rods 28 on the right side, causing the two movable plates 8 to slide back and forth alternately within the fixed plate 7. This causes the two movable plates 8 to move alternately above the placement platform 2, in conjunction with the corresponding cleaning plates 11 and high-pressure nozzles 12. The alternating cleaning mode effectively avoids mutual interference of airflow generated when the two cleaning plates 11 are working simultaneously, ensuring that the high-speed airflow ejected by the high-pressure nozzles 12 can accurately act on the cleaning area, achieving efficient cleaning of the surface of the placement platform 2, further reducing the labor intensity of the staff, and providing a guarantee for the rapid development of subsequent tests.

[0028] Example 6 This embodiment is based on embodiment 5 above, such as Figure 3 and Figure 7 A brush plate 38 is fixedly connected to both the left side of the front cleaning plate 11 and the right side of the rear cleaning plate 11. With the brush plates 38 set on the outer side of the two cleaning plates 11, when the movable plate 8 moves back and forth above the placement platform 2 in conjunction with the cleaning plates 11 and the high-pressure nozzle 12, the cleaning plates 11 will move the brush plates 38 together in sync. The bristles of the brush plates 38 are in close contact with the surface of the placement platform 2. During the reciprocating process, it can physically clean the adhering dust and fine rock debris that are difficult to blow away by the high-pressure airflow, which complements the airflow cleaning of the high-pressure nozzle 12, thereby increasing the cleaning efficiency.

[0029] Furthermore, such as Figure 1 As shown, the front surface of the L-shaped shield 6 located in front of the U-shaped bracket 1 has an integrally formed observation window 35. The upper left side of the front surface of the U-shaped bracket 1 is provided with a data display screen 36. Multiple control buttons 37 are provided on the front surface of the U-shaped bracket 1 and below the data display screen 36. The device features an observation window 35 made of high-strength transparent polycarbonate. The one-piece molding process ensures the integrity of the L-shaped shield 6's seal, preventing debris from splashing through the seams, while also providing excellent impact resistance to withstand impacts from flying rock fragments during the experiment. Through the observation window 35, operators can clearly observe the shear deformation process of the test rock mass 3, the cracking trajectory of the structural surfaces, and the state of debris generation in real time, facilitating timely identification of experimental anomalies and providing intuitive evidence. Simultaneously, the data display screen 36 is linked in real time with the device's measurement system, dynamically displaying shear force and shear displacement. Core mechanical parameters such as displacement and vertical pressure can be presented in real-time curves, allowing operators to intuitively grasp the mechanical response characteristics of the rock mass. Compared with traditional paper recording methods, this not only improves data reading efficiency but also avoids errors caused by manual recording, providing accurate data support for the analysis of test results. The multiple control buttons 37 below the data display screen 36 are arranged in a functional category, which can control the start and stop adjustment of multiple hydraulic telescopic rods, the operation control of air pump 23 and drive motor 30, and other core operations, significantly improving the safety, convenience and data reliability of the test, and further improving the practical performance of the device.

[0030] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0031] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A constant stiffness direct shear test apparatus for rock mass discontinuities, characterized in that, The U-shaped support (1) is provided with a placing platform (2) on the inner side, a test rock mass (3) is placed on the placing platform (2), and the upper edge of the placing platform (2) is provided with a fixed plate (7) on the front and back sides of the U-shaped support (1); The top of the U-shaped support (1) is provided with a lifting plate (5), the two sides of the lifting plate (5) are connected with L-shaped shielding covers (6), the long edge lower surface of the L-shaped shielding cover (6) is in abutment with the upper surface of the fixed plate (7), the two L-shaped shielding covers (6) and the fixed plate (7) form a protection space, the fixed plate (7) is connected with a cleaning plate (11) on one side in the protection space, the cleaning plate (11) is provided with a high-pressure nozzle (12) for blowing away debris, and the placing platform (2) is provided with a collection drawer (20) below.

2. The apparatus according to claim 1, wherein The top of the U-shaped support (1) is provided with a placing platform (2) on the inner side, a test rock mass (3) is placed on the placing platform (2), and the upper edge of the placing platform (2) is provided with a fixed plate (7) on the front and back sides of the U-shaped support (1); The two side walls on the inner side of the U-shaped support (1) are respectively provided with a limiting vertical groove (39) in the vertical direction, the limiting vertical groove (39) is slidably connected with a limiting sliding block (40), and the limiting sliding block (40) is fixedly connected with the two L-shaped shielding covers (6).

3. The apparatus according to claim 1, wherein The fixed plate (7) is connected with a movable plate (8) on one side in the protection space, the movable plate (8) has a hollow structure, one side of the movable plate (8) forms an air outlet cavity (10), and the air outlet cavity (10) penetrates through the fixed plate (7) and is connected with the cleaning plate (11); the cleaning plate (11) also has a hollow structure and is in communication with the inner cavity of the movable plate (8); The fixed plate (7) is connected with a movable plate (8) on one side in the protection space, the movable plate (8) has a hollow structure, one side of the movable plate (8) forms an air outlet cavity (10), and the air outlet cavity (10) penetrates through the fixed plate (7) and is connected with the cleaning plate (11); the cleaning plate (11) also has a hollow structure and is in communication with the inner cavity of the movable plate (8); 4. The constant stiffness direct shear test apparatus for rock mass discontinuities according to claim 3, wherein, The U-shaped support (1) is provided with a through-type equipment installation cavity (22) on one side of the placing platform (2), an air pump (23) is installed in the equipment installation cavity (22), a three-way pipe (24) is connected to the air outlet end of the air pump (23), and the other two ends of the three-way pipe (24) are respectively connected with air conveying hoses (25); one end of the air conveying hose (25) away from the air pump (23) is connected with the inner cavities of the two movable plates (8) in communication.

5. The constant stiffness direct shear test apparatus for rock mass discontinuities according to claim 4, wherein, A control cavity (26) is formed in the U-shaped support (1) on the side opposite to the equipment installation cavity (22), a pair of sliding plates (27) are arranged in the control cavity (26), the sliding plates (27) are arranged in a straight line, a support rod (28) is fixedly connected to the side of the sliding plate (27) close to the placing platform (2), and the other end of the support rod (28) is connected with the movable plate (8) on the corresponding side; The U-shaped support (1) is fixed with a connecting plate (29) at the port of the control cavity (26), a drive motor (30) is installed on one end of the connecting plate (29), the output end of the drive motor (30) is connected with a control rod (31) penetrating through the connecting plate (29), the other end of the control rod (31) is connected with the connecting plate (29) on the other side through a rotating shaft, the control rod (31) is located on the side of the sliding plate (27) away from the support rod (28), and the outer side of the control rod (31) is fixedly connected with a plurality of extrusion cams (32).

6. The constant stiffness direct shear test apparatus for rock mass discontinuities according to claim 5, wherein, A plurality of guide rods (33) are arranged in the control cavity (26) and are parallel to the movement direction of the support rod (28), the two ends of the guide rod (33) are connected with the U-shaped support (1), and the guide rod (33) penetrates through the sliding plate (27) and is movably connected with the sliding plate (27), the outer side of the guide rod (33) is further sleeved with a reset spring (34), one end of the reset spring (34) abuts against the inner wall of the control cavity (26) close to the placement platform (2), and the other end of the reset spring (34) abuts against the sliding plate (27).

7. The apparatus according to claim 1, wherein The two cleaning plates (11) are provided with a brush plate (38) therebetween; The collection drawer (20) is slidably connected with the U-shaped support (1), and a plurality of discharge grooves (21) are formed in the placement platform (2), and the debris falls into the collection drawer (20) through the discharge grooves (21).

8. The apparatus according to claim 1, wherein The lifting plate (5) is provided with a first hydraulic telescopic rod (14), and the telescopic end of the first hydraulic telescopic rod (14) is connected with a first pressing plate (15) penetrating through the lifting plate (5), and the bottom of the first pressing plate (15) is connected with a rolling plate (41), and the bottom of the rolling plate (41) is connected with a second pressing plate (42). The test rock mass (3) comprises an upper rock mass (301) and a lower rock mass (302), and a structural layer (303) is arranged between the upper rock mass (301) and the lower rock mass (302), and the bottom of the second pressing plate (42) abuts against the upper rock mass (301). A second hydraulic telescopic rod (16) is installed on one side of the inner side of the U-shaped support (1), the second hydraulic telescopic rod (16) is located above the placement platform (2), and the telescopic end is connected with a pushing plate (17), and the pushing plate (17) abuts against the side wall of the upper rock mass (301); A pair of adjusting screws (44) are further arranged below the second hydraulic telescopic rod (16), the lower rock mass (302) is located between the pair of adjusting screws (44), one end of the adjusting screw (44) is fixedly connected with the U-shaped support (1), the other end is connected with a fixing piece (43), the fixing piece (43) is arranged on the side opposite to the pushing plate (17), and the adjusting screw (44) is connected with a locking nut (45) penetrating through the fixing piece (43).

9. The apparatus according to claim 1, wherein An observation window (35) is integrally formed on one side of the L-shaped shielding cover (6), and a data display screen (36) and a control button (37) are further arranged on the U-shaped support (1) on one side of the observation window (35).

10. The apparatus according to claim 1, wherein The bottom of the U-shaped support (1) is fixedly connected with a plurality of anti-skid supporting legs (13).

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