A finite rock mass passive earth pressure test device and a use method thereof

Abstract

The application provides a limited rock mass passive earth pressure test device and a use method, which comprises a bottom plate and a box body fixed on the bottom plate, a baffle plate is slidably arranged in the box body, a retaining wall plate is arranged on one side of the box body, the retaining wall plate is connected with a horizontal driving mechanism, four linearly arranged pressure sensors are fixedly arranged on the retaining wall plate, a space with an open upper end is formed between the retaining wall plate and the baffle plate, a pressing plate one is slidably arranged along the depth direction of the box body, a pressing plate two is slidably arranged in the pressing plate one, and the pressing plate two is slidably matched with a T-shaped groove arranged on the baffle plate. The baffle plate which can slide in the box body is arranged, so that the volume of the soil during the test can be flexibly adjusted, and the structure is simple and the operation is convenient.

Description

Technical Field

[0001] This invention belongs to the technical field of civil engineering testing equipment, and specifically relates to a finite rock mass passive earth pressure testing device and its usage method. Background Technology

[0002] During civil construction, structures such as retaining walls, foundation pit supports, and slopes are used to support the soil and prevent it from shifting, which could affect construction progress and the safety of workers. In foundation pit support design, complex pits often employ cantilever piles. These cantilever piles need to penetrate the rock strata to a certain depth, and there may be finite rock masses before and after the cantilever piles. In such cases, the passive earth pressure on the cantilever piles needs to be theoretically calculated. Therefore, to clearly analyze the earth pressure, it is often necessary to conduct experiments using specialized testing equipment to draw conclusions.

[0003] Chinese Patent Publication No. CN108507878A discloses an earth pressure simulation testing device and method, including a test chamber and supporting legs. The test chamber has a groove at the top and includes a front baffle, a rear baffle, and a lower baffle that can slide vertically between the front and rear baffles. A baffle and an adjusting baffle are slidably connected to the lower baffle in the left-right direction. The adjusting baffle is connected to a driving mechanism. The test chamber is filled with several layers of soil simulating material evenly distributed vertically. Although this invention can perform earth pressure simulation testing, it cannot adjust the soil volume or simultaneously measure the force under different working conditions. Summary of the Invention

[0004] To address the shortcomings of the existing technology, this invention provides a finite rock mass passive earth pressure testing device and its usage method. The sliding retaining plate inside the box can flexibly adjust the volume of soil during the test, and can measure the force under different working conditions, making it convenient to use.

[0005] The technical solution provided by this invention is as follows: A finite rock mass passive earth pressure testing device includes a base plate and a box fixed on the base plate. A retaining plate is slidably installed inside the box. A retaining wall plate is provided on one side of the box. The retaining wall plate is connected to a horizontal drive mechanism. Four pressure sensors arranged linearly are fixedly installed on the retaining wall plate. An open space is formed between the retaining wall plate and the retaining plate. A pressure plate one is slidably installed along the depth direction of the box. A pressure plate two is slidably installed inside the pressure plate one. The pressure plate two slides with a T-shaped groove provided on the retaining plate. A moving mechanism that drives the retaining plate to slide is provided inside the box. The moving mechanism is connected to a limiting mechanism to limit the movement of the retaining plate.

[0006] Furthermore, the moving mechanism includes a crossbeam installed above the retaining plate, the crossbeam passing through the box body and slidably mounted on the box body, with horizontal sliding rods fixedly installed at both ends of the crossbeam, the horizontal sliding rods located on the outer surface of the long side of the bottom plate, a return spring provided between the horizontal sliding rod and the box body, and guide rollers slidably engaged on both the upper and lower end faces of the horizontal sliding rod, the guide rollers being rotatably mounted on the box body, a boss and a T-shaped rod fixedly installed on one of the horizontal sliding rods, the boss and the T-shaped rod being connected to a pushing mechanism, the pushing mechanism pushing the horizontal sliding rod and the crossbeam to slide on the box body, so that the crossbeam drives the retaining plate to slide inside the box body, and a pointer fixedly installed on the other horizontal sliding rod, with a scale installed below the pointer, the scale being fixedly mounted on the box body.

[0007] Furthermore, the pushing mechanism includes a lever with a U-shaped groove that slides with a boss. The lever and the T-shaped rod slide with a turntable. The turntable has two symmetrically arranged cylindrical rods. The turntable is rotatably mounted on the outer side of the housing. The turntable is fixedly connected to the output shaft of the motor. The motor is fixedly mounted on the base plate.

[0008] Furthermore, a triangular block is fixedly installed on the upper surface of each end of the crossbeam. The triangular block is a right triangle, and one of the right-angled sides of the triangular block is in contact with the upper surface of the crossbeam. The triangular block is limited by a limiting mechanism.

[0009] Furthermore, the limiting mechanism includes two symmetrically arranged limiting rods, each located above two horizontal sliding rods. Each limiting rod has multiple linearly arranged right-angled teeth. The slope of the first inclined surface on each right-angled tooth is the same as the slope of the second inclined surface on the triangular block. The triangular block slides into contact with the right-angled teeth. The two limiting rods are slidably mounted on the outer side of the housing. Two return springs are provided between the limiting rods and the housing. The two limiting rods are connected together by a connecting frame, which is slidably mounted on the housing. One end of a return spring is fixedly mounted on the connecting frame, and the other end of the return spring is fixedly mounted on an intermediate plate. The intermediate plate is fixedly mounted on a hydraulic cylinder.

[0010] Furthermore, a rack is fixedly installed on the crossbeam. The rack is connected to a rack via a gear set. The rack is fixedly installed on a fixed frame. Both ends of the fixed frame are slidably installed on the housing. A hydraulic cylinder is fixedly installed at the center of the fixed frame. A long groove is provided along the length of the pressure plate. The long groove is slidably engaged with the extended end of the hydraulic cylinder.

[0011] Furthermore, the gear set includes a first gear and a second gear rotatably mounted on the housing. The first gear meshes with a first rack, and the second gear meshes with a second rack, and the first gear and the second gear mesh with each other.

[0012] Furthermore, the horizontal drive mechanism includes a hydraulic cylinder three, which is fixedly mounted on the base plate. A circular plate is rotatably mounted on the extended end of the hydraulic cylinder three, and the central axis of the circular plate coincides with the central axis of the hydraulic cylinder three. Two short rods arranged symmetrically in the upper and lower positions are slidably mounted on the side of the circular plate opposite to the hydraulic cylinder three, and the short rods are mounted on the retaining wall plate.

[0013] Furthermore, the circular plate is provided with a through hole, the diameter of which is larger than the diameter of the short rod, and the distance between the central axis of the through hole and the central axis of the circular plate is equal to the distance between the central axis of the short rod and the central axis of the circular plate.

[0014] Furthermore, the box body is a cuboid, with an open upper surface and a short side surface. The height of the retaining plate is less than the depth of the box body, and the ratio of the moving speed of rack one to the moving speed of rack two is 2:1.

[0015] The present invention also provides a method for using a finite rock mass passive earth pressure testing device, comprising the following steps:

[0016] Step 1: Start the motor to make the turntable rotate. Move the lever or T-shaped rod on the turntable to make the horizontal slide bar slide on the bottom plate until the retaining plate moves to the appropriate position inside the box. The retaining plate is then limited by the limiting mechanism.

[0017] Step 2: Start hydraulic cylinder 2. When the extended end of hydraulic cylinder 2 extends, pressure plate 1 and pressure plate 2 can slide in the depth direction of the retaining plate to adapt to soil of different thicknesses.

[0018] Step 3: Add the soil used for the experiment between the retaining wall and the retaining wall;

[0019] Step 4: Start hydraulic cylinder three, so that the extended end of hydraulic cylinder three pushes the circular plate. As needed, select to make the retaining wall plate move horizontally, rotate around the bottom, or rotate around the top. Obtain the pressure detection result through the pressure sensor.

[0020] The advantages of this invention compared with the prior art are: (1) This invention can flexibly adjust the volume of soil during the test by setting a soil retaining plate that can slide inside the box. The structure is simple and the operation is convenient; (2) Four pressure sensors are set on the retaining plate, which can monitor the pressure value in real time when the retaining plate squeezes the soil. The retaining plate includes three modes: translation, rotation around the bottom and rotation around the top, which can adapt to different test requirements; (3) A limiting rod is set above the horizontal sliding rod, which can effectively limit the sliding of the horizontal sliding rod and ensure the accuracy of the test. Attached Figure Description

[0021] Figure 1 This is a front view of the overall structure of the present invention.

[0022] Figure 2 for Figure 1 A magnified schematic diagram of the structure at point A in the middle.

[0023] Figure 3 for Figure 1 Another structural diagram from a different angle.

[0024] Figure 4 for Figure 3 A magnified schematic diagram of the structure at point B in the middle.

[0025] Figure 5 This is a top view of the overall structure of the present invention.

[0026] Figure 6 This is a cross-sectional view along the AA direction in diagram 5.

[0027] Figure 7 for Figure 6 A magnified schematic diagram of the structure at point C.

[0028] Figure 8 for Figure 6 A magnified schematic diagram of the structure at point D.

[0029] In the diagram: 1-Base plate; 2-Box body; 3-Motor; 4-Turntable; 5-Cylindrical rod; 6-Pulley; 7-U-shaped groove; 8-T-shaped rod; 9-Horizontal slide bar; 10-Crossbeam; 11-T-shaped groove; 12-Soil retaining plate; 13-Pointer; 14-Scale; 15-Guide roller; 16-Triangular block; 17-Limit rod; 18-Reset spring one; 19-Connecting frame; 20-Reset spring two; 21-... - Hydraulic cylinder one; 22 Intermediate plate; 23 Rack one; 24 Gear one; 25 Gear two; 26 Rack two; 27 Fixing frame; 28 Hydraulic cylinder two; 29 Pressure plate one; 30 Pressure plate two; 31 Baffle plate; 32 Pressure sensor; 33 Short rod; 34 Circular plate; 35 Through hole; 36 Hydraulic cylinder three; 37 Return spring three; 38 Boss; 39 Right angle tooth. Detailed Implementation

[0030] 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.

[0031] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "top / bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0032] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "sleeved / connected," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0033] like Figures 1-8 The device shown is a finite rock mass passive earth pressure test device, including a base plate 1, on which a rectangular box 2 is fixedly installed. The upper end face and one short side face of the box 2 are open.

[0034] A retaining plate 12 is provided along the long side of the box body 2. The retaining plate 12 can be slidably installed inside the box body 2, and the height of the retaining plate 12 is less than the depth of the box body 2. A retaining wall plate 31 is provided at the opening on the short side of the box body 2. The retaining wall plate 31 is connected to the horizontal drive mechanism. Four pressure sensors 32 arranged linearly are fixedly installed on the retaining wall plate 31. A space with an upper opening is formed between the retaining wall plate 31 and the retaining plate 12.

[0035] A pressure plate 29 is slidably installed along the depth direction of the box body 2. The pressure plate 29 is located inside the box body 2. A pressure plate 30 is slidably installed inside the pressure plate 29. The pressure plate 30 is slidably engaged with the T-shaped groove 11 provided on the retaining plate 12. The pressure plate 29 and the pressure plate 30 are located above the space formed by the retaining wall plate 31 and the retaining plate 12.

[0036] A crossbeam 10 is fixedly installed above the retaining plate 12. The crossbeam 10 passes through the box body 2 and is slidably installed on the box body 2. Horizontal sliding rods 9 are fixedly installed at both ends of the crossbeam 10. The horizontal sliding rods 9 are located on the outer surface of the long side of the bottom plate 1. A return spring 37 is provided between the horizontal sliding rods 9 and the box body 2. Guide rollers 15 are slidably fitted on both the upper and lower ends of the horizontal sliding rods 9. The guide rollers 15 are rotatably installed on the box body 2. A boss 38 and a T-shaped rod 8 are fixedly installed on one horizontal sliding rod 9. The boss 38 and the T-shaped rod 8 are connected to the pushing mechanism. The pushing mechanism pushes the horizontal sliding rods 9 and the crossbeam 10 to slide on the box body 2, so that the crossbeam 10 drives the retaining plate 12 to slide inside the box body 2. A pointer 13 is fixedly installed on the other horizontal sliding rod 9. A scale 14 is installed below the pointer 13. The scale 14 is fixedly installed on the box body 2.

[0037] The pushing mechanism includes a lever 6, on which a U-shaped groove 7 is provided. The U-shaped groove 7 is slidably engaged with the boss 38. The lever 6 and the T-shaped rod 8 are slidably engaged with the turntable 4. The turntable 4 is provided with two symmetrically arranged cylindrical rods 5. The turntable 4 is rotatably mounted on the outer side of the housing 2. The turntable 4 is fixedly connected to the output shaft of the motor 3. The motor 3 is fixedly mounted on the base plate 1.

[0038] A triangular block 16 is fixedly installed on the upper surface of each end of the crossbeam 10. The triangular block 16 is a right triangle, and one of the right-angled sides of the triangular block 16 is in contact with the upper surface of the crossbeam 10. The triangular block 16 is limited by a limiting mechanism.

[0039] The limiting mechanism includes two symmetrically arranged limiting rods 17, which are located above two horizontal sliding rods 9. Each limiting rod 17 has multiple right-angled teeth 39 arranged linearly. The slope of the first inclined surface on the right-angled teeth 39 is the same as that of the second inclined surface on the triangular block 16. The triangular block 16 slides with the right-angled teeth 39. The two limiting rods 17 are slidably mounted on the outer side of the housing 2. Two return springs 18 are provided between the limiting rods 17 and the housing 2. The two limiting rods 17 are connected together by a connecting frame 19. The connecting frame 19 is slidably mounted on the housing 2. One end of the return spring 20 is fixedly mounted on the connecting frame 19. The other end of the return spring 20 is fixedly mounted on the intermediate plate 22. The intermediate plate 22 is fixedly mounted on the hydraulic cylinder 21.

[0040] Specifically, the connecting frame 19 and the intermediate plate 22 can slide along the depth direction of the housing 2.

[0041] A rack 23 is also fixedly installed on the crossbeam 10. The rack 23 is connected to the rack 26 via a gear set. The rack 26 is fixedly installed on the fixed frame 27. The two ends of the fixed frame 27 are slidably installed on the housing 2. A hydraulic cylinder 28 is fixedly installed at the center of the fixed frame 27. A long groove is provided along the length of the pressure plate 29. The long groove is slidably engaged with the extended end of the hydraulic cylinder 28.

[0042] Specifically, the gear set includes a first gear 24 and a second gear 25 rotatably mounted on the housing 2. The first gear 24 meshes with a first rack 23, and the second gear 25 meshes with a second rack 26.

[0043] Gear 24 and gear 25 mesh with each other. The ratio of the moving speed of rack 23 to the moving speed of rack 26 is 2:1.

[0044] The horizontal drive mechanism includes a hydraulic cylinder 36, which is fixedly mounted on the base plate 1. A circular plate 34 is rotatably mounted on the extended end of the hydraulic cylinder 36. The central axis of the circular plate 34 coincides with the central axis of the hydraulic cylinder 36. Two short rods 33 are slidably mounted on the side of the circular plate 34 opposite to the hydraulic cylinder 36. The short rods 33 are mounted on the retaining wall plate 31.

[0045] A through hole 35 is provided on the circular plate 34. The diameter of the through hole 35 is larger than the diameter of the short rod 33, and the distance between the central axis of the through hole 35 and the central axis of the circular plate 34 is equal to the distance between the central axis of the short rod 33 and the central axis of the circular plate 34.

[0046] A method for using a finite rock mass passive earth pressure testing device includes the following steps:

[0047] Step 1: Start motor 3 to drive turntable 4 to rotate. Move lever 6 or T-shaped rod 8 on turntable 4 via cylindrical rod 5 to make horizontal slide bar 9 slide on bottom plate 1 until retaining plate 12 moves to a suitable position inside box 2. Limit retaining plate 12 is then limited by limiting mechanism.

[0048] Step 2: Start hydraulic cylinder 28. When the extended end of hydraulic cylinder 28 extends, pressure plate 29 and pressure plate 30 can slide in the depth direction of retaining plate 12 to adapt to soil of different thicknesses.

[0049] Step 3: Add the soil used for the test between the retaining wall plate 31 and the retaining soil plate 12.

[0050] Step 4: Start hydraulic cylinder 36, so that the extended end of hydraulic cylinder 36 pushes the circular plate 34. As needed, select to make the retaining wall plate move horizontally, rotate around the bottom or around the top, and obtain the pressure detection result through the pressure sensor.

[0051] Working principle: Based on the required soil volume for the experiment, motor 3 is started, causing the turntable 4 fixedly mounted on the output shaft of motor 3 to rotate clockwise. The cylindrical rod 5 mounted on the turntable 4 will then rotate. When the cylindrical rod 5 rotates to contact the T-shaped rod 8 (e.g., ...), ... Figure 2 The clockwise rotation of the cylindrical rod 5 pushes the T-shaped rod 8 to the right. Since the T-shaped rod 8 is fixedly installed on the horizontal sliding rod 9, the horizontal sliding rod 9 will move to the right. This causes the horizontal sliding rod 9 to drive the crossbeam 10 to slide on the box body 2. At this time, the soil retaining plate 12, which is fixedly installed on the lower surface of the crossbeam 10, will move to the right. This will move the soil retaining plate 12 away from the retaining wall plate 31, thus increasing the space between the retaining wall plate 31 and the soil retaining plate 12. Therefore, the volume of soil filled into this space will increase. At the same time, another horizontal sliding rod 9, which is fixedly installed at the other end of the crossbeam 10, will also move. The pointer 13 on the horizontal slide bar 9 will also move, and the lower end of the pointer 13 will move along the scale 14. The scale 14 clearly shows the distance the retaining plate 12 moves inside the box 2, making it easier to observe. When the turntable 4 continues to rotate, the cylindrical rod 5 that is in contact with the T-shaped rod 8 will gradually move away from the T-shaped rod 8. At this time, another cylindrical rod 5 will gradually approach the lever 6 and eventually contact one end of the lever 6. The cylindrical rod 5 and the lever 6 will slide. Under the action of the cylindrical rod 5, the lever 6 will rotate counterclockwise (e.g., Figure 2 At this time, the U-shaped groove 7 on the lever 6 will move relative to the boss 38. In this way, the lever 6 will move the boss 38 through the U-shaped groove 7, causing the boss 38 to drive the horizontal slide bar 9 to move to the left. Then, the soil retaining plate 12 will move to the left inside the box 2, that is, the soil retaining plate 12 gradually blocks the wall plate 31, making the space between the soil retaining plate 12 and the circular plate 34 smaller, that is, the volume of soil required for the test decreases. During this process, the return springs 37 on both sides of the horizontal slide bar 9 will deform and generate elastic force. The function of the return springs 37 is to assist the return of the horizontal slide bar 9. It should be noted that the second pressure plate 30 slides into the T-groove 11 on the retaining plate 12. The sliding direction of the second pressure plate 30 on the retaining plate 12 is along the depth direction of the retaining plate 12. Therefore, when the retaining plate 12 moves to the right, the second pressure plate 30 will slide out from the first pressure plate 29 and move to the right. When the retaining plate 12 moves to the left, the second pressure plate 30 will move to the left.

[0052] Furthermore, when the horizontal slide bar 9 moves to the left, the crossbeam 10, which is fixedly connected to the horizontal slide bar 9, also moves to the left. This is because the slope of the second inclined surface of the triangular block 16 on the crossbeam 10 is the same as the slope of the first inclined surface of the right-angle tooth 39 on the limiting rod 17 (e.g., ...). Figure 1Therefore, when the crossbeam 10 and the triangular block 16 move to the left, the inclined surface 1 on the triangular block 16 will slide over the inclined surface 2 on the right-angle tooth 39, gradually pushing the limiting rod 17 upward and compressing the return spring 18. At the same time, the connecting bracket 19 connecting the limiting rods 17 will also move upward. Due to the presence of the return spring 20, even if the extended end of the hydraulic cylinder 21 does not extend, the hydraulic cylinder 21 will not restrict the upward movement of the connecting bracket 19. The function of the return spring 18 is to assist the return of the limiting rod 17. When the horizontal slide bar 9 moves to the right, the right angle on the limiting rod 17... The right-angled side of tooth 39 will block the right-angled side of triangle block 16, preventing triangle block 16 from moving to the right. At this time, hydraulic cylinder 21 needs to be activated to extend the end of hydraulic cylinder 21. The extended end of hydraulic cylinder 21 drives the intermediate plate 22 to slide upward along the end face of the short side of the box 2. The reset spring 20 pushes the connecting frame 19 upward. The upward-moving connecting frame 19 moves the two symmetrically arranged limit rods 17 upward. Then the right-angled tooth 39 on the limit rod 17 will leave triangle block 16, removing the restriction on triangle block 16, allowing triangle block 16 to move to the right. The purpose of this is twofold: firstly, when the retaining plate 12 needs to move to the left, the position adjustment can be easily completed without activating the hydraulic cylinder 21; secondly, when the retaining plate 12 needs to move to the right, the hydraulic cylinder 21 needs to be activated due to the limiting action of the right-angle tooth 39; furthermore, during the test, the force applied by the hydraulic cylinder 36 is to the right, so the limiting action of the right-angle tooth 39 is also essential to prevent the retaining plate 12 from moving itself.

[0053] As the crossbeam 10 moves to the right along with the retaining plate 12, the rack 23 fixedly installed on the crossbeam 10 will also move to the right (e.g., Figure 6 During the movement of rack 23 to the right, gear 24 meshing with rack 23 will rotate. Gear 24 drives gear 25 to rotate, and gear 25 moves rack 26, causing rack 26 to move to the right. Since rack 26 is fixedly connected to fixed frame 27, fixed frame 27 will slide to the right on housing 2. Hydraulic cylinder 28 on fixed frame 27 will move to the right together. The extended end of hydraulic cylinder 28 moves to the right along the long groove on pressure plate 29. It should be noted that the moving speed of rack 26 is half that of rack 23. That is, in the same time interval, the distance that rack 26 drives the fixed frame 27 to move is equal to half the distance that the crossbeam 10 drives the retaining plate 12 to move. This is done to ensure that hydraulic cylinder 28 is always positioned in the middle of the space formed by the retaining plate 12 and the retaining wall plate 31. This allows for more even force distribution on pressure plates 29 and 30 when the extended end of hydraulic cylinder 28 extends. Furthermore, pressure plates 29 and 30 can slide along the depth of the retaining plate 12, thus adapting to soil thicknesses.

[0054] After the distance between the retaining plate 12 and the retaining wall plate 31 is adjusted, test soil is added between the retaining wall plate 31 and the retaining plate 12.

[0055] After the test soil is added, the position of the through hole 35 on the circular plate 34 is adjusted according to the test mode. Specifically, when the retaining wall plate 31 needs to be moved horizontally, the circular plate 34 is rotated so that the central axis of the through hole 35 on the circular plate 34 does not coincide with the central axis of any of the short rods 33. Then, the hydraulic cylinder 36 is activated, causing the extended end of the hydraulic cylinder 36 to push the circular plate 34. At this time, the circular plate 34 squeezes the retaining wall plate 31 through the short rods 33, causing the retaining wall plate 31 to be subjected to a force to the right. At this time, the retaining wall plate 31 will be squeezed against the soil between the retaining wall plate 31 and the retaining plate 12. At this time, the pressure sensor 32 fixedly installed on the retaining wall plate 31 will... The system will detect the soil pressure and transmit the detection data vertically to the terminal. When the retaining wall plate 31 needs to rotate around the top, the central axis of the through hole 35 will coincide with the central axis of the short rod 33 located above. In this way, when the circular plate 34 pushes the short rod 33, the circular plate 34 can only push the short rod 33 located below, while the short rod 33 located above will pass through the through hole 35. When the retaining wall plate 31 needs to rotate around the bottom, the central axis of the through hole 35 will coincide with the central axis of the short rod 33 located below. In this way, the circular plate 34 will push the short rod 33 located above, while the short rod 33 located below will pass through the through hole 35.

[0056] Of course, during the experiment, hydraulic cylinder 28 can be activated, causing its extended end to push pressure plate 29. This subjects pressure plate 29 and pressure plate 30 to a downward force, compressing the soil between retaining plate 12 and retaining wall plate 31, thus generating pressure. It should be noted that, for those skilled in the art, obtaining pressure detection results through pressure sensors and displaying them on a computer is feasible.

[0057] The above description is merely a detailed description of specific embodiments of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made based on the design concept of the present invention should be included within the protection scope of the present invention.

Claims

1. A finite rock mass passive earth pressure testing device, comprising a base plate (1) and a box (2) fixed on the base plate (1), characterized in that: A retaining plate (12) is slidably installed inside the box (2). A retaining wall plate (31) is provided on one side of the box (2). The retaining wall plate (31) is connected to a horizontal drive mechanism. Four pressure sensors (32) arranged linearly are fixedly installed on the retaining wall plate (31). A space with an open upper end is formed between the retaining wall plate (31) and the retaining plate (12). A pressure plate (29) is slidably installed along the depth direction of the box (2). A pressure plate (30) is slidably installed inside the pressure plate (29). The pressure plate (30) is slidably engaged with the T-shaped groove (11) provided on the retaining plate (12). A moving mechanism that drives the retaining plate (12) to slide is provided inside the box (2). The moving mechanism limits the retaining plate through a limiting mechanism. The moving mechanism includes a crossbeam (10) installed above the retaining plate. The crossbeam (10) passes through the box (2) and is slidably installed on the box (2). Horizontal slide rods (9) are fixedly installed at both ends of the crossbeam (10). A return spring (37) is provided between the horizontal slide rod (9) and the box (2). Guide rollers (15) are slidably fitted on both the upper and lower ends of the horizontal slide rod (9). The guide rollers (15) are rotatably installed on the box (2). One of the horizontal slide rods (9) is fixedly mounted on the horizontal slide rod (9). A boss (38) and a T-shaped rod (8) are fixedly installed. The boss (38) and the T-shaped rod (8) are connected to a pushing mechanism. The pushing mechanism pushes the horizontal slide rod (9) and the crossbeam (10) to slide on the box (2) so that the crossbeam (10) drives the retaining plate (12) to slide inside the box (2). Another pointer (13) is fixedly installed on the horizontal slide rod (9). A scale (14) is installed below the pointer (13). The scale (14) is fixedly installed on the box (2). A triangular block (16) is fixedly installed on the upper surface of each end of the crossbeam (10). The triangular block (16) is a right triangle. The face of one right-angled side of the triangular block (16) is in contact with the upper surface of the crossbeam (10). The triangular block (16) is limited by a limiting mechanism. The limiting mechanism includes two symmetrically arranged limiting rods (17). The two limiting rods (17) are located above two horizontal sliding rods (9). The limiting rods (17) are provided with a plurality of right-angled teeth (39) arranged linearly. The slope of the first inclined surface on the right-angled teeth (39) is the same as that of the second inclined surface on the triangular block (16). The triangular block (16) and the right-angled teeth (39) are slidably engaged. The two limiting rods (17) are slidably installed on the outer side of the box (2). Two return springs (18) are provided between the limiting rods (17) and the box (2). The two limiting rods (17) are connected together by a connecting frame (19). The connecting frame (19) is slidably installed on the box (2). One end of the return spring (20) is fixedly installed on the connecting frame (19). The other end of the return spring (20) is fixedly installed on the intermediate plate (22). The intermediate plate (22) is fixedly installed on the hydraulic cylinder (21).

2. The finite rock mass passive earth pressure testing device according to claim 1, characterized in that: The pushing mechanism includes a lever (6), on which a U-shaped groove (7) is provided. The U-shaped groove (7) is slidably engaged with a boss (38). The lever (6) and the T-shaped rod (8) are slidably engaged with a turntable (4). The turntable (4) is provided with two symmetrically arranged cylindrical rods (5). The turntable (4) is rotatably mounted on the outer side of the housing (2). The turntable (4) is fixedly connected to the output shaft of the motor (3). The motor (3) is fixedly mounted on the base plate (1).

3. The finite rock mass passive earth pressure testing device according to claim 1, characterized in that: A rack (23) is also fixedly installed on the crossbeam (10). The rack (23) is connected to the rack (26) via a gear set. The rack (26) is fixedly installed on the fixed frame (27). The two ends of the fixed frame (27) are slidably installed on the box (2). A hydraulic cylinder (28) is fixedly installed at the center of the fixed frame (27). A long groove is provided along the length of the pressure plate (29). The long groove is slidably engaged with the extended end of the hydraulic cylinder (28).

4. The finite rock mass passive earth pressure testing device according to claim 3, characterized in that: The gear set includes a gear one (24) and a gear two (25) rotatably mounted on the housing (2). The gear one (24) meshes with the rack one (23), and the gear two (25) meshes with the rack two (26). The gear one (24) and the gear two (25) mesh with each other.

5. The finite rock mass passive earth pressure testing device according to claim 1, characterized in that: The horizontal drive mechanism includes a hydraulic cylinder three (36), which is fixedly installed on the base plate (1). A circular plate (34) is rotatably installed on the extended end of the hydraulic cylinder three (36). The central axis of the circular plate (34) coincides with the central axis of the hydraulic cylinder three (36). Two short rods (33) are slidably installed on the side of the circular plate (34) opposite to the hydraulic cylinder three (36). The short rods (33) are installed on the retaining wall plate (31).

6. The finite rock mass passive earth pressure testing device according to claim 5, characterized in that: The circular plate (34) is provided with a through hole (35), the diameter of the through hole (35) is larger than the diameter of the short rod (33), and the distance between the central axis of the through hole (35) and the central axis of the circular plate (34) is equal to the distance between the central axis of the short rod (33) and the central axis of the circular plate (34).

7. A method of using a finite rock mass passive earth pressure testing device, implemented based on the testing device according to any one of claims 1-6, characterized in that, Includes the following steps: Step 1: Start the motor (3) to make the motor (3) drive the turntable (4) to rotate. Move the lever (6) or T-shaped rod (8) on the turntable (4) by the cylindrical rod (5) to make the horizontal slide bar (9) slide on the bottom plate (1) until the retaining plate (12) moves to a suitable position inside the box (2). Limit the retaining plate (12) by the limiting mechanism. Step 2: Start hydraulic cylinder 2 (28). When the extended end of hydraulic cylinder 2 (28) extends, pressure plate 1 (29) and pressure plate 2 (30) can slide in the depth direction of the retaining plate (12) to adapt to soil of different thicknesses. Step 3: Add the soil used in the experiment between the retaining wall plate (31) and the retaining wall plate (12); Step 4: Start hydraulic cylinder three (36) to push the circular plate (34) with the extended end of hydraulic cylinder three (36). Select the wall plate to move horizontally, rotate around the bottom or around the top as needed, and obtain the pressure detection result through the pressure sensor.

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