Rock sample crack grouting experiment device and method based on parallel guide rails

Abstract

The invention discloses a rock sample crack grouting experimental device and method based on parallel guide rails, the experimental device comprises: a fixed seat, one side of which is provided with two guide rails at intervals in parallel along the same horizontal plane to form a guide structure for bearing a sample; the lower portion of the first sleeve frame is connected with the two guide rails through sliding blocks, so that a two-point contact guide pair is formed between the first sleeve frame and the guide structure, and a plurality of first locking pieces used for clamping samples are further arranged on the first sleeve frame in the circumferential direction at intervals; the screw rod is mounted on the fixed seat in a threaded fit manner, and the end part of the screw rod is connected with the first sleeve frame through a thrust revolute pair; the limiting structure is used for providing supporting force for one end, far away from the fixed seat, of the guide rail and fixing one sample for forming the crack on the guide rail. The experiment device can solve the problems that in a traditional rock mass grouting experiment, the fracture opening degree control precision is insufficient, and sample deflection is difficult to restrain.

Description

Technical Field

[0001] The present invention relates to the technical field of mining engineering, and in particular to a rock sample crack grouting experimental device and method based on parallel guide rails. Background Art

[0002] In the study of rock mass grouting reinforcement technology, precisely controlling the separation distance between fracture surfaces and maintaining their parallelism is a key prerequisite for ensuring uniform distribution of grouting material. Traditional experimental setups often rely on simple fixtures and manual measurement to align specimens. This operation suffers from systemic flaws: First, manual adjustment makes it difficult to avoid specimen eccentricity, resulting in uneven separation of the fracture surfaces and a tendency for actual displacement to deviate from the preset value. Second, the guide mechanisms of existing devices generally employ single-axis slides with large clearances. For example, a fixture is connected to a bearing at one end of a screw, which holds the specimen. The crack gap is adjusted by controlling the screw's advancement. As the screw rotates, the bearing connection allows the fixture to move horizontally. However, frictional torque causes circumferential deflection between the inner and outer rings of the bearing, which in turn causes circumferential deflection of the specimen in the fixture. This can cause the fracture surfaces to shift from their initial fully aligned state to partial contact, severely impacting the repeatability of the slurry diffusion pattern. Although some researchers have tried to improve displacement control accuracy by adding a multi-stage gear reduction mechanism, the complex transmission chain will introduce additional assembly errors and elastic deformation, and the reverse backlash error caused by the gear meshing clearance is difficult to eliminate, making it difficult to meet the millimeter-level micro-adjustment requirements.

[0003] In view of this, it is necessary to design a rock specimen crack grouting experimental device and method based on parallel guide rails to solve the above problems. Summary of the Invention

[0004] The purpose of the present invention is to provide a rock sample crack grouting experimental device and method based on parallel guide rails, so as to solve the problems of insufficient crack opening control accuracy and difficulty in suppressing sample deflection in traditional rock grouting experiments.

[0005] To achieve the above-mentioned purpose, the present invention provides a rock sample crack grouting experimental device based on parallel guide rails, comprising: A fixed seat, one side of which is provided with two guide rails spaced parallel to each other along the same horizontal plane, forming a guide structure for carrying the specimen; The first frame has a lower portion connected to the two guide rails via sliders, so that a two-point contact guide pair is formed between the first frame and the guide structure. The first frame is also provided with a plurality of first locking members for clamping the specimen at intervals along the circumference. A screw rod is mounted on the fixed seat through threaded engagement and is connected to the first sleeve frame at its end through a thrust-rotation pair; and The limiting structure is used to provide support force for the end of the guide rail away from the fixing seat and to fix one of the specimens used to form the crack on the guide rail.

[0006] As a further improvement of the present invention, the slider is sleeved on the guide rail and is loosely matched with the guide rail, and the gap between the slider and the guide rail contact surface is less than or equal to 0.005 mm.

[0007] As a further improvement of the present invention, the sliding block is provided with a notch which does not affect the fitting state between the sample and the guide rail.

[0008] As a further improvement of the present invention, the diameter of the notch is smaller than the diameter of the guide rail.

[0009] As a further improvement of the present invention, scale lines are provided on the guide rail.

[0010] As a further improvement of the present invention, the limiting structure includes a movable seat installed on two guide rails in a manner that the relative position with the fixed seat is adjusted by a sliding guide mechanism, a fixing member for locking the relative position of the movable seat and the guide rails, and a second frame mounted on the guide structure and connected to the movable seat through a connecting member, and a plurality of second locking members for clamping the sample are arranged on the second frame at intervals along the circumference.

[0011] As a further improvement of the present invention, at least three of the first locking members and the second locking members are provided, wherein the first locking members are respectively provided at the top and both sides of the middle of the first sleeve; the second locking members are respectively provided at the top and both sides of the middle of the second sleeve.

[0012] As a further improvement of the present invention, the middle portion of the guide rail protrudes outward, so that an outward expansion area is formed in the middle portion of the guide structure to facilitate grouting treatment.

[0013] As a further improvement of the present invention, the distance between the two guide rails is 0.6-0.8 times the diameter of the sample.

[0014] The present invention also provides a method for a rock sample crack grouting experimental device based on parallel guide rails, comprising the following steps: S1. Place two specimens on the guide rail and secure them using the limiting structure, the first bracket, and the first locking member, respectively, so that the two specimens are relatively stable and attached to the guide rail. S2. The screw is rotated by the driving member so that the first frame drives one of the specimens to move away from the other specimen, forming a crack between the two specimens. The displacement of the first frame is the crack width. S3. Carry out grouting treatment on the cracks.

[0015] As a further improvement of the present invention, in step S3, before grouting, a mold is placed on the crack to ensure the grouting effect.

[0016] The beneficial effects of the present invention are: 1. The present invention utilizes two guide rails to form a specimen bearing area, and at the same time cooperates with a locking member, so that the guide rails can play both a guiding role and a limiting role, so that when the screw drives the specimen to move back and forth, the specimen always fits on the guide rails, ensuring that the specimen moving during the experiment is always in the same horizontal position, thereby ensuring that the two specimens used to form the crack are always at the same horizontal height during the experiment, thereby ensuring the vertical alignment accuracy of the crack. Compared with the prior art in which the specimen is loaded by a fixture, the present invention utilizes a guide rail for load-bearing and guiding and limiting design, which can achieve relatively uniform force on the specimen, ensure the stability of the specimen during movement and during movement to a predetermined position for grouting experiments, and at the same time prevent the gravity of the specimen from affecting the fixing effect of the locking member and its service life.

[0017] 2. The present invention realizes the connection between the first sleeve and the guide rail through the slider, so that a two-point contact guide pair is formed between the first sleeve and the guide structure, and the guide structure can be used to limit the first sleeve circumferentially, and further cooperate with multiple first locking members to lock the sample. When the position of the first sleeve is adjusted by rotating the screw to perform precise adjustment of the crack, under the coordinated action of the first locking member, the first sleeve and the guide rail, the sample is fixed circumferentially and always fits on the guide rail for translation, which can avoid the sample from rotating circumferentially due to the friction torque during the adjustment of the crack surface separation distance by rotating the screw, thereby affecting the crack surface engagement state.

[0018] 3. The experimental device of the present invention has a simple structure and is easy to operate. The crack opening can be precisely adjusted by controlling the rotation of the screw. At the same time, it ensures that the two specimens fixed on the first frame and the limiting structure respectively can always maintain a relatively stable state during the experiment, so that the crack surface formed by the two specimens is always in a complete matching state, thereby achieving uniform distribution of the grouting material. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of the overall structure of the rock specimen crack grouting experimental device based on parallel guide rails.

[0020] Figure 2 It is a structural diagram of the first frame part.

[0021] Figure 3 It is a structural diagram of the second frame part.

[0022] Reference numerals 11. Fixed seat; 12. Movable seat; 121. Fixed part; 20. Guide rail; 21. Outward expansion area; 31. Screw; 32. Driving part; 41. First bracket; 42. Slider; 421. Notch; 43. First locking part; 51. Second bracket; 52. Second locking part; 61. Grouting pipe; 70. Test sample; 80. Mold. DETAILED DESCRIPTION

[0023] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] It should also be noted here that, in order to avoid obscuring the present invention due to unnecessary details, only structures and / or processing steps closely related to the solutions of the present invention are shown in the drawings, while other details that are not closely related to the present invention are omitted.

[0025] In addition, it should be noted that the terms "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or apparatus.

[0026] like Figure 1 As shown, the present invention provides a rock sample crack grouting experimental device based on parallel guide rails, comprising: The fixing base 11 has two guide rails 20 arranged parallel to each other along the same horizontal plane on one side, forming a guide structure for carrying the sample 70; The first frame 41 is connected to the two guide rails 20 at the bottom through the slider 42, so that a two-point contact guide pair is formed between the first frame 41 and the guide structure. The first frame 41 is also provided with a plurality of first locking members 43 for clamping the sample 70 at intervals along the circumference. The screw rod 31 is mounted on the fixed seat 11 through threaded engagement and is connected to the first sleeve 41 at its end through a thrust rotation pair; and The limiting structure is used to provide support force for the end of the guide rail 20 away from the fixing seat 11 and to fix one of the specimens 70 used to form the crack on the guide rail 20.

[0027] Exemplarily, the guide rails 20 are made of nitrided 38CrMoAl alloy steel; the distance between the two guide rails 20 is 0.6-0.8 times the diameter of the sample 70 , so as to support the sample 70 .

[0028] In this example, the surface of guide rail 20 is laser-etched with microscale lines with a resolution of 0.1mm. Rotating screw 31, in conjunction with the laser scale on guide rail 20, enables bidirectional, reversible adjustment of specimen 70's displacement, with a resolution of 0.1mm. Each rotation corresponds to an axial displacement of 1mm, achieving a displacement control accuracy of ±0.1mm, meeting the required precision for controlling the crack opening.

[0029] Specifically, the middle portion of the guide rail 20 bulges outward, forming an expanded area 21 in the middle of the guide structure for grouting. For example, the expanded area 21 is rectangular, with dimensions perpendicular to the guide rails 20 greater than the distance between the two guide rails 20 and greater than the diameter of the specimen 70.

[0030] Specifically, the slider 42 is mounted on the guide rail 20 and is clearance-matched with the guide rail 20; the contact surface clearance between the slider 42 and the guide rail 20 is less than or equal to 0.005 mm, so that when the slider 42 is driven by the screw 31 and can move along the guide rail 20, the slider 42 and the guide rail 20 basically maintain a relatively stable state in the vertical direction, that is, when the slider 42 is subjected to force, its micro-displacement relative to the guide rail 20 in the vertical direction will not affect the grouting test results. At the same time, the slider 42 forms a two-point contact guide pair between the first sleeve 41 and the guide structure, and can use the two guide rails 20 to circumferentially limit the first sleeve 41, so that when the first sleeve 41 moves horizontally along the guide rail 20 under the drive of the screw 31, it always remains circumferentially fixed.

[0031] For example, the slider 42 is provided with a notch 421 ( Figure 2 Notch 421 is located at the contact point between guide rail 20 and specimen 70, allowing slider 42 to drive movement of first bracket 41 without obstructing specimen 70, ensuring that specimen 70 remains firmly in contact with guide rail 20. This means that the adjustment of specimen 70's displacement by slider 42 does not affect the horizontal position of specimen 70. In other examples, notch 421 may not be provided on slider 42, and the thickness of the contact area between slider 42 and specimen 70 may be controlled based on actual conditions, ensuring that the presence of slider 42 does not affect the experimental results.

[0032] Specifically, the thrust-rotation pair includes a frame body connected to the first sleeve 41 and a bearing provided on the frame body, and the end of the screw rod 31 is connected to the frame body through the bearing.

[0033] For example, Figure 2As shown, three first locking members 43 are provided, and the three first locking members 43 are respectively located at the top and both sides of the middle portion of the first housing 41. By providing the locking members at the top of the first housing 41, the bottom of the sample 70 can always remain in contact with the guide rail 20 under the action of the top locking members. Furthermore, in conjunction with the locking members on both sides of the middle portion of the first housing 41, the sample 70 and the first housing 41 can be kept relatively fixed. Since the first housing 41 can always remain circumferentially fixed when the screw 31 is driven, by fixing the sample 70 to the first housing 41, the first housing 41 can be used to circumferentially limit the sample 70, thereby preventing the sample 70 from circumferentially deflecting due to the rotation of the screw 31.

[0034] Specifically, the limiting structure includes a movable base 12 mounted on two guide rails 20 so as to adjust its relative position to the fixed base 11 via a sliding guide mechanism, a fixing member 121 for locking the relative position of the movable base 12 and the guide rails 20, and a second bracket 51 mounted on the guide structure and connected to the movable base 12 via a connector. The second bracket 51 is provided with a plurality of second locking members 52 spaced circumferentially for clamping the specimen 70. For example, the movable base 12 is mounted on the two guide rails 20 and can slide along the guide rails 20, and the second bracket 51 is mounted on the guide structure.

[0035] Exemplarily, the fixed seat 11 and the movable seat 12 are both annular. The bottom structure and bottom surface of the fixed seat 11 and the movable seat 12 can be configured accordingly using existing technology so that the fixed seat 11 and the movable seat 12 and the operating platform maintain a relatively stable state during experimental operations.

[0036] For example, Figure 3 As shown, three second locking members 52 are provided, and the three second locking members 52 are located at the top and both sides of the middle of the second frame 51. The fixing principle of the second locking members 52 located at the top and both sides of the middle of the second frame 51 is the same as the design of the first locking member 43 on the first frame 41.

[0037] The first locking member 43 and the second locking member 52 have the same locking method, and the first locking member 43 is taken as an example for description.

[0038] First bracket 41 has first threaded holes at the top and on both sides of its center. First locking member 43 is a first threaded rod that fits into the first threaded holes. Specimen 70 is locked by rotating the first threaded rod so that one end abuts against the surface of specimen 70. The surface of the first threaded rod is coated with a 3mm thick polyurethane friction layer (friction coefficient μ = 0.8), ensuring that the specimen and the first bracket are fully locked together.

[0039] Specifically, the movable seat 12 is provided with second threaded holes corresponding to the positions of the two guide rails 20; the fixing member 121 is a second threaded rod adapted to the second threaded hole, and the position of the movable seat 12 and the guide rail 20 is fixed by rotating the second threaded rod so that one end thereof is pressed against the surface of the guide rail 20.

[0040] The present invention also provides a method for a rock sample crack grouting experimental device based on parallel guide rails, comprising the following steps: S1. Place two specimens 70 together on the guide rail 20 with the crack located in the outer expansion area 21. Adjust the position of the movable base 12 and the first bracket 41. Place the two specimens 70 on the first bracket 41 and the second bracket 51, with one end of the two specimens facing away from each other. Secure the two specimens 70 with the first locking member 43 and the second locking member 52, respectively, so that the two specimens 70 are relatively stable and attached to the guide rail 20. S2. The screw 31 is rotated by the driving member 32, so that the first bracket 41 drives one of the specimens 70 to move away from the other specimen 70, forming a crack between the two specimens 70. The scale values ​​corresponding to the positions before and after the movement of the first bracket 41 are read. The difference between the two scale values ​​is the crack width, that is, the thickness of the grouting material after grouting. S3. Carry out grouting treatment on the cracks.

[0041] Specifically, in step S3, before grouting, a mold 80 needs to be set on the crack to ensure the grouting effect. The crack is located in the outer expansion area 21, which is convenient for the mold setting process. For example, the mold 80 is made of steel, and a grouting hole is set on the top of the mold 80. By inserting the grouting pipe 61 through the grouting hole to the bottom of the crack, the slurry slowly flows into the crack, and at the same time, the air in the crack is also discharged from the unsealed grouting hole. When the slurry just fills the grouting hole, the grouting is stopped, and then the grouting pipe 61 is slowly withdrawn to complete the grouting.

[0042] After grouting is completed, the mold 80 is removed after 24 hours of initial setting. The specimen 70 is then placed in a constant temperature and humidity chamber at 25±1°C for 28 days and nights of continuous curing. This curing method effectively simulates the hardening process of materials on-site, ensuring that the slurry forms a stable structural system, thereby ensuring the engineering reference value and scientific rigor of the experimental data.

[0043] During the experiment, under the action of the top locking piece, the sample 70 is always attached to the guide rail 20. Therefore, when the screw 31 drives the sample 70 to move horizontally, the top locking piece cooperates with the fixed limit of the guide rail 20 and the guiding action of the guide rail 20 to ensure that the two samples 70 are always at the same horizontal height, so that the crack surface will not be affected by the change in the height of one of the samples 70 and the matching state of the crack surface.

[0044] Regarding the stability of the sample 70 locked in the first sleeve 41: due to the clearance fit between the slider 42 and the guide rail 20, and the first sleeve 41 forms a two-point contact guide pair between the slider 42 and the guide structure, the two guide rails 20 can circumferentially limit the first sleeve 41, that is, when the screw 31 rotates to drive the first sleeve 41 to move horizontally, the first sleeve 41 is in a circumferentially stable state, and then the first sleeve 41 and the first locking member 43 are used to fix the relative position of the sample 70 and the first sleeve 41, which can ensure that the sample 70 is always in a stable state during the experiment and will not deflect circumferentially.

[0045] Regarding the stability of the sample 70 locked on the second bracket 51: Since the movable seat 12 is arranged on the two guide rails 20, the two guide rails 20 can be used to limit the movable seat 12 circumferentially to prevent the movable seat 12 from rotating under force. When the fixing member 121 is used to fix the guide rail 20 and the movable seat 12, the movable seat 12 is in a relatively stable state, and the movable seat 12 can be used to provide supporting force for the second bracket 51, so that the second bracket 51 and the guide rail 20 remain relatively stable. Further, when the second locking member 52 and the second bracket 51 are used to fix the sample 70, the sample 70 and the guide rail 20 are always in a stable state.

[0046] Furthermore, the guiding action of the guide rail 20 enables the smooth movement of the sample 70, and the coordinated cooperation of the guide rail 20 with the slider 42, the sleeve, the locking member and the fixed seat 12 enables the horizontal, vertical and circumferential limiting action of the sample 70 fixed on the first sleeve 41, and the limiting structure is used to keep the other sample and the guide rail 20 in a relatively stable state, thereby achieving precise alignment of the two samples 70, so that the crack surface is always in a complete alignment state during the experiment.

[0047] Since the grouting experiment has high requirements for the matching state of the cracks, in the existing technology, due to the effect of friction torque, a small circumferential deflection between the inner and outer rings of the bearing will also affect the matching state of the crack surface, seriously affecting the repeatability of the slurry diffusion law. The present invention uses the guide rail 20 to bear the weight of the sample 70, which can avoid the locking effect of the locking part being affected by the gravity of the sample 70 and being reduced. In addition, the guide rail 20 can be used for mobile guidance and the connection between the guide rail 20 and the first bracket 41 can be used to fix the sample 70 circumferentially. The setting of fixing another sample on the guide rail 20 with the limiting structure can ensure that the crack surface is always in a complete matching state, thereby ensuring the accuracy of the experiment.

[0048] Regarding the displacement control of the sample 70, based on the coordinated cooperation of the guide rail 20 and the slider 42, the sleeve and the locking member to achieve stable limiting of the sample 70, the present application can complete the precise control of the displacement of the sample 70 through the control of the screw 31. The adjustment structure is simple and will not introduce too much assembly error, and the adjustment accuracy is high, which can fully meet the millimeter-level macro adjustment requirements in the crack grouting experiment of the rock sample 70.

[0049] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A rock sample crack grouting experimental device based on parallel guide rails, characterized in that: include: A fixed seat, one side of which is provided with two guide rails spaced parallel to each other along the same horizontal plane, forming a guide structure for carrying the specimen; The first frame has a lower portion connected to the two guide rails via sliders, so that a two-point contact guide pair is formed between the first frame and the guide structure. The first frame is also provided with a plurality of first locking members for clamping the specimen at intervals along the circumference. A screw rod is mounted on the fixed seat through threaded engagement and is connected to the first sleeve frame at its end through a thrust-rotation pair; and The limiting structure is used to provide support force for the end of the guide rail away from the fixing seat and to fix one of the specimens used to form the crack on the guide rail.

2. The rock sample crack grouting experimental device based on parallel guide rails according to claim 1 is characterized by: The slider is sleeved on the guide rail and is clearance-matched with the guide rail, and the clearance between the slider and the guide rail contact surface is less than or equal to 0.005 mm.

3. The rock sample crack grouting experimental device based on parallel guide rails according to claim 2 is characterized by: The sliding block is provided with a notch which does not affect the fitting state between the sample and the guide rail.

4. The rock sample crack grouting experimental device based on parallel guide rails according to claim 3 is characterized by: The diameter of the notch is smaller than the diameter of the guide rail.

5. The rock sample crack grouting experimental device based on parallel guide rails according to claim 1 is characterized in that: Scale lines are provided on the guide rail.

6. The rock sample crack grouting experimental device based on parallel guide rails according to claim 1 is characterized in that: The limiting structure includes a movable seat installed on two guide rails in a manner that the relative position with the fixed seat is adjusted by a sliding guide mechanism, a fixing member for locking the relative position of the movable seat and the guide rails, and a second frame mounted on the guide structure and connected to the movable seat by a connecting member, wherein the second frame is provided with a plurality of second locking members for clamping the sample at intervals along the circumferential direction.

7. The rock sample crack grouting experimental device based on parallel guide rails according to claim 6 is characterized in that: There are at least three first locking members and second locking members, wherein the first frame is provided with first locking members at the top and both sides of the middle; the second frame is provided with second locking members at the top and both sides of the middle.

8. The rock sample crack grouting experimental device based on parallel guide rails according to claim 1 is characterized by: The middle portion of the guide rail protrudes outward, so that an outward expansion area is formed in the middle portion of the guide structure to facilitate grouting treatment.

9. A method for a rock sample crack grouting experimental device based on parallel guide rails according to claim 1, characterized in that: The following steps are involved: S1. Place two specimens on the guide rail and secure them using the limiting structure, the first bracket, and the first locking member, respectively, so that the two specimens are relatively stable and attached to the guide rail. S2. The screw is rotated by the driving member so that the first frame drives one of the specimens to move away from the other specimen, forming a crack between the two specimens. The displacement of the first frame is the crack width. S3. Carry out grouting treatment on the cracks.

10. The method according to claim 9, characterized in that: In step S3, before grouting, a mold is placed on the crack to ensure the grouting effect.

Images