A coal-rock fissure visualization grouting device and test method

Abstract

The present invention discloses a visual grouting device and test method for coal rock fissures, the test device comprising a visual fissure grouting box, a box support, a grouting device and a monitoring device. The bottom plate is divided into four equal-sized areas, and rubber pads of different specifications are respectively arranged to simulate different fissure widths and tortuosity. An artificial original rock film is pasted inside, and a grouting hole and a plurality of pressure measuring holes are arranged in the center of the upper top plate; the grouting device is composed of an air compressor, a slurry storage barrel, a pneumatic agitator, a slurry delivery pipe, a grouting pipe and an air guide pipe. The grouting hole and the slurry control valve at the bottom of the slurry storage barrel are connected by a slurry delivery pipe, and the air compressor is respectively connected to the slurry storage barrel and the pneumatic agitator. The present invention can simulate the fissure grouting process under different grouting conditions such as different fissure widths, roughness, grouting resistance, and tortuosity of pore channels, and can also simulate grouting under different fissure conditions at the same time. Through the visual box, the differences in different grouting diffusion forms can be clearly and intuitively analyzed and compared.

Description

Technical Field

[0001] The invention relates to the field of grouting simulation test equipment, and in particular to a coal rock fissure visualization grouting device and a test method. Background Art

[0002] Grouting is a common technical means to control the deformation of surrounding rocks and improve the stability of surrounding rocks. Fracture grouting refers to injecting slurry into fractured rock mass through a certain grouting pressure. As the slurry spreads, the fracture space is continuously filled, which not only prevents the seepage of groundwater and blocks the water flow channel, but also the solidified slurry can make the broken rock mass form a complete whole, jointly bear the external stress to resist the deformation of surrounding rocks, greatly improve the stability and bearing capacity of the surrounding rock mass, and thus improve the mechanical properties of the rock mass structure.

[0003] At present, grouting reinforcement engineering has been widely used. However, due to the concealment of grouting engineering, the development of grouting theory lags far behind engineering practice. Grouting engineering, especially fissure grouting, still lacks scientific theoretical guidance. The final diffusion distance of slurry in the fissure and the impact of grouting on rock structure are difficult to ascertain; the determination of grouting parameters and the design of grouting engineering rely heavily on construction experience. These problems seriously restrict the development of grouting theory. It is often difficult to determine a reasonable grouting scheme based on engineering experience alone. If the grouting parameters and grouting scheme are too conservative, although the ideal reinforcement effect is achieved, it is easy to cause a waste of resources; if the grouting parameters and grouting scheme are too simple, although resources are saved, the ideal grouting effect cannot be achieved, leaving serious safety hazards for the construction of the tunnel.

[0004] As the main controlling factor for evaluating the grouting effect, it is extremely important to grasp the diffusion range of the slurry in time. However, the fractured rock mass is deeply buried in the stratum, and the fracture network is complex. The flow and diffusion of the grouting slurry in the rock mass fractures is extremely hidden, and it is extremely difficult to visually observe the diffusion flow of the slurry. At present, in actual field projects, there is a lack of methods for monitoring and identifying the diffusion flow of slurry in fractured rock mass, and a lack of methods for visually displaying the shape, size and impact range of the slurry diffusion.

[0005] Therefore, improving the fracture grouting test device and method in the prior art to meet the needs of different application scenarios is a technical problem that urgently needs to be solved. Summary of the invention

[0006] The main purpose of the present invention is to provide a grouting device that simulates the visualization of coal rock fissures to solve the problems existing in the prior art. The present invention can simulate the diffusion law of slurry in the fissures under various fissures and fissure geological conditions, as well as different slurry materials and grouting conditions. And due to the visualization of the device, the diffusion law of the slurry can be intuitively tested and the actual grouting effect after grouting can be detected.

[0007] In order to solve the above technical problems, the technical solution provided by the present invention is as follows: a visual grouting device for coal rock fissures, comprising a visual grouting box for fissures and a grouting device; the fissure grouting box is composed of an upper top plate and a lower bottom plate, and artificial original rock films are respectively attached to the inner sides of the two upper top plates and the lower bottom plates, and a grouting hole and a plurality of pressure measuring holes are arranged in the center of the upper top plate; the upper top plate and the lower bottom plate are divided into four completely identical square areas, and a plurality of irregular cylindrical rubber pads of different sizes are arranged in different areas, and the pads are attached to the original rock films;

[0008] The grouting device includes an air compressor, a slurry storage barrel, a pneumatic agitator, a slurry delivery pipe, a grouting pipe and an air duct; the top of the slurry storage barrel is connected to the air compressor through the air duct, and a slurry control valve is provided at the bottom of the slurry storage barrel, the slurry control valve is connected to the grouting pipe on the fracture grouting box through the slurry delivery pipe, and an electromagnetic flowmeter is also installed at the slurry control valve to measure the grouting amount and grouting speed during the grouting process, and pressure gauges are also provided on the slurry storage barrel and the air compressor; an air control valve is provided on the air compressor, which is connected to the slurry storage barrel through the air duct; the pneumatic agitator is connected to the air compressor through the air duct.

[0009] Furthermore, the upper top plate and the lower bottom plate are made of transparent organic glass and are fixed together by fastening bolts on all sides, and the artificial original rock film is respectively attached to the inner side of the upper top plate and the lower bottom plate in one layer.

[0010] Furthermore, the peripheries of the upper top plate and the lower bottom plate are sealed by gasket strips with a certain air permeability.

[0011] Furthermore, it also includes a rotatable and adjustable bracket, including a rotating shaft, an angle adjuster and a stabilizing plate;

[0012] The angle adjuster is provided with an anti-rotation pin, which can fix the rotating shaft after rotating a certain angle, so as to simulate the grouting test under different crack inclination angles; the stabilizing plate is connected to the bottom plate of the crack grouting box to ensure the stability of the crack grouting box during grouting, and also plays a role in reinforcing the bottom plate.

[0013] Furthermore, it also includes a data acquisition system, including a sensor, a high-speed camera, and a computer; the sensor is connected to the pressure measuring hole on the top plate of the fracture grouting box; the high-speed camera is used to shoot and record the entire grouting process; the computer is used to collect and organize analysis data.

[0014] A test method for a visualized grouting device for coal rock fissures is characterized in that it includes the following steps: a layer of artificial original rock film is affixed to the inner sides of an upper top plate and a lower bottom plate respectively, and the lower bottom plate is divided into four square areas of the same size, wherein one area is not processed; a prismatic rubber pad with a triangular side is affixed to the bottom plate of one area, and an artificial original rock film of a corresponding size is affixed to the rubber pad to simulate grouting conditions of different fissure openings; a plurality of cylindrical rubber pads with the same thickness and different diameters are affixed to the bottom of one area, and the pads are randomly distributed in the area to simulate a pore channel with a certain tortuosity; a plurality of cylindrical rubber pads with gradually increasing thickness from the center to the edge and different diameters are affixed to the bottom of one area, and the pads are randomly distributed in the area to simulate a pore channel with different widths and a certain tortuosity.

[0015] The top and bottom plates are sealed with gaskets with a certain degree of air permeability and fixed together with bolts to form a crack visualization grouting box;

[0016] The fracture grouting box is supported by a rotating bracket, the bottom plate of the grouting box is fixed on the stable plate on the top of the bracket, and the grouting diffusion test with different fracture inclination angles is simulated by adjusting the rotation angle of the bracket shaft;

[0017] There are several pressure measuring holes on the top plate of the grouting box, which are connected to sensors to record the pressure parameters of the grouting box in real time;

[0018] A fixed grouting pipe is inserted into the grouting hole on the top plate of the grouting box, and the grouting pipe is connected to the grouting control valve at the bottom of the grouting bucket through a grouting pipe;

[0019] The top of the slurry storage barrel is connected to the air control valve on the air compressor through an air guide pipe;

[0020] The air compressor is connected to the pneumatic agitator through an air pipe;

[0021] Check the connection status of each pipeline and the accuracy of each instrument to ensure that the test can proceed normally. Pour the slurry material into the slurry storage barrel according to the designed ratio, open the air control valve on the air compressor to inject air into the slurry storage barrel, and turn on the pneumatic agitator in the slurry storage barrel to prevent slurry sedimentation. When the pressure gauge reading on the slurry storage barrel reaches the specified value, open the slurry control valve at the bottom of the slurry storage barrel to start grouting;

[0022] Turn on the sensors and high-speed cameras, record the sensor data, and observe and record the diffusion form and range of the slurry in each area during the grouting process;

[0023] Observe the slurry diffusion state of the fracture grouting box, stop grouting after the slurry fills about 3 / 4 of the fracture grouting box, and close the slurry control valve and air control valve;

[0024] After the pressure is released, disassemble and clean the fracture grouting box and grouting equipment.

[0025] Replace the original rock film with different particle sizes, replace the sealing gasket strips with different thickness and permeability, replace the rubber pads with different sizes, and adjust the simulated crack width by adjusting the bolts, repeat the above steps, collect the test data under different grouting conditions, and complete all grouting tests according to the design.

[0026] The advantages of the present invention over the prior art are as follows: the present invention studies the relationship between grouting pressure, grouting speed, grouting time, slurry volume, slurry properties, crack width, crack inclination, crack roughness, crack permeability, pore channel tortuosity and slurry diffusion radius through simulation tests, thereby studying the diffusion law of slurry in coal rock bodies;

[0027] The present invention can simulate the tortuous pore channels of rock and soil media under real conditions by setting irregularly distributed pads of different sizes, and reveal the actual flow process of slurry in rock and soil media;

[0028] The present invention can change the crack width by adjusting the thickness of the rubber pad, and can simulate the rock crack morphology under real conditions;

[0029] The present invention uses gaskets with different air permeabilities to seal the fracture grouting box, which can simulate the fracture grouting resistance under different density and air permeability of the medium;

[0030] In the present invention, the fracture box is divided into four square areas of the same size, and different treatments are performed on the four areas. The grouting diffusion effects and forms under different fracture conditions can be simulated and tested at the same time. Due to the visualization of the device, it can not only reflect the grouting effect under real grouting conditions, but also clearly and intuitively observe and compare the differences in grouting diffusion forms under different fracture conditions.

[0031] advantage:

[0032] The present invention arranges a plurality of rubber pads in a fracture box to simulate the particle skeleton inside the medium, and uses cylindrical rubber pads of different diameters and arranges them randomly to simulate the tortuous pore channels in the rock medium under real conditions, thereby simulating a flow trajectory of slurry in the rock medium that is closer to the actual flow trajectory.

[0033] In the prior art, "A visual fracture grouting test device and method for simulating multiple main control variables" discloses a fracture simulation grouting device that can simulate and study the grouting diffusion law in fractures and the quantitative relationship between the grouting diffusion radius and multiple grouting main control factors under static water or water-free conditions; "A dynamic water grouting test device for simulating fractures with different fillings" discloses a fracture simulation grouting device that can simulate and study the slurry diffusion law when grouting in fractures filled with seepage conditions.

[0034] At present, most experiments use a single flat plate fracture to simulate the diffusion law of slurry on the dominant fracture surface inside broken rock and soil. However, the fracture network in the rock structure is intricate, and the prior art still lacks consideration of the tortuosity effect of slurry flowing in porous media. Based on the previous consideration of various grouting influencing factors, the present invention sets pads in the fracture plate to simulate the tortuous channels in the porous medium, which further improves the rationality and accuracy of the experiment.

[0035] At the same time, since the grouting fissure designed in the experiment is a single fracture surface, and the intricate fracture network inside the medium under real conditions determines that different media have different permeabilities, the previous single flat plate fracture simulation grouting device is limited to the consideration of grouting influencing factors of a single fracture plane. In order to make up for the difference between the experiment and the actual situation, the present invention changes the permeability of the grouting medium by changing the air permeability of the fracture box sealing strip, so as to simulate and obtain a calculation result of the grouting diffusion radius that is closer to the actual one.

[0036] In addition, in the previous single flat plate fissure simulation grouting experiment, only one grouting main control factor can be changed each time, and the equipment must be disassembled and cleaned again to conduct the next experiment. The present invention divides the fissure box into four square areas of the same size, and makes different arrangements in the four areas to simulate different fissure conditions. Grouting experiments under different fissure conditions are carried out at the same time, which greatly simplifies the repeated steps of the experiment and saves a lot of experimental time. In addition, due to the visualization of the experimental device, the differences in the grouting diffusion forms under different fissure conditions can be observed and compared more clearly and intuitively. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 Schematic diagram of the overall test device of the present invention.

[0038] Figure 2 Schematic diagram of the top plate of the fracture box.

[0039] Figure 3 Schematic diagram of the bottom plate of the fracture box.

[0040] Figure 4 Schematic diagram of the simulated slurry diffusion route in areas (c) and (d).

[0041] Figure 5It is a schematic cross-sectional diagram of the four areas of the fracture box cut two by two along the midline.

[0042] As shown in the figure: 1. Slurry storage barrel; 2. Air compressor; 3. Air control valve; 4. Pressure gauge; 5. Air guide pipe; 6. Pneumatic agitator; 7. Slurry control valve; 8. Flow meter; 9. Slurry delivery pipe; 10. Grouting pipe; 11. Fastening bolts; 12. Stabilizing plate; 13. Angle adjuster; 14. Rotating shaft; 15. Bracket; 16. Pressure measuring hole; 17. Grouting hole; 18. Sealing strip. DETAILED DESCRIPTION

[0043] The specific implementation of the present invention is further described below in conjunction with the accompanying drawings, wherein the same components are represented by the same reference numerals.

[0044] In the description of the present invention, it should be understood that the terms "center", "lateral", "up", "down", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more. In addition, the term "including" and any variation thereof are intended to cover non-exclusive inclusions.

[0045] Example

[0046] like Figure 1 As shown, it shows the overall schematic diagram of the test device of the present invention, including a crack grouting box, a rotating bracket 15 and a grouting device;

[0047] like Figure 2 , 3As shown, the fracture grouting box includes an upper top plate, a lower bottom plate, a sealing gasket 18, and a fastening bolt 11. The top and bottom plates are made of transparent organic glass with a size of (1000×1000×20mm), and artificial original rock films with a size of (980×980×0.1mm) are attached to the inner sides of the two upper top plates and the lower bottom plate, respectively. A grouting hole 17 and a plurality of pressure measuring holes 16 are provided in the center of the upper top plate. The lower floor is divided into four square areas of the same size, one of which is not treated; a prismatic rubber pad with a triangular side is pasted on the bottom plate of one area, and an artificial original rock film of corresponding size is pasted on the rubber pad to simulate the grouting conditions of different crack openings; a number of cylindrical rubber pads with the same thickness and different diameters are pasted on the bottom of one area, and the pads are randomly distributed in the area to simulate pore channels with a certain tortuosity; a number of cylindrical rubber pads with different diameters and gradually increasing thickness from the center to the edge are pasted on the bottom of one area, and the pads are randomly distributed in the area to simulate pore channels with different widths and a certain tortuosity.

[0048] During the experiment, according to different test requirements, the sealing gasket strips 18 with different air permeabilities, the artificial original rock films with different sizes and original rock particle sizes, the rubber pads with different sizes, and the rubber pads with different sizes were replaced, and the spacing between the fastening bolts 11 was adjusted to simulate the grouting process under different crack widths, crack roughness and grouting resistance conditions.

[0049] like Figure 1 , 3 As shown, the rotating bracket 15 includes a rotating shaft 14, an angle adjuster 13 and a stabilizing plate 12. The angle adjuster 13 is provided with an anti-rotation pin, which can fix the rotating shaft 14 after each rotation of a certain angle to simulate the grouting process under different crack inclination angles; the stabilizing plate 12 is welded on the rotating shaft 14 and connected to the lower bottom plate of the crack grouting box to ensure the stability of the crack grouting box during grouting and play a role in reinforcing the lower bottom plate.

[0050] like Figure 2 , 4As shown in FIG. 1 , the fracture box is divided into four small square areas (a), (b), (c), and (d) of the same size, wherein in area (a), a rock film of corresponding size is pasted on the bottom plate; in area (b), a prismatic rubber pad with a triangular side is pasted on the bottom plate, and an artificial rock film of corresponding size is pasted on the rubber pad to simulate the grouting conditions of different fracture openings; in area (c), a rock film of corresponding size is pasted on the bottom, and a number of cylindrical rubber pads with the same thickness and different diameters are pasted on the rock film, and the pads are randomly distributed in the area to simulate pore channels with a certain tortuosity; in area (d), a rock film of corresponding size is pasted on the bottom, and a number of cylindrical rubber pads with different diameters and gradually increasing thickness from the center to the edge are pasted on the rock film, and the pads are randomly distributed in the area to simulate pore channels with different widths and a certain tortuosity. The periphery of the top and bottom plates are sealed with gaskets having certain air permeability and fixed together with fastening bolts 11 to form a fracture grouting box body that simulates different fracture conditions at the same time;

[0051] like Figure 1 As shown, the grouting device includes an air compressor 2, a slurry storage barrel 1, a pneumatic agitator 6, a slurry delivery pipe 9, a grouting pipe 10 and an air guide pipe 5. Among them, the top of the slurry storage barrel 1 is connected to the air compressor 2 through the air guide pipe 5, and a slurry control valve 7 is provided at the bottom of the slurry storage barrel 1. The slurry control valve 7 is connected to the grouting pipe 10 on the fracture grouting box through the slurry delivery pipe 9. An electromagnetic flowmeter 8 is also installed at the slurry control valve 7 to measure the grouting amount and grouting speed during the grouting process. A pressure gauge 4 is also provided on the slurry storage barrel 1 and the air compressor 2; an air control valve 3 is provided on the air compressor 2, which is connected to the slurry storage barrel 1 through the air guide pipe 5; and the pneumatic agitator 6 is connected to the air compressor 2 through the air guide pipe 5.

[0052] The specific implementation steps are as follows:

[0053] 1) Assemble the experimental device

[0054] (1) Production of rubber pads. Select rubber pads with good pressure bearing capacity and not easy to deform, and cut them into prisms with right-angled triangle sides by machine. Process multiple rubber pads of different sizes, and the thickness is controlled between 0.1-0.5mm; similarly, the rubber pads are cut into cylinders of different thicknesses and diameters by machine, and multiple rubber pads of different sizes are processed, and the thickness is controlled between 0.1-0.7mm.

[0055] (2) Production of original rock film. The original rock samples are ground by a rock grinding machine, and the original rock particles of different particle sizes are screened and selected into different grades. Then, a layer of glue is applied on the transparent film, and the selected original rock particles (selected according to different roughness) are evenly spread on the film. After drying, the artificial original rock film is cut into corresponding sizes according to the size of the glass plate area and the different specifications of the rubber pad, and the artificial original rock film is pasted on the upper top plate, the lower bottom plate and the rubber pad to make artificial original rock cracks with different roughness and widths;

[0056] (3) Production of sealing strip 18. Select a sealing material with a certain air permeability, make it into a size of 980mm long, 20mm wide, and 0.1-1mm thick, and stick it around the fracture grouting box;

[0057] (4) Adjust the angle of the rotating shaft 14 according to the test design and fix the crack box on the stabilizing plate 12 of the rotating shaft 14;

[0058] (5) Connecting pipelines. Connect the sensor to the pressure measuring hole 16 on the top plate of the fracture box through a data line; connect the slurry control valve 7 at the bottom of the slurry storage barrel 1 to the grouting pipe 10 at the top of the fracture grouting box through a slurry delivery pipe 9, connect the slurry storage barrel 1 to the air compressor 2 through an air guide pipe 5, and connect the air compressor 2 to the pneumatic agitator 6 through an air guide pipe 5.

[0059] 2) Conduct grouting experiment

[0060] (1) Check the tightness of the equipment and pipelines, check whether the switches of each instrument can work normally, and ensure that the equipment can carry out the experiment normally;

[0061] (2) Prepare the slurry material according to the required proportion, pour it into the slurry storage barrel 1, open the air control valve 3 on the air compressor 2 to inject air into the slurry storage barrel 1, and at the same time turn on the pneumatic agitator 6 in the slurry storage barrel 1 to prevent slurry sedimentation. When the reading of the pressure gauge 4 on the slurry storage barrel 1 reaches the set value, open the slurry control valve 7 at the bottom of the slurry storage barrel 1 to start grouting;

[0062] (3) During the grouting process, turn on the sensor and high-speed camera to observe and record the diffusion form and range of the slurry in each area during the grouting process in real time;

[0063] (4) Before the slurry fills the fracture box, stop grouting and close the valve. After the pressure is eliminated, disassemble the fracture box and clean the box and grouting equipment.

[0064] 3) Repeat the experiment

[0065] According to the experimental plan, the sealing gasket strips 18 of different sizes and air permeabilities are replaced to change the grouting resistance; the rubber pads and artificial rock films of different specifications and sizes are replaced, and the fastening bolts 11 are adjusted to adjust the crack width to change the grouting conditions. The above operations are repeated under different grouting conditions to conduct grouting diffusion experiments under different grouting conditions.

[0066] 4) Experimental data analysis

[0067] After all grouting experiments are completed, the experimental data are sorted out, the monitoring data and images are statistically analyzed, and the slurry migration and diffusion laws are analyzed.

[0068] The present invention and its implementation methods are described above, and such description is not restrictive. The specific implementation methods are only part of the embodiments of the present invention, not all of the embodiments, and the actual structure is not limited thereto. In short, if ordinary technicians in the field are inspired by it, without departing from the purpose of the invention, they can design a structure and implementation method similar to the technical solution without creativity, which should fall within the protection scope of the present invention.

Claims

1. A visual grouting device for coal and rock fissures, It is characterized in that It comprises a visualized fracture grouting box and a grouting device; the fracture grouting box is composed of an upper top plate and a lower bottom plate, the inner sides of the two upper top plates and the lower bottom plates are respectively affixed with artificial original rock films, a grouting hole (17) and a plurality of pressure measuring holes (16) are arranged at the center of the upper top plate, the upper top plate and the lower bottom plate are divided into four identical square areas, a plurality of irregular cylindrical rubber pads of different sizes are arranged in different areas, and the pads are affixed to the original rock films; The grouting device comprises an air compressor (2), a slurry storage barrel (1), a pneumatic agitator (6), a slurry delivery pipe (9), a grouting pipe (10) and an air guide pipe (5); the top of the slurry storage barrel (1) is connected to the air compressor (2) via the air guide pipe (5), and a slurry control valve (7) is provided at the bottom of the slurry storage barrel (1); the slurry control valve (7) is connected to the grouting pipe (10) on the fracture grouting box via the slurry delivery pipe (9), and an electromagnetic flowmeter (8) is also installed at the slurry control valve (7) for measuring the grouting amount and grouting speed during the grouting process. A pressure gauge (4) is also provided on the slurry storage barrel (1) and the air compressor (2); the air compressor (2) is provided with an air control valve (3) connected to the slurry storage barrel (1) via the air guide pipe (5); and the pneumatic agitator (6) is connected to the air compressor (2) via the air guide pipe (5).

2. A coal rock fissure visualization grouting device according to claim 1, It is characterized in that The upper top plate and the lower bottom plate are made of transparent organic glass and are fixed together by fastening bolts (11) on all sides. The artificial original rock film is respectively attached to the inner side of the upper top plate and the lower bottom plate.

3. A coal rock fissure visualization grouting device according to claim 2, It is characterized in that The peripheries of the upper top plate and the lower bottom plate are sealed by gasket strips with certain air permeability.

4. A coal-rock fissure visualization grouting device according to claim 1, It is characterized in that It also includes a rotatable and adjustable bracket (15), which includes a rotating shaft (14), an angle adjuster (13) and a stabilizing plate (12); The angle adjuster (13) is provided with an anti-rotation pin, which can fix the rotating shaft (14) after rotating a certain angle, so as to simulate the grouting test under different crack inclination angles; the stabilizing plate (12) is connected to the bottom plate of the crack grouting box body, so as to ensure the stability of the crack grouting box body during grouting, and also plays a role in reinforcing the bottom plate.

5. A coal rock fissure visualization grouting device according to claim 1, It is characterized in that It also includes a data acquisition system, including a sensor, a high-speed camera, and a computer; the sensor is connected to a pressure measuring hole (16) on the top plate of the fracture grouting box; the high-speed camera is used to shoot and record the entire grouting process; The computer is used to collect and organize analytical data.

6. A test method for a coal-rock fissure visualization grouting device, It is characterized in that The following steps are involved: 1) A layer of artificial original rock film is attached to the inner side of the upper top plate and the lower bottom plate respectively, and the lower bottom plate is divided into four square areas of the same size. Among them, one area was not processed; In one area, a prismatic rubber pad with a triangular side is attached to the bottom plate, and an artificial original rock film of corresponding size is attached to the rubber pad to simulate the grouting conditions of different fracture openings; A number of cylindrical rubber pads with the same thickness and different diameters are attached to the bottom of an area, and the pads are randomly distributed in the area to simulate a porous channel with a certain degree of tortuosity; A number of cylindrical rubber pads with different diameters and increasing thickness from the center to the edge are attached to the bottom of an area. The pads are randomly distributed in the area to simulate pore channels with different widths and a certain degree of tortuosity. The top and bottom plates are sealed with gaskets with a certain degree of air permeability and fixed together with bolts to form a crack visualization grouting box; 2) The fissure grouting box is supported by a rotating bracket (15), the bottom plate of the grouting box is fixed on the stabilizing plate (12) on the top of the bracket (15), and the grouting diffusion test with different fissure inclination angles is simulated by adjusting the rotation angle of the rotating shaft of the bracket (15); 3) A plurality of pressure measuring holes (16) are provided on the top plate of the grouting box body, which are connected to sensors, and the pressure parameters of the grouting box body are recorded in real time through the sensors; 4) Turn on the sensor and high-speed camera, record the sensor data and observe and record the diffusion form and range of the slurry in each area during the grouting process; Observe the slurry diffusion state in the fracture grouting box, stop grouting after the slurry has filled about 3 / 4 of the fracture grouting box, and close the slurry control valve (7) and the air control valve (3); After the pressure is eliminated, disassemble and clean the fracture grouting box and grouting equipment; Replace the original rock film with different particle sizes, replace the sealing pads (18) with different thicknesses and air permeabilities, replace the rubber pads with different sizes, and adjust the simulated crack width by adjusting the bolts. Repeat the above steps, collect the test data under different grouting conditions, and complete all the grouting tests in accordance with the design.

Images