Three-dimensional large-size dynamic water grouting simulation diffusion test device and test method

Abstract

The invention discloses a three-dimensional large-size dynamic water grouting simulation diffusion test device and a test method, and belongs to the technical field of dynamic water grouting engineering. The test device comprises a variable-pressure water supply device, a grouting device, a simulation grouting pipeline and a monitoring system. The simulated grouting pipeline comprises a water inlet pipeline, a grouting pipeline and a drainage pipeline, and the grouting pipeline can be split into an upper part and a lower part, so that the grouting plugging body can be conveniently taken out for subsequent research. The monitoring system comprises a pressure sensor, an ultrasonic flowmeter, a high-speed camera, a computer, a distributed optical fiber and an optical fiber decoder. According to the testing device and the testing method, the plugging performance of the slurry in the flowing water karst pipeline under the complex geological condition can be measured, the optimal construction parameters are selected according to site conditions, and research on flowing water grouting slurry rheological characteristics and a diffusion theoretical model is achieved through the optical fiber monitoring technology.

Description

Technical Field

[0001] The invention relates to the technical field of dynamic water grouting engineering, and in particular to a three-dimensional large-scale dynamic water grouting simulation diffusion test device and a test method. Background Art

[0002] In karst areas, due to the development of underground caves, landfill leachate can easily pollute water bodies on a large scale through underground caves, which is a serious hazard. Therefore, it is often necessary to grout and seal the underground dynamic water karst channels during construction. However, in actual grouting projects, the underground rock geological conditions are complex, and underground grouting projects are hidden. The diffusion range and anti-seepage effect of the slurry can only be judged by the feedback of the grouting pressure during the construction process or the results of local detection after grouting, and there is a lack of theoretical guidance. Therefore, people observe the diffusion process of the slurry under different influencing factors through model box tests, and theoretically establish a grouting diffusion model to predict grouting parameters or judge the grouting effect through known engineering geological conditions.

[0003] At present, according to the different grouting objects, the existing grouting theory can be divided into fracture grouting, porous medium compaction grouting and water pipe grouting. In the existing technology:

[0004] Chinese patent CN 1908371 A provides a grouting diffusion test device with a variable inclination angle of the cracks in the device, including a fluid generating device, a slurry diffusion test device and a waste liquid recovery device. The fluid generating device generates grouting slurry for testing and provides test materials to the grouting diffusion device according to the designed grouting pressure and grouting volume; the slurry diffusion device includes a cross-crack platform and a crack surface inclination angle and width control device. The grouting medium is a crack, and the slurry can be simulated on the slurry diffusion device according to different diffusion modes; the recovery device is used to complete the recovery of the test slurry.

[0005] Chinese patent CN 114636657A discloses a visualized laboratory simulation grouting device, including an air source pressurizing device, a grouting penetration device and a data acquisition system, wherein the grout storage tube and the grouting pipe are both made of transparent materials, the grouting medium is a porous medium, the grouting penetration process is visualized, and the data acquisition system includes two pore water pressure sensors electrically connected to the data processing system respectively, and the installation positions of the pore water pressure sensors are respectively located at the inlet and outlet positions of the grouting pipe.

[0006] Chinese patent CN 115524263 A discloses a three-dimensional pressurized water grouting device, including a grouting device, a simulated slurry diffusion device, a loading device and a monitoring device. The simulated slurry diffusion device is composed of two upper and lower top plates and surrounding edge plates. The upper and lower top plates are loaded with the loading device to simulate pressurized water conditions, and the injected rock and soil medium is filled between the upper and lower top plates. The grouting medium studied belongs to a porous material medium. The monitoring device includes a soil pressure monitoring device and a permeability pressure monitoring device.

[0007] Chinese patent CN 115343416B discloses a post-coal seam dynamic water grouting simulation device and a testing method, including a dynamic water device, a grouting device, a model component, a loading system and a detection system. The dynamic water system is a pressure head that is directly injected into a square box by a small round tube. The square box is a medium model component, which is composed of a simulated coal seam, a goaf, and a crack. The grouting device injects slurry into the box from a round tube by an air compressor. The loading device acts on the top surface of the square box to apply a vertical load. The monitoring equipment includes pressure monitoring and flow rate monitoring.

[0008] Chinese patent CN 112985757 B discloses a dynamic water grouting test device for coastal karst areas, which includes dynamic water equipment that can control the mixing ratio of fresh water and seawater, a grouting pump, an ultrasonic pipeline flow meter, and an ion concentration detector and other monitoring equipment. The device is equipped with an additional grouting valve between the pipeline and the grouting body to simulate tidal fluctuation conditions and dry-wet cycle conditions.

[0009] Comprehensive analysis of the test equipment of the above units shows that there are still the following deficiencies:

[0010] 1) There is insufficient research on model devices for dynamic water grouting theory;

[0011] 2) Only the diffusion morphology of the slurry and the pressure-flow feedback during the slurry diffusion process are studied, while the study of the rheological properties of the slurry is ignored. It is assumed that the rheological law of the slurry conforms to the Bingham fluid or other existing non-Newtonian fluid theoretical models. However, underground water dynamic conditions or other conditions will affect the rheological law of the slurry, so there is a lack of in-depth research on the slurry rheological model;

[0012] 3) Point sensors can only monitor fixed points and cannot obtain continuous data in space;

[0013] 4) The conventional photography method has low accuracy in monitoring the slurry diffusion morphology, making it difficult to accurately study the morphological changes during the slurry diffusion process and to analyze the influence mechanism of different influencing factors on the slurry diffusion process;

[0014] 5) The dynamic water grouting test device is small in size and cannot simulate the slurry loss problem caused by the grouting process in large-sized channels;

[0015] 6) Ignore whether the water flow is in a laminar or turbulent state under dynamic water conditions, and ignore the influence of the distance between the simulated water inlet, simulated grouting area and the water outlet on the simulation effect.

[0016] Therefore, a three-dimensional large-scale dynamic water grouting simulation diffusion test device and test method are proposed to address the above problems. Summary of the invention

[0017] The technical problem to be solved by the present invention is the deficiency existing in the above-mentioned prior art. Specifically, the present invention provides a large-scale channel dynamic water grouting test device and test method in karst areas. The method can measure the rheological property change law, diffusion law and plugging performance of the slurry in the large-scale dynamic water karst channel, and then guide the project to select the optimal grouting parameters and improve the grouting efficiency.

[0018] In order to achieve the above-mentioned object, the present invention provides a three-dimensional large-scale dynamic water grouting simulation diffusion test device, which includes a variable pressure water supply device, a liquid accumulation device, a grouting device, a simulated grouting pipeline and a monitoring system:

[0019] The grouting equipment comprises a slurry storage tank, a grouting pump and a grouting pipe, wherein the inlet of the grouting pump is communicated with the slurry storage tank, the outlet is communicated with the inlet of the grouting pipe, and a pressure gauge is installed at the outlet of the grouting pump;

[0020] The simulated grouting pipeline is a horizontally placed circular pipeline, which is composed of three water inlet pipelines with the same inner diameter, a grouting pipeline and a drainage pipeline connected in sequence. The water inlet pipeline is connected to the variable pressure water supply equipment through a section of water pipe, and the drainage pipeline is connected to the liquid accumulation equipment through a section of water pipe. The grouting pipeline is provided with a through hole adapted to the grouting pipe, and is connected to the outlet of the grouting pipe through the through hole; a rectifier plate for stabilizing flow is installed in the water inlet pipeline;

[0021] The monitoring system includes a pressure sensor, an ultrasonic flow meter, a high-speed camera, a computer, an optical fiber and an optical fiber decoder;

[0022] There are multiple pressure sensors, which are evenly arranged on the inner wall of the simulated grouting pipe; the ultrasonic flow meter is installed on the outer wall of the drainage pipe; there are at least two high-speed cameras, which are symmetrically installed on both sides of the grouting pipe, that is, the shooting object is the grouting pipe; there are multiple optical fibers, which are evenly distributed along the axial direction of the pipe on the inner wall of the simulated grouting pipe for monitoring temperature changes; specifically, multiple distributed optical fibers enter the simulated grouting pipe from the pipe wall on the right side of the rectifier plate, and extend rightward along the inner wall of the simulated grouting pipe to the tail of the simulated grouting pipe.

[0023] Preferably, the water inlet pipe, grouting pipe and drainage pipe are all made of transparent acrylic material with an inner diameter of ≥30 cm.

[0024] Preferably, the water inlet pipe, grouting pipe and drainage pipe are connected via a flange interface.

[0025] Preferably, the grouting pipe is composed of two identical upper and lower semicircular pipes. Specifically, a pipe handle extending outward is provided at the two openings of each semicircular pipe, and a plurality of screw holes are evenly arranged on the pipe handle along the axial direction of the semicircular pipe. During installation, the upper and lower semicircular pipes are aligned, and the upper and lower semicircular pipes are fixedly connected to the screw holes on the pipe handle by bolts to form a grouting pipe; a waterproof gasket is placed at the contact point of the two pipe handles.

[0026] Preferably, the number of the optical fibers is at least 6, and the optical fibers are connected to an optical fiber decoder. The pressure sensor, ultrasonic flow meter, high-speed camera and optical fiber decoder are connected to a computer respectively.

[0027] The present invention also provides a three-dimensional large-scale dynamic water grouting simulation diffusion test method, comprising the following steps:

[0028] Step 1, setting the pressure head of the variable pressure water supply equipment and supplying water so that the water flow fills the simulated grouting pipeline and flows stably; placing the prepared slurry in the slurry storage tank, pumping the slurry into the grouting pump, observing the reading of the pressure gauge and adjusting the grouting pressure to the set value, and then injecting the slurry into the simulated grouting pipeline through the grouting pipe;

[0029] Step 2: After grouting begins, monitor using the following methods:

[0030] The slurry diffusion process is recorded by a high-speed camera, the collected image information is processed by a computer, and the slurry phase and the water phase are identified according to the time step; the diffusion path and diffusion morphology of the slurry are recorded, and the diffusion path and diffusion morphology of the slurry are drawn into three-dimensional graphics and three-dimensional dynamic animation in real time by a high-speed camera and processing software in the computer and stored;

[0031] Use pressure sensors to monitor the grouting process and monitor the grout hardening and water blocking process to simulate the inner wall pressure of the grouting pipe and store data;

[0032] Use ultrasonic flowmeter to record the flow rate change of drainage pipe during grouting process and record data, analyze the water blocking effect of slurry and the water blocking effect of slurry during hardening process;

[0033] Use optical fiber to monitor the temperature change during the slurry hardening process and use optical fiber decoder to decode the signal. Use computer to monitor the hydration heat release during the slurry hardening process. According to the hydration heat release, the hardening law of the slurry is judged, and then the change law of the rheological properties of the slurry during the dynamic water grouting process is monitored.

[0034] Step 3, when the ultrasonic flow meter records that the flow rate of the drainage pipe is 0 or the flow rate change reaches stability, stop grouting;

[0035] Step 4, dismantling the flange connection ports of the water inlet pipe, the grouting pipe and the drainage pipe;

[0036] Step 5, after the slurry is initially solidified, the grouting pipe is disassembled into two parts, the upper and lower parts;

[0037] The grouting plugging body in the grouting pipeline was taken out for CT scanning to study the internal pore characteristics during the formation of the grouting plugging body under dynamic water grouting and to determine the grouting permeability and water plugging effect.

[0038] Preferably, the diffusion path and morphology include the diffusion speed, diffusion radius and diffusion distance of the slurry in different directions.

[0039] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0040] 1) The three-dimensional large-scale dynamic water grouting simulation diffusion test device provided by the present invention can simulate the flow, diffusion and plugging effects of slurry in karst pipelines under grouting conditions of different dynamic water pressures, different grouting pressures, and different slurry types.

[0041] 2) The three-dimensional large-scale dynamic water grouting simulation diffusion test device provided by the present invention uses a fiber optic monitoring method to obtain continuous data on temperature changes in space, determine the hydration heat release during the slurry setting process, and then measure the viscosity changes and rheological property changes during the slurry setting process.

[0042] 3) The three-dimensional large-scale dynamic water grouting simulation diffusion test device provided by the present invention uses high-speed photography equipment to accurately obtain the diffusion path and diffusion form of the slurry during the dynamic water grouting process, and form a three-dimensional animation, and then quantitatively analyze the diffusion parameters such as the diffusion speed, diffusion radius and diffusion distance of the slurry in different directions.

[0043] 4) The three-dimensional large-scale dynamic water grouting simulation diffusion test device provided by the present invention simulates a grouting pipe with a diameter greater than or equal to 30 cm, and can simulate the situation where the slurry is washed away during the grouting process of a large-scale channel.

[0044] 5) The three-dimensional large-scale dynamic water grouting simulation diffusion test device provided by the present invention can simulate the grouting pipeline to be disassembled and the grouting plugging body can be taken out for further research such as CT scanning to determine the anti-seepage performance and plugging effect of the grouting plugging. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 A schematic structural diagram of a three-dimensional large-scale dynamic water grouting simulation diffusion test device provided by the present invention;

[0046] Figure 2 A schematic diagram of a grouting pipeline cross section and an optical fiber layout method in a three-dimensional large-scale dynamic water grouting simulation diffusion test device provided by the present invention;

[0047] Figure 3 A schematic flow chart of a three-dimensional large-scale dynamic water grouting simulation diffusion test method provided by the present invention;

[0048] In the figure, 1. transformer water supply equipment; 2. water inlet pipe; 3. grouting pipe; 4. drainage pipe; 5. rectifier plate; 6. flange interface; 7. slurry storage tank; 8. grouting pump; 9. pressure gauge; 10. grouting pipe; 11. liquid collecting equipment; 12. pressure sensor; 13. ultrasonic flow meter; 14. high-speed camera; 15. computer; 16. optical fiber; 17. optical fiber decoder; 18. bolt; 19. pipe handle; 20. semicircular pipe. DETAILED DESCRIPTION

[0049] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0050] Figure 1 A schematic diagram of the structure of a three-dimensional large-scale dynamic water grouting simulation diffusion test device provided by the present invention. Figure 2 This is a schematic diagram of the cross section of the grouting pipeline and the optical fiber layout method in a three-dimensional large-scale dynamic water grouting simulation diffusion test device provided by the present invention. Figure 1 , Figure 2 It can be seen that the test device includes a variable pressure water supply device 1, a liquid accumulation device 11, a grouting device, a simulated grouting pipeline and a monitoring system.

[0051] The grouting equipment includes a slurry storage tank 7, a grouting pump 8 and a grouting pipe 10, wherein the inlet of the grouting pump 8 is communicated with the slurry storage tank 7, the outlet is communicated with the inlet of the grouting pipe 10, and a pressure gauge 9 is installed at the outlet of the grouting pump 8.

[0052] In this embodiment, the grouting pump 8 adopts a single-screw pump. The specific parameters of the equipment are shown in Table 1. The grouting pump 8 is connected to the slurry storage tank 7. The configured slurry medium is extracted from the slurry storage tank 7 and transported to the simulated grouting pipeline through the grouting pipe 10. At the same time, the reading of the grouting pump pressure gauge 9 is observed to adjust the grouting pressure to the set working condition.

[0053] Table 1 Detailed parameters of grouting pump 8 in Example 1

[0054] model G Series Single Screw Pump Flow range <![CDATA[2~300m 3 / h]]> Lift range 60～120m caliber 25~150mm Work Pressure ≤1.6MPa Temperature of the transported medium ≤80℃

[0055] The simulated grouting pipe is a horizontally placed circular pipe, which is composed of three water inlet pipes 2, a grouting pipe 3 and a drainage pipe 4 with the same inner diameter, which are connected in sequence from left to right. The water inlet pipe 2 is connected to the variable pressure water supply equipment 1 through a section of water pipe, and the drainage pipe 4 is connected to the liquid accumulation equipment 11 through a section of water pipe. The grouting pipe 3 is provided with a through hole that is compatible with the grouting pipe 10, and is connected to the outlet of the grouting pipe 10 through the through hole; a rectifier plate 5 for stabilizing the flow is installed in the water inlet pipe 2.

[0056] The monitoring system includes a pressure sensor 12 , an ultrasonic flow meter 13 , a high-speed camera 14 , a computer 15 , an optical fiber 16 and an optical fiber decoder 17 .

[0057] There are multiple pressure sensors 12, and the multiple pressure sensors 12 are evenly arranged on the inner wall of the simulated grouting pipe; the ultrasonic flow meter 13 is installed on the outer wall of the drainage pipe 4; there are at least two high-speed cameras 14, which are symmetrically installed on both sides of the grouting pipe 3, that is, the shooting object is the grouting pipe 3; there are multiple optical fibers 16, and the multiple optical fibers 16 are evenly distributed along the axial direction of the pipe on the inner wall of the simulated grouting pipe for monitoring temperature changes. Specifically, the multiple distributed optical fibers 16 enter the simulated grouting pipe from the pipe wall on the right side of the rectifier plate 5, and extend to the right along the inner wall of the simulated grouting pipe to the tail of the simulated grouting pipe.

[0058] In this embodiment, the water inlet pipe 2, the grouting pipe 3 and the drainage pipe 4 are all made of transparent acrylic material, with an inner diameter of ≥30 cm.

[0059] In this embodiment, the water inlet pipe 2 , the grouting pipe 3 and the drainage pipe 4 are connected via a flange interface 6 .

[0060] In this embodiment, the grouting pipe 3 is composed of two identical upper and lower semicircular pipes 20. Specifically, a pipe handle 19 extending outward is provided at the two openings of each semicircular pipe 20, and a plurality of screw holes are evenly arranged on the pipe handle 19 along the axial direction of the semicircular pipe 20. During installation, the upper and lower semicircular pipes 20 are aligned, and the upper and lower semicircular pipes 20 are fixedly connected to form the grouting pipe 3 by connecting the bolts 18 with the screw holes on the pipe handle 19; a waterproof gasket is placed at the contact point of the two pipe handles 19.

[0061] In this embodiment, there are at least six optical fibers 16 , and the optical fibers 16 are connected to an optical fiber decoder 17 . The pressure sensor 12 , the ultrasonic flow meter 13 , the high-speed camera 14 and the optical fiber decoder 17 are connected to a computer 15 , respectively.

[0062] In this embodiment, there are six optical fibers 16 .

[0063] In this embodiment, the pressure sensor 12 is a thin film pressure sensor, which is arranged on the inner wall of the simulated grouting pipe to monitor the inner wall pressure. Specifically, four pressure sensors 12 are evenly distributed in the grouting pipe 3, and one pressure sensor is arranged at the tail of the water inlet pipe 2.

[0064] The present invention also provides a three-dimensional large-scale dynamic water grouting simulation diffusion test method, comprising the following steps:

[0065] Step 1, setting the pressure head of the variable pressure water supply equipment 1 and supplying water so that the water flow fills the simulated grouting pipeline and flows stably; placing the prepared slurry in the slurry storage tank 7, pumping the slurry into the grouting pump 8, observing the reading of the pressure gauge 9 and adjusting the grouting pressure to the set value, and then injecting the slurry into the simulated grouting pipeline through the grouting pipe 10;

[0066] Step 2: After grouting begins, monitor using the following methods:

[0067] The slurry diffusion process is recorded by a high-speed camera 14, and the collected image information is processed by a computer 15, and the slurry phase and the water phase are identified according to the time step; the diffusion path and diffusion morphology of the slurry are recorded, and the diffusion path and diffusion morphology of the slurry are drawn into a three-dimensional graph and a three-dimensional dynamic animation in real time by using the high-speed camera 14 and the processing software in the computer 15 and stored;

[0068] Using the pressure sensor 12 to monitor the grouting process and the slurry hardening and water blocking process to simulate the inner wall pressure of the grouting pipe and store the data;

[0069] Using an ultrasonic flowmeter 13 to record the flow rate change of the drainage pipe 4 during the grouting process and record the data, and analyze the water blocking effect of the slurry and the water blocking effect during the slurry setting process;

[0070] The temperature change during the slurry setting process is monitored by the optical fiber 16 and the signal is decoded by the optical fiber decoder 17. The hydration heat release during the slurry setting process is monitored by the computer 15. The setting law of the slurry is determined according to the hydration heat release, and the change law of the rheological properties of the slurry during the dynamic water grouting process is monitored.

[0071] Step 3, when the ultrasonic flowmeter 13 records that the flow rate of the drainage pipe 4 is 0 or the flow rate change reaches stability, stop grouting;

[0072] Step 4, dismantling the flange connection ports of the water inlet pipe 2, the grouting pipe 3 and the drainage pipe 4;

[0073] Step 5, after the slurry is initially solidified, the grouting pipe 3 is disassembled into two parts, the upper and lower parts;

[0074] The grouting plugging body in the grouting pipe 3 is taken out for CT scanning to study the internal pore characteristics during the formation of the grouting plugging body under dynamic water grouting and to determine the grouting permeability and water plugging effect.

[0075] In this embodiment, the diffusion path and morphology include the diffusion speed, diffusion radius and diffusion distance of the slurry in different directions.

[0076] As can be seen from the above, the test device provided by the present invention can be used to conduct multiple tests. By continuously adjusting the dynamic water pressure, grouting pressure, and slurry type, the plugging and anti-seepage effect of grouting under different working conditions can be judged according to the monitoring data results to guide the selection of grouting parameters for actual projects. Furthermore, the temperature data obtained by optical fiber monitoring in this embodiment can analyze the change law of slurry viscosity and rheological properties of different slurry types under different dynamic water pressures during the grouting process, thereby improving the slurry diffusion theoretical model of dynamic water grouting.

[0077] The three-dimensional large-scale dynamic water grouting simulation diffusion test device provided by the present invention can realize the research on the plugging effect of different working condition combinations and different slurry types in large-scale karst dynamic water pipelines and the rheological characteristics and diffusion theoretical model of slurry.

Claims

1. A three-dimensional large-scale dynamic water grouting simulation diffusion test device, characterized in that: The test device comprises a variable pressure water supply device (1), a liquid accumulation device (11), a grouting device, a simulated grouting pipeline and a monitoring system: The grouting equipment comprises a slurry storage tank (7), a grouting pump (8) and a grouting pipe (10), wherein the inlet of the grouting pump (8) is communicated with the slurry storage tank (7), the outlet is communicated with the inlet of the grouting pipe (10), and a pressure gauge (9) is installed at the outlet of the grouting pump (8); The simulated grouting pipeline is a horizontally placed circular pipeline, which is composed of three water inlet pipelines (2) with the same inner diameter, a grouting pipeline (3) and a drainage pipeline (4) connected in sequence, wherein the water inlet pipeline (2) is connected to the variable pressure water supply equipment (1) through a section of water pipe, and the drainage pipeline (4) is connected to the liquid accumulation equipment (11) through a section of water pipe. The grouting pipeline (3) is provided with a through hole that matches the grouting pipe (10) and is connected to the outlet of the grouting pipe (10) through the through hole; a rectifying plate (5) for stabilizing flow is installed in the water inlet pipeline (2); The monitoring system comprises a pressure sensor (12), an ultrasonic flow meter (13), a high-speed camera (14), a computer (15), an optical fiber (16) and an optical fiber decoder (17); The pressure sensors (12) are multiple, and the multiple pressure sensors (12) are evenly arranged on the inner wall of the simulated grouting pipe; the ultrasonic flow meter (13) is installed on the outer wall of the drainage pipe (4); the high-speed cameras (14) are at least two, and are symmetrically installed on both sides of the grouting pipe (3), that is, the shooting object is the grouting pipe (3); the optical fibers (16) are multiple, and the multiple optical fibers (16) are evenly distributed along the axial direction of the pipe on the inner wall of the simulated grouting pipe for monitoring temperature changes; specifically, the multiple distributed optical fibers (16) enter the simulated grouting pipe from the pipe wall on the right side of the rectifier plate (5), and are extended to the right along the inner wall of the simulated grouting pipe to the tail of the simulated grouting pipe.

2. A three-dimensional large-scale dynamic water grouting simulation diffusion test device according to claim 1, characterized in that: The water inlet pipe (2), the grouting pipe (3) and the drainage pipe (4) are all made of transparent acrylic material, with an inner diameter of ≥30 cm.

3. A three-dimensional large-scale dynamic water grouting simulation diffusion test device according to claim 1, characterized in that: The water inlet pipe (2), the grouting pipe (3) and the drainage pipe (4) are connected via a flange interface (6).

4. A three-dimensional large-scale dynamic water grouting simulation diffusion test device according to claim 1, characterized in that: The grouting pipe (3) is composed of two identical upper and lower semicircular pipes (20). Specifically, a pipe handle (19) extending outward is provided at two openings of each semicircular pipe (20), and a plurality of screw holes are evenly provided on the pipe handle (19) along the axial direction of the semicircular pipe (20). During installation, the upper and lower semicircular pipes (20) are aligned, and the upper and lower semicircular pipes (20) are fixedly connected to each other through bolts (18) and the screw holes on the pipe handle (19) to form the grouting pipe (3); a waterproof gasket is placed at the contact point of the two pipe handles (19).

5. A three-dimensional large-scale dynamic water grouting simulation diffusion test device according to claim 1, characterized in that: There are at least six optical fibers (16), and the optical fibers (16) are connected to an optical fiber decoder (17). The pressure sensor (12), ultrasonic flow meter (13), high-speed camera (14) and optical fiber decoder (17) are respectively connected to a computer (15).

6. A three-dimensional large-scale dynamic water grouting simulation diffusion test method, using a three-dimensional large-scale dynamic water grouting simulation diffusion test device as described in any one of claims 1 to 5, characterized in that: The following steps are involved: Step 1, setting the pressure head of the variable pressure water supply equipment (1) and supplying water so that the water flow fills the simulated grouting pipeline and flows stably; placing the prepared slurry in the slurry storage tank (7), pumping the slurry into the grouting pump (8), observing the reading of the pressure gauge (9) and adjusting the grouting pressure to the set value, and then injecting the slurry into the simulated grouting pipeline through the grouting pipe (10); Step 2: After grouting begins, monitor using the following methods: The slurry diffusion process is recorded by a high-speed camera (14), the collected image information is processed by a computer (15), and the slurry phase and the water phase are identified according to the time step; the diffusion path and diffusion morphology of the slurry are recorded, and the diffusion path and diffusion morphology of the slurry are drawn into a three-dimensional graph and a three-dimensional dynamic animation in real time by the high-speed camera (14) and the processing software in the computer (15) and stored; Using a pressure sensor (12) to monitor the grouting process and the grout hardening and water blocking process to simulate the inner wall pressure of the grouting pipe and store the data; Using an ultrasonic flow meter (13) to record the change in water flow through the drainage pipe (4) during the grouting process and record the data, and analyze the water blocking effect of the slurry and the water blocking effect during the slurry solidification process; The temperature change during the slurry hardening process is monitored by an optical fiber (16) and the signal is decoded by an optical fiber decoder (17), and the hydration heat release during the slurry hardening process is monitored by a computer (15), and the hardening law of the slurry is determined according to the hydration heat release, so as to monitor the change law of the slurry rheological properties during the dynamic water grouting process; Step 3, when the ultrasonic flow meter (13) records that the flow rate of the drainage pipe (4) is 0 or the flow rate change reaches stability, stop grouting; Step 4, disassembling the flange connection ports of the water inlet pipe (2), the grouting pipe (3) and the drainage pipe (4); Step 5, after the slurry is initially solidified, the grouting pipe (3) is disassembled into two parts, the upper and lower parts; The grouting plugging body in the grouting pipe (3) is taken out for CT scanning to study the internal pore characteristics during the formation of the grouting plugging body under dynamic water grouting, and to determine the grouting permeability and water blocking effect.

7. A three-dimensional large-scale dynamic water grouting simulation diffusion test method according to claim 6, characterized in that: The diffusion path and morphology include the diffusion speed, diffusion radius and diffusion distance of the slurry in different directions.

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