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

Abstract

The application discloses a three-dimensional large-size dynamic water grouting simulation diffusion test device and 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 simulated grouting pipeline and a monitoring system. The simulated grouting pipeline comprises a water inlet pipeline, a grouting pipeline and a water outlet pipeline. The grouting pipeline can be divided into two parts, i.e., an upper part and a lower part, so as to facilitate taking out of the grouting plugging body after unfolding and 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. The test device and test method provided by the application can be used for measuring the plugging performance of slurry in a dynamic water karst pipeline under complex geological conditions, selecting the best construction parameters according to site conditions, and realizing the research on the rheological properties of dynamic water grouting slurry and the diffusion theoretical model through the optical fiber monitoring technology.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of dynamic water grouting engineering, and particularly relates to a three-dimensional large-size dynamic water grouting simulation diffusion test device and a test method. BACKGROUND

[0002] In karst areas, due to the development of underground caves, landfill leachate is easy to pollute water bodies on a large scale through underground caves, which is very harmful. Therefore, during construction, it is often necessary to grout and block the underground karst passages. However, in actual grouting engineering, the geological conditions of underground rock mass are complex, and underground grouting engineering is hidden. The diffusion range and impermeability effect of the slurry can only be judged by the feedback of the grouting pressure during the construction process or the results of the 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 establish a grouting diffusion model in theory to realize the prediction of grouting parameters or the judgment of grouting effect through known engineering geological conditions.

[0003] At present, according to different grouting objects, the existing grouting theory can be divided into fissure grouting, porous medium compaction grouting and dynamic water pipeline grouting. In the prior art:

[0004] Chinese patent CN 1908371 A provides a grouting diffusion test device, and the fissure angle in the device is variable, which includes 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 fissure platform and a fissure surface angle and width control device. The grouting medium is a fissure, and the slurry can be simulated according to different diffusion modes on the slurry diffusion device. The recovery device is used for recovering the test slurry.

[0005] Chinese patent CN 114636657A discloses a visual laboratory simulation grouting device, which includes a gas source pressurizing device, a grouting penetration device and a data acquisition system. The slurry storage cylinder 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 which are electrically connected to a data processing system. 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 pressure-bearing dynamic water grouting device, which comprises a grouting device, a simulated grout diffusion device, a loading device and a monitoring device. The simulated grout diffusion device is composed of two top plates and four peripheral edge plates. The loading device is used to load the upper and lower top plates to simulate the pressure-bearing water condition. The grouting medium studied belongs to porous material medium. The monitoring device includes soil pressure monitoring equipment and permeation pressure monitoring equipment.

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

[0008] Chinese patent CN 112985757 B discloses a dynamic water grouting test device for coastal karst areas. The device includes a controllable dynamic water equipment with mixed ratio of fresh water and seawater, a grouting pump, an ultrasonic pipeline flowmeter and an ion concentration detector. The device additionally sets a grouting valve between the pipeline and the grouting body to simulate the tidal fluctuation and dry-wet cycle conditions.

[0009] Through comprehensive analysis of the test devices of the above units, the following deficiencies still exist:

[0010] 1) The model device research on dynamic water grouting theory is insufficient;

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

[0012] 3) The point sensor can only monitor fixed points and cannot obtain continuous data in space;

[0013] 4) The conventional photography method for monitoring grout diffusion form has low precision, and it is difficult to accurately study the form change in the grout diffusion process, and further analyze the influence mechanism of different influence factors on the grout diffusion process;

[0014] 5) The dynamic water grouting test device has small size, and cannot simulate the grout loss problem in the grouting process in large-size channels;

[0015] 6) Ignoring the water flow in the laminar or turbulent state under the dynamic water condition, ignoring the influence of the distance between the simulated water inlet, the simulated grouting area and the water outlet on the simulation effect.

[0016] Therefore, a three-dimensional large-size dynamic water grouting simulation diffusion test device and test method are provided to solve the above problems. SUMMARY

[0017] The technical problem to be solved by the present application is the deficiency in the prior art described above. Specifically, the present disclosure provides a large-size channel dynamic water grouting test device and test method in karst areas. The method can determine the rheological property change law, diffusion law and plugging performance of the slurry in the large-size dynamic water karst channel, and further guide the selection of optimal grouting parameters in engineering and improve the grouting efficiency.

[0018] To achieve the above purpose, the present application provides a three-dimensional large-size dynamic water grouting simulation diffusion test device, which comprises a variable pressure water supply device, a liquid accumulation device, a grouting device, a simulated grouting pipeline and a monitoring system.

[0019] The grouting device 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 sequentially connected by three water inlet pipelines, a grouting pipeline and a drainage pipeline with the same inner diameter. The water inlet pipeline is communicated with the variable pressure water supply device through a section of water pipe. The drainage pipeline is communicated with the liquid accumulation device through a section of water pipe. The grouting pipeline is provided with a through hole matched with the grouting pipe, and the outlet of the grouting pipe is communicated with the through hole. A fairing plate for flow stabilization is installed in the water inlet pipeline.

[0021] The monitoring system comprises a pressure sensor, an ultrasonic flowmeter, a high-speed camera, a computer, an optical fiber and an optical fiber decoder.

[0022] The pressure sensor is a plurality of pressure sensors, which are uniformly arranged on the inner wall of the simulated grouting pipeline. The ultrasonic flowmeter is installed on the outer wall of the drainage pipeline. The high-speed camera is at least 2, which are symmetrically installed on both sides of the grouting pipeline, i.e. the shooting object is the grouting pipeline. The optical fiber is a plurality of optical fibers, which are uniformly distributed along the pipe axis and arranged on the inner wall of the simulated grouting pipeline for monitoring temperature changes. Specifically, the plurality of distributed optical fibers enter the simulated grouting pipeline from the right side of the fairing plate, and extend along the inner wall of the simulated grouting pipeline to the tail of the simulated grouting pipeline.

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

[0024] Preferably, the water inlet pipe, the grouting pipe and the drainage pipe are connected through flange interfaces.

[0025] Preferably, the grouting pipe is composed of two identical semicircular pipes arranged in an up-down manner, and each semicircular pipe is provided with pipe handles extending outward at two openings thereof, and a plurality of screw holes are uniformly arranged on the pipe handles in the axial direction of the semicircular pipes; during installation, the two semicircular pipes are aligned, and the two semicircular pipes are fixedly connected to form the grouting pipe through the connection of bolts and the screw holes on the pipe handles; a waterproof gasket is arranged at the contact position of the two pipe handles.

[0026] Preferably, the optical fibers are at least 6, the optical fibers are connected with an optical fiber decoder, and the pressure sensor, the ultrasonic flowmeter, the high-speed camera and the optical fiber decoder are respectively connected with a computer.

[0027] The application further provides a three-dimensional large-size dynamic water grouting simulation diffusion test method, which comprises the following steps:

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

[0029] Step 2: after starting grouting, the following methods are used for monitoring:

[0030] The high-speed camera is used to record the slurry diffusion process, the collected picture information is processed by using a computer, and the slurry phase and the water phase are identified according to time steps; the diffusion path and the diffusion form of the slurry are recorded, the diffusion path and the diffusion form of the slurry are real-timely drawn into three-dimensional graphics and three-dimensional dynamic animations by using the high-speed camera and processing software in the computer, and the three-dimensional graphics and the three-dimensional dynamic animations are stored;

[0031] The pressure sensor is used to monitor the grouting process, monitor the pressure on the inner wall of the simulation grouting pipe during the process of blocking water by the hardened slurry and store data;

[0032] The ultrasonic flowmeter is used to record the change of the water flow in the drainage pipe during the grouting process and record data, and the water blocking effect of the slurry and the water blocking effect during the hardening process of the slurry are analyzed;

[0033] The optical fibers are used to monitor the temperature change during the hardening process of the slurry, the optical fiber decoder is used for signal decoding, the computer is used to monitor the hydration heat release during the hardening process of the slurry, the hardening law of the slurry is judged according to the hydration heat release, and then the change law of the rheological property of the slurry during the dynamic water grouting process is monitored;

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

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

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

[0037] Take out the grouting plugging body in the grouting pipe to perform CT scanning, research the internal pore characteristics of the grouting plugging body during the formation process under the dynamic water grouting, and 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 application are as follows:

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

[0041] 2) The three-dimensional large-size dynamic water grouting simulation diffusion test device provided by the present disclosure uses the optical fiber monitoring method to obtain continuous data of temperature changes in space, determine the hydration heat release of the slurry hardening process, and further measure the viscosity change and rheological property change law in the slurry hardening process.

[0042] 3) The three-dimensional large-size dynamic water grouting simulation diffusion test device provided by the present disclosure uses high-speed photography equipment to accurately obtain the diffusion path and diffusion morphology of the slurry during the dynamic water grouting process, and forms a three-dimensional animation, and further quantitatively analyzes 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-size dynamic water grouting simulation diffusion test device provided by the present disclosure simulates the grouting pipe diameter greater than or equal to 30 cm, and can simulate the slurry being washed away and other situations during the large-size channel grouting process.

[0044] 5) The three-dimensional large-size dynamic water grouting simulation diffusion test device provided by the present disclosure simulates the disassembly of the grouting pipe and the removal of the grouting plugging body for CT scanning and further research, to determine the anti-seepage performance and plugging effect of the grouting plugging. BRIEF DESCRIPTION OF DRAWINGS

[0045] Figure 1 A structure diagram of a three-dimensional large-size dynamic water grouting simulation diffusion test device provided by the present disclosure;

[0046] Figure 2 A schematic diagram of the grouting pipe section and optical fiber layout method in the three-dimensional large-size dynamic water grouting simulation diffusion test device provided by the present application is shown in Figure 2.

[0047] Figure 3 A schematic diagram of the process of the three-dimensional large-size dynamic water grouting simulation diffusion test method provided by the present application is shown in Figure 3.

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

[0049] The present application will be further described in detail below in combination with the drawings and specific examples.

[0050] Figure 1 A schematic diagram of the structure of the three-dimensional large-size dynamic water grouting simulation diffusion test device provided by the present application is shown in Figure 1. Figure 2 A schematic diagram of the grouting pipe section and optical fiber layout method in the three-dimensional large-size dynamic water grouting simulation diffusion test device provided by the present application is shown in Figure 2. Figure 1 、 Figure 2 As can be seen, the test device comprises a variable pressure water supply device 1, a liquid collecting device 11, a grouting device, a simulated grouting pipe, and a monitoring system.

[0051] The grouting device comprises a slurry storage tank 7, a grouting pump 8, and a grouting pipe 10, wherein the inlet of the grouting pump 8 is in communication with the slurry storage tank 7, the outlet is in communication 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 is a single screw pump, and the specific parameters of the device are shown in Table 1. The grouting pump 8 is connected to the slurry storage tank 7, and the prepared slurry medium is extracted from the slurry storage tank 7 and delivered to the simulated grouting pipe through the grouting pipe 10, while observing the reading of the grouting pump pressure gauge 9 and adjusting 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 2-300 m 3 / h]] Head range 60～120m Bore 25~150mm Working pressure ≤1.6MPa Temperature of the conveyed medium ≤80℃

[0055] The simulation grouting pipeline is a horizontally placed circular pipeline, which is sequentially connected from left to right by three water inlet pipelines 2, a grouting pipeline 3 and a drainage pipeline 4 with the same inner diameter, the water inlet pipeline 2 is communicated with the variable pressure water supply device through a section of water pipe, the drainage pipeline 4 is communicated with the liquid accumulation device 11 through a section of water pipe, the grouting pipeline 3 is provided with a through hole matched with the grouting pipe 10, and the through hole is communicated with the outlet of the grouting pipe 10, and a rectifier plate 5 for flow stabilization is arranged in the water inlet pipeline 2.

[0056] 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.

[0057] The pressure sensor 12 is a plurality of pressure sensors 12 which are uniformly arranged on the inner wall of the simulation grouting pipeline, the ultrasonic flow meter 13 is installed on the outer wall of the drainage pipeline 4, the high-speed camera 14 is at least two high-speed cameras 14 which are symmetrically installed on the two sides of the grouting pipeline 3, and the shooting object is the grouting pipeline 3, and the optical fiber 16 is a plurality of optical fibers 16 which are uniformly distributed along the pipe axis and arranged on the inner wall of the simulation grouting pipeline for monitoring temperature changes, specifically, the plurality of distributed optical fibers 16 enter the simulation grouting pipeline from the pipe wall on the right side of the rectifier plate 5 and extend along the inner wall of the simulation grouting pipeline to the tail of the simulation grouting pipeline.

[0058] In the embodiment, the water inlet pipeline 2, the grouting pipeline 3 and the drainage pipeline 4 are all made of transparent acrylic material with an inner diameter of greater than or equal to 30 cm.

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

[0060] In the embodiment, the grouting pipeline 3 is composed of two identical semicircular pipelines 20, specifically, a pipe handle 19 extending outward is arranged at each opening of the semicircular pipeline 20, a plurality of screw holes are uniformly arranged on the pipe handle 19 in the axial direction of the semicircular pipeline 20, the upper and lower semicircular pipelines 20 are aligned during installation, and the upper and lower semicircular pipelines 20 are fixedly connected to form the grouting pipeline 3 through the connection of the bolts 18 and the screw holes on the pipe handle 19, and a waterproof gasket is arranged at the contact position of the two pipe handles 19.

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

[0062] In the embodiment, the optical fiber 16 is six optical fibers 16.

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

[0064] The application further provides a three-dimensional large-size dynamic water grouting simulation diffusion test method, which comprises the following steps:

[0065] Step 1: set the pressure head of the variable pressure water supply device 1 and supply water, so that the water flow fills the simulated grouting pipeline and stably flows; place the prepared slurry in the slurry storage tank 7, pump the slurry into the simulated grouting pipeline through the grouting pump 8, observe the reading of the pressure gauge 9, adjust the grouting pressure to the set value, and then inject the slurry into the simulated grouting pipeline through the grouting pipe 10;

[0066] Step 2: after starting grouting, the following method is used for monitoring:

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

[0068] The pressure sensor 12 is used to monitor the inner wall pressure of the simulated grouting pipeline during the grouting process and the water plugging process of the slurry hardening, and store the data;

[0069] The ultrasonic flowmeter 13 is used to record the change of the water flow of the drainage pipeline 4 during the grouting process and record the data, analyze the water plugging effect of the slurry and the water plugging effect during the hardening process of the slurry;

[0070] The optical fiber 16 is used to monitor the temperature change during the hardening process of the slurry, and the optical fiber decoder 17 is used for signal decoding; the computer 15 is used to monitor the hydration heat release during the hardening process of the slurry, the hardening law of the slurry is judged according to the hydration heat release, and then the change law of the rheological property of the slurry during the dynamic water grouting process is monitored;

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

[0072] Step 4: disassemble the flange connection ports of the water inlet pipeline 2, the grouting pipeline 3 and the drainage pipeline 4;

[0073] Step 5: after the slurry is preliminarily solidified, the grouting pipeline 3 is disassembled into two parts;

[0074] The grouting plugging body in the grouting pipeline 3 is taken out to perform CT scanning, internal pore characteristics in a formation process of the grouting plugging body under the dynamic water grouting are researched, and grouting permeability and water plugging effect are judged.

[0075] In the embodiment, the diffusion path and form include 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 application can perform multiple tests, by continuously adjusting the dynamic water pressure, the grouting pressure and the slurry type, according to the monitoring data, the sealing and anti-seepage effect of grouting under different working condition combinations can be judged to guide the selection of grouting parameters in actual engineering. Further, the temperature data obtained by the optical fiber monitoring in the embodiment can analyze the change rule of the slurry viscosity and rheological property of different slurry types under different dynamic water pressures in the grouting process, and then improve the slurry diffusion theoretical model of the dynamic water grouting.

[0077] The three-dimensional large-size dynamic water grouting simulation diffusion test device provided by the application can realize the research on the sealing effect of different working condition combinations and different slurry types in the large-size karst dynamic water pipeline, and the rheological property and diffusion theoretical model of the slurry.

Claims

1. A three-dimensional large-size dynamic water grouting simulation diffusion test device, characterized in that, The test device comprises a variable pressure water supply device (1), an accumulated liquid device (11), a grouting device, a simulated grouting pipeline and a monitoring system: The grouting device 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 arranged at the outlet of the grouting pump (8); The simulated grouting pipeline is a horizontally placed circular pipeline, which is sequentially connected by three water inlet pipelines (2), a grouting pipeline (3) and a drainage pipeline (4) with the same inner diameter, the water inlet pipeline (2) is communicated with the variable pressure water supply device (1) through a section of water pipe, the drainage pipeline (4) is communicated with the accumulated liquid device (11) through a section of water pipe, the grouting pipeline (3) is provided with a through hole matched with the grouting pipe (10), and the through hole is communicated with the outlet of the grouting pipe (10); and a rectifier plate (5) for flow stabilization is arranged in the water inlet pipeline (2); The monitoring system comprises a pressure sensor (12), an ultrasonic flowmeter (13), a high-speed camera (14), a computer (15), an optical fiber (16) and an optical fiber decoder (17); The pressure sensor (12) is a plurality of pressure sensors (12) which are uniformly arranged on the inner wall of the simulated grouting pipeline; the ultrasonic flowmeter (13) is installed on the outer wall of the drainage pipeline (4); the high-speed camera (14) is at least two, which are symmetrically installed on both sides of the grouting pipeline (3), i.e. the shooting object is the grouting pipeline (3); the optical fiber (16) is a plurality of optical fibers (16) which are uniformly distributed along the pipe axis and arranged on the inner wall of the simulated grouting pipeline for monitoring temperature changes; specifically, the plurality of distributed optical fibers (16) enter the simulated grouting pipeline from the right wall of the rectifier plate (5) and extend along the inner wall of the simulated grouting pipeline to the tail of the simulated grouting pipeline.

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

3. The three-dimensional large-size dynamic water grouting simulation diffusion test device according to claim 1, characterized in that, The water inlet pipeline (2), the grouting pipeline (3) and the drainage pipeline (4) are connected through flange interfaces (6).

4. The three-dimensional large-size dynamic water grouting simulation diffusion test device according to claim 1, characterized in that, The grouting pipeline (3) is composed of two identical semicircular pipelines (20) arranged one above the other, specifically, a pipe handle (19) extending outward is arranged at each opening of the semicircular pipeline (20), a plurality of screw holes are uniformly arranged on the pipe handle (19) in the axial direction of the semicircular pipeline (20), during installation, the two semicircular pipelines (20) are aligned, and the two semicircular pipelines (20) are fixedly connected to form the grouting pipeline (3) through the connection of the bolts (18) and the screw holes on the pipe handle (19); a waterproof gasket is arranged at the contact position of the two pipe handles (19).

5. The three-dimensional large-size dynamic water grouting simulation diffusion test device according to claim 1, characterized in that, The optical fiber (16) is at least six, the optical fiber (16) is connected with the optical fiber decoder (17), and the pressure sensor (12), the ultrasonic flowmeter (13), the high-speed camera (14) and the optical fiber decoder (17) are respectively connected with the computer (15).

6. A three-dimensional large-size dynamic water grouting simulation diffusion test method, using a three-dimensional large-size dynamic water grouting simulation diffusion test device according to any one of claims 1-5, characterized in that, The method comprises the following steps: Step 1, set the pressure head of the variable pressure water supply device (1) and supply water, so that the water flow fills the simulated grouting pipeline and stabilizes the flow; the prepared slurry is placed in the slurry storage tank (7), the slurry is pumped into the slurry storage tank (7) by using the grouting pump (8), the reading of the pressure gauge (9) is observed, and the grouting pressure is adjusted to the set value, then the slurry is injected into the simulated grouting pipeline through the grouting pipe (10); Step 2, after starting grouting, monitoring is carried out in the following manner: The diffusion process of the slurry is recorded by using a high-speed camera (14), the collected picture information is processed by using a computer (15), and the slurry phase and water phase are identified according to time steps; the diffusion path and diffusion form of the slurry are recorded, and the diffusion path and diffusion form of the slurry are real-time drawn into three-dimensional graphics and three-dimensional dynamic animation and stored by using the high-speed camera (14) and processing software in the computer (15); The pressure sensor (12) is used to monitor the grouting process, monitor the pressure on the inner wall of the simulated grouting pipeline during the hardening and water plugging process of the slurry, and store the data; The ultrasonic flowmeter (13) is used to record the change of the water flow of the drainage pipeline (4) during the grouting process and record the data, analyze the water plugging effect of the slurry and the water plugging effect during the hardening process of the slurry; The optical fiber (16) is used to monitor the temperature change during the hardening process of the slurry, and the optical fiber decoder (17) is used for signal decoding, the computer (15) is used to monitor the hydration heat release during the hardening process of the slurry, the hardening law of the slurry is judged according to the hydration heat release, and then the change law of the rheological property of the slurry during the dynamic water grouting process is monitored; Step 3, when the ultrasonic flowmeter (13) records that the flow of the drainage pipeline (4) is 0 or the flow change reaches stability, stop grouting; Step 4, disassemble the flange connection port of the water inlet pipeline (2), the grouting pipeline (3) and the drainage pipeline (4); Step 5, after the slurry is preliminarily solidified, the grouting pipeline (3) is disassembled into upper and lower two parts; The grouting plugging body in the grouting pipeline (3) is taken out for CT scanning, the internal pore characteristics during the formation process of the grouting plugging body under the dynamic water grouting are studied, and the grouting permeability and water plugging effect are judged.

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

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