A water plugging device and method for realizing visual analysis under different flow rate conditions

Abstract

The application provides a water plugging device and method for realizing visual analysis under different flow rate conditions, which comprises a plastic pipe frame, a plastic cylinder sleeve supported on the top of the plastic pipe frame through a steel pipe elbow and a steel cylinder guard frame, the plastic cylinder sleeve is connected with an air pressure tank through a rubber conduit hole and a rubber pipe, the air pressure tank is provided with a grouting opening and is used for storing special magnetic slurry, the plastic cylinder sleeve is connected with a power supply through a valve, a direct current intelligent electromagnetic flowmeter and a rubber pipe, one end of the plastic cylinder sleeve is connected with a water tank through a self-made steel frame mold and a water pipe, the other end of the plastic cylinder sleeve is provided with a magnetic self-aggregation magnetic bar, and the magnetic self-aggregation magnetic bar is connected with a pressure test pump through a rubber pipe. The water plugging device can be used for simulating the water plugging example under the water gushing condition of a real karst area tunnel, can effectively control the water gushing disaster, and avoids serious economic loss and heavy casualties.

Description

Technical Field

[0001] This invention belongs to the field of tunnel water inrush plugging engineering in karst areas, specifically a water plugging device and method for achieving visual analysis under different flow velocity conditions. Background Technology

[0002] During the construction of large-scale water conservancy, hydropower, energy, transportation, and national defense projects, geological conditions are extremely complex, often leading to geological disasters such as karst collapse, water inrush, and landslides, causing severe economic losses and significant casualties. Mountain tunnel projects, in particular, involve complex fluid-structure interaction processes, greatly increasing the likelihood and severity of disasters and raising the difficulty of prediction and prevention.

[0003] Karst is widely distributed in southwestern my country, and with the continuous advancement of infrastructure construction, karst tunnels are constantly emerging in this region. Tunnel construction in karst areas often encounters geological disasters such as sudden water inrush, mudslides, and landslides. Among these, sudden water inrush is characterized by its difficulty in prediction, sudden occurrence, and high destructiveness, easily causing widespread damage to the surrounding rock of the tunnel and severe loss of life and property, making it one of the most serious geological hazards in tunnel construction. With the construction of numerous tunnels in the karst regions of southwestern my country, to prevent sudden water inrush disasters in karst tunnels, it is necessary to adopt simple and effective leakage sealing methods, or a highly feasible, low-cost, and effective device to effectively reduce the losses caused by sudden water inrush disasters in karst tunnels. Summary of the Invention

[0004] To address the existing technical problems, the main objective of this invention is to provide a water-blocking device and method that simulates different flow velocity states and enables visual analysis. This device can be used to simulate water-blocking instances under real karst tunnel inrush water conditions, effectively controlling inrush water disasters and avoiding serious economic losses and significant casualties.

[0005] To achieve the aforementioned technical features, the present invention aims to provide a water-blocking device for visual analysis under simulated flow velocity conditions. The device includes a plastic pipe frame, the top of which is supported by a plastic cylindrical sleeve via a steel pipe elbow and a steel cylindrical support. The plastic cylindrical sleeve is connected to a pressure tank via a rubber conduit hole and a rubber tube. The pressure tank has an injection port for storing a specially formulated magnetic slurry. The plastic cylindrical sleeve is connected to a power source via a valve, a DC intelligent electromagnetic flowmeter, and a rubber tube. One end of the plastic cylindrical sleeve is connected to a water tank via a self-made steel frame mold and a water pipe. The other end of the plastic cylindrical sleeve is equipped with a magnetic self-aggregating rod, which is connected to a pressure testing pump via a rubber tube.

[0006] The pressure tank is a pressure sensor storage tank, which is a tank that receives and stores compressed air after it leaves the pressure sensor. It stores a special magnetic slurry and uses air pressure to inject the special magnetic slurry into a plastic cylindrical sleeve through a rubber tube.

[0007] The pressure tank is connected to a pressure sensor via a rubber tube. When the specially made magnetic slurry is injected into the pressure tank, the pressure gauge reading is observed to determine whether the air pressure inside the water-blocking device has reached a critical state. When the air pressure is uncontrollable, the pressure sensor receives the maximum pressure and the water-blocking device will automatically stop operating, thereby achieving the purpose of safe experimentation.

[0008] A paperless recorder is also connected to the plastic cylindrical sleeve through a rubber conduit hole;

[0009] The pressure testing pump uses a reciprocating plunger pump. The plunger is driven by a motor, which drives the slider to move and inject water into the object being tested, so that the pressure gradually increases.

[0010] The pressure gauge is a precision instrument that can measure dynamic water pressure with an accuracy of 0.2%. It is used to measure dynamic water pressure in real time when the water-blocking device is running, so that the paperless recorder can record the collected data.

[0011] The water tank is connected to the pneumatic loading reaction frame;

[0012] The flow calculation formula of the DC intelligent electromagnetic flowmeter is Q=Sv, where S is the cross-sectional area of ​​the pipe and v is the water flow velocity. It is used to observe the maximum flow rate reached in the water blocking device in real time.

[0013] The paperless recorder records the collected and processed data in the internal storage system of the instrument with time as the basis. It does not consume any commonly used recording facilities. The data stored in the instrument is then processed and simulated and displayed on the LCD screen. In the water-blocking device, it acts as a real-time recorder of multiple data such as water-blocking pressure and water head flow rate to facilitate the operation of the water-blocking device.

[0014] The plastic cylindrical sleeve is provided with an external hole for the device;

[0015] It also includes high-definition cameras.

[0016] The specially formulated magnetic slurry is prepared by uniformly mixing epoxy resin A, Fe3O4 magnetic powder, fly ash, and large-particle iron sand of 0.5mm, 1.5mm, and 2.0mm. The specific weight ratio of epoxy resin A, Fe3O4 magnetic powder, fly ash, and large-particle iron sand is 1:1~1.5:1.5~1.75:2, with each ratio range increasing or decreasing by 0.05. The weight ratio of the three different particle sizes of 0.5mm, 1.5mm, and 2.0mm in the large-particle iron sand is always 1:1:1.

[0017] The specially formulated magnetic grout is prepared by mixing and stirring 100g of epoxy resin A, 100g of Fe3O4 magnetic powder, 150g of fly ash, and 67g each of large-particle iron sand with diameters of 0.5mm, 1.5mm, and 2.0mm. The epoxy resin A is a high-penetration modified resin grouting liquid, which is light yellow and turns grayish-black after stirring.

[0018] The magnetic self-aggregating magnetic rod is made by covering the magnetic rod with a plastic film, placing it in a beaker containing a special magnetic slurry, and stirring it back and forth. The magnetic rod attracts the special magnetic slurry, causing the special magnetic slurry to adhere to the magnetic rod, making the magnetic rod magnetic. At the same time, the diameter expands and the special magnetic slurry adheres to the entire surface of the magnetic rod.

[0019] By inserting the self-aggregating magnetic rod into a pre-made cylindrical membrane bag of a certain diameter (one side has a hole, the other side does not), the cylindrical membrane bag will wrap around the self-aggregating magnetic rod. Then, push it into the steel cylindrical protective frame. Stop pushing after the self-aggregating magnetic rod is completely submerged in the plastic tube frame. At the same time, pour the special magnetic grout into the pressure tank, ensuring that the special magnetic grout enters the bottom completely and is not blocked by air in the middle of the pressure tank, which would affect the subsequent grouting work.

[0020] During the water-blocking experiment, square magnetic blocks are also used. After the cylindrical membrane bag with attached magnetic self-aggregating rods is inserted into the steel cylindrical protective frame, square magnetic blocks are filled around it. As the dynamic water pressure changes continuously, the square magnetic blocks are attracted by the magnetic field generated by the magnetic self-aggregating rods and squeezed in by the water flow, filling the gaps in the inner wall of the water-blocking device. At the same time, when the water blocking stops, the square magnetic blocks can be pulled out along the outer hole of the device, saving the time of grouting in the pressure tank.

[0021] Oil-based polyurethane grout is also used. The oil-based polyurethane grout is a polyurethane grouting material, which is a leak-stopping product. It has the characteristics of no disassembly and rapid leak-stopping. After being injected into the concrete, it reacts chemically with water. The expansion and continuous pressure can penetrate the oil-based polyurethane grout into the micro-cracks, expand and solidify in a short time, and achieve the purpose of complete water stoppage.

[0022] It also includes PUP / SBS composite modified asphalt, which is a solid asphalt material prepared by melt blending polyurethane solid-solid phase change material and styrene-butadiene-styrene block copolymer. By placing the PUP / SBS composite modified asphalt into the water-blocking device, the PUP / SBS composite modified asphalt will coat the special magnetic slurry. As the water pressure in the plastic cylindrical sleeve increases, the temperature also rises, softening into a liquid state. When the water pressure decreases and the temperature decreases, it solidifies again, thereby improving the reusability of the special magnetic slurry.

[0023] An experimental method for visual analysis of a water-blocking device under simulated flow velocity conditions includes the following steps:

[0024] Step 1.1: Prepare the special magnetic slurry, and prepare the magnetic rod and all experimental components;

[0025] Step 1.2: Assemble the experimental components, including the plastic pipe frame, grouting port, steel pipe elbow, steel cylindrical protective frame, self-made steel frame mold, plastic cylindrical sleeve, and pneumatic loading reaction frame, along with the pressure sensor, pressure tank, pressure testing pump, pressure gauge, DC intelligent electromagnetic flowmeter, and high-definition camera, and connect them to the water tank via water pipes; then connect them with rubber hoses and connect them to a power source to form a water-blocking device.

[0026] Step 1.3: Cover a magnetic rod with a diameter of d1 with a plastic film and put it into a beaker containing a special magnetic slurry. Stir it back and forth. Utilize the attraction between the magnetic rod and the special magnetic slurry to make the special magnetic slurry adsorb onto the magnetic rod, making the magnetic rod magnetic. At the same time, the diameter expands to d2, and the magnetic rod is covered with a binder mainly composed of magnetic mortar, thus forming a self-aggregating magnetic rod.

[0027] Step 1.4: Insert the self-aggregating magnetic rod into a pre-made cylindrical membrane bag with a diameter of d2. One side has a hole and the other side does not. The cylindrical membrane bag will wrap around the self-aggregating magnetic rod. Then push it into the steel cylindrical protective frame. Stop pushing after the self-aggregating magnetic rod is completely submerged in the plastic tube frame. At the same time, inject the special magnetic slurry into the pressure tank with an air pump. Ensure that the special magnetic slurry is injected into the plastic cylindrical sleeve through the rubber tube using air pressure, and is not blocked by air in the middle of the pressure tank, which would affect the subsequent grouting work.

[0028] Step 1.5: Before conducting the water-blocking experiment, square magnetic blocks and PUP / SBS composite modified asphalt were added to the plastic cylindrical sleeve in advance to prepare for the analysis of the water-blocking effect of the special magnetic grout in the later experiment.

[0029] Step 1.6: After inserting the self-aggregating magnetic rod, that is, after it is completely submerged in the plastic tube frame, turn on the power and add water to the pressure test pump. The generated pressure will send the water to the plastic cylindrical sleeve through the rubber tube, simulating the scouring pressure of the moving water on the self-aggregating magnetic rod under real working conditions. Observe and record the real-time water pressure data on the pressure gauge. When the moving water completely pushes the self-aggregating magnetic rod out of the water blocking device, press the switch to stop the pressure test pump from working and stop injecting water into the plastic cylindrical sleeve. The paperless recorder records and stores the water blocking pressure, temperature and other data throughout the process.

[0030] Step 1.7: Conduct experiments with different ratios of the specially formulated magnetic slurry, repeating Steps 3-6. Summarize the collected water-blocking pressure data for comparison. Record the actual movement of the magnetic self-aggregating rods using a high-definition camera, and perform frame-by-frame image processing on the captured video. Then, extract the data from the images using image processing software. Simultaneously, compare the adsorption diameter of the magnetic rods obtained with different ratios of the specially formulated magnetic slurry from these experiments. Analyze and determine the ratio of the specially formulated magnetic slurry that enables the water-blocking device to reach the maximum water-blocking pressure, thereby obtaining the relevant data for the maximum water-blocking pressure and achieving the true purpose of the water-blocking experiment.

[0031] It also includes experimental methods under different water flow conditions, and includes the following steps:

[0032] Step 2.3: After the water-blocking device is installed in Step 1.2 and the magnetic self-aggregating rod is prepared, turn on the power and control the water flow from the water tank to the DC intelligent electromagnetic flow meter through the valve. Set three different flow velocities: 0.5 m / s, 1.0 m / s, and 1.5 m / s. The DC intelligent electromagnetic flow meter displays the flow rate of water through the plastic cylindrical sleeve. According to the flow formula Q=Sv, where S is the cross-sectional area of ​​the pipe and v is the pipe diameter, the flow rates at the three different flow velocities of 0.5 m / s, 1.0 m / s, and 1.5 m / s can be obtained.

[0033] Step 2.4: After repeating Step 1.4 and Step 1.6, it is also necessary to note that after injecting the special magnetic slurry into the pressure tank, the pressure gauge reading is observed to determine whether the air pressure inside the device has reached the critical state. When the air pressure is uncontrollable, the pressure sensor receives the maximum pressure sensing, and the water blocking device will automatically stop operating, thus achieving the purpose of visualization.

[0034] It also includes experimental methods under conditions of varying water flow velocities, and further includes the following steps:

[0035] Step 3.3: In Step 3.7, use an air pump to inject the oil-based polyurethane grout into the pipe through the interface on the plastic cylindrical sleeve. Utilizing its slow expansion and continuous pressure, the special magnetic grout penetrates into the tiny gaps in the pipe and expands and solidifies in a short time to achieve complete water stoppage.

[0036] Step 11: As the oil-based polyurethane grout is continuously added, it expands violently, causing some minor cracks to appear in the pipe. In addition, the special magnetic grout is washed away, and the water-blocking device loses its water-blocking effect. Therefore, oil-based polyurethane grout is not considered as a new water-blocking material.

[0037] The present invention has the following beneficial effects:

[0038] 1. The specially formulated magnetic grout used in this invention is prepared by mixing 100g of epoxy resin A, 150g of Fe3O4 magnetic powder, 150g of fly ash, and 67g each of 0.5mm, 1.5mm, and 2.0mm large-particle iron sand evenly. Epoxy resin A refers to the existing KD-508 model high-penetration modified resin grouting liquid. A is a resin, and after mixing, it turns pale yellow. Both adsorption and viscosity are significantly improved, resulting in a very obvious effect when quickly sealing leaks. Simultaneously, the innovative use of large-particle iron sand has the advantage that the magnetic grout prepared with large-particle iron sand is more affected by the magnetic field strength than that prepared with fine-particle iron powder; it will segregate and adsorb within a 2-3cm range around the magnetic rod, changing the grout from a highly fluid liquid state to a plastic state. Compared to the previous fine-particle iron sand, this is significantly superior, allowing for better adsorption onto the self-aggregating magnetic rod, resulting in better water-sealing performance.

[0039] 2. This invention designs a water-blocking testing device. Its core consists of a self-made component comprising a plastic pipe frame, grouting port, steel pipe elbow, steel cylindrical protective frame, self-made steel frame mold, plastic cylindrical sleeve, and pneumatic loading reaction frame. This component is then assembled with a pressure sensor, pressure tank, pressure testing pump, pressure gauge, DC intelligent electromagnetic flowmeter, and high-definition camera. A water pipe is connected to the water tank. The device is then connected with a rubber hose and powered on. By adjusting the switch of the DC intelligent electromagnetic flowmeter through a valve, the flow rate of the water in the water tank is controlled. This simulates the water pressure generated by the water flowing through the grouting pipe under different flow rates, thereby accurately predicting the size of the water inrush.

[0040] 3. This invention also proposes the concept of a self-aggregating magnetic rod, which refers to a cylindrical magnetic rod with a length of 50cm and a diameter of 5cm covered with a plastic film, placed in a beaker containing a special magnetic slurry, and stirred back and forth. The magnetic rod attracts the special magnetic slurry, causing the special magnetic slurry to adhere to the magnetic rod, making the magnetic rod magnetic. At the same time, the diameter expands to 7cm, and the magnetic rod is covered with a binder mainly composed of the magnetic slurry.

[0041] 4. The cylindrical membrane bag with a diameter of 7cm used in this invention is used to better wrap the magnetic self-aggregating rod and increase its resistance to water pressure during water blocking tests.

[0042] 5. This invention also utilizes a DC intelligent electromagnetic flowmeter, which is an instrument that measures the flow rate of a conductive fluid based on the principle of electromagnetic induction and the electromotive force induced when the fluid passes through an external magnetic field. It is used to measure the flow rate of water flowing from a water tank through a plastic cylindrical sleeve. A flow rate calculation formula, Q=Sv, is derived, where S is the cross-sectional area of ​​the pipe and v is the water flow velocity, used to monitor the maximum flow rate reached in the water-blocking device in real time.

[0043] 6. This invention also utilizes a paperless recorder, which records the collected and processed data in the instrument's internal storage system with time as the axis, without consuming any commonly used recording facilities. The stored data is then processed and simulated before being displayed on an LCD screen. When the water-blocking device conducts multiple water-blocking tests, data such as the maximum water-blocking pressure generated needs to be recorded quickly and accurately. The paperless recorder effectively fills this gap, eliminating the traditional reliance on paper for recording, significantly improving the progress of water-blocking tests, and increasing the economic benefits of actual engineering projects.

[0044] 7. The visualization concept mentioned in this invention refers to placing a high-definition camera in a suitable position on the water-blocking device to observe the actual water-blocking effect of the specially made magnetic slurry with different apertures and ratios during the water-blocking test, thus achieving true visualization analysis. After the test, the collected data needs to be observed frame by frame to analyze its spatiotemporal evolution mechanism, as well as the comparison between the magnetic slurry ratio, water-blocking pressure, and dynamic water flow velocity. Based on the differences in water-blocking effect under different positions and apertures, the ratio with the best effect is selected to conduct the water-blocking test, i.e., water-blocking under real sudden water inrush conditions.

[0045] 8. This invention also utilizes square magnetic blocks. After the cylindrical membrane bag with attached magnetic self-aggregating rods is inserted into the steel cylindrical protective frame, square magnetic blocks are filled around it. As the water pressure continuously changes, the square magnetic blocks are attracted by the magnetic field generated by the magnetic rods and squeezed in by the water flow, slowly filling the gaps in the inner wall of the device. Simultaneously, when the water blocking stops, the magnetic blocks can be extracted along the outer hole of the device, greatly saving the time required for grouting in the pressure tank.

[0046] 9. This invention comprehensively selects an oil-based epoxy resin magnetic slurry made from epoxy resin A liquid, Fe3O4 magnetic powder, fly ash, and large-particle iron sand as raw materials. Combined with a magnetic self-aggregating rod, a water-blocking device was used to conduct water-blocking performance tests. A DC intelligent electromagnetic flowmeter was used to simulate different flow velocities to determine the maximum water-blocking pressure achievable by the specially formulated magnetic slurry. The following conclusions were drawn: A specially formulated magnetic slurry made with 100g of epoxy resin A liquid, 150g of Fe3O4 magnetic powder, 150g of fly ash, and 67g each of 0.5mm, 1.5mm, and 2.0mm large-particle iron sand reached its maximum water-blocking pressure of 105.3kPa at a blocking length of 30cm. Furthermore, a higher water flow rate also affects the water-blocking pressure, potentially leading to pipe rupture upon reaching its peak. Overall, however, this device and method have significant guiding value for simulating real flowing water environments for water inrush sealing and show promising prospects. Attached Figure Description

[0047] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0048] Figure 1 This is a schematic diagram of a water-blocking device that simulates different flow velocity conditions to achieve visual analysis.

[0049] Figure 2 This is an overall effect diagram of a magnetic self-aggregating rod after it has been fully adsorbed with magnetic slurry.

[0050] Figure 3 This is a partial view showing the effect of a magnetic self-aggregating rod being fully adsorbed with magnetic slurry.

[0051] Figure 4 This is a schematic diagram of a magnetic rod being propelled by water flow.

[0052] Figure 5 This is a diagram showing the erosion damage to a plastic cylindrical pipe.

[0053] Figure 6 When the pressure gauge reading is too high and the pressure sensor senses the maximum pressure, the pressure tank stops grouting.

[0054] Figure 7 This is a schematic diagram of a magnetic rod being coated with magnetic slurry.

[0055] Figure 8 After the oil-based polyurethane grout was injected, a minor crack occurred in the pipeline.

[0056] Figure 9 This is a comparison of the adsorption diameters of different magnetic slurries after the magnetic rod adsorbs them.

[0057] In the diagram: 1. Special magnetic grout; 2. Large-particle iron sand; 3. Plastic pipe frame; 4. Grouting port; 5. Steel pipe elbow; 6. Steel cylindrical protective frame; 7. Self-made steel frame mold; 8. Water pipe; 9. Plastic cylindrical sleeve; 10. Pressure sensor; 11. Pressure tank; 12. Pressure testing pump; 13. Pressure gauge; 14. DC intelligent electromagnetic flow meter; 15. Water tank; 16. Cylindrical membrane bag; 17. Magnetic self-aggregating rod; 18. Paperless recorder; 19. Air pump; 20. Oil-based polyurethane grout; 21. Rubber hose; 22. Power supply; 23. Water blocking device; 24. Valve; 25. Rubber guide tube hole; 26. High-definition camera; 27. Pneumatic loading reaction frame; 28. Square magnetic block; 29. ​​PUP / SBS composite modified asphalt; 30. External hole of the device. Detailed Implementation

[0058] The embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0059] Example 1:

[0060] See Figure 1-9A water-blocking device 23 for simulating different flow velocity states and achieving visual analysis includes a plastic pipe frame 3. The top of the plastic pipe frame 3 is supported by a plastic cylindrical sleeve 9 through a steel pipe elbow 5 and a steel cylindrical guard 6. The plastic cylindrical sleeve 9 is connected to a pressure tank 11 through a rubber conduit hole and a rubber tube. The pressure tank 11 is provided with a grouting port 4 for storing a special magnetic grout 1. The plastic cylindrical sleeve 9 is connected to a power supply 22 through a valve 24, a DC intelligent electromagnetic flowmeter 14 and a rubber tube. One end of the plastic cylindrical sleeve 9 is connected to a water tank 15 through a self-made steel frame mold 7 and a water pipe 8. The other end of the plastic cylindrical sleeve 9 is provided with a magnetic self-aggregating rod 17, which is connected to a pressure testing pump 12 through a rubber tube. This paper presents an innovative device and method for plugging water inrush in tunnels in karst areas, simulating a real-world example of water inrush. This method effectively controls water inrush disasters and avoids severe economic losses and significant casualties.

[0061] Furthermore, the pressure tank 11 is a pressure sensor storage tank, which is a tank that receives and stores compressed air after it leaves the pressure sensor 10, stores a special magnetic slurry 1, and uses air pressure to inject the special magnetic slurry 1 into the plastic cylindrical sleeve 9 through the rubber tube 21. The pressure tank 11 can provide the power for grouting.

[0062] Furthermore, the pressure tank 11 is connected to the pressure sensor 10 via a rubber tube. When the special magnetic slurry 1 is injected into the pressure tank 11, the pressure gauge 13 is observed to determine whether the air pressure inside the water-blocking device has reached a critical state. When the air pressure is uncontrollable, the pressure sensor 10 receives the maximum pressure sensing, and the water-blocking device 23 will automatically stop operating, thereby achieving the purpose of safe experiment.

[0063] Furthermore, a paperless recorder 18 is connected to the plastic cylindrical sleeve 9 via a rubber conduit hole. The paperless recorder 18 records the collected and processed data in its internal storage system based on time, without consuming any conventional recording equipment. The stored data is then processed and simulated before being displayed on an LCD screen. In the water-blocking device, it acts as a real-time recorder of multiple data points, including water-blocking pressure and head flow, to facilitate the operation and maintenance of the water-blocking device.

[0064] Furthermore, the pressure testing pump 12 is a reciprocating plunger pump. A motor drives the plunger, which in turn moves the slider to inject water into the object being tested, gradually increasing the pressure. The pressure testing pump 12 provides the injection pressure to propel the test object. The machine consists of a pump body, switch, pressure gauge, water tank, and motor. Existing pressure testing pumps can be used.

[0065] Furthermore, the pressure gauge 13 is a precision instrument capable of measuring dynamic water pressure with an accuracy of 0.2%. It is used to measure the dynamic water pressure in real time during the operation of the water-blocking device 23, so that the paperless recorder 18 can record the collected data. The pressure gauge 13 is a precision instrument for measuring dynamic water pressure with low power consumption, fast response, strong overload capacity, small drift, and high accuracy. A suitable pressure gauge can be selected. Its principle is based on the elastic deformation of the sensitive elements inside the gauge: Bourdon tube, diaphragm, and bellows. The pressure deformation is then transmitted to the pointer by the conversion mechanism of the gauge's internal movement, causing the pointer to rotate and display the pressure.

[0066] Furthermore, the water tank 15 is connected to the pneumatic loading reaction frame 27;

[0067] Furthermore, the flow calculation formula for the DC intelligent electromagnetic flowmeter 14 is Q=Sv, where S is the cross-sectional area of ​​the pipe and v is the water flow velocity, used to observe the maximum flow rate reached in the water-blocking device in real time. The DC intelligent electromagnetic flowmeter 14 is an instrument that uses the principle of electromagnetic induction to measure the flow rate of a conductive fluid based on the electromotive force induced when the fluid passes through an external magnetic field. It is used to measure the flow rate of water from the water tank 15 through the plastic cylindrical sleeve 9.

[0068] The DC intelligent electromagnetic flowmeter 14 features: 1. Measurement is unaffected by changes in fluid density, viscosity, temperature, pressure, and conductivity; 2. No flow-obstructing components within the measuring tube, resulting in no pressure loss and lower straight pipe section requirements. It has unique adaptability to slurry measurement; 3. Appropriate selection of sensor lining and electrode materials ensures excellent corrosion and wear resistance; 4. The converter employs a novel excitation method, resulting in low power consumption, zero-point stability, and high accuracy. Flow range accuracy can reach 150:1; 5. The converter can be integrated with the sensor or used separately.

[0069] Furthermore, the plastic cylindrical sleeve 9 is provided with an external hole 30. The external hole 30 facilitates the subsequent removal of the magnetic block inside the plastic cylindrical sleeve 9.

[0070] Furthermore, a high-definition camera 26 is also included. A high-definition camera 26 is placed in a suitable position on the water-blocking device 23 to observe the actual water-blocking effect of the specially made magnetic slurry 1 under different apertures and ratios during the water-blocking test, achieving true visualization analysis. After the test, the collected data needs to be observed frame by frame to analyze its spatiotemporal evolution mechanism, as well as the comparison between the magnetic slurry ratio, water-blocking pressure, and dynamic water flow velocity. Based on the differences in water-blocking effect under different positions and apertures, the ratio with the best effect is selected to conduct the water-blocking test, that is, water-blocking under the actual sudden water inrush condition.

[0071] Furthermore, the specially prepared magnetic slurry 1 is prepared by mixing and stirring epoxy resin A liquid, Fe3O4 magnetic powder, fly ash and large-particle iron sand 2 with 0.5mm, 1.5mm and 2.0mm particles evenly.

[0072] Among them, the special magnetic slurry 1 has a variety of different proportions. In this embodiment, six different proportions are provided, as detailed in Table 1:

[0073] Table 1. Test table for the proportioning of specially made magnetic slurry materials.

[0074] Serial Number Epoxy Resin A / g Fe3O4 magnetic powder / g fly ash / g Large iron sand / g 1 100 100 175 0.5mm 200g 2 100 125 150 0.5mm per 100g, 1.0mm per 100g 3 100 100 175 0.5mm67g, 1.0mm67g, 1.5mm67g 4 100 125 150 0.5mm67g, 1.5mm67g, 2.0mm67g 5 100 150 150 0.5mm 100g, 1.5mm 100g 6 100 150 150 0.5mm67g, 1.5mm67g, 2.0mm67g

[0075] Furthermore, the epoxy resin A liquid is a high-penetration modified resin grouting liquid, which is light yellow and turns grayish-black after stirring.

[0076] Furthermore, the magnetic self-aggregating rod 17 is made by covering the magnetic rod with a plastic film, placing it in a beaker containing a special magnetic slurry 1, and stirring it back and forth. The magnetic rod attracts the special magnetic slurry 1, causing the special magnetic slurry 1 to adhere to the magnetic rod, making the magnetic rod magnetic. At the same time, the diameter expands, and the special magnetic slurry 1 adheres to the entire surface of the magnetic rod.

[0077] Furthermore, by inserting the self-aggregating magnetic rod 17 into a pre-made cylindrical membrane bag 16 with a hole on one side and no hole on the other, the cylindrical membrane bag 16 will wrap around the self-aggregating magnetic rod 17. Then, push it into the steel cylindrical protective frame 6. After the self-aggregating magnetic rod 17 is completely submerged in the plastic tube frame 3, stop pushing. At the same time, pour the special magnetic slurry 1 into the pressure tank 11 to ensure that the special magnetic slurry 1 enters the bottom and is not blocked by air in the middle of the pressure tank 11, which would affect the subsequent grouting work.

[0078] Furthermore, during the water-blocking experiment, square magnetic blocks 28 are also used. After the cylindrical membrane bag 16 with attached magnetic self-aggregating rods 17 is inserted into the steel cylindrical protective frame 6, square magnetic blocks 28 are filled around it. As the dynamic water pressure changes continuously, the square magnetic blocks 28 are attracted by the magnetic field generated by the magnetic self-aggregating rods 17 and squeezed in by the water flow, filling the gaps in the inner wall of the water-blocking device. At the same time, when the water blocking stops, the square magnetic blocks 28 can be pulled out along the outer hole 30 of the device, saving the time of grouting in the pressure tank 11.

[0079] Furthermore, an oil-based polyurethane grout 20 is also used. The oil-based polyurethane grout 20 is a polyurethane grouting material, which is a leak-stopping product. It has the characteristics of being able to stop leaks quickly without disassembly. After being injected into the concrete, it reacts chemically with water. The expansion and continuous pressure enable the oil-based polyurethane grout 20 to penetrate into the micro-cracks, expand and solidify in a short time, and achieve the purpose of completely stopping water.

[0080] Furthermore, it also includes PUP / SBS composite modified bitumen 29, which is a solid bitumen material prepared by melt blending polyurethane solid-solid phase change material and styrene-butadiene-styrene block copolymer. By placing PUP / SBS composite modified bitumen 29 into the water-blocking device 23, PUP / SBS composite modified bitumen 29 will coat the special magnetic slurry 1. As the water pressure in the plastic cylindrical sleeve 9 increases, the temperature also rises, softening into a liquid state. When the water pressure decreases, the temperature decreases, and it solidifies again, thereby improving the reusability of the special magnetic slurry 1.

[0081] It has the following characteristics: 1. It has high temperature adaptability; it is solid at room temperature but softens and becomes liquid at high temperatures; 2. PUP causes a decrease in the low-temperature creep performance of asphalt, meaning it has good elasticity but poor plasticity. When the axial pressure is too high, it will bend and the overall structure will be damaged. However, when it is placed in the water-blocking device 23, the modified asphalt will coat the special magnetic grout 1. As the water pressure in the pipeline increases, the temperature also rises, and the asphalt softens into a liquid state; when the water pressure decreases and the temperature decreases, the asphalt solidifies again; thus improving the reusability of the special magnetic grout 1.

[0082] Example 2:

[0083] An experimental method for visual analysis of a water-blocking device under simulated flow velocity conditions includes the following steps:

[0084] Step 1.1: Prepare the special magnetic slurry 1, and prepare the magnetic rod and all experimental components;

[0085] Step 1.2: Assemble the following experimental components together: plastic pipe frame 3, grouting port 4, steel pipe elbow 5, steel cylindrical protective frame 6, self-made steel frame mold 7, plastic cylindrical sleeve 9, and pneumatic loading reaction frame 27, along with pressure sensor 10, pressure tank 11, pressure testing pump 12, pressure gauge 13, DC intelligent electromagnetic flowmeter 14, and high-definition camera 26. Connect the water pipe 8 to the water tank 15. Then connect the components with rubber hose 21 and power supply 22 to form a water blocking device 23.

[0086] Step 1.3: Cover a 50cm long and 5cm diameter magnetic rod with a plastic film and put it into a beaker containing a special magnetic slurry 1. Stir it back and forth. Utilize the attraction between the magnetic rod and the special magnetic slurry 1 to make the special magnetic slurry 1 adsorb onto the magnetic rod, making the magnetic rod magnetic. At the same time, the diameter expands to 7cm. The magnetic rod is covered with a binder mainly composed of magnetic mortar, thus forming a self-aggregating magnetic rod 17.

[0087] Step 1.4: Insert the self-aggregating magnetic rod 17 into the pre-made cylindrical membrane bag 16 with a diameter of 7cm. One side has a hole and the other side does not. The cylindrical membrane bag 16 will wrap around the self-aggregating magnetic rod 17. Then push it into the steel cylindrical protective frame 6. Stop pushing after the self-aggregating magnetic rod 17 is completely submerged in the plastic tube frame 3. At the same time, inject the special magnetic slurry 1 into the pressure tank 11 using the air pump 19. Ensure that the special magnetic slurry 1 is injected into the plastic cylindrical sleeve 9 through the rubber tube 21 using air pressure, and is not blocked by air in the middle of the pressure tank 11, which would affect the subsequent grouting work.

[0088] Step 1.5: Before the formal water-blocking experiment, square magnetic blocks 28 and PUP / SBS composite modified asphalt 29 are added to the plastic cylindrical sleeve 9 in advance to prepare for the analysis of the water-blocking effect of the special magnetic slurry 1 in the later experiment.

[0089] Step 1.6: After inserting the self-aggregating magnetic rod 17, that is, after it is completely submerged in the plastic tube frame 3, turn on the power supply 22 and add water to the pressure test pump 12. The generated pressure will send the water to the plastic cylindrical sleeve 9 through the rubber tube 21 to simulate the scouring pressure of the moving water on the self-aggregating magnetic rod 17 under real working conditions. Observe and record the real-time water pressure data on the pressure gauge 13. When the moving water completely pushes the self-aggregating magnetic rod 17 out of the water blocking device, press the switch, the pressure test pump 12 will stop working, and the water injection into the plastic cylindrical sleeve 9 will stop. The paperless recorder 18 will record and store the water blocking pressure, temperature and other data throughout the process.

[0090] Step 1.7: Conduct experiments with different ratios of the specially formulated magnetic slurry 1, repeating Steps 3 to 6. Summarize the collected water-blocking pressure data for comparison. Record the actual movement of the magnetic self-aggregating rod 17 captured by the high-definition camera 26, and perform frame-by-frame image processing on the captured video. Then, extract the data from the images using image processing software. Simultaneously, compare the adsorption diameter of the magnetic rods obtained with different ratios of the specially formulated magnetic slurry 1 from these multiple experiments. Analyze and determine the ratio of the specially formulated magnetic slurry 1 that enables the water-blocking device to reach the maximum water-blocking pressure, thereby obtaining the relevant data for the maximum water-blocking pressure and achieving the true purpose of the water-blocking experiment.

[0091] It also includes experimental methods under different water flow conditions, and includes the following steps:

[0092] Step 2.3: After the water-blocking device 23 is installed in Step 1.2 and the magnetic self-aggregating rod 17 is prepared, turn on the power supply 22 and control the water flow from the water tank 15 to the DC intelligent electromagnetic flow meter 14 through the valve 24, setting it to three different flow velocity states: 0.5m / s, 1.0m / s, and 1.5m / s. The DC intelligent electromagnetic flow meter 14 displays the flow rate of the water flowing through the plastic cylindrical sleeve 9. According to the flow formula Q=Sv, where S is the cross-sectional area of ​​the pipe and v is the pipe diameter, the flow rate under the three different flow velocity states of 0.5m / s, 1.0m / s, and 1.5m / s can be obtained.

[0093] Step 2.4: After repeating Step 1.4 and Step 1.6, it is also necessary to note that after injecting the special magnetic slurry 1 into the pressure tank 11, the pressure gauge 13 is observed to determine whether the air pressure inside the device has reached the critical state. When the air pressure is uncontrollable, the pressure sensor 10 receives the maximum pressure sensing, and the water blocking device 23 will automatically stop operating, thus achieving the purpose of visualization.

[0094] It also includes experimental methods under conditions of varying water flow velocities, and further includes the following steps:

[0095] Step 3.3: In Step 3.7, use the air pump 19 to inject the oil-based polyurethane grout 20 into the pipe through the interface on the plastic cylindrical sleeve 9. Utilizing its slow expansion and continuous pressure, the special magnetic grout 1 penetrates into the micro gaps of the pipe and expands and solidifies in a short time to achieve complete water stoppage.

[0096] Step 11: As the oil-based polyurethane grout 20 is continuously added, it expands violently, causing some minor cracks to appear in the pipe. In addition, the special magnetic grout 1 is washed away, and the water-blocking device 23 loses its water-blocking effect. Therefore, the oil-based polyurethane grout 20 is not considered as a new water-blocking material.

[0097] Table 2 shows the results of water plugging pressure under different magnetic slurries and different plugging lengths, obtained through the above experiments.

[0098] Table 2. Water plugging pressure under different magnetic grouts and different plugging lengths

[0099]

[0100] Through the above experiments, the flow rate generated by the water-blocking device under different flow rates was obtained (Table 3).

[0101] Table 3. Flow rate generated by the water-blocking device under different flow velocities.

[0102]

Claims

1. A water-blocking device for simulating different flow velocity states and achieving visual analysis, characterized in that, The water-blocking device (23) includes a plastic pipe frame (3), the top of which is supported by a plastic cylindrical sleeve (9) through a steel pipe elbow (5) and a steel cylindrical guard (6). The plastic cylindrical sleeve (9) is connected to a pressure tank (11) through a rubber conduit hole and a rubber tube. The pressure tank (11) is provided with a grouting port (4) for storing special magnetic slurry (1). The plastic cylindrical sleeve (9) is connected to a power supply (22) through a valve (24), a DC intelligent electromagnetic flow meter (14) and a rubber tube. One end of the plastic cylindrical sleeve (9) is connected to a water tank (15) through a self-made steel frame mold (7) and a water pipe (8). The other end of the plastic cylindrical sleeve (9) is provided with a magnetic self-aggregating rod (17), which is connected to a test pump (12) through a rubber tube. The plastic cylindrical sleeve (9) is also connected to a paperless recorder (18) through a rubber conduit hole; the pressure test pump (12) is a reciprocating plunger pump, which drives the plunger through a motor, drives the slider to move, and then injects water into the pressure test object, so that the pressure gradually increases; the pressure gauge (13) is a precision instrument that can measure the dynamic water pressure value with an accuracy of 0.2%, which is used to measure the dynamic water pressure in real time when the water blocking device (23) is running, so that the paperless recorder (18) can record the collected data; the water tank (15) is connected to the air pressure loading reaction frame (27); The flow calculation formula of the DC intelligent electromagnetic flowmeter (14) is Q=Sv, where S is the cross-sectional area of ​​the pipe and v is the water flow velocity. It is used to observe the maximum flow rate reached in the water blocking device in real time. The paperless recorder (18) records the collected data and calculated data in the storage system inside the instrument with time as the basis. It does not consume any commonly used recording facilities. The stored data recorded inside the instrument is displayed on the LCD screen after calculation and simulation. In the water blocking device, it acts as a real-time recorder of multiple data such as water blocking pressure and water head flow rate for the operation of the water blocking device. The plastic cylindrical sleeve (9) is provided with an outer hole (30). It also includes a high-definition camera (26). The special magnetic slurry (1) is prepared by mixing epoxy resin A liquid, Fe3O4 magnetic powder, fly ash and large-particle iron sand (2) with 0.5mm, 1.5mm and 2.0mm. The specific weight ratio of epoxy resin A liquid, Fe3O4 magnetic powder, fly ash and large-particle iron sand (2) is 1:1~1.5:1.5~1.75:

2. The increase or decrease range of each ratio range is 0.

05. The weight ratio of the three different particle sizes of 0.5mm, 1.5mm and 2.0mm in the large-particle iron sand (2) is always 1:1:

1. The self-aggregating magnetic rod (17) is made by covering the magnetic rod with a plastic film, placing it in a beaker containing a special magnetic slurry (1), and stirring it back and forth. The magnetic rod attracts the special magnetic slurry (1), causing the special magnetic slurry (1) to adhere to the magnetic rod, making the magnetic rod magnetic. At the same time, the diameter expands and the special magnetic slurry (1) adheres to the entire magnetic rod. The self-aggregating magnetic rod (17) is inserted into a pre-made cylindrical membrane bag (16) with holes on one side and no holes on the other. The cylindrical membrane bag (16) will wrap around the self-aggregating magnetic rod (17). Then, it is pushed into a steel cylindrical protective frame (6) until the self-aggregating magnetic rod (17) is completely submerged in the plastic tube frame (3). Then, the pushing is stopped. At the same time, the special magnetic slurry (1) is poured into the pressure tank (11) to ensure that the special magnetic slurry (1) is completely submerged at the bottom and is not blocked by air in the middle of the pressure tank (11), which would affect the subsequent grouting work.

2. The water-blocking device for simulating different flow velocity states and realizing visual analysis according to claim 1, characterized in that: The pressure tank (11) is a pressure sensor storage tank, which is a tank that receives and stores compressed air after the compressed air leaves the pressure sensor (10), stores special magnetic slurry (1), and uses air pressure to inject the special magnetic slurry (1) into the plastic cylindrical sleeve (9) through the rubber tube (21). The pressure tank (11) is connected to the pressure sensor (10) via a rubber tube. When the special magnetic slurry (1) is injected into the pressure tank (11), the pressure gauge (13) is observed to determine whether the air pressure in the water-blocking device has reached the critical state. When the air pressure is uncontrollable, the pressure sensor (10) receives the maximum pressure and the water-blocking device (23) will automatically stop operating, thereby achieving the purpose of safe experiment.

3. The water-blocking device for simulating different flow velocity states and realizing visual analysis according to claim 2, characterized in that: The specially made magnetic grout (1) is prepared by mixing and stirring 100g of epoxy resin A liquid, 100g of Fe3O4 magnetic powder, 150g of fly ash and 67g each of large-particle iron sand of 0.5mm, 1.5mm and 2.0mm evenly; wherein, epoxy resin A liquid is a high-penetration modified resin grouting liquid, which is light yellow and turns gray-black after stirring.

4. The water-blocking device for simulating different flow velocity states and realizing visual analysis according to claim 3, characterized in that: When conducting the water-blocking experiment, square magnetic blocks (28) are also used. After the cylindrical membrane bag (16) with attached magnetic self-aggregating rod (17) is inserted into the steel cylindrical protective frame (6), square magnetic blocks (28) are filled around it. As the dynamic water pressure changes continuously, the square magnetic blocks (28) are attracted by the magnetic field generated by the magnetic self-aggregating rod (17) and squeezed in by the water flow, filling the gaps in the inner wall of the water-blocking device. At the same time, when the water blocking stops, the square magnetic blocks (28) can be pulled out along the outer hole (30) of the device, saving the time of grouting in the pressure tank (11).

5. The water-blocking device for simulating different flow velocity states and realizing visual analysis according to claim 4, characterized in that: Oil-based polyurethane grout (20) is also used. The oil-based polyurethane grout (20) is a polyurethane grouting material, which is a leak-stopping product. It has the characteristics of no disassembly and quick leak-stopping. After being injected into the concrete, it reacts chemically with water. The expansion and continuous pressure can penetrate the oil-based polyurethane grout (20) into the micro-cracks, expand and solidify in a short time, and achieve the purpose of complete water stop. It also includes PUP / SBS composite modified bitumen (29), which is a solid bitumen material prepared by melt blending of polyurethane solid-solid phase change material and styrene-butadiene-styrene block copolymer. By placing PUP / SBS composite modified bitumen (29) into the water-blocking device (23), PUP / SBS composite modified bitumen (29) will wrap around the special magnetic slurry (1). As the water pressure in the plastic cylindrical sleeve (9) increases, the temperature also rises, softening into a liquid state. When the water pressure decreases, the temperature decreases, and it solidifies again, thereby improving the reusability of the special magnetic slurry (1).

6. The experimental method for a water-blocking device to achieve visual analysis under simulated flow velocity conditions as described in claim 5, characterized in that, Includes the following steps: Step 1.1: Prepare a special magnetic slurry (1), and prepare the magnetic rod and various experimental components; Step 1.2: Assemble the following experimental components together: plastic pipe frame (3), grouting port (4), steel pipe elbow (5), steel cylindrical protective frame (6), self-made steel frame mold (7), plastic cylindrical sleeve (9), pneumatic loading reaction frame (27), pressure sensor (10), pressure tank (11), pressure test pump (12), pressure gauge (13), DC intelligent electromagnetic flow meter (14), and high-definition camera (26), and connect them to water pipe (8) to water tank (15); then connect them with rubber tube (21) and power supply (22) to form water blocking device (23). Step 1.3: Cover the magnetic rod with a diameter of d1 with a plastic film and put it into a beaker containing a special magnetic slurry (1). Stir it back and forth. Utilize the attraction between the magnetic rod and the special magnetic slurry (1) to make the special magnetic slurry (1) adsorb onto the magnetic rod, making the magnetic rod magnetic. At the same time, the diameter expands to d2, and the magnetic rod is covered with a binder mainly composed of magnetic mortar, thus forming a self-aggregating magnetic rod (17). Step 1.4: Insert the self-aggregating magnetic rod (17) into the pre-made cylindrical membrane bag (16) with a diameter of d2. One side has a hole and the other side does not. The cylindrical membrane bag (16) will wrap around the self-aggregating magnetic rod (17). Then push it into the steel cylindrical protective frame (6) with force. Stop pushing after the self-aggregating magnetic rod (17) is completely submerged in the plastic tube frame (3). At the same time, inject the special magnetic slurry (1) into the pressure tank (11) with an air pump (19) to ensure that the special magnetic slurry (1) is injected into the plastic cylindrical sleeve (9) through the rubber tube (21) using air pressure, and is not blocked by air in the middle of the pressure tank (11), which will affect the subsequent grouting work. Step 1.5: Before the formal water-blocking experiment, square magnetic blocks (28) and PUP / SBS composite modified asphalt (29) were added to the plastic cylindrical sleeve (9) in advance to prepare for the analysis of the water-blocking effect of the special magnetic slurry (1) in the later experiment. Step 1.6: After inserting the self-aggregating magnetic rod (17), that is, after it is completely submerged in the plastic tube frame (3), turn on the power supply (22), add water to the pressure test pump (12), and send the water to the plastic cylindrical sleeve (9) through the rubber tube (21) to simulate the scouring pressure of the moving water on the self-aggregating magnetic rod (17) under real working conditions. Make sure to observe and record the real-time water pressure data on the pressure gauge (13). When the moving water completely pushes the self-aggregating magnetic rod (17) out of the water blocking device, press the switch, the pressure test pump (12) stops working, and stops injecting water into the plastic cylindrical sleeve (9). The paperless recorder (18) records and stores the water blocking pressure, temperature and other data throughout the process. Step 1.7: Conduct experiments on the proportion of special magnetic slurry (1) according to multiple sets of different proportions, repeat experiments Step 3 to Step 6, summarize the statistical water-blocking pressure data together, and compare and refer to it; record the real motion state of the magnetic self-aggregating magnetic rod (17) captured by the high-definition camera (26), and perform frame-by-frame image processing on the captured video, and then extract the data in the image through image processing software; at the same time, compare the adsorption diameter of the magnetic rod obtained by the different proportions of special magnetic slurry (1) obtained from these multiple sets of experiments; use the data obtained by these two methods to analyze and judge the proportion of special magnetic slurry (1) when the water-blocking device can reach the maximum water-blocking pressure, thereby obtaining the relevant data of the maximum water-blocking pressure, and achieving the true purpose of the water-blocking experiment; It also includes experimental methods under different water flow conditions, and includes the following steps: Step 2.3: After the water blocking device (23) is installed in Step 1.2 and the magnetic self-aggregating rod (17) is prepared, start the power supply (22) and control the water flow from the water tank (15) to the DC intelligent electromagnetic flow meter (14) through the valve (24). Set it to three different flow velocity states: 0.5m / s, 1.0m / s, and 1.5m / s. The DC intelligent electromagnetic flow meter (14) displays the flow rate of the water flowing through the plastic cylindrical sleeve (9). According to the flow formula Q=Sv, where S is the cross-sectional area of ​​the pipe and v is the water flow velocity, the flow rate under the three different flow velocity states of 0.5m / s, 1.0m / s, and 1.5m / s can be obtained. Step 2.4: After repeating Step 1.4 and Step 1.6, it is also necessary to note that after injecting the special magnetic slurry (1) into the pressure tank (11), by observing the reading of the pressure gauge (13), it is determined whether the air pressure in the device has reached the critical state. When the air pressure is uncontrollable, the pressure sensor (10) receives the maximum pressure sensing, and the water blocking device (23) will automatically stop running, so as to achieve the purpose of visualization. It also includes experimental methods under conditions of varying water flow velocities, and further includes the following steps: Step 3.3: In Step 3.7, use an air pump (19) to inject oil-based polyurethane grout (20) into the pipe through the interface on the plastic cylindrical sleeve (9). Utilizing its slow expansion and continuous pressure, the special magnetic grout (1) penetrates into the fine gaps of the pipe and expands and solidifies in a short time to achieve complete water stoppage. Step 11: As the oily polyurethane grout (20) is continuously added, it expands violently, causing some minor cracks to appear in the pipe. The special magnetic grout (1) is washed away, and the water-blocking device (23) loses its water-blocking effect. Therefore, the oily polyurethane grout (20) is not considered as a new water-blocking material.

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