Method for testing internal hydrodynamic characteristics and particle motion of reverse erosion piping

Abstract

The invention discloses a method for testing internal hydrodynamic characteristics and particle motion of reverse erosion piping, and relates to the technical field of piping testing, and the method comprises the following steps: a, preparing a test material; b, connecting equipment; c, preparing a sample; d, sample saturation; e, the water container needs to be filled with the solution before measurement is started; f, reverse erosion piping development is measured; g, the video recorded by the second macro camera is intercepted according to different light sources and position profiles, and the first macro camera is intercepted according to different light sources and profiles. According to the device and the method, the dyke foundation silt is simulated through fused quartz particles, the silt loss condition in soil and the erosion condition of water flow to silt can be visually observed, a visual observation object is provided for people to analyze the piping phenomenon, non-intrusive measurement is achieved, the mesoscopic law of the reverse erosion piping development process can be obtained, and the measurement accuracy is improved. Comprising internal hydrodynamic characteristics and motion states of fine particles.

Description

Technical Field

[0001] The invention relates to the technical field of piping test, in particular to a method for testing the internal hydrodynamic characteristics and particle movement of reverse erosion piping. Background Art

[0002] Reverse erosion piping is a common seepage disease in earth-rock dams. It refers to the process in which gravel in the riverbed gradually moves to the weak part of the weak permeable layer downstream of the dam under the action of seepage force and flows away. Under certain hydraulic conditions, sand particles are carried out and form concentrated seepage channels in the dam foundation. The channels expand upstream along the contact surface between the strong permeable layer and the weak permeable layer, and finally penetrate the entire dam, causing it to collapse. The invisibility of reverse erosion piping makes the study of piping difficult.

[0003] The defects of existing piping research are:

[0004] 1. Prior art CN102411042A discloses a seepage erosion stress coupled piping test device. This technology does not have the function of visualizing piping. When studying piping, it is impossible to study the water flow direction and sediment loss direction inside the piping. Therefore, a test method for reverse erosion piping internal hydrodynamic characteristics and particle movement that can directly observe the water flow direction and sediment loss inside the piping is needed to solve this problem.

[0005] 2. The prior art CN104931401A discloses a model for the dynamic change of permeability coefficient during pipe erosion of gravel soil. This technology does not have the function of efficiently measuring the flow of fluid and sediment inside the pipe, and does not propose a method for directly observing the changes in the fluid inside the pipe. Therefore, a test method for the internal hydrodynamic characteristics and particle movement of reverse erosion pipes that can directly study the changes in the fluid and sediment inside the pipe and improve the measurement efficiency is needed to solve this problem.

[0006] 3. The prior art CN207908318U discloses a non-stable erosive internal piping test device. This technology does not have the function of simulating the pressure change of river bank dam caused by the change of river velocity, and cannot study the influence of river velocity change on dam piping. Therefore, a test method for the internal hydrodynamic characteristics and particle movement of reverse erosive piping that can simulate the pressure change of river bank dam caused by the change of river velocity is needed to solve this problem.

[0007] 4. The prior art CN220961144U discloses a visualization test device for particle erosion behavior of pipe bursts intervened by a suspended anti-seepage wall. This technology does not simulate the pressure generated by human activities on the embankments on both sides of the river, and thus cannot study the changes inside the pipe bursts when the embankments on both sides of the river are subjected to the pressure generated by human activities. Therefore, a test method for the internal hydrodynamic characteristics and particle movement of reverse erosion pipe bursts that can simulate the pressure generated by human activities on the embankments on both sides of the river is needed to solve this problem. Summary of the invention

[0008] One purpose of the present application is to provide a method for testing the internal hydrodynamic characteristics and particle movement of reverse erosion piping, which can solve the technical problems raised in the prior art.

[0009] To achieve the above object, the present invention provides the following technical solution: a method for testing the internal hydrodynamic characteristics and particle movement of reverse erosion piping, the method for testing the internal hydrodynamic characteristics and particle movement of reverse erosion piping comprising the following steps:

[0010] a: Preparation of test materials: Spray the fine particles with red fluorescent paint and dry them in a constant temperature box at 60°C. Mix No. 15 white oil and n-dodecane in a mass ratio of 10:1, and sprinkle polyamide particles in it. The ratio is 0.02 g of polyamide particles per 1 liter of solution.

[0011] b: Connect the equipment, connect the water inlet pipe of the head box to the output end of the water pump, connect the output end of the hose connected to the output end of the head box to the water inlet side of the model box, place the return pipe of the head box in the water supply tank, and use latex plugs to block the exhaust hole and the pipe burst port. Take the center of the top surface of the model box as point O, the central axis as the x-axis, that is, the direction toward the pipe burst port is positive, the y-axis is perpendicular to the central axis, the inside of the y-axis is positive, the z-axis is perpendicular to the xy plane, and the z-axis is vertically downward as the positive direction. The surface light source of the green laser transmitter 2 is parallel to the top surface of the model box, and the laser plane is 5mm away from the top surface of the model box, that is, z=5mm. The surface light source of the green laser transmitter 1 is perpendicular to the top surface of the model box and is 20mm away from the central axis, that is, y=-20mm. Adjust the position of the macro camera 1 so that its position is directly opposite to the center of the model box and its distance from the center of the top surface of the model box is lower than the height of the electric slide frame 2. Adjust the position of the macro camera 2 so that its viewing angle is perpendicular to the model box and its position needs to be higher than the height of the electric slide frame 3.

[0012] c: Sample preparation. The sample is made by layered compaction. First, the side plate of the model box is placed upside down, and the side plate of the model box is opened. Particles with uniform particle size are placed in the permeable layer. The ratio of the particle size to the shortest side of the permeable layer is 1: (5-10) to generate uniform water flow. A permeable baffle is placed to separate it from the sample. Fused quartz particles are placed in five batches. The sample is fused quartz particles. After the fused quartz particles are placed, they are compacted with a rubber hammer. Then, the upstream head box is slowly lifted to allow the liquid in the head box to enter the model box. When the liquid level is flush with the fused quartz particles, the next layer of quartz particles is placed and compacted until the sample fills the model box. Then the side plate is installed and the model box is straightened.

[0013] d: When the sample is saturated, pull out the latex plugs of the vent and the latex plugs of the pipe outlet, and slowly raise the upstream water head box at a speed of 2 mm per minute. When the height of the upstream water head box is flush with the top surface of the sample, stop lifting and let it stand for more than 24 hours to discharge the bubbles in the sample and make the sample completely saturated;

[0014] e: Before the measurement begins, the water container must be filled with solution to ensure that the solution flowing out of the reverse erosion piping model box can be measured by the electronic scale in time after the test begins;

[0015] f: Reverse erosion piping development measurement, lift the upstream water head box, lift it 20mm each time, measure the current water head, first turn on the green laser emitter 1 and macro camera 2, keep them for 5 seconds and then turn them off, turn on the green laser emitter 2 and macro camera 1 at the same time, keep them for 5 seconds and then turn off the green laser emitter 2, turn on the top ultraviolet light emitter and macro camera 2, keep them for 5 seconds and then turn off the top ultraviolet light emitter, macro camera 1 and macro camera 2, then lower the green laser emitter 2 horizontally by 10mm at a speed of 2mm / s, and at the same time lower the green laser emitter 1 along the Move 10mm in the positive direction of the y-axis, stop after reaching the specified position, and repeat the above steps to measure different sections. When the green laser emitter 2 moves to the position of z=45mm, and the green laser emitter 1 moves to the position of y=20mm, and the measurement is completed, the green laser emitter 1 and the green laser emitter 2 move to the initial position, and repeat the above measurement steps, that is, repeat the measurement 3 times in total under each water head condition, and then lift the upstream water head box. When the concentrated leakage channel in the sample develops to the inlet end or the water head box is lifted to the maximum height, stop the measurement;

[0016] g: The video recorded by macro camera 2 is intercepted according to different light sources and sections, and the video recorded by macro camera 1 is intercepted according to different light sources and sections. The number of frames between the intercepted pictures is the number of frames of the video recorded by the camera. The intercepted pictures are imported into the image processing software, and the pictures are corrected according to the transparent ruler pasted on the model box. The corrected images are used to calculate the flow field and the movement of fine particles using the particle image velocimetry algorithm and particle tracking velocimetry method.

[0017] Preferably, the step f also includes the following steps:

[0018] The electric telescopic unit drives the pressure plate to move up and down, thereby adjusting the pressure of the water in the head box on the permeable layer and the head box, thereby simulating the impact of the flow of water in the river on the river bank dam.

[0019] Preferably, the test system for the internal hydrodynamic characteristics and particle movement of reverse erosion piping includes a model box, a head box, a water supply tank, a water pump, a hose, a water container, a water tank, an electronic scale and a synchronous controller, the input end of the model box is connected to the output end of the hose, the output end of the head box is connected to the input end of the hose, the output end of the water supply tank is connected to the input end of the water pump, a piping outlet is opened through the top of the model box, a rectangular box is installed on the top of the model box, the rectangular box is located on the outside of the piping outlet, and the rectangular box is connected to the water container through a water guide frame, the output end of the water container is connected to the input end of the water tank through a pipe, the water tank is installed on the top of the electronic scale, and the synchronous controller is respectively connected to the water pump and the electronic scale electrical signals.

[0020] Preferably, a water-permeable layer is provided inside the model box, a water-permeable baffle is provided inside the model box, and the water-permeable baffle is located on one side of the water-permeable layer, a sample is provided inside the model box, a transparent ruler is installed on the front and top of the model box, a plurality of exhaust holes are opened through the top of the model box, a side panel is provided on the back of the model box, a latex water-stop pad is installed on the front of the side panel, and the side panel and the model box are connected by pressure bolts.

[0021] Preferably, the test system for the internal hydrodynamic characteristics and particle movement of reverse erosion piping also includes a winch and a fixed pulley. The winch and the head box are connected by a steel wire rope, and the winch is connected to the synchronous controller by electrical signals. The fixed pulley is used to guide the steel wire rope.

[0022] Preferably, the test system for the internal hydrodynamic characteristics and particle movement of reverse erosion piping also includes a return pipe, the input end of the return pipe is connected to the front output end of the head box, and the output end of the return pipe is connected to the top input end of the water supply tank.

[0023] Preferably, a frame body 2 is installed on the top of the water container, a plurality of tension sensors are installed on the bottom of the frame body 2, and the tension sensors are connected to the synchronous controller via electrical signals, and a tray with a filter is installed on the bottom input end of the tension sensor.

[0024] Preferably, the test system for the internal hydrodynamic characteristics and particle movement of reverse erosion piping also includes a green laser emitter 1, a green laser emitter 2, an ultraviolet light emitter, a macro camera 1, a macro camera 2, an electric slide rail frame 1, an electric slide rail frame 2, an electric slide rail frame 3, a camera bracket 1 and a camera bracket 2, the green laser emitter 1 is installed on the top inner wall of the electric slide rail frame 2, and the green laser emitter 1 is located above the model box, the green laser emitter 2 is installed on the top of the electric slide rail frame 3, and the green laser emitter 2 is located below the model box, and the ultraviolet light emitter is installed on the electric slide rail frame The top inner wall of the camera bracket 1 is connected to the top inner wall of the camera bracket 1, and the ultraviolet light emitter is located above the model box, the macro camera 1 is installed on the top inner wall of the camera bracket 1, and the macro camera 1 is located above the model box, the macro camera 2 is installed on the top of the camera bracket 2, and the macro camera 2 is located in front of the model box, the electric slide frame 1 is slidingly connected with the electric slide frame 2 and the electric slide frame 3 respectively, and the synchronization controller is respectively connected with the green laser emitter 1, the green laser emitter 2, the ultraviolet light emitter, the macro camera 1, the macro camera 2, the electric slide frame 1, the electric slide frame 2, the electric slide frame 3, the camera bracket 1 and the camera bracket 2 by electrical signals.

[0025] Preferably, a frame body 1 is installed on the top of the water head box, an electric telescopic unit 1 is installed on the top of the frame body 1, a pressure sensor is installed on the output end of the electric telescopic unit 1, a lifting rod is installed on the bottom input end of the pressure sensor, a pressure plate is installed on one end of the lifting rod, and the pressure plate is located inside the water head box, and the synchronous controller is respectively connected to the electric telescopic unit 1 and the pressure sensor by electrical signals.

[0026] Preferably, an electric telescopic unit 2 is installed on the front of the model box, and the electric telescopic unit 2 is connected to the synchronous controller via an electrical signal, and a scraping rod is installed at the output end of the electric telescopic unit 2.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. The present invention simulates the embankment foundation sediment by fused quartz particles, which can visually observe the sediment loss inside the soil and the erosion of the sediment by water flow, providing an intuitive observation object for people to analyze the piping phenomenon, realizing non-invasive measurement, and obtaining the microscopic laws of the development process of reverse erosion piping, including the internal hydrodynamic characteristics and the movement state of fine particles.

[0029] 2. The test steps proposed in the present invention ensure the effectiveness of sample preparation, and the designed observation method can effectively improve the measurement efficiency. This technology is of great significance for clarifying the development characteristics of reverse erosion piping, and provides support for predicting the development of reverse erosion piping.

[0030] 3. The present invention drives the pressure plate to move up and down through the electric telescopic unit, thereby adjusting the pressure of the water in the water head box on the permeable layer and the water head box, and then simulating the impact of the flow of water in the river on the river bank dam.

[0031] 4. The present invention drives the scraper rod to move forward and backward through the electric telescopic unit 2, thereby simulating the pressure generated by human activities on the embankments on both sides of the river. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a flow chart of the testing method of the present invention;

[0033] Figure 2 It is a schematic diagram of the system structure of the present invention;

[0034] Figure 3 It is a schematic diagram of the structure of the model box of the present invention;

[0035] Figure 4 It is a front cross-sectional view of a model box of the present invention;

[0036] Figure 5 It is a schematic diagram of the structure of the scraping rod of the present invention;

[0037] Figure 6 It is a schematic diagram of the structures of the electric slide rail frame 1, the electric slide rail frame 2 and the electric slide rail frame 3 of the present invention;

[0038] Figure 7 It is a schematic diagram of the water tank structure of the present invention;

[0039] Figure 8 It is a schematic structural diagram of a water container of the present invention;

[0040] Fig. 9 It is a schematic diagram of the water head box structure of the present invention.

[0041] In the figure: 1. Model box; 2. Permeable layer; 3. Head box; 4. Water supply tank; 5. Water pump; 6. Return pipe; 7. Hose; 8. Winch; 10. Fixed pulley; 11. Green laser transmitter 1; 12. Green laser transmitter 2; 13. Ultraviolet light transmitter; 14. Macro camera 1; 15. Macro camera 2; 16. Water container; 17. Water tank; 18. Electronic scale; 19. Synchronous controller; 20. Electric slide frame 1; 21. Electric slide frame 2; 22. Electric slide frame Frame three; 23. Camera bracket one; 24. Camera bracket two; 25. Pipe burst; 26. Permeable baffle; 27. Side panel; 28. Latex water-stop pad; 29. ​​Exhaust hole; 30. Transparent ruler; 31. Tension sensor; 32. Tray with filter; 33. Test specimen; 34. Frame one; 35. Electric telescopic unit one; 36. Pressure sensor; 37. Lifting rod; 38. Pressure plate; 39. Electric telescopic unit two; 40. Scraping rod; 41. Frame two; 42. Rectangular box; 43. Wire rope. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "front end", "rear end", "two ends", "one end", "the other end" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0044] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0045] See also Figure 1, an embodiment provided by the present invention: a method for testing the internal hydrodynamic characteristics and particle movement of reverse erosion piping;

[0046] The test method for the internal hydrodynamic characteristics and particle movement of reverse erosion piping includes the following steps:

[0047] a: Preparation of test materials: Spray the fine particles with red fluorescent paint and dry them in a constant temperature box at 60°C. Mix No. 15 white oil and n-dodecane in a mass ratio of 10:1, and sprinkle polyamide particles in it. The ratio is 0.02 g of polyamide particles per 1 liter of solution.

[0048] b: Connect the equipment, connect the water inlet pipe of the head box 3 to the output end of the water pump 5, connect the output end of the hose 7 connected to the output end of the head box 3 to the water inlet side of the model box 1, place the return pipe 6 of the head box 3 in the water supply tank 4, and use latex plugs to seal the exhaust hole 29 and the pipe outlet 25. Take the center of the top surface of the model box 1 as point O, the central axis as the x-axis, that is, the direction toward the pipe outlet 25 is positive, the y-axis is perpendicular to the central axis, the y-axis has the inner side as the positive direction, the z-axis is perpendicular to the xy plane, and the z-axis is vertically downward as the positive direction. The green laser emitter 212 The surface light source is parallel to the top surface of the model box 1, the laser plane is 5mm away from the top surface of the model box 1, that is, z=5mm, the surface light source of the green laser emitter 11 is perpendicular to the top surface of the model box 1, and is 20mm away from the central axis, that is, y=-20mm, adjust the position of the macro camera 14 so that its position is directly opposite to the center of the model box 1, and the distance from the center of the top surface of the model box 1 is lower than the height of the electric slide frame 21, adjust the position of the macro camera 2 15 so that its viewing angle is perpendicular to the model box 1, and its position needs to be higher than the height of the electric slide frame 3 22;

[0049] c: Preparation of sample 33. Sample 33 is made by layered compaction. First, the side plate 27 of the model box 1 is placed upside down, and the side plate 27 of the model box 1 is opened. Particles with uniform particle size are placed in the permeable layer 2. The ratio of the particle size to the shortest side of the permeable layer 2 is 1: (5-10) to generate uniform water flow. A permeable baffle 26 is placed to separate it from sample 33. Fused quartz particles are placed in five batches. Sample 33 is fused quartz particles. After the fused quartz particles are placed, they are compacted with a rubber hammer. Then, the upstream head box 3 is slowly lifted to allow the liquid in the head box 3 to enter the model box 1. When the liquid level is flush with the fused quartz particles, the next layer of quartz particles is placed and compacted until the sample 33 fills the model box 1. Then, the side plate 27 is installed to straighten the model box 1.

[0050] d: When the sample 33 is saturated, the latex plugs of the vent 29 and the latex plugs of the pipe outlet 25 are pulled out, and the upstream water head box 3 is slowly raised at a speed of 2 mm per minute. When the height of the upstream water head box 3 is flush with the top surface of the sample 33, the lifting is stopped and the sample is left to stand for more than 24 hours to discharge the bubbles in the sample 33 and make the sample 33 completely saturated;

[0051] e: Before the measurement begins, the water container 16 needs to be filled with the solution. This is to ensure that after the test begins, the solution flowing out of the reverse erosion piping model box 1 can be measured by the electronic scale 18 in a timely manner;

[0052] f: Reverse erosion piping development measurement, lift the upstream water head box 3, each time lift 20mm, measure the current water head, first turn on the green laser emitter 11 and the macro camera 15, keep them on for 5 seconds and then turn them off, turn on the green laser emitter 12 and the macro camera 14 at the same time, keep them on for 5 seconds and then turn them off, turn on the top ultraviolet light emitter 13 and the macro camera 15, keep them on for 5 seconds and then turn them off, then lower the green laser emitter 12 horizontally by 10mm at a speed of 2mm / s, and at the same time turn on the green laser emitter 12 and the macro camera 14 at the same time ... at the same time, turn on the top ultraviolet light emitter 13 and the macro camera 14 at the same time, turn on the top ultraviolet light emitter 13 and the macro camera 14 at the same time, turn on the top ultraviolet light emitter 13 and the macro camera 14 at the same time, The green laser emitter 11 moves 10 mm in the positive direction of the y-axis, stops when it reaches the specified position, and repeats the above steps to measure different sections. When the green laser emitter 12 moves to the position of z=45 mm, and the green laser emitter 11 moves to the position of y=20 mm, and the measurement is completed, the green laser emitter 11 and the green laser emitter 2 move to the initial position, and repeat the above measurement steps, that is, the measurement is repeated 3 times in total under each water head condition, and then the upstream water head box 3 is lifted. When the concentrated leakage channel in the sample 33 develops to the inlet end or the water head box 3 is lifted to the maximum height, the measurement is stopped;

[0053] g: The video recorded by the macro camera 2 15 is intercepted according to different light sources and sections, and the macro camera 1 14 is intercepted according to different light sources and sections. The number of frames between the intercepted pictures is the number of frames of the video recorded by the camera. The intercepted pictures are imported into the image processing software, and the pictures are corrected according to the transparent ruler 30 pasted on the model box 1. The corrected images are used to calculate the flow field and the movement of fine particles using the particle image velocimetry algorithm and the particle tracking velocimetry method.

[0054] Step f also includes the following steps:

[0055] The pressure plate 38 is driven to move up and down by the electric telescopic unit 35, so as to adjust the pressure of the water in the water head box 3 on the permeable layer 2 and the water head box 3, thereby simulating the impact of the flow of water in the river on the river bank dam.

[0056] See also Figure 2 , Figure 3and Figure 4 , an embodiment provided by the present invention: a method for testing the internal hydrodynamic characteristics and particle movement of reverse erosion piping;

[0057] The test system for the internal hydrodynamic characteristics and particle movement of reverse erosion piping includes a model box 1, a head box 3, a water supply box 4, a water pump 5, a hose 7, a water container 16, a water tank 17, an electronic scale 18 and a synchronous controller 19. The input end of the model box 1 is connected to the output end of the hose 7, the output end of the head box 3 is connected to the input end of the hose 7, the output end of the water supply box 4 is connected to the input end of the water pump 5, a piping port 25 is opened through the top of the model box 1, and a rectangular box 42 is installed on the top of the model box 1. The rectangular box 42 is located outside the pipe burst port 25, and the rectangular box 42 is connected to the water container 16 through a water guide frame. The output end of the water container 16 is connected to the input end of the water tank 17 through a pipeline. The water tank 17 is installed on the top of the electronic scale 18. The synchronous controller 19 is connected to the water pump 5 and the electronic scale 18 respectively. The model box 1 is used to provide a space for pipe burst testing. The water head box 3 can provide water for the model box 1. The water supply tank 4 can provide a water source for the water head box 3. The water pump 5 can convert electrical energy into power. The water in the water supply tank 4 can be transferred into the water head tank 3, the hose 7 can provide a path for the water in the water head tank 3 to enter the model box 1, the water container 16 can provide a storage space for the water from the model box 1, the water tank 17 can store the water from the water container 16, the electronic scale 18 can measure the weight of the water in the water tank 17, the pipe spurt port 25 can provide a path for the water in the model box 1 to flow out, and the rectangular box 42 can provide a path for the water flowing out of the pipe spurt port 25 to enter the water guide frame between the rectangular box 42 and the water container 16. The synchronous controller 19 can receive signals from the macro camera 14, the macro camera 15, the electronic scale 18, the tension sensor 31 and the pressure sensor 36, and can also control the water pump 5, the winch 8, the green laser emitter 11, the green laser emitter 2 12, the ultraviolet light emitter 13, the electric slide frame 1 20, the electric slide frame 21, the electric slide frame 3 22, the camera bracket 1 23, the camera bracket 24, the electric telescopic unit 1 35 and the electric telescopic unit 2 39.

[0058] See also Figure 2 and Figure 3 , an embodiment provided by the present invention: a method for testing the internal hydrodynamic characteristics and particle movement of reverse erosion piping;

[0059] It includes a water-permeable layer 2, the interior of the model box 1 is provided with the water-permeable layer 2, the interior of the model box 1 is provided with a water-permeable baffle 26, and the water-permeable baffle 26 is located on one side of the water-permeable layer 2, the interior of the model box 1 is provided with a sample 33, a transparent ruler 30 is installed on the front and top of the model box 1, a plurality of exhaust holes 29 are opened through the top of the model box 1, a side panel 27 is provided on the back of the model box 1, a latex water-stop pad 28 is installed on the front of the side panel 27, the side panel 27 and the model box 1 are connected by pressurized bolts, the water-permeable layer 2 can make the water entering the model box 1 flow evenly, the water-permeable baffle 26 is a hollow baffle, which can make water enter the sample 33 from the water-permeable layer 2, the transparent ruler 30 can facilitate people to measure the position of the water-permeable baffle 26 in the model box 1, the exhaust holes 29 can provide a path for the gas in the model box 1 to be discharged, the side panel 27 can close the back opening of the model box 1, and the latex water-stop pad 28 can seal the gap between the side panel 27 and the model box 1.

[0060] See also Figure 2 , an embodiment provided by the present invention: a method for testing the internal hydrodynamic characteristics and particle movement of reverse erosion piping;

[0061] The test system for the internal hydrodynamic characteristics and particle movement of reverse erosion piping also includes a winch 8 and a fixed pulley 10. The winch 8 and the head box 3 are connected by a wire rope 43, and the winch 8 is electrically connected to the synchronization controller 19. The fixed pulley 10 is used to guide the wire rope 43. The winch 8 can convert electrical energy into kinetic energy, thereby driving the wire rope 43 to move. The wire rope 43 can drive the head box 3 to move up and down by moving, and the fixed pulley 10 can change the direction of one end of the wire rope 43.

[0062] See also Figure 2 , an embodiment provided by the present invention: a method for testing the internal hydrodynamic characteristics and particle movement of reverse erosion piping;

[0063] The test system for the internal hydrodynamic characteristics and particle movement of reverse erosion pipe surge also includes a return pipe 6, the input end of the return pipe 6 is connected to the front output end of the head tank 3, and the output end of the return pipe 6 is connected to the top input end of the water supply tank 4. The return pipe 6 can provide a transmission path for the liquid in the head tank 3 to enter the water supply tank 4.

[0064] See also Figure 2 , Figure 7 and Figure 8 , an embodiment provided by the present invention: a method for testing the internal hydrodynamic characteristics and particle movement of reverse erosion piping;

[0065] It includes a frame body 41, the frame body 41 is installed on the top of the water container 16, a plurality of tension sensors 31 are installed on the bottom of the frame body 41, and the tension sensors 31 are electrically connected to the synchronization controller 19, a tray 32 with a filter is installed at the bottom input end of the tension sensor 31, the frame body 41 can provide an installation position for the tension sensor 31, the tension sensor 31 can detect the tension from the tray 32 with a filter, thereby detecting the weight of the material inside the tray 32 with a filter, and the tray 32 with a filter can separate the sample 33 and water that enters the water container 16 in the model box 1.

[0066] See also Figure 1 , Figure 2 and Figure 6 , an embodiment provided by the present invention: a method for testing the internal hydrodynamic characteristics and particle movement of reverse erosion piping;

[0067] The test system for the internal hydrodynamic characteristics and particle movement of reverse erosion piping also includes a green laser emitter 11, a green laser emitter 2 12, an ultraviolet light emitter 13, a macro camera 14, a macro camera 2 15, an electric slide rail frame 1 20, an electric slide rail frame 2 21, an electric slide rail frame 3 22, a camera bracket 1 23 and a camera bracket 2 24. The green laser emitter 11 is installed on the top inner wall of the electric slide rail frame 21, and the green laser emitter 11 is located above the model box 1, and the green laser emitter 2 12 is installed At the top of the electric slide rail frame 3 22, and the green laser emitter 2 12 is located below the model box 1, the ultraviolet light emitter 13 is installed on the top inner wall of the electric slide rail frame 21, and the ultraviolet light emitter 13 is located above the model box 1, the macro camera 1 14 is installed on the top inner wall of the camera bracket 1 23, and the macro camera 1 14 is located above the model box 1, the macro camera 2 15 is installed on the top of the camera bracket 24, and the macro camera 2 15 is located in front of the model box 1, the electric slide rail frame 1 20 is respectively connected to the electric slide rail frame 2 21 and The electric slide rail frame 3 22 is slidably connected, and the synchronous controller 19 is respectively connected with the green laser emitter 1 11, the green laser emitter 2 12, the ultraviolet light emitter 13, the macro camera 1 14, the macro camera 2 15, the electric slide rail frame 1 20, the electric slide rail frame 2 21, the electric slide rail frame 3 22, the camera bracket 1 23 and the camera bracket 2 24 for electrical signals. The green laser emitter 1 11 and the green laser emitter 2 12 can emit lasers to excite the polyamide particles, which is convenient for tracing the polyamide particles. The ultraviolet light emitter 13 can trace the fluorescently dyed particles when emitting ultraviolet light, macro camera 1 14 and macro camera 2 15 can respectively record the top and bottom of the model box 1, and record the activities of the liquid and particles inside the model box 1 from the top and bottom, the electric slide frame 1 20 can drive the electric slide frame 1 20 and the electric slide frame 2 21 to move forward and backward, the electric slide frame 2 21 can drive the green laser emitter 1 1 to move up, down, left and right, and the electric slide frame 3 22 can drive the green laser emitter 2 12 to move up, down, left and right.

[0068] See also Figure 2 and Fig. 9 , an embodiment provided by the present invention: a method for testing the internal hydrodynamic characteristics and particle movement of reverse erosion piping;

[0069] The water head box 3 includes a frame 34, a frame 34 is installed on the top of the frame 34, an electric telescopic unit 35 is installed on the top of the frame 34, a pressure sensor 36 is installed on the output end of the electric telescopic unit 35, a lifting rod 37 is installed on the bottom input end of the pressure sensor 36, a pressure plate 38 is installed on one end of the lifting rod 37, and the pressure plate 38 is located inside the water head box 3, and the synchronous controller 19 is connected to the electric telescopic unit 35 and the pressure sensor 36 respectively. The frame 34 can be used for the electric telescopic unit 35. 5 improves the installation position. The electric telescopic unit 1 35 is an electric telescopic rod, which can convert electrical energy into kinetic energy, thereby driving the pressure sensor 36 and the lifting rod 37 to move up and down. The pressure sensor 36 can detect the pressure of the pressure plate 38 on the water in the water head box 3. The lifting rod 37 can drive the pressure plate 38 to move up and down by moving up and down. The pressure plate 38 can pressurize the water in the water head box 3 by moving downward, thereby increasing the pressure of the water in the water head box 3 on the permeable layer 2 in the model box 1, simulating the pressure of water on the river bank dam when the river flows.

[0070] See also Figure 2 , Figure 3 , Figure 4 and Figure 5 , an embodiment provided by the present invention: a method for testing the internal hydrodynamic characteristics and particle movement of reverse erosion piping;

[0071] It includes an electric telescopic unit 39. The front of the model box 1 is equipped with the electric telescopic unit 39, and the electric telescopic unit 39 is electrically connected to the synchronous controller 19. The output end of the electric telescopic unit 39 is equipped with a scraping rod 40. The electric telescopic unit 39 is an electric telescopic rod, which can convert electrical energy into kinetic energy, thereby driving the scraping rod 40 to move back and forth. The scraping rod 40 moves back and forth to scrape and pressurize the sample 33, thereby simulating the pressure of the embankments on both sides of the river when they are subjected to human activities.

[0072] Working principle: Before using the test system for the internal hydrodynamic characteristics and particle movement of reverse erosion piping, you should first check whether the test method for the internal hydrodynamic characteristics and particle movement of reverse erosion piping has any problems that affect the use. The water pump 5 transports the water in the water supply tank 4 into the water head tank 3, lifts the upstream water head tank 3, and lifts it 20mm each time. The current water head is measured. First, turn on the green laser transmitter 11 and the macro camera 2 15, and turn them off after 5 seconds. At the same time, turn on the green laser transmitter 2 12 and the macro camera 14, and turn them off after 5 seconds. The top ultraviolet light emitter 13 is turned on for 5 seconds, and then the top ultraviolet light emitter 13 and the macro camera 14 are turned off. Then the green laser emitter 12 is lowered horizontally by 10mm at a speed of 1mm / s. At the same time, the green laser emitter 11 moves 10mm along the positive direction of the y-axis and stops after reaching the specified position. The above steps are repeated to measure different sections. When the green laser emitter 12 moves to the position of z=45mm, and the green laser emitter 11 moves to the position of y=20mm, and the measurement is completed, the green laser The light emitter 11 and the green laser emitter 2 12 are moved to the initial position, and the aforementioned measurement steps are repeated, that is, the measurement is repeated 3 times in total under each water head condition, and then the upstream water head box 3 is lifted. When the concentrated leakage channel in the sample 33 develops to the inlet end, the lifting of the water head box 3 is stopped, and the measurement is stopped. The video recorded by the macro camera 2 15 is intercepted according to the profiles at different positions, and the macro camera 1 14 is intercepted according to different light sources and profiles. The number of frames between the intercepted pictures is the number of frames of the camera recording video. The intercepted pictures are imported into the image processing software, and the image is used. The particle image velocimetry algorithm and the particle tracking velocimetry method are used to calculate the flow field and the movement of fine particles. When it is necessary to simulate the impact of the flow of water in the river on the river bank dam, the electric telescopic unit 1 35 is used to drive the pressure plate 38 to move up and down, thereby adjusting the pressure of the water in the head box 3 on the permeable layer 2 and the head box 3, thereby simulating the impact of the flow of water in the river on the river bank dam. When the pressure generated by human activities on the dams on both sides of the river is needed, the electric telescopic unit 2 39 is used to drive the scraper rod 40 to move back and forth, thereby simulating the pressure generated by human activities on the dams on both sides of the river.

[0073] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, from all points of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention, and any reference signs in the claims should not be regarded as limiting the rights involved.

Claims

1. A method for testing the internal hydrodynamic characteristics and particle movement of reverse erosion piping, characterized in that: The test method for the internal hydrodynamic characteristics and particle movement of reverse erosion piping comprises the following steps: a: Preparation of test materials: Spray the fine particles with red fluorescent paint and dry them in a constant temperature box at 60°C. Mix No. 15 white oil and n-dodecane in a mass ratio of 10:1, and sprinkle polyamide particles in it. The ratio is 0.02 g of polyamide particles per 1 liter of solution. b: Connect the equipment, connect the water inlet pipe of the head box (3) to the output end of the water pump (5), connect the output end of the hose (7) connected to the output end of the head box (3) to the water inlet side of the model box (1), place the return pipe (6) of the head box (3) in the water supply tank (4), seal the exhaust hole (29) and the pipe opening (25) with a latex plug, take the center of the top surface of the model box (1) as point O, the central axis as the x-axis, that is, the direction toward the pipe opening (25) is positive, the y-axis is perpendicular to the central axis, the y-axis is positive with the inner side as the positive direction, the z-axis is perpendicular to the xy plane, and the z-axis is vertically downward as the positive direction, and the green laser transmitter II (12 ) Its surface light source is parallel to the top surface of the model box (1), the laser plane is 5 mm away from the top surface of the model box (1), that is, z=5 mm, the surface light source of the green laser emitter (11) is perpendicular to the top surface of the model box (1), and is 20 mm away from the central axis, that is, y=-20 mm, the position of the macro camera (14) is adjusted so that its position is directly opposite to the center of the model box (1), and the distance from the center of the top surface of the model box (1) is lower than the height of the electric slide frame (21), the position of the macro camera (15) is adjusted so that its viewing angle is perpendicular to the model box (1), and its position needs to be higher than the height of the electric slide frame (22); c: Preparation of sample (33). Sample (33) is prepared by layered compaction. First, the side plate (27) of the model box (1) is placed upside down, the side plate (27) of the model box (1) is opened, and particles with uniform particle size are placed in the permeable layer (2). The ratio of the particle size to the shortest side of the permeable layer (2) is 1: (5-10) to generate a uniform water flow, and place a water-permeable baffle (26) to separate it from the sample (33), put the fused quartz particles in five times, the sample (33) is the fused quartz particles, and after the fused quartz particles are placed, they are compacted with a rubber hammer, and then the upstream head box (3) is slowly lifted to allow the liquid in the head box (3) to enter the model box (1). When the liquid surface is flush with the fused quartz particles, the next layer of quartz particles is placed and compacted until the sample (33) fills the model box (1), and then the side plate (27) is installed to straighten the model box (1); d: When the sample (33) is saturated, the latex plugs of the vent (29) and the latex plugs of the pipe outlet (25) are pulled out, and the upstream water head box (3) is slowly raised at a speed of 2 mm per minute. When the height of the upstream water head box (3) is flush with the top surface of the sample (33), the lifting is stopped and the sample (33) is left to stand for more than 24 hours to discharge the bubbles in the sample (33) and make the sample (33) completely saturated; e: Before the measurement begins, the water container (16) needs to be filled with solution, in order to ensure that after the test begins, the solution flowing out of the reverse erosion piping model box (1) can be measured promptly by the electronic scale (18); f: Reverse erosion piping development measurement, lift the upstream water head box (3), lift it 20mm each time, measure the current water head, first turn on the green laser emitter 1 (11) and macro camera 2 (15), keep them on for 5 seconds and then turn them off, turn on the green laser emitter 2 (12) and macro camera 1 (14) at the same time, keep them on for 5 seconds and then turn off the green laser emitter 2 (12), turn on the top ultraviolet light emitter (13) and macro camera 2 (15), keep them on for 5 seconds and then turn off the top ultraviolet light emitter (13), macro camera 1 (14) and macro camera 2 (15), then lower the green laser emitter 2 (12) horizontally by 10mm at a speed of 2mm / s, and at the same time turn on the green laser emitter 2 (12) and macro camera 1 (14). The green laser emitter 1 (11) moves 10 mm in the positive direction of the y-axis, stops when it reaches the specified position, and repeats the above steps to measure different sections. When the green laser emitter 2 (12) moves to the position of z=45 mm, the green laser emitter 1 (11) moves to the position of y=20 mm, and after the measurement is completed, the green laser emitter 1 (11) and the green laser emitter 2 (12) move to the initial position, and repeat the above measurement steps, that is, the measurement is repeated 3 times in total under each water head condition, and then the upstream water head box (3) is lifted. When the concentrated leakage channel in the sample (33) develops to the inlet end or the water head box (3) is lifted to the maximum height, the measurement is stopped; g: The video recorded by the macro camera 2 (15) is intercepted according to different light sources and sections, and the macro camera 1 (14) is intercepted according to different light sources and sections. The number of frames between the intercepted pictures is the number of frames of the video recorded by the camera. The intercepted pictures are imported into the image processing software, and the pictures are corrected according to the transparent ruler (30) pasted on the model box (1). The corrected images are used to calculate the flow field and the movement of fine particles using the particle image velocimetry algorithm and the particle tracking velocimetry method.

2. A method for testing the internal hydrodynamic characteristics and particle movement of reverse erosion piping according to claim 1, characterized in that: The step f also includes the following steps: The pressure plate (38) is driven to move up and down by the electric telescopic unit (35), thereby adjusting the pressure of the water in the water head box (3) on the permeable layer (2) and the water head box (3), thereby simulating the impact of the flow of water in the river on the river bank dam.

3. A testing system for the internal hydrodynamic characteristics and particle movement of reverse erosion piping, applicable to the testing method for the internal hydrodynamic characteristics and particle movement of reverse erosion piping as claimed in any one of claims 1 to 2, characterized in that: The test system for the internal hydrodynamic characteristics and particle movement of reverse erosion piping comprises a model box (1), a head box (3), a water supply box (4), a water pump (5), a hose (7), a water container (16), a water tank (17), an electronic scale (18) and a synchronous controller (19), wherein the input end of the model box (1) is connected to the output end of the hose (7), the output end of the head box (3) is connected to the input end of the hose (7), the output end of the water supply box (4) is connected to the input end of the water pump (5), and the model A pipe outlet (25) is provided through the top of the mold box (1), a rectangular box (42) is installed on the top of the mold box (1), the rectangular box (42) is located outside the pipe outlet (25), and the rectangular box (42) is connected to a water container (16) through a water guide frame, the output end of the water container (16) is connected to the input end of a water tank (17) through a pipeline, the water tank (17) is installed on the top of an electronic scale (18), and a synchronous controller (19) is respectively connected to the water pump (5) and the electronic scale (18) through electrical signals.

4. A test system for the internal hydrodynamic characteristics and particle movement of reverse erosion piping according to claim 3, characterized in that: The model box (1) is provided with a water-permeable layer (2) inside, a water-permeable baffle (26) inside, and the water-permeable baffle (26) is located on one side of the water-permeable layer (2), a sample (33) is provided inside the model box (1), a transparent scale (30) is installed on the front and top of the model box (1), a plurality of exhaust holes (29) are opened through the top of the model box (1), a side panel (27) is provided on the back of the model box (1), a latex water-stop pad (28) is installed on the front of the side panel (27), and the side panel (27) and the model box (1) are connected by pressure bolts.

5. A test system for the internal hydrodynamic characteristics and particle movement of reverse erosion piping according to claim 3, characterized in that: The test system for the internal hydrodynamic characteristics and particle movement of reverse erosion piping also includes a winch (8) and a fixed pulley (10), the winch (8) and the head box (3) are connected via a steel wire rope (43), the winch (8) is electrically connected to a synchronous controller (19), and the fixed pulley (10) is used to guide the steel wire rope (43).

6. A testing system for the internal hydrodynamic characteristics and particle movement of reverse erosion piping according to claim 3, characterized in that: The test system for the internal hydrodynamic characteristics and particle movement of reverse erosion piping also includes a return pipe (6), the input end of the return pipe (6) is connected to the front output end of the head box (3), and the output end of the return pipe (6) is connected to the top input end of the water supply box (4).

7. A testing system for the internal hydrodynamic characteristics and particle movement of reverse erosion piping according to claim 3, characterized in that: A frame body 2 (41) is installed on the top of the water container (16), a plurality of tension sensors (31) are installed on the bottom of the frame body 2 (41), and the tension sensors (31) are connected to the synchronous controller (19) via electrical signals, and a tray (32) with a filter is installed at the bottom input end of the tension sensor (31).

8. A testing system for the internal hydrodynamic characteristics and particle movement of reverse erosion piping according to claim 3, characterized in that: The test system for the internal hydrodynamic characteristics and particle movement of reverse erosion piping also includes a green laser emitter 1 (11), a green laser emitter 2 (12), an ultraviolet light emitter (13), a macro camera 1 (14), a macro camera 2 (15), an electric slide rail frame 1 (20), an electric slide rail frame 2 (21), an electric slide rail frame 3 (22), a camera bracket 1 (23) and a camera bracket 2 (24), wherein the green laser emitter 1 (11) is mounted on the top inner wall of the electric slide rail frame 2 (21), and the green laser emitter 1 (11) is located above the model box (1), the green laser emitter 2 (12) is mounted on the top of the electric slide rail frame 3 (22), and the green laser emitter 2 (12) is located below the model box (1), the ultraviolet light emitter (13) is mounted on the top inner wall of the electric slide rail frame 2 (21), and the ultraviolet light emitter (13) is mounted on the top inner wall of the electric slide rail frame 2 (21), and the ultraviolet light emitter (14) is mounted on the top inner wall of the electric slide rail frame 2 (21). The light emitter (13) is located above the model box (1), the macro camera 1 (14) is mounted on the top inner wall of the camera bracket 1 (23), and the macro camera 1 (14) is located above the model box (1), the macro camera 2 (15) is mounted on the top of the camera bracket 2 (24), and the macro camera 2 (15) is located in front of the model box (1), the electric slide rail frame 1 (20) is respectively slidably connected with the electric slide rail frame 2 (21) and the electric slide rail frame 3 (22), and the synchronous controller (19) is respectively connected with the green laser emitter 1 (11), the green laser emitter 2 (12), the ultraviolet light emitter (13), the macro camera 1 (14), the macro camera 2 (15), the electric slide rail frame 1 (20), the electric slide rail frame 2 (21), the electric slide rail frame 3 (22), the camera bracket 1 (23) and the camera bracket 2 (24) by electrical signals.

9. A testing system for internal hydrodynamic characteristics and particle movement of reverse erosion piping according to claim 3, characterized in that: A frame body (34) is installed on the top of the water head box (3), an electric telescopic unit (35) is installed on the top of the frame body (34), a pressure sensor (36) is installed on the output end of the electric telescopic unit (35), a lifting rod (37) is installed on the bottom input end of the pressure sensor (36), a pressure plate (38) is installed on one end of the lifting rod (37), and the pressure plate (38) is located inside the water head box (3), and the synchronous controller (19) is connected to the electric telescopic unit (35) and the pressure sensor (36) respectively through electrical signals.

10. A testing system for internal hydrodynamic characteristics and particle movement of reverse erosion piping according to claim 3, characterized in that: The front of the model box (1) is equipped with an electric telescopic unit 2 (39), which is connected to the synchronous controller (19) by electrical signals, and the output end of the electric telescopic unit 2 (39) is equipped with a scraping rod (40).

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