Testing device and method for migration and loss of filler particles inside karst pipelines

Abstract

This is a test device and method for the migration and washout of filler particles inside a karst pipeline. [Solution] A glass pipe is filled with a transparent material similar to a karst pipeline. A pressurizing module is installed at one end of the glass pipe. A colored solution is installed between the pressurizing module and the karst pipeline filler material. A sealing module is installed at the other end of the glass pipe, with a seepage slit in the center. Pressurizing the pressurizing module causes the colored solution to flow through the karst pipeline filler material, carrying filler particles through the seepage slit and into a seepage liquid collection pipe, where they are finally collected in a flow metering module. During the testing process, a laser is used to irradiate the karst pipeline filler material to form a laser cut surface. Digital photogrammetry analysis is then performed to obtain the changes in the seepage path of the colored solution and the change patterns of particle migration within the filler material. The permeability coefficient and porosity of the karst pipeline fill structure are analyzed based on the water body mass and particle mass of the seepage liquid, thereby studying the particle migration and loss patterns of the filler material within the karst pipeline.

Description

[Technical Field]

[0001] The present invention relates to the technical field of karst pipelines, and particularly to a migration loss test device and method for filling particles in karst pipelines. [Background technology]

[0002] In underground construction projects such as karst tunneling, understanding the migration and loss of fill particles inside karst pipelines can help engineers formulate rational construction plans and safety measures. Affected by the geological and hydrological conditions of the construction site, the particle structure inside karst pipelines is often very complex. After exposure during the tunnel excavation process, erosion can cause a variety of inconsistent migration, deformation, and failure characteristics, leading to various types of water and mud intrusion disasters. Therefore, in the geological exploration and construction design process of karst tunnels, it is necessary to take into account the migration and loss patterns of fill particles inside karst pipelines in order to formulate rational construction plans and preventive measures.

[0003] Therefore, there is a need to provide an improved technical solution to address the shortcomings of the prior art. Summary of the Invention [Problem to be solved by the invention]

[0004] SUMMARY OF THE INVENTION The object of the present invention is to overcome the above-mentioned shortcomings in the prior art, and the present invention provides an apparatus and method for testing the migration and loss of filler particles inside a karst pipeline. [Means for solving the problem]

[0005] To achieve the above objectives, the present application provides the following technical solutions:

[0006] A testing device for migration and loss of particles packed inside a karst pipeline, comprising a glass pipe, a pressurizing module, a sealing module, and a laser irradiation module, The glass pipe is an L-shaped transparent pipe body with both ends open, and the inside of the glass pipe is filled with a transparent karst pipeline filling material to simulate a karst pipeline filling structure material. The pressurizing module is installed at one end of the glass pipe, and a colored solution (colored solution) is installed between the pressurizing module and the karst pipeline filling material. By pressurizing the colored solution, the hydraulic coupling action of the karst pipeline is simulated; the sealing module is provided at the other end of the glass pipe, and a permeation slit is provided in the center of the sealing module, and the permeation slit is connected to a flow rate measuring module via a permeate collecting pipe; The laser irradiation module is installed on the opposite side of the glass pipe and the sealing module, and the laser irradiation module is a movable red planar laser, and forms a laser cutting surface after the laser irradiates the transparent similar material filled with karst pipeline inside the glass pipe, and uses an image collector immediately before the glass pipe to continuously collect laser cutting surface images; The pressure module applies pressure, causing the colored solution to seep from the karst fill material into the flow metering module, and the permeability coefficient and porosity (porosity) of the karst pipeline fill structure are analyzed based on the water body mass and particle mass of the seeping liquid. During the test process, laser cross-sectional images of the karst pipeline fill material are continuously collected and analyzed by digital photogrammetry to obtain the changes in the infiltration path of the colored solution and the rules of change in particle movement inside the karst pipeline fill material. This is a test device for the movement and loss of filled particles inside karst pipelines.

[0007] A test method for the movement and loss of particles filled inside a karst pipeline, which is conducted using the test device described in any one of claims 1 to 5, and which analyzes the permeability coefficient and porosity of the karst pipeline filling structure by obtaining the water body mass and particle mass of the seepage liquid from the test device, and continuously collects laser cross-sectional images of the karst pipeline filling material during the test process and performs digital photogrammetry analysis to obtain the changes in the seepage path of the colored solution and the change rules of particle movement inside the filling material.

[0008] Preferably, Step S1: sealing the bottom of the glass pipe with a temporary cover plate; Step S2: Prepare a transparent karst pipeline filling material, mix multi-walled carbon nanotubes into the karst pipeline filling material, and then fill it into a glass pipe in multiple batches, each time to a filling height of 40 mm. After filling, place it in a vacuum box and vacuum it for 15 minutes until the filling height reaches 360 mm; Step S3: Fixing the glass pipe to a test stand via a fixing steel frame (fixing steel frame) and attaching a sealing module and a pressure module; Step S4: sliding the slide plate of the sealing module to close the penetration slit, closing the pressurizing pump of the colored solution, and bringing the piston plate of the pressurizing module into close contact with the transparent-like material filled in the karst pipeline. Applying a rated pressure to the piston plate of the pressurizing module, and allowing the transparent-like material filled in the pipeline to rest and solidify under the rated solidifying pressure for a rated time; After the fixing is completed, the planar laser is opened, and the transparent similar material for filling the karst pipeline inside the glass pipe is irradiated with the laser cutting surface to form a laser cutting surface. An image collector is used immediately before the glass pipe to continuously collect images of the laser cutting surface. Digital photogrammetry analysis is performed on the collected images to obtain the change in the infiltration path of the colored solution and the change in particle movement inside the karst pipeline filling material. Step S5. Step S6: Adjust the width of the infiltration slit to a predetermined value by sliding the sliding plate of the sealing module, open the pressure module and the pressure pump of the colored solution, allow the colored solution to infiltrate from the top of the karst pipeline filling material to the flow metering module, filter the infiltrate through a filter net and then discharge it into the metering tank, and analyze the infiltration coefficient and porosity of the karst pipeline filling structure according to the water body mass and particle mass of the infiltrate; and step S7 of stopping the test, closing the meter, and cleaning and storing the meter.

[0009] A transparent karst pipeline filler similar to the one used to simulate the karst pipeline fill structure was applied, and pressurization was performed using a pressurization module. After the colored solution flowed through the karst pipeline filler material, it carried the filler particles through the infiltration slits and into the seepage liquid collection pipe, and was finally collected in the flow metering module. During the testing process, a laser was used to irradiate the karst pipeline filler material to form a laser cut surface. Digital photogrammetry analysis was then performed to obtain the changes in the infiltration path of the colored solution and the change patterns of particle migration within the filler material. The permeability coefficient and porosity of the karst pipeline filler structure were then analyzed using the water body mass and particle mass of the seepage liquid, thereby studying the particle migration and loss patterns of the filler within the karst pipeline. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram of the experimental equipment. [Figure 2] FIG. 2 is a schematic diagram of an assembled glass pipe. [Figure 3] FIG. 10 is a schematic assembly diagram of a slide plate and a second piston plate. [Figure 4] FIG. 2 is a diagram illustrating the configuration of a slide plate. [Figure 5] FIG. 1 is a side view of the fixed steel frame side. DETAILED DESCRIPTION OF THE INVENTION

[0011] As shown in Figures 1 to 5, in order to study the particle migration and loss patterns and deformation and fracture characteristics inside the karst pipeline filling structure under hydraulic coupling action, the present application provides a test device for the migration and loss of filling particles inside the karst pipeline, the test device includes a glass pipe 3, a pressure module, a sealing module, and a laser irradiation module, the glass pipe 3 is a transparent pipe body with both ends open, the glass pipe 3 is preferably made of organic glass, and the glass pipe 3 is a square pipe formed by bonding multiple organic glass plates together, the inside of the glass pipe 3 is filled with a transparent karst pipeline filling material 4, and fused silica sand is used to simulate the gravel and sand particles in the karst pipeline filling, Amorphous silicon powder is used to simulate the clay particles in the fill of a karst pipeline, and liquid paraffin and n-tridecane are mixed in a mass ratio of 1:0.85 to simulate the pore water in the karst pipeline fill structure, thereby simulating the fill structure material of a karst passage. A pressure module is installed at one end of the glass pipe 3, and a colored solution is installed between the pressure module and the karst pipeline fill material to simulate the internal pore water in the karst pipeline fill. The colored solution is made by adding 1% water-color dye to a mineral oil solution, and the colored solution is pressurized and seeped through the transparent karst pipeline fill material 4 to simulate the hydraulic coupling effect of the karst pipeline.

[0012] A sealing module is installed at the other end of the glass pipe 3, and a seepage slit 23 is installed in the center of the sealing module to discharge the seepage liquid through the transparent similar-looking karst pipeline filling material 4. The seepage slit 23 is connected to the flow metering module via a seepage liquid collection pipe 27. The flow metering module separates the water body and particles in the seepage liquid, and in response to pressurization by the pressurizing module, the colored solution seeps from the karst pipeline filling material to the flow metering module. The permeability coefficient and porosity of the karst pipeline filling structure are analyzed according to the water body mass and particle mass of the seepage liquid, and the migration and loss rules of the fill particles inside the karst pipeline are studied and observed.

[0013] In this example, the colored solution was prepared by mixing liquid paraffin and n-tridecane in a mass ratio of 1:0.85, and adding 1% of a light blue dye. The refractive indices of the fused silica sand, amorphous silicon powder (amorphous silicon powder), and colored solution were basically the same, which avoided errors in image collection.

[0014] In one alternative embodiment, the glass pipe 3 is L-shaped, has a circumferential length of 250 mm, a height of 450 mm, a thickness of 150 mm, an irregularly uneven inner surface, and an internal space cross-sectional dimension of approximately 100 mm in side length. The glass pipe 3 is composed of a rectangular glass pipe 3 and an outer steel frame fixing device, and is used to simulate an actual curved karst pipeline with an irregular inner surface. The transparent karst pipeline filling material 4 includes fused silica sand, amorphous silicon powder, liquid paraffin, and n-tridecane, with a mass ratio of the four being 1:5:5:4.25.

[0015] Fused silica sand was used to simulate the gravel and sand particles in the karst pipeline fill, amorphous silicon powder was used to simulate the clay particles in the karst pipeline fill, and a mineral oil solution (liquid paraffin and n-tridecane mixed in a mass ratio of 1:0.85) was used to simulate the pore water in the karst pipeline fill structure. When a transparent material similar to the karst tunnel fill structure was filled into the inside of the glass pipe 3, it was possible to combine it with a digital photogrammetry system to observe and analyze the particle movement patterns and deformation and failure characteristics inside the karst pipeline fill structure.

[0016] Specifically, the mass and particle size range of fused silica sand and amorphous silicon powder are determined based on the composition and particle size distribution curve of the actual karst pipeline filling structure medium, and then mixed with a mineral oil solution and vacuumed to prepare a transparent material similar to the karst pipeline filling material.

[0017] In one alternative embodiment, the glass pipe 3 is mounted on one side of a fixed steel frame 8, which is used to ensure the safety and stability of the L-shaped glass pipe 3 under test load, and is fixed to the test bench surface steel plate using a "diagonal bracing" method. Specifically, a bottom support for fixing the test bench 26 is provided at the bottom of the fixed steel frame 8, and a diagonal bracing (backstay) 17 connecting the bottom support is provided on the side of the glass pipe 3 away from the fixed steel frame 8, and both ends of the diagonal bracing 17 are fixed to the fixed steel frame 8 by bolts and bottom supports.

[0018] The test stand 26 is composed of a test stand surface steel plate and a bottom support base, the length of the test stand surface steel plate is 1200 mm, the width is 500 mm, and it mainly provides a test operation platform for the pressure module and the sealing module.

[0019] In addition, a water passage hole is pre-installed at a position corresponding to the infiltration slit 23 of the sealing module of the test stand 26 to conveniently introduce the water body and particles flowing out from the infiltrate collection pipe 27 into the flow metering module below through the effluent collection port.

[0020] Specifically, a diaphragm or guide groove is provided at the lower end of the glass pipe 3 or at the outlet of the permeation slit 23 of the sealing module to collect the permeate and then guide it through the permeate collection pipe 27 below to the flow rate measuring module.

[0021] In this example, the height of the bottom support platform is 600 mm, and its main purpose is to ensure the stability of the visualization infiltration test system for deep-buried karst tunnel filling structures, provide a height space, and facilitate test operations.

[0022] In one possible embodiment, a rod-shaped hole (striped hole) 16 is provided in the center of the diagonal bracing 17 and the fixed steel frame 8, directly facing the glass pipe 3, and the vertical length of the rod-shaped hole 16 is adapted to the height of the karst filling material, ensuring that the planar laser light emitted from the laser 24 can penetrate the entire glass pipe 3. The laser light emitted from the laser 24 passes through the rod-shaped hole 16 and then irradiates the karst pipeline filling transparent-like material 4, forming a laser cutting surface.

[0023] The testing equipment further includes an image collector and a pressure collector 7 correspondingly connected to a controller 12. The image collector is a digital camera 1, which faces the glass pipe 3 and collects images of the transparent material 4 used to fill the karst pipeline inside the glass pipe 3. A laser 24 emits laser light to complete planar laser spot control of the interior of the transparent material used to fill the karst pipeline. The digital camera 1 is connected to a computer and is responsible for realizing the timely and fixed-point collection of laser spot control images. The controller 12 is a PC terminal and can be pre-installed with a software system for data processing. The software system analyzes the collected test images for details such as seepage path, particle movement, and deformation and failure characteristics of the filler.

[0024] Furthermore, a pressure collector is connected to the pressurizing module and the sealing module to collect rated pressure data from the pressurizing module and the sealing module. The pressure collector collects pressure using pressure sensors and pressure gauges. Specifically, two sets of pressure sensors are provided corresponding to the first pressurizing rod 10 and the second pressurizing rod 18 and are used for pressure collection. A pressure gauge is disposed corresponding to the pressurizing pipe 2 to collect data on the internal hydraulic pressure, thereby collecting data such as the pressure at the inlet and outlet positions of the glass pipe 3 and the inner wall water pressure, which are used to analyze the water pressure, hydraulic gradient, sliding force, etc. of the karst pipeline filling structure. The pressure collector is connected to a computer, so that the data collected by the data collection system can be stored in the computer, facilitating subsequent test data analysis.

[0025] In one embodiment, the pressure module includes a main frame 9 and a pressure pipe 2. The main frame 9 is bolted to the test table surface. A first pressure rod 10 is provided in the center of the main frame 9 and faces the glass pipe 3. The first pressure rod 10 can be a screw, a worm, a hydraulic rod, or a movable electromagnetic cylinder rod. One end of the first pressure rod 10 extending to the glass pipe 3 is provided with a first piston plate 11. The first piston plate 11 has a rectangular structure corresponding to the inner cavity of the upper end of the glass pipe 3. The first piston plate 11 includes multiple rectangular plates with a rubber layer between them. Alternatively, the first piston plate 11 has a certain thickness, and two layers of rubber waterproof strips are fitted on the outside of the first piston plate 11 to form a piston structure.

[0026] Therefore, a piston structure is formed, and a pressurized pipeline is provided on the first piston plate 11 to connect the pressurized pipe 2, one end of which is connected to a pressure pump and the other end of which passes through the first piston plate 11 and is then directed toward the karst pipeline filling transparent-like material 4, thereby pumping high-pressure colored solution between the first piston plate 11 and the karst pipeline filling transparent-like material 4.

[0027] The pressure pump is mainly composed of an oil pump 15, a water pump 14, an injection pressure device 13, a pipeline, and a connecting joint. The injection pressure device 13 has a pressure piston attached to the inner wall of a piston cylinder. One end of the piston cylinder corresponding to the pressure piston is connected to the oil pump 15, and the side wall of the other end is connected to the pressure pipe 2 via a three-way valve. The other end of the three-way valve is connected to the water pump 14 via a shutoff valve and a selector valve. A colored solution container is connected to the water pump 14, and a shutoff valve is provided in the pressure pipe 2 between the three-way valve and the glass pipe 3.

[0028] In one alternative embodiment, the infiltration slit 23 of the sealing module can adjust the width of the slit, so that by adjusting the width of the infiltration slit 23, it is possible to realize the simulation of different infiltration slit widths and bearing capacity at the outlet of the karst pipeline filling structure.

[0029] The sealing module includes a second piston plate 19, a second pressure rod 18, and a slide plate 21. The second piston plate 19 is a square plate corresponding to its lower end, with two layers of rubber waterproof strips fitted on its outer wall, allowing it to be slidably attached to the glass pipe 3 to form a piston structure. When driven by the second pressure rod 18, it comes into contact with the transparent-like material 4 filled in the karst pipeline, thereby preventing it from being displaced. A seepage slit 23 is provided in the center of the second piston plate 19, which is a rectangular hole. A slide plate 21 is slidably attached to the seepage slit 23, allowing the width of the seepage slit 23 to be adjusted. The second pressure rod 18 can be a screw, a worm, a hydraulic rod, or a cylinder-type movable electromagnetic rod.

[0030] The second pressure rod 18 supports the second piston plate 19 by corresponding to the edge angle of the second piston plate 19 through a plurality of support jaws, thereby not affecting the mounting and sliding of the slide plate 21.

[0031] In one alternative embodiment, the infiltration slit 23 is a rectangular hole provided in the center of the second piston plate 19, and a chute is provided on one side of the second piston plate 19 close to the karst pipeline filling transparent-like material 4, the chute is adapted to the length of the infiltration slit 23, so that the slide plate 21 can slide into the infiltration slit 23 within the chute to shield the infiltration slit 23, thereby adjusting the infiltration slit 23 according to the width of the shielding portion, and the chute is positioned on one side of the infiltration slit 23, and the depth of the chute is adapted to the thickness of the slide plate 21, so that the second piston plate 19 has a flat surface directly facing the karst pipeline filling transparent-like material 4, and further it can be ensured that the second piston plate 19 is in close contact with the karst pipeline filling transparent-like material 4.

[0032] In this embodiment, the edge of the slide plate 21 is provided with a folded portion 22 corresponding to the infiltration slit 23, the length of the folded portion 22 matches the length of the infiltration slit 23, and the width of the folded portion 22 matches the depth of the infiltration slit 23, the side of the folded portion 22 facing away from the transparent-like karst pipeline filling material 4 and the side of the second piston plate 19 facing away from the transparent-like karst pipeline filling material 4 are on the same plane, and the side of the second piston plate 19 facing away from the transparent-like karst pipeline filling material 4 is provided with a stopper bar 20 that correspondingly stops the folded portion 22, thereby shielding and limiting the position of the folded portion 22 and preventing the slide plate 21 from tilting due to excessive pressure.

[0033] In one alternative embodiment, the flow metering module includes a metering vessel 5, a filter screen 6, and an electronic scale 25, where the filter screen 6 is disposed above the metering vessel 5 to filter particles in the permeate and perform water body and particle mass measurements, respectively.

[0034] In one alternative embodiment, the present application further provides a method for testing the migration and loss of fill particles inside a karst pipeline, which analyzes the permeability coefficient and porosity of the karst pipeline filling structure by conducting a test using any of the above-mentioned test devices and obtaining the water body mass and particle mass of the seepage liquid from the test device.

[0035] Specifically, it is Step S1: Put a water-permeable stone vertically into the bottom of the glass pipe 3 and seal it with a temporary cover plate (with a plurality of regular small holes drilled to allow for drainage); Step S2: Prepare a transparent karst pipeline filling material 4 based on the type of filling structure medium, mix 0.5% by mass of multi-walled carbon nanotubes into the karst pipeline filling material, and then fill it into the glass pipe 3 in multiple batches, each time to a filling height of 40 mm, until the filling height reaches 360 mm. After filling, place it in a vacuum box and perform a 15-minute vacuum process. Step S3: Fixing the glass pipe 3 to the test stand 26 via the fixed steel frame 8, and attaching a sealing module and a pressure module; Step S4: sliding the slide plate 21 of the sealing module to close the penetration slit 23, closing the pressurizing pump of the colored solution, and adhering the piston plate of the pressurizing module to the karst pipeline filling transparent-like material 4, applying a rated pressure to the piston plate of the pressurizing module, and fixing the filling transparent-like material at a rated fixing pressure for a rated time; After the fixing is completed, connect the injection pressurizer 13 and the pressurized pipe 2, open the valve between them, open the planar laser, irradiate the transparent similar material 4 filled with karst pipeline, and form a laser cutting surface. Use the image collector immediately before the glass pipe 3 to continuously collect laser cutting surface images. Control the computer to make the digital camera 1 periodically collect spot-controlled planar images, with the collection speed set to one per second. Open the data collector and electronic scale 25 to collect the pressure and mass of the seepage liquid at each location. Use digital photogrammetry analysis on the collected images to obtain the change in the seepage path of the colored solution and the internal particle movement change rule of the karst pipeline filling material. Step S5. The width of the infiltration slit 23 is adjusted to a predetermined value by sliding the sliding plate 21 of the sealing module. The pressure module and the colored solution pressure pump are opened. The oil pump 15 drives the injection pressure generator 13 to gradually increase the water pressure inside the glass pipe 3, increasing it by 0.1 MPa per step. After the pressure is applied, the pressure is stabilized for another 600 seconds. The protective pressure value of the second pressure rod 18 is synchronously increased based on the applied water pressure until it reaches the designed support pressure. During the water pressure step-by-step loading process, the colored solution is allowed to infiltrate through the karst pipeline transparent-like material 4 into the flow metering module. The infiltrate is filtered through the filter net 6 and then discharged into the metering tank 5. When particles begin to appear on the filter net 6, the filter net 6 is replaced every 60 seconds until the infiltration structure experiences flooding or unstable failure. In step S6, the water mass and particle mass of the infiltrate are obtained to analyze the infiltration coefficient and porosity of the karst pipeline infill structure. and step S7 of stopping the test, closing the meter, and cleaning and storing the meter. [Explanation of symbols]

[0036] 1. Digital camera 2 pressurized pipes 3. Glass Pipe 4. Karst pipeline filling transparent similar material 5 Measuring tank 6 Filter net 7. Image and pressure collectors 8 Fixed steel frame 9. Mainframe 10 First pressure rod 11 First piston plate 12 Controllers 13 Injection pressurizer 14 Water pump 15 Oil pump 16 Rod hole 17 Diagonal Bracing 18 Second pressure rod 19 Second piston plate 20 Stopper bar 21 Slide plate 22 Folded section 23 Penetration slit 24 Laser 25 Electronic scales 26 Test Stand 27 Permeate collection pipe

Claims

1. A testing device for the migration and loss of filler particles inside a karst pipeline, comprising: a glass pipe; a pressurizing module; a sealing module; and a laser irradiation module; The glass pipe is an L-shaped transparent pipe body with both ends open, and the inside of the glass pipe is filled with a transparent karst pipeline filling material to simulate a karst pipeline filling structure material. The pressurizing module is installed at one end of the glass pipe, and a colored solution is installed between the pressurizing module and the karst pipeline filling material. The colored solution is pressurized to simulate the hydraulic coupling effect of the karst pipeline; the sealing module is provided at the other end of the glass pipe, and a permeation slit is provided in the center of the sealing module, and the permeation slit is connected to a flow rate measuring module via a permeate collecting pipe; The laser irradiation module is located on the opposite side of the glass pipe and the sealing module, and the laser irradiation module is a movable red planar laser, and forms a laser cutting surface after the laser irradiates the transparent similar material filled with karst pipeline inside the glass pipe, and uses an image collector immediately before the glass pipe to continuously collect laser cutting surface images; The pressurizing module applies pressure to cause the colored solution to permeate from the karst filler material into the flow metering module, and the permeability coefficient and porosity of the karst pipeline fill structure are analyzed based on the water body mass and particle mass of the permeating liquid. During the testing process, laser cross-sectional images of the karst pipeline filler material are continuously collected and analyzed by digital photogrammetry to obtain the changes in the permeation path of the colored solution and the rules of particle movement change inside the karst pipeline filler material.

2. The testing device for the migration and loss of filling particles inside a karst pipeline as described in claim 1, characterized in that the inner wall of the glass pipe is formed as an irregularly uneven surface, and the karst filling material includes fused silica sand, amorphous silicon powder, liquid paraffin and n-tridecane.

3. The testing device for the movement and loss of filling particles inside a karst pipeline as described in claim 1, characterized in that the glass pipe is mounted on one side of a fixed steel frame, a bottom support for fixing a test stand is provided at the bottom of the fixed steel frame, and a diagonal bracing is provided on the other side of the glass pipe away from the fixed steel frame to connect the bottom support.

4. The testing device for the movement and loss of filling particles inside a karst pipeline as described in claim 3, characterized in that a rod-shaped hole is provided in the center of the diagonal bracing and the fixed steel frame, directly facing the glass pipe, the vertical length of the rod-shaped hole is adapted to the height of the karst filling material, the laser light emitted from the planar laser passes through the rod-shaped hole and then irradiates the karst pipeline filling transparent-like material, forming a laser cutting surface, and images of the laser cutting surface are continuously collected using an image collector.

5. the pressurizing module includes a main frame and a pressurizing pipe; a first pressure rod directed toward the glass pipe is provided in the center of the main frame, and a first piston plate is provided at one end of the first pressure rod extending toward the glass pipe; The test device for testing the migration and loss of filler particles inside a karst pipeline as described in claim 1, characterized in that one end of the pressurized pipe is connected to a pressure pump, and the other end passes through the first piston plate and is then directed toward the karst pipeline filler material, thereby pumping high-pressure colored solution between the first piston plate and the karst pipeline filler material.

6. the sealing module includes a second piston plate, a second pressure rod, and a slide plate; The second piston plate is slidably mounted on the glass pipe so as to contact the karst pipeline filling material, and a penetration slit is provided in the center of the second piston plate; the second pressure rod supports the second piston plate through a plurality of support jaws in correspondence with an edge angle of the second piston plate; A chute is provided on one side of the second piston plate that is close to the karst pipeline filling material, and the chute is located on one side of the infiltration slit. The depth of the chute is adapted to the thickness of the slide plate, so that the second piston plate has a flat surface directly facing the karst pipeline filling material, and the width of the infiltration slit can be adjusted by sliding the slide plate. The testing device for the movement and loss of filling particles inside a karst pipeline as described in claim 1, characterized in that the edge of the slide plate is provided with a folded portion corresponding to the penetration slit, and the one side of the second piston plate away from the karst pipeline filling material is provided with a stopper bar that correspondingly stops the folded portion.

7. The test device for the movement and loss of filling particles inside a karst pipeline as described in claim 1, characterized in that the flow metering module includes a seepage liquid collection pipe, a metering tank, a filtering net, and an electronic scale, and the filtering net is installed above the metering tank to filter particles in the seepage liquid.

8. the test device further includes an image collector and a pressure collector correspondingly connected to the controller; The testing device for the migration and loss of filler particles inside a karst pipeline according to claim 4, characterized in that the image collector faces the glass pipe and continuously collects laser cross-sectional images of the karst pipeline filler material inside the glass pipe, and the pressure collector is correspondingly connected to the pressurizing module and the sealing module and collects rated pressure data of the pressurizing module and the sealing module.

9. A testing method for the movement and loss of filler particles inside a karst pipeline, which is carried out using the testing device described in any one of claims 1 to 8, wherein the water body mass and particle mass of the seepage liquid are acquired by the testing device to analyze the permeability coefficient and porosity of the karst pipeline filling structure; and the laser cross-sectional images of the karst pipeline filling material are continuously collected during the testing process and digital photogrammetry analysis is performed to obtain the changes in the seepage path of the colored solution and the change rules of particle movement inside the filling material.

10. Step S1: sealing the bottom of the glass pipe with a temporary cover plate; Step S2: Prepare a transparent karst pipeline filling material, mix multi-walled carbon nanotubes into the karst pipeline filling material, and then fill the glass pipe in multiple batches, each time to a filling height of 40 mm. After filling, place the glass pipe in a vacuum box and vacuum it for 15 minutes until the filling height reaches 360 mm. Step S3: Fixing the glass pipe to a test stand via a fixed steel frame, and attaching a sealing module and a pressure module; Step S4: sliding the slide plate of the sealing module to close the penetration slit, closing the pressurizing pump of the colored solution, and making the piston plate of the pressurizing module adhere to the transparent similar material filled in the karst pipeline; applying a rated pressure to the piston plate of the pressurizing module, and fixing the transparent similar material filled in the pipeline at a rated fixing pressure for a rated time; After the fixing is completed, open the planar laser, irradiate the transparent similar material filling the karst pipeline inside the glass pipe, and then form a laser cutting surface; use an image collector immediately before the glass pipe to continuously collect images of the laser cutting surface; and perform digital photogrammetry analysis on the collected images to obtain the change in the infiltration path of the colored solution and the change in particle movement inside the karst pipeline filling material. Step S5; Step S6: adjust the width of the infiltration slit to a predetermined value by sliding the sliding plate of the sealing module, open the pressure module and the pressure pump of the colored solution, allow the colored solution to infiltrate from the top of the karst pipeline filling material to the flow metering module, filter the infiltrate through a filter net and then discharge it into the metering tank, and analyze the infiltration coefficient and porosity of the karst pipeline filling structure according to the water body mass and particle mass of the infiltrate; The method for testing the migration and loss of filler particles inside a karst pipeline as described in claim 9, further comprising step S7 of stopping the test, closing the meter, and arranging and storing the meter.

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