Test apparatus and method for the movement and leakage of packing particles inside a karst pipeline

Abstract

This is a test apparatus and method for the movement and leakage of packing particles inside a karst pipeline. [Solution] The inside of the glass pipe is filled with a karst pipeline transparent-like material, a colored solution is placed between the pressurizing module and the karst pipeline filling material, and a permeation slit is provided in the center of the sealing module. Pressurizing the pressurizing module carries the filling particles through the permeation slit into the permeate collection pipe, and finally collects them in the flow metering module. In the test process, a laser is used to irradiate the karst pipeline filling material to form a laser cross-section, and digital photogrammetry analysis is performed to analyze the permeation coefficient and porosity of the karst pipeline filling structure based on the water mass and particle mass of the permeate, thereby studying the particle movement and outflow rules of the filling material inside the karst pipeline.

Description

Technical Field

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

Background Art

[0002] In underground construction such as karst tunnel construction, understanding the migration and loss situation of the filling particles inside the karst pipeline is helpful for engineers to formulate reasonable construction plans and safety measures. Affected by the engineering geology and hydrogeological conditions, the situation of the particle structure filled inside the karst pipeline is often very complex. After being exposed in the tunnel excavation process, various inconsistent migration deformations and destruction characteristics appear due to erosion, inducing different types of water and mud inrush disasters. Therefore, in the geological exploration and engineering design process of karst tunnels, it is necessary to consider the transfer and loss rules of the filling particles inside the karst pipeline and formulate reasonable construction plans and preventive measures.

[0003] Therefore, it is necessary to provide a technical solution to improve the deficiencies of the above prior art.

Summary of the Invention

Problems to be Solved by the Invention

[0004] The purpose of the present invention is to overcome the deficiencies in the above prior art, and the present invention provides a migration loss test device and method for filling particles in karst pipeline.

Means for Solving the Problems

[0005] To achieve the above object, the present application provides the following technical solution.

[0006] A test apparatus for the migration and leakage of particles filling 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 material similar to karst pipeline filling, and is used to simulate karst pipeline filling structure material. The pressurizing module is provided at one end of the glass pipe, and a colored solution is provided 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 the flow metering module via a permeate collection pipe. The laser irradiation module is located on the opposite side from the glass pipe and sealing module, and the laser irradiation module is a movable red planar laser, which irradiates the karst pipeline filling transparent-like material inside the glass pipe to form a single laser cross-section, and an image collector is used immediately before the glass pipe to continuously collect images of the laser cross-section. This test apparatus for the movement and outflow of particles filling a karst pipeline is used to test the movement and outflow of particles inside a karst pipeline. It involves pressurizing the karst pipeline filling material with a pressurizing module, allowing a colored solution to permeate from the karst pipeline filling material into a flow metering module, and analyzing the permeation coefficient and porosity (porosity) of the karst pipeline filling structure based on the water mass and particle mass of the permeate. By continuously collecting laser cross-sectional images of the karst pipeline filling material during the test process and performing digital photogrammetry analysis, the changes in the permeation path of the colored solution and the rules governing the changes in particle movement inside the karst pipeline filling material are obtained.

[0007] A method for testing the movement and runoff of particles filling a karst pipeline, wherein the test is conducted using a test apparatus described in any one of the paragraphs, and the permeability coefficient and porosity of the karst pipeline filling structure are analyzed by obtaining the water mass and particle mass of the permeate liquid from the test apparatus, and the changes in the permeation path of the colored solution and the rules of particle movement changes inside the filling material are obtained by continuously collecting laser cross-sectional images of the karst pipeline filling material during the test process and performing digital photogrammetry analysis.

[0008] Preferably, Step S1 involves sealing the bottom of the glass pipe with a temporary cover plate, Step S2 involves preparing a transparent material similar to karst pipeline packing material, mixing multi-walled carbon nanotubes into the karst pipeline packing material, and then filling it into glass pipes in multiple stages, with each stage having a filling height of 40 mm, until the filling height reaches 360 mm. After filling, the pipes are placed in a vacuum chamber and vacuumed for 15 minutes. Step S3 involves fixing the glass pipe to the test stand via a fixed steel frame (fixing steel frame), and then attaching the sealing module and the pressurizing module. Step S4 involves sliding the slide plate of the sealing module to close the penetration slit, closing the pressure pump for the colored solution, bringing the piston plate of the pressure module into close contact with the karst pipeline filling transparent-like material, applying the rated pressure to the piston plate of the pressure module, and allowing the filling pipeline transparent-like material to solidify under the rated solidification pressure for the rated time. Step S5 involves opening a planar laser after the fixing is complete, irradiating the transparent material similar to the karst pipeline filling inside the glass pipe to form a single laser cross-section, continuously collecting images of the laser cross-section using an image collector immediately before the glass pipe, and performing digital photogrammetry analysis on the collected images to obtain the changes in the penetration path of the colored solution and the rules of particle movement changes inside the karst pipeline filling material. Step S6 involves adjusting the width of the permeation slit to a predetermined value by sliding the slide plate of the sealing module, opening the pressurizing module and the pressurizing pump for the colored solution, allowing the colored solution to permeate from the top of the karst pipeline filling material to the flow metering module, filtering the permeate through a filter mesh and then discharging it into a metering tank, and analyzing the permeation coefficient and porosity of the karst pipeline filling structure based on the water mass and particle mass of the permeate. Step S7 includes stopping the test, closing the instruments, tidying up the instruments, and storing them. Beneficial effects

[0009] The karst pipeline filling structure is simulated using a transparent, imitation material of karst pipeline filling. By pressurizing it in a pressurizing module, a colored solution flows through the karst pipeline filling material, carrying the filling particles through permeation slits and into a permeate collection pipe, where it is finally collected in a flow metering module. In the test process, the karst pipeline filling material is irradiated with a laser to form laser cross-sections, and digital photogrammetry analysis is performed to obtain the rules of change in the permeation path of the colored solution and the changes in particle movement within the filling material. The permeation coefficient and porosity of the karst pipeline filling structure are analyzed based on the water mass and particle mass of the permeate, thereby studying the rules of particle movement and outflow of the filling material inside the karst pipeline. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic diagram of the experimental setup. [Figure 2] This is a schematic diagram of the glass pipe assembly. [Figure 3] This is a schematic diagram of the assembly of the slide plate and the second piston plate. [Figure 4] This is a diagram showing the configuration of the slide plate. [Figure 5] This is a side view of the fixed steel frame. [Modes for carrying out the invention]

[0011] As shown in Figures 1-5, in order to study the particle movement and runoff rules and deformation fracture characteristics inside a karst pipeline filling structure under hydraulic coupling, this application provides a test apparatus for the movement and runoff of filling particles inside a karst pipeline. The test apparatus includes a glass pipe 3, a pressurizing module, a sealing module, and a laser irradiation module. The glass pipe 3 is a transparent pipe body with both ends open, preferably made of organic glass, and is a rectangular pipe formed by bonding multiple organic glass plates together. The inside of the glass pipe 3 is filled with a transparent material 4 similar to karst pipeline filling, and molten silica sand is used to simulate gravel and sand particles in the karst pipeline filling. Amorphous silicon powder is used to simulate clay particles in the karst pipeline packing, 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 packing structure, thereby simulating the packing material of the karst passage. A pressurized module is provided at one end of glass pipe 3, and a colored solution is provided between the pressurized module and the karst pipeline packing material, thereby simulating the internal pore water in the karst pipeline packing. The colored solution is made by adding 1% light blue dye to a mineral oil solution, and the colored solution is pressurized and permeated through a transparent material 4 similar to the karst pipeline packing to simulate the hydraulic coupling action of the karst pipeline.

[0012] The sealing module is provided at the other end of the glass pipe 3. A permeation slit 23 is provided in the center of the sealing module to discharge permeate through the karst pipeline filling transparent-like material 4. The permeation slit 23 is connected to a flow metering module via a permeate collection pipe 27. The flow metering module separates the water and particles in the permeate, and in response to pressurization by the pressurization module, a colored solution permeates from the karst pipeline filling material to the flow metering module. The permeation coefficient and porosity of the karst pipeline filling structure are analyzed based on the water and particle masses of the permeate, and the rules of particle movement and outflow within the karst pipeline are studied and observed.

[0013] In this example, the colored solution is prepared by mixing liquid paraffin and n-tridecane in a mass ratio of 1:0.85 and adding 1% of a light blue dye. Since the refractive indices of fused silica sand, amorphous silicon powder, and the colored solution are essentially the same, errors in image acquisition are avoided.

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

[0015] The gravel and sand particles in the karst pipeline packing are simulated using molten silica sand, the clay particles in the karst pipeline packing are simulated using amorphous silicon powder, and the pore water in the karst pipeline packing structure is simulated using a mineral oil solution (liquid paraffin and n-tridecane mixed in a mass ratio of 1:0.85). When a transparent material similar to the karst tunnel packing structure is loaded inside glass pipe 3, it is possible to observe and analyze the particle movement rules and deformation fracture characteristics inside the karst pipeline packing structure by combining it with a digital photogrammetry system.

[0016] Specifically, the composition and particle size distribution curve of actual karst pipeline packing materials are used to determine the combined mass and particle size range of molten silica sand and amorphous silicon powder. These are then mixed with a mineral oil solution and subjected to a vacuum treatment to prepare a transparent material similar to karst pipeline packing.

[0017] In one selectable embodiment, the glass pipe 3 is provided on one side of the fixed steel frame 8. The fixed steel frame 8 is used to ensure the safety and stability of the L-shaped glass pipe 3 in the test load state and is fixed to the test table top steel plate by using the "diagonal bracing" method. Specifically, at the bottom of the fixed steel frame 8, a bottom support member for fixing the test table 26 is provided. On one side away from the fixed steel frame 8 of the glass pipe 3, a diagonal bracing 17 for connecting the bottom support members is provided. Both ends of the diagonal bracing 17 are fixed to the fixed steel frame 8 by bolts and the bottom support members.

[0018] The test table 26 is composed of a test table top steel plate and a bottom support base. The length of the test table top steel plate is 1200 mm and the width is 500 mm, mainly providing a test operation platform for the pressurization module and the sealing module.

[0019] Also, at a position corresponding to the penetration slit 23 of the sealing module of the test table 26, water holes are provided in advance to facilitate introducing the water body and particles flowing out from the penetration liquid collection pipe 27 into the lower flow rate measurement module through the loss collection port.

[0020] Specifically, at the lower end of the glass pipe 3 or the outlet of the penetration slit 23 of the sealing module, a diaphragm or a guide groove is provided for guiding the penetration liquid to the flow rate measurement module through the lower penetration liquid collection pipe 27 after collecting the penetration liquid.

[0021] In this embodiment, the height of the bottom support base is 600 mm. The main purpose is to ensure the stability of the visualization penetration test system for the deep-buried karst tunnel filling structure, provide a certain height space, and facilitate the test operation.

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

[0023] The test apparatus further includes an image collector and a pressure collector 7, which are connected in correspondence to the controller 12. The image collector is a digital camera 1, which is positioned directly toward the glass pipe 3 and collects images of the karst pipeline-filled transparent-like material 4 inside the glass pipe 3. The laser 24 completes planar laser spot control within the transparent-like material of the karst pipeline-filled structure by emitting laser light. The digital camera 1, connected to a computer, is responsible for achieving timed and fixed-point acquisition of laser spot-controlled images. The controller 12 is a PC terminal and can have a data processing software system pre-installed. The software system analyzes the collected test images for content such as penetration paths, particle movement, and filler deformation and fracture characteristics.

[0024] Furthermore, the pressure collector is connected correspondingly to the pressurizing module and the sealing module, and collects 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 positioned corresponding to the pressurizing pipe 2, thereby collecting data on the internal hydraulic pressure. This data, such as the pressure at the inlet and outlet positions of the glass pipe 3 and the water pressure on the inner wall, is 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, and the data collection system can store the collected data on the computer, which is convenient for subsequent analysis of test data.

[0025] In one selectable embodiment, the pressurizing module includes a main frame 9 and a pressurizing pipe 2, the main frame 9 being bolted to a test bench surface, and a first pressurizing rod 10 directed toward the glass pipe 3 being provided in the center of the main frame 9, the first pressurizing rod 10 being a screw, worm, hydraulic rod, or cylinder movable electromagnetic rod, and a first piston plate 11 being provided at one end of the first pressurizing rod 10 extending toward the glass pipe 3, the first piston plate 11 being a rectangular structure corresponding to the lumen of the upper end of the glass pipe 3, and including a multilayer rectangular plate with a rubber layer between the multilayer rectangular plates, or the first piston plate 11 having a constant thickness, and two layers of rubber waterproof strips fitted to the outside of the first piston plate 11 to form a piston structure.

[0026] Therefore, a piston structure is formed, and the first piston plate 11 is provided with a pressurized pipeline for connecting a pressurized pipe 2. The pressurized pipe 2 has one end connected to a pressurized pump and the other end passes through the first piston plate 11 and is directed towards the karst pipeline-filled transparent-like material 4, thereby pumping a high-pressure colored solution between the first piston plate 11 and the karst pipeline-filled transparent-like material 4.

[0027] The pressurizing pump mainly consists of an oil pump 15, a water pump 14, an injection pressurizer 13, a piping system, and connecting fittings. The injection pressurizer 13 has a pressurizing piston on the inner wall of a piston cylinder. The oil pump 15 is connected to one end of the piston cylinder corresponding to the pressurizing piston, and a pressurizing pipe 2 is connected to the side wall of the other end via a three-way valve. The other end of the three-way valve is connected to the water pump 14 via a shut-off valve and a switching valve. A colored solution storage tank is connected to the water pump 14, and a shut-off valve is provided in the pressurizing pipe 2 between the three-way valve and the glass pipe 3.

[0028] In one selectable embodiment, the infiltration slit 23 of the sealing module can be adjusted in width, thereby enabling the simulation of different infiltration slit widths and bearing capacities at the outlet of the karst pipeline filling structure by adjusting the width of the infiltration slit 23.

[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 rectangular plate corresponding to its lower end, with two layers of rubber watertight strips fitted to its outer wall, thereby slidably mounted on the glass pipe 3 to form a piston structure, which contacts the karst pipeline filling transparent-like material 4 under the drive of the second pressure rod 18, thereby preventing displacement of the karst pipeline filling transparent-like material 4. A penetration slit 23 is provided in the center of the second piston plate 19, which is a rectangular hole, and a slide plate 21 is provided which is slidably mounted on the penetration slit 23, thereby adjusting the width of the penetration slit 23. The second pressure rod 18 may be a screw, a worm, a hydraulic rod, or a cylinder-movable electromagnetic rod.

[0030] The second pressure rod 18 is supported by multiple support jaws corresponding to the edge corners of the second piston plate 19, thereby not affecting the mounting and sliding of the slide plate 21.

[0031] In one selectable embodiment, the penetration slit 23 is a rectangular hole located in the center of the second piston plate 19, and a chute is provided on one side of the second piston plate 19 adjacent to the karst pipeline filling transparent-like material 4, the chute being matched to the length of the penetration slit 23, thereby allowing the slide plate 21 to slide within the chute into the penetration slit 23 and shield the penetration slit 23, thereby adjusting the penetration slit 23 by the width of the shielded portion, and by positioning the chute on one side of the penetration slit 23 and the depth of the chute matching the thickness of the slide plate 21, the second piston plate 19 has a flat surface directly facing the karst pipeline filling transparent-like material 4, and further ensures 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 permeation slit 23. The folded portion 22 has a length that matches the length of the permeation slit 23 and a width that matches the depth of the permeation slit 23. The side of the folded portion 22 that is away from the karst pipeline filling transparent-like material 4 and the side of the second piston plate 19 that is away from the karst pipeline filling transparent-like material 4 are on the same plane. A stopper bar 20 is provided on the side of the second piston plate 19 that is away from the karst pipeline filling transparent-like material 4 to stop the folded portion 22 in a corresponding manner. This shields and restricts the position of the folded portion 22, thereby preventing the slide plate 21 from tilting due to excessive pressure.

[0033] In one selectable embodiment, the flow metering module includes a measuring tank 5, a filter screen 6, and an electronic balance 25, the filter screen 6 being positioned above the measuring tank 5 to filter particles in the permeate and to measure the mass of the water and particles, respectively.

[0034] In one selectable embodiment, the present invention further provides a method for testing the movement and runoff of packing particles inside a karst pipeline, which is used to perform a test using one of the above-described test apparatuses and to obtain the water mass and particle mass of the permeate relative to the test apparatus, thereby analyzing the permeability coefficient and porosity of the karst pipeline packing structure.

[0035] Specifically, that is, Step S1 involves placing a permeable stone vertically into the bottom of the glass pipe 3 and sealing it with a temporary cover plate (with multiple regularly spaced small holes for drainage), Step S2 involves preparing a karst pipeline-filled transparent analogue material 4 based on the type of packing structure medium, mixing multi-walled carbon nanotubes at a mass ratio of 0.5% into the karst pipeline packing material, and then filling it into glass pipes 3 in multiple stages, with each stage having a filling height of 40 mm, until the filling height reaches 360 mm, after which the pipes are placed in a vacuum chamber and a vacuum treatment is performed for 15 minutes. Step S3 involves fixing the glass pipe 3 to the test stand 26 via the fixed steel frame 8 and installing the sealing module and pressurizing module. Step S4 involves sliding the slide plate 21 of the sealing module to close the penetration slit 23, closing the pressure pump for the colored solution, bringing the piston plate of the pressurizing module into close contact with the karst pipeline filling transparent imitation material 4, applying the rated pressure to the piston plate of the pressurizing module, and fixing the filling transparent imitation material by leaving it stationary for a rated time under the rated fixing pressure. After the curing is complete, the injection pressurizer 13 and the pressurizing pipe 2 are connected, the valve between them is opened, the planar laser is opened and irradiated onto the karst pipeline-filled transparent-like material 4 to form a single laser cross-section, an image collector is used to continuously collect images of the laser cross-section directly in front of the glass pipe 3, the computer is controlled to periodically collect spot-controlled planar images with the digital camera 1 at a collection rate of one image per second, the data collector and electronic scale 25 are opened to collect the pressure and mass of the permeate liquid at each location, and by performing digital photogrammetry analysis on the collected images, the changes in the permeation path of the colored solution and the rules of particle movement changes inside the karst pipeline-filled material are obtained in step S5. The width of the permeation slit 23 is adjusted to a predetermined value by sliding the slide plate 21 of the sealing module, the pressurizing module and the pressurizing pump for the colored solution are opened, and the injection pressurizer 13 is driven via the oil pump 15 to gradually increase the water pressure inside the glass pipe 3, pressurizing by 0.1 MPa in each step, stabilizing for another 600 s after pressurization, and the protective pressure value of the second pressurizing rod 18 is synchronously increased based on the applied water pressure value until the designed support pressure is reached. In the stepwise water pressure loading process, the colored solution is permeated from the karst pipeline filling transparent-like material 4 to the flow metering module, the permeate is filtered through the filter screen 6 and then discharged into the metering tank 5, and when leachate particles begin to appear on the filter screen 6, the filter screen 6 is replaced every 60 s until water bursts or unstable fractures occur in the filling structure, and the permeation coefficient and porosity of the karst pipeline filling structure are analyzed by obtaining the water mass and particle mass of the permeate in step S6. Step S7 includes stopping the test, closing the instruments, tidying up the instruments, and storing them. [Explanation of symbols]

[0036] 1 Digital camera 2 Pressurized pipe 3 Glass pipes 4. Karst pipeline filling transparent similar material 5 Measuring tank 6 Filter net 7. Image collector and pressure collector 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 Bars 21 Slide Plate 22 Folded section 23 Penetration slits 24 lasers 25 Electronic scales 26 Test benches 27. Permeate collection pipe

Claims

1. A test apparatus for the movement and outflow of packing 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 material similar to karst pipeline filling, and is used to simulate karst pipeline filling structure material. The pressurizing module is provided at one end of the glass pipe, and a colored solution is provided 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 the flow metering module via a permeate collection pipe. The laser irradiation module is located on the opposite side from the glass pipe and sealing module, and the laser irradiation module is a movable red planar laser, which irradiates the karst pipeline filling transparent-like material inside the glass pipe to form a single laser cross-section, and an image collector is used to continuously collect images of the laser cross-section immediately before the glass pipe. A test apparatus for the movement and outflow of filling particles inside a karst pipeline, characterized by pressurizing the karst filling material with the aforementioned pressurizing module, allowing a colored solution to permeate from the karst filling material to a flow metering module, analyzing the permeation coefficient and porosity of the karst pipeline filling structure based on the water mass and particle mass of the permeate, continuously collecting laser cross-sectional images of the karst pipeline filling material during the test process, and performing digital photogrammetry analysis to obtain changes in the permeation path of the colored solution and rules for changes in particle movement inside the karst pipeline filling material.

2. The apparatus for testing the movement and leakage of packing particles inside a karst pipeline according to claim 1, characterized in that the inner wall of the glass pipe is provided as an irregular uneven surface, and the karst packing material comprises fused silica sand, amorphous silicon powder, liquid paraffin, and n-tridecane.

3. The apparatus for testing the movement and outflow of packing particles inside a karst pipeline according to claim 1, characterized in that the glass pipe is provided on one side of a fixed steel frame, a bottom support member for fixing a test stand is provided at the bottom of the fixed steel frame, and a diagonal bracing for connecting the bottom support member is provided on the side of the glass pipe that is away from the fixed steel frame.

4. The apparatus for testing the movement and outflow of filling particles inside a karst pipeline according to claim 3, characterized in that a rod-shaped hole facing the glass pipe is provided in the central part of the diagonal bracing and the fixed steel frame, the vertical length of the rod-shaped hole matches the height of the karst filling material, the laser light emitted from a planar laser passes through the rod-shaped hole and then irradiates the karst pipeline filling transparent-like material to form a single laser cross-section, and an image collector is used to continuously collect images of the laser cross-section.

5. The pressurizing module includes a main frame and pressurizing pipes. A first pressure rod directed toward the glass pipe is provided in the central part of the main frame, and a first piston plate is provided at one end of the first pressure rod that extends toward the glass pipe. The apparatus for testing the movement and outflow of packing particles inside a karst pipeline according to claim 1, characterized in that one end of the pressurized pipe is connected to a pressurized pump, and the other end passes through the first piston plate and is directed toward the karst pipeline packing material, thereby pumping a high-pressure colored solution between the first piston plate and the karst pipeline packing 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 is supported by a plurality of support jaws corresponding to the edge angle of the second piston plate, A chute is provided on one side of the second piston plate adjacent to the karst pipeline filling material, the chute is located on one side of the penetration slit, and the depth of the chute matches 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 penetration slit can be adjusted by sliding the slide plate. The apparatus for testing the movement and outflow of packing particles inside a karst pipeline according to claim 1, characterized in that the edge of the slide plate is provided with a folded portion corresponding to the permeation slit, and the side of the second piston plate that is separated from the karst pipeline packing material is provided with a stopper bar that correspondingly stops the folded portion.

7. The flow rate metering module comprises a permeate collection pipe, a metering tank, a filter mesh, and an electronic scale, wherein the filter mesh is provided above the metering tank and filters particles in the permeate, characterized in that it is a test apparatus for the movement and outflow of packing particles inside a karst pipeline according to claim 1.

8. The test apparatus further includes an image collector and a pressure collector connected to a controller, The image collector is positioned directly opposite the glass pipe and continuously collects laser cross-sectional images of the karst pipeline filling material inside the glass pipe, and the pressure collector is connected in correspondence with the pressurizing module and the sealing module and collects rated pressure data of the pressurizing module and the sealing module, characterized in that it is a test apparatus for the movement and outflow of filling particles inside a karst pipeline according to claim 4.

9. A method for testing the movement and outflow of packing particles inside a karst pipeline, performed using a test apparatus described in any one of claims 1 to 8, wherein the permeability coefficient and porosity of the karst pipeline packing structure are analyzed by obtaining the water mass and particle mass of the permeate liquid from the test apparatus, and changes in the permeation path of the colored solution and rules for changes in particle movement inside the packing material are obtained by continuously collecting laser cross-sectional images of the karst pipeline packing material during the test process and performing digital photogrammetry analysis.

10. Step S1 involves sealing the bottom of the glass pipe with a temporary cover plate, Step S2 involves preparing a transparent material similar to karst pipeline filling, mixing multi-walled carbon nanotubes into the karst pipeline filling material, and then filling it into glass pipes in multiple stages, with each stage having a filling height of 40 mm, until the filling height reaches 360 mm, after which the pipes are placed in a vacuum chamber and a 15 min vacuum treatment is performed. Step S3 involves fixing the glass pipe to the test stand via a fixed steel frame and attaching the sealing module and pressurizing module. Step S4 involves sliding the slide plate of the sealing module to close the penetration slit, closing the pressure pump for the colored solution, bringing the piston plate of the pressure module into close contact with the karst pipeline filling transparent-like material, applying the rated pressure to the piston plate of the pressure module, and fixing the filling pipeline transparent-like material by leaving it stationary for the rated time under the rated fixing pressure. Step S5 involves opening a planar laser after the fixing is complete, irradiating the transparent material similar to the karst pipeline filling inside the glass pipe to form a single laser cross-section, continuously collecting images of the laser cross-section using an image collector immediately before the glass pipe, and performing digital photogrammetry analysis on the collected images to obtain the changes in the penetration path of the colored solution and the rules of particle movement changes inside the karst pipeline filling material. Step S6 involves adjusting the width of the permeation slit to a predetermined value by sliding the slide plate of the sealing module, opening the pressurizing module and the pressurizing pump for the colored solution, allowing the colored solution to permeate from the top of the karst pipeline filling material to the flow metering module, filtering the permeate through a filter mesh and then discharging it into a metering tank, and analyzing the permeation coefficient and porosity of the karst pipeline filling structure based on the water mass and particle mass of the permeate. A method for testing the migration and leakage of packing particles inside a karst pipeline according to claim 9, comprising step S7 of stopping the test, closing the instrument, tidying up the instrument and storing it.

Images