A Visual Test Apparatus and Method for Seepage Flow in Rough Fractures of Rock Mass with Variable Roughness

Abstract

This invention belongs to the field of rock fracture seepage testing technology, specifically relating to a variable roughness visualized rock mass rough fracture seepage testing device and method. The technical solution of this invention is as follows: A variable roughness visualized rock mass rough fracture seepage testing device includes a base, a shell, a fracture geometry simulation system, a hydraulic loading system, an information acquisition system, and a control system. The fracture geometry simulation system, hydraulic loading system, and information acquisition system are integrated on the base. The shell is mounted on the base and encloses the fracture geometry simulation system, hydraulic loading system, and information acquisition system within it. The control system is located on the front end face of the shell, and the fracture geometry simulation system, hydraulic loading system, and information acquisition system are controlled by the control system. This invention can achieve variable simulation of any fracture surface, solving the problems of frequent sample replacement, high manufacturing cost, long cycle time, and difficulty in controlling geometric parameters in fracture seepage testing.

Description

Technical Field

[0001] This invention belongs to the field of rock fracture seepage testing technology, specifically relating to a visual rock mass rough fracture seepage testing device and method with variable roughness. Background Technology

[0002] In geotechnical engineering projects such as tunnel engineering, slope engineering, and petroleum engineering, the geological conditions of the surrounding rock are complex due to natural geological conditions and the influence of construction dynamics. Numerous fissures exist within the rock mass, forming a vast network of fissures. Compared to the high permeability of the rock matrix fissures, these fissures become dominant channels for groundwater or other fluids within the rock mass. Furthermore, the fluid-structure interaction between the fluids within the fissures and the rock mass continuously affects the hydraulic properties and stability of the rock mass, thus impacting the quality of geotechnical engineering projects. Therefore, clarifying the seepage characteristics and dynamic laws of single-phase and multi-phase fluids within rock fissures is of great significance for both academic research and engineering practice in geotechnical engineering.

[0003] Because the geometry of fractures within real rock masses is heterogeneous and invisible, and accurate measurement techniques for characterizing real rock mass fractures are currently lacking, it is necessary to describe fluid flow within fractures through visualization experiments and other methods. A single fracture, as the fundamental unit for studying rock mass fracture seepage, is the basis for research on seepage in complex fracture networks and engineering-scale seepage, thus it is of great significance in rock mass fracture seepage experimental research. Furthermore, due to the geometric heterogeneity of the upper and lower fracture surfaces in natural rock masses, the current parallel plate model assumption is no longer sufficient to meet the needs of practical research; it is necessary to consider the influence of more complex geometric properties such as roughness of the fracture surface in fracture seepage experiments.

[0004] To visualize the impact of fracture geometry on experimental results, the preparation of transparent fracture specimens is crucial. Currently, domestic and international researchers primarily employ methods for specimen preparation including: 3D printing using point cloud data from Brazilian split rock specimens or randomly generated fracture surfaces using fractal functions; creating molds after Brazilian split rock specimen preparation, pouring resin, and then demolding; and carving acrylic sheets. However, these commonly used methods still have the following shortcomings: ① The preparation cycle for 3D printing and acrylic carving using point cloud data is long, requires a large number of specimens, and is costly; ② The point cloud data obtained from Brazilian splitting or fractal function generation is highly random, making it difficult to achieve targeted adjustments to the fracture surface geometry, and specimens are frequently discarded in Brazilian splitting due to unmet requirements, resulting in excessive waste; ③ Specimens frequently need to be replaced during the experiment, which is very inconvenient; ④ Only seepage morphology can be observed, and hydraulic data at various points within the fracture cannot be obtained.

[0005] Currently, there are still limitations in the devices and methods for visual experimental research on the seepage characteristics of rock fractures. At present, it is necessary to improve the controllability of the geometric parameters of the simulated fractures and the reusability of the specimens in order to reduce experimental costs, reduce the number of test specimens, and increase the diversity of the geometric parameters of the fracture surface. Summary of the Invention

[0006] This invention provides a visual rock mass roughness fracture seepage test device and method with variable roughness, which can realize variable simulation of arbitrary fracture surfaces and solve the problems of frequent sample replacement, high manufacturing cost, long cycle and difficulty in controlling geometric parameters in fracture seepage test.

[0007] The technical solution of the present invention is as follows:

[0008] A variable roughness visualization rock mass rough fracture seepage test device includes a base, a shell, a fracture geometry simulation system, a hydraulic loading system, an information acquisition system, and a control system. The fracture geometry simulation system, the hydraulic loading system, and the information acquisition system are integrated on the base. The shell is installed on the base and encloses the fracture geometry simulation system, the hydraulic loading system, and the information acquisition system. The control system is located on the front end face of the shell, and the fracture geometry simulation system, the hydraulic loading system, and the information acquisition system are controlled by the control system.

[0009] Furthermore, the aforementioned variable roughness visualization rock mass roughness fracture seepage test device comprises an upper and lower fracture geometry simulation system, arranged in a mirror image. The fracture geometry simulation system includes micro hydraulic rods, micro transparent movable columns, a column clamping mechanism, a column movement control module, and a transparent rubber membrane. Each micro transparent movable column is fixedly connected to the front end of a micro hydraulic rod. The tail ends of multiple micro hydraulic rods are integrated on the bottom surface of the column clamping mechanism. The micro transparent movable column has a square cross-section, and the column clamping mechanism gathers multiple micro transparent movable columns together. The transparent rubber membrane is a cap-shaped sleeve bonded to the top surface of the cluster of multiple micro transparent movable columns. The column movement control module is located at the bottom of the column clamping mechanism, and the micro hydraulic rods are controlled by the column movement control module, which is connected to the control system. The lower part of the fracture geometry simulation system is fixedly mounted on the base, and the space between the upper and lower transparent rubber membranes is used to simulate fracture geometry.

[0010] Furthermore, the variable roughness visualization rock mass rough fracture seepage test device includes a columnar body clamping mechanism comprising a frame, a base plate, wall plates, and a clamping plate. The base plate and four wall plates are fixedly installed together with the frame to form a square cylinder with an open upper surface. The clamping plate has uniformly arranged square holes. The clamping plate is arranged parallel to the base plate and fixedly connected to the wall plates and the frame. A miniature transparent movable columnar body is placed in each square hole. The upper end of the frame has two symmetrically distributed crossbeams with outward protrusions. When the upper and lower parts of the fracture geometry simulation system are fastened together, the crossbeams with outward protrusions are fastened together in pairs.

[0011] Furthermore, the variable roughness visualization rock mass rough fracture seepage test device includes a hydraulic loading system comprising a sealing structure, a liquid injection structure, a peristaltic pump, a liquid storage tank, and a vacuum conduit. Two sealing structures are symmetrically arranged, each of which is installed together with two outwardly protruding crossbeams. Two liquid injection structures are symmetrically arranged on the other two transverse sides of the frame, forming, together with the two sealing structures, the external structure between the upper and lower parts of the fracture geometry simulation system. Two liquid storage tanks are set on the base, each equipped with a peristaltic pump connected to a liquid injection structure via a vacuum conduit.

[0012] Furthermore, in the aforementioned variable roughness visualization rock mass rough fracture seepage test device, the sealing structure includes a tank shell and a sealing strip. The inner wall of the tank shell is provided with two opposing convex strips. The upper end of the outwardly protruding crossbeam is provided with a sealing groove, and the lower end is provided with an installation groove. The two crossbeams with outward protrusions are fastened together. The sealing strip is inserted into the space where the two sealing grooves are joined together. The two convex strips of the tank shell are respectively installed in the installation grooves of the two crossbeams. A liquid accumulation tank is formed between the tank shell and the crossbeams for collecting the seeping liquid.

[0013] Furthermore, in the aforementioned variable roughness visualization rock mass rough fracture seepage test device, the injection structure includes a cuboid, a groove, and three injection nozzles. The cuboid is fixedly connected to the upper end of the frame. The three injection nozzles are provided on the outer side of the cuboid, and the groove is provided on the inner side of the cuboid, with the groove communicating with the three injection nozzles. The groove extends into the space between the upper and lower parts of the fracture geometry simulation system. The injection nozzles are connected to the peristaltic pump through the vacuum conduit.

[0014] Furthermore, the variable roughness visualization rock mass rough fracture seepage test device includes an information acquisition system comprising a CCD high-speed camera, a liquid velocity meter, a first liquid pressure meter, a second liquid pressure meter, a third liquid pressure meter, and a fourth liquid pressure meter. The CCD high-speed camera is mounted on the top of a designated miniature transparent movable column to acquire dynamic images during the seepage process. The liquid velocity meter and the first liquid pressure meter are mounted on the surface of a transparent rubber membrane to measure the flow velocity and pressure of the liquid in a specific area inside the fracture. The second liquid pressure meter is mounted at the groove to measure the pressure of the liquid before it enters the fracture. The third liquid pressure meter is mounted in the accumulation tank to detect whether there is liquid seepage. The fourth liquid pressure meter is mounted at the bottom of the storage tank to measure the weight of the outflowing liquid.

[0015] Furthermore, in the aforementioned variable roughness visualization rock mass rough fracture seepage test device, the control system is a microcomputer connected to a column movement control module, a peristaltic pump, a CCD high-speed camera, a liquid flow meter, a first liquid pressure gauge, a second liquid pressure gauge, a third liquid pressure gauge, and a fourth liquid pressure gauge. It is used to input the preset geometric parameters of the fracture and the pressure of the peristaltic pump, receive information data, and output the acquired images and data.

[0016] Furthermore, in the aforementioned variable roughness visualization rock mass rough fracture seepage test device, the base is equipped with a light plate, which provides light for the seepage process and facilitates image acquisition; the miniature transparent movable column is made of fully transparent photosensitive resin; and the liquid storage tank and tank shell are made of transparent acrylic.

[0017] A method for visualizing rock mass rough fracture seepage flow with variable roughness, utilizing the aforementioned visualizing rock mass rough fracture seepage flow test apparatus with variable roughness, includes the following steps:

[0018] Step 1: Reset all miniature transparent movable cylinders to their initial height using a microcomputer, and extend and retract all miniature transparent movable cylinders to a uniform height according to the set required slit opening.

[0019] Step 2: Input the point cloud data of the rough fracture surface into the microcomputer, control all the micro transparent movable cylinders to move according to the coordinates, generate the required simulated rough fracture surface and lock it, and check whether the groove is properly located in the fracture.

[0020] Step 3: Turn on the light plate, CCD high-speed camera, liquid flow meter, first liquid pressure gauge, second liquid pressure gauge, third liquid pressure gauge and fourth liquid pressure gauge through the microcomputer, and reset the values ​​of the liquid flow meter, first liquid pressure gauge, second liquid pressure gauge, third liquid pressure gauge and fourth liquid pressure gauge to the initial value state;

[0021] Step 4: Turn on the peristaltic pump via the microcomputer, select single or double operation according to the test requirements, and set the hydraulic parameters of the peristaltic pump;

[0022] Step 5: Observe the images and data of the seepage process using a microcomputer;

[0023] Step Six: After the seepage is completed, record and store the test data such as pressure, flow rate, and images. These data can be used to study the seepage characteristics of single-phase or multiphase liquids under different fracture geometry.

[0024] The beneficial effects of this invention are as follows: The device approximates the rough fracture surface with micro-elements, using the surface of a micro-transparent movable column to simulate the micro-planes of the rough fracture. The micro-transparent movable column is connected to a micro-hydraulic rod, and under the control of the micro-hydraulic rod, the normal coordinates of each micro-transparent movable column can be transformed according to the input point cloud data. Furthermore, a transparent coating enhances the details between each micro-transparent movable column, thereby simulating the geometric heterogeneity of the rough fracture structure. This device can arbitrarily adjust the shape of the rough fracture surface according to the provided point cloud coordinate data, better meeting the diverse needs of fracture seepage tests. It solves the problems of large sample quantities, high cost, long time, and frequent sample replacement required in current fracture seepage tests, thus reducing costs and increasing efficiency. The mobility of the simulated fracture surface enables targeted and accurate simulation of complex rough fracture surfaces, solving the problem of uncontrollable geometric parameters of prefabricated fracture surfaces in current tests. This invention allows for the addition of sensors at arbitrary coordinate positions within the fracture, solving the problem of difficulty in acquiring data inside the fracture in current fracture seepage tests. This invention is an integrated testing device that simplifies the testing process and is easy to operate. Attached Figure Description

[0025] Figure 1 A schematic diagram of the external appearance of a visual rock mass roughness fracture seepage test device with variable roughness.

[0026] Figure 2 Axonometric view of the internal structure of a rock mass roughness fracture seepage test device with variable roughness;

[0027] Figure 3 Rear view of a visualization test setup for seepage flow in rough rock fractures with variable roughness;

[0028] Figure 4 Axonometric drawing of the sealing structure and the liquid injection structure;

[0029] Figure 5 This is a half-section front view of the sealing structure and the liquid injection structure;

[0030] Figure 6 Axonometric drawing of the fracture geometry simulation system;

[0031] Figure 7 This is the main view of the fracture geometry simulation system;

[0032] Figure 8 This is a top view of the fracture geometry simulation system. Detailed Implementation

[0033] like Figure 1-8 As shown, a variable roughness visualization rock mass rough fracture seepage test device includes a base 1, a shell 2, a fracture geometry simulation system, a hydraulic loading system, an information acquisition system, and a control system. The fracture geometry simulation system, the hydraulic loading system, and the information acquisition system are integrated on the base 1. The shell 2 is installed on the base 1 and encloses the fracture geometry simulation system, the hydraulic loading system, and the information acquisition system within it. The control system is located on the front end face of the shell 2, and the fracture geometry simulation system, the hydraulic loading system, and the information acquisition system are controlled by the control system.

[0034] The fracture geometry simulation system is divided into upper and lower parts, arranged in a mirror image. The system includes miniature hydraulic rods 19, miniature transparent movable cylindrical bodies 18, a cylindrical body clamping mechanism, a cylindrical body movement control module 6, and a transparent rubber coating. Each miniature transparent movable cylindrical body 18 is fixedly connected to the front end of a miniature hydraulic rod 19. The tail ends of multiple miniature hydraulic rods 19 are integrated on the bottom surface of the cylindrical body clamping mechanism. The extension range of the miniature hydraulic rods 19 is -15mm to 15mm. The miniature transparent movable cylindrical body 18 has a square cross-section with a side length of 4mm and a height of 50mm. The cylindrical body clamping mechanism holds 2500 miniature transparent movable cylindrical bodies. The columnar bodies 18 are clustered together, forming a simulated fracture surface that is also square, with 50 miniature transparent movable columnar bodies 18 in each row; the transparent rubber coating is a cap-shaped sleeve, bonded to the top surface of the cluster of 2500 miniature transparent movable columnar bodies 18, serving to isolate and prevent seepage and increase the geometric continuity of the simulated fracture surface; the columnar body movement control module 6 is located at the bottom of the columnar body clamping mechanism, and the miniature hydraulic rod 19 is controlled by the columnar body movement control module 6, which is connected to the control system; the lower part of the fracture geometry simulation system is fixedly installed on the base 1, and the space between the upper and lower transparent rubber coatings is used to simulate the fracture geometry.

[0035] The columnar body clamping mechanism includes a frame 4, a base plate, wall panels 5, and a clamping plate 20. The base plate and four wall panels 5 are fixedly installed together with the frame 4 to form a square cylinder with an open upper surface. The clamping plate 20 has 2,500 square holes evenly arranged. The clamping plate 20 is arranged parallel to the base plate and is fixedly connected to the wall panels 5 and the frame 4. A miniature transparent movable columnar body 18 is placed in each square hole. The clamping plate 20 is used to limit the lateral displacement of each miniature transparent columnar body 18 during its movement. The upper end of the frame 4 has two symmetrically distributed crossbeams 16 with outward protrusions. When the upper and lower parts of the fracture geometry simulation system are fastened together, the crossbeams 16 with outward protrusions are fastened together in pairs.

[0036] The hydraulic loading system includes a sealing structure, a liquid injection structure, a peristaltic pump 8, a liquid storage tank 10, and a vacuum conduit 9. The two sealing structures are symmetrically arranged, and each sealing structure is installed together with two crossbeams 16 with outward protrusions that are fastened together. The two liquid injection structures are symmetrically arranged on the other two transverse sides of the frame 4, and together with the two sealing structures, they form the external structure between the upper and lower parts of the fracture geometry simulation system. The two liquid storage tanks 10 are set on the base 1, and each liquid storage tank 10 is equipped with a peristaltic pump 8 and connected to a liquid injection structure through a vacuum conduit 9. The sealing structure includes a groove shell 13 and a sealing strip 14. The inner wall of the groove shell 13 is provided with two opposing protrusions 15. The upper end of the outwardly protruding crossbeam 16 is provided with a sealing groove, and the lower end is provided with an installation groove. The two crossbeams 16 with outward protrusions are fastened together. The sealing strip 14 is inserted into the space where the two sealing grooves are joined together to prevent liquid from flowing out of the crack. The two protrusions 15 of the groove shell 13 are respectively installed in the installation grooves of the two crossbeams 16. A liquid accumulation groove is formed between the groove shell 13 and the crossbeam 16 to collect the seeping liquid. The liquid injection structure includes a cuboid 7, a groove 12, and three injection nozzles 11. The cuboid 7 is fixedly connected to the upper end of the frame 4. The three injection nozzles 11 are provided on the outer side of the cuboid 7, and the groove 12 is provided on the inner side of the cuboid 7. The groove 12 communicates with the three injection nozzles 11. The groove 12 is made of soft rubber and extends into the space between the upper and lower parts of the fracture geometry simulation system to prevent concentrated seepage in the region. The injection nozzles 11 are connected to the peristaltic pump 8 through the vacuum conduit 9. The peristaltic pump 8 provides pressure for the seepage liquid as needed.

[0037] The information acquisition system includes a CCD high-speed camera, a liquid flow meter, a first liquid pressure gauge, a second liquid pressure gauge, a third liquid pressure gauge, and a fourth liquid pressure gauge. Five CCD high-speed cameras are installed on the top of designated miniature transparent movable cylindrical bodies 18, one in the middle and one at each of the four corners, for acquiring dynamic images during the seepage process. The liquid flow meter and the first liquid pressure gauge are installed on the surface of a transparent rubber membrane for measuring the flow velocity and pressure of the liquid in specific areas inside the fissure. The second liquid pressure gauge is installed at the groove 12 for measuring the pressure of the liquid before it enters the fissure. The third liquid pressure gauge is installed in the accumulation tank for detecting whether liquid is seeping out. The fourth liquid pressure gauge is installed at the bottom of the storage tank 10 for measuring the weight of the outflowing liquid.

[0038] The control system is a microcomputer 3, which is connected to a columnar body movement control module 6, a peristaltic pump 8, a CCD high-speed camera, a liquid flow meter, a first liquid pressure gauge, a second liquid pressure gauge, a third liquid pressure gauge, and a fourth liquid pressure gauge. It is used to input the preset geometric parameters of the fracture and the pressure of the peristaltic pump, receive information data, and output the acquired images and data.

[0039] The base 1 is provided with a light plate 17, which is a white LED flat panel light source. The light plate 17 provides light for the seepage process and facilitates image acquisition. The miniature transparent movable column 18 is made of fully transparent photosensitive resin. The liquid storage tank 10 and the tank shell 13 are made of transparent acrylic.

[0040] The base 1 is equipped with casters for easy movement.

[0041] A method for visualizing rock mass rough fracture seepage flow with variable roughness, utilizing the aforementioned visualizing rock mass rough fracture seepage flow test apparatus with variable roughness, includes the following steps:

[0042] Step 1: The microcomputer 3 controls the micro hydraulic rod 19 through the column movement control module 6 to move the micro transparent movable column 18 along the normal direction, reset all micro transparent movable column 18 back to the starting height, and make all micro transparent movable column 18 extend and retract to a uniform height according to the set required crack opening.

[0043] Step 2: Input the point cloud data of the rough fracture surface into the microcomputer 3, control all the micro transparent movable columnar bodies 18 to move according to the coordinates, simulate the undulation of each point of the rough fracture surface, generate the required simulated rough fracture surface and lock it, and check whether the groove 12 is properly located in the fracture.

[0044] Step 3: Turn on the light plate 17, CCD high-speed camera, liquid flow meter, first liquid pressure gauge, second liquid pressure gauge, third liquid pressure gauge and fourth liquid pressure gauge through microcomputer 3, and reset the values ​​of the liquid flow meter, first liquid pressure gauge, second liquid pressure gauge, third liquid pressure gauge and fourth liquid pressure gauge to the initial value state.

[0045] Step 4: Turn on the peristaltic pump 8 via the microcomputer 3, select single or double operation according to the test requirements, and set the hydraulic parameters of the peristaltic pump 8;

[0046] Step 5: Observe the images and data of the seepage process using microcomputer 3;

[0047] Step Six: After the seepage is completed, record and store the test data such as pressure, flow rate, and images. These data can be used to study the seepage characteristics of single-phase or multiphase liquids under different fracture geometry.

Claims

1. A visual rock mass roughness fracture seepage test device with variable roughness, characterized in that, The system includes a base, a shell, a fracture geometry simulation system, a hydraulic loading system, an information acquisition system, and a control system. The fracture geometry simulation system, the hydraulic loading system, and the information acquisition system are integrated on the base. The shell is mounted on the base and encloses the fracture geometry simulation system, the hydraulic loading system, and the information acquisition system within it. The control system is located on the front end face of the shell, and the fracture geometry simulation system, the hydraulic loading system, and the information acquisition system are controlled by the control system. The fracture geometry simulation system is divided into upper and lower parts, arranged in a mirror image. The system includes miniature hydraulic rods, miniature transparent movable cylinders, a cylinder clamping mechanism, a cylinder movement control module, and a transparent rubber membrane. Each miniature transparent movable cylinder is fixedly connected to the front end of a miniature hydraulic rod. The tail ends of multiple miniature hydraulic rods are integrated on the bottom surface of the cylinder clamping mechanism. The cross-section of each miniature transparent movable cylinder is square, and the clamping mechanism brings multiple miniature transparent movable cylinders together. The transparent rubber membrane, a cap-shaped sleeve, is bonded to the top surface of the cluster of multiple miniature transparent movable cylinders. The cylinder movement control module is located at the bottom of the clamping mechanism, and the miniature hydraulic rods are controlled by the module, which is connected to the control system. The lower part of the fracture geometry simulation system is fixedly mounted on the base, and the space between the upper and lower transparent rubber membranes is used to simulate fracture geometry. The columnar clamping mechanism includes a frame, a base plate, wall panels, and a clamping plate. The base plate and four wall panels are fixedly installed together with the frame to form a square cylinder with an open upper surface. The clamping plate has evenly arranged square holes. The clamping plate is arranged parallel to the base plate and fixedly connected to the wall panels and the frame. A miniature transparent movable columnar body is placed in each square hole. The upper end of the frame has two symmetrically distributed crossbeams with outward protrusions. When the upper and lower parts of the fracture geometry simulation system are fastened together, the crossbeams with outward protrusions are fastened together in pairs. The control system is a microcomputer connected to a columnar body movement control module, a peristaltic pump, a CCD high-speed camera, a liquid flow meter, a first liquid pressure gauge, a second liquid pressure gauge, a third liquid pressure gauge, and a fourth liquid pressure gauge. It is used to input the preset geometric parameters of the fracture and the pressure of the peristaltic pump, receive information data, and output the acquired images and data. Point cloud data of the rough fracture surface is input into a microcomputer, and all micro-transparent movable cylinders are controlled to move according to coordinates to generate the required simulated rough fracture surface. The surfaces of the micro-transparent movable cylinders are used to simulate the micro planes of the rough fracture. The micro-transparent movable cylinders are connected to micro hydraulic rods. Under the control of the micro hydraulic rods, the normal coordinates of each micro-transparent movable cylinder can be transformed according to the input point cloud data. The details between each micro-transparent movable cylinder are enhanced by a transparent coating, thereby realizing the simulation of the geometric heterogeneity of the rough fracture structure surface.

2. The variable roughness visualization rock mass rough fracture seepage test device according to claim 1, characterized in that, The hydraulic loading system includes a sealing structure, a liquid injection structure, a peristaltic pump, a liquid storage tank, and a vacuum conduit. Two sealing structures are symmetrically arranged, each of which is installed together with two outwardly protruding crossbeams. Two liquid injection structures are symmetrically arranged on the other two transverse sides of the frame, forming the external structure between the upper and lower parts of the fracture geometry simulation system together with the two sealing structures. Two liquid storage tanks are set on the base, and each liquid storage tank is equipped with a peristaltic pump connected to a liquid injection structure through a vacuum conduit.

3. The variable roughness visualization rock mass rough fracture seepage test device according to claim 2, characterized in that, The sealing structure includes a groove shell and a sealing strip. The inner wall of the groove shell is provided with two opposing protrusions. The upper end of the outwardly protruding crossbeam is provided with a sealing groove and the lower end is provided with an installation groove. The two crossbeams with outward protrusions are fastened together. The sealing strip is inserted into the space where the two sealing grooves are joined together. The two protrusions of the groove shell are respectively installed in the installation grooves of the two crossbeams. A liquid collection trough is formed between the tank shell and the crossbeam to collect the seeping liquid.

4. The variable roughness visualization rock mass rough fracture seepage test device according to claim 2, characterized in that, The liquid injection structure includes a cuboid, a groove, and three injection nozzles. The cuboid is fixedly connected to the upper end of the frame. The three injection nozzles are provided on the outer side of the cuboid, and the groove is provided on the inner side of the cuboid. The groove communicates with the three injection nozzles. The groove extends into the space between the upper and lower parts of the fracture geometry simulation system. The injection nozzles are connected to the peristaltic pump through the vacuum conduit.

5. The variable roughness visualization rock mass rough fracture seepage test device according to any one of claims 1-4, characterized in that, The information acquisition system includes a CCD high-speed camera, a liquid flow meter, a first liquid pressure gauge, a second liquid pressure gauge, a third liquid pressure gauge, and a fourth liquid pressure gauge. The CCD high-speed camera is mounted on the top of a designated miniature transparent movable column to acquire dynamic images during the seepage process. The liquid flow meter and the first liquid pressure gauge are mounted on the surface of a transparent rubber membrane to measure the flow velocity and pressure of the liquid in a specific area inside the fissure. The second liquid pressure gauge is mounted at the groove to measure the pressure of the liquid before it enters the fissure. The third liquid pressure gauge is mounted inside the accumulation tank to detect whether there is liquid seepage. The fourth liquid pressure gauge is mounted at the bottom of the storage tank to measure the weight of the outflowing liquid.

6. The variable roughness visualization rock mass rough fracture seepage test device according to claim 5, characterized in that, The base is equipped with a light plate, which provides light for the seepage process and facilitates image acquisition; the miniature transparent movable column is made of fully transparent photosensitive resin; the liquid storage tank and the tank shell are made of transparent acrylic.

7. A method for visualizing rock mass roughness fracture seepage test with variable roughness, characterized in that, The method of using the variable roughness visualization rock mass rough fracture seepage test apparatus as described in claim 6 includes the following steps: Step 1: Reset all miniature transparent movable cylinders to their initial height using a microcomputer, and extend and retract all miniature transparent movable cylinders to a uniform height according to the set required slit opening. Step 2: Input the point cloud data of the rough fracture surface into the microcomputer, control all the micro transparent movable cylinders to move according to the coordinates, generate the required simulated rough fracture surface and lock it, and check whether the groove is properly located in the fracture. Step 3: Turn on the light plate, CCD high-speed camera, liquid flow meter, first liquid pressure gauge, second liquid pressure gauge, third liquid pressure gauge and fourth liquid pressure gauge through the microcomputer, and reset the values ​​of the liquid flow meter, first liquid pressure gauge, second liquid pressure gauge, third liquid pressure gauge and fourth liquid pressure gauge to the initial value state; Step 4: Turn on the peristaltic pump via the microcomputer, select single or double operation according to the test requirements, and set the hydraulic parameters of the peristaltic pump; Step 5: Observe the images and data of the seepage process using a microcomputer; Step Six: After seepage is completed, the pressure, flow rate, and image test data are recorded and stored, which can be used to study the seepage characteristics of single-phase or multiphase liquids under different fracture geometry.

Images