Three-dimensional fracture network dynamic water environment thermal-fluid-solid coupling grouting test device and test method

Abstract

The invention discloses a three-dimensional fracture network rock mass dynamic water environment thermal-fluid-solid coupling grouting test device and a corresponding test method. The device comprises a grouting system and a high-temperature flowing water simulation system, and the grouting system is used for conducting simulation grouting on the three-dimensional fracture network rock mass model in the grouting test process; and the high-temperature dynamic water simulation system is used for providing a dynamic water source with a set temperature for the grouting test. The high-temperature flowing water simulation system comprises a constant-temperature water source (4), a flowing water pipe (5) and an electric heating wire (22). The device and the method can be used for high-temperature dynamic water grouting and triaxial loading tests, so that the three-dimensional fracture network rock mass model is in a high-temperature dynamic water and triaxial compression environment, and therefore, a heat-fluid-solid multi-field coupling environment in an actual underground rock mass can be effectively simulated.

Description

Technical Field

[0001] The invention belongs to the technical field of grouting test devices for deep underground engineering, and specifically relates to a thermal-fluid-solid coupling grouting test device and a test method for a three-dimensional fracture network rock mass dynamic water environment. Background Art

[0002] During the construction of underground projects such as tunnels, water conservancy projects, and coal mines, there are often cracks and weak joints in the strata, which can easily lead to problems such as water inrush, mud inrush, and rock leakage. The most common solution to these problems is to use appropriate grouting technology. Grouting can effectively fill the cracks in the rock mass, thereby enhancing the strength and stability of the rock mass and reducing the permeability of the surrounding rock. However, due to the concealment of grouting projects, the diffusion law of slurry in the rock mass fracture network is still unclear. Therefore, the simple and easy-to-use fracture grouting simulation test device has become an indispensable tool in the study of grouting mechanism.

[0003] In recent years, the rapid development of 3D printing technology has enabled us to conveniently and accurately produce rock mass fracture entities with complex structures, greatly saving time and cost. Therefore, it is urgent to carry out grouting tests on fracture network rock mass based on 3D printing technology, deeply study the diffusion mechanism of slurry in fracture network rock mass, and provide theoretical support for the implementation of grouting engineering.

[0004] During the grouting process of deep projects such as underground tunnels and mines, the temperature of the rock will change with the increase of depth, and it may be exposed to dynamic water conditions and deep ground stress. The dynamic water environment has an important influence on the diffusion morphology and solidification and plugging time of the slurry, while the ground stress may cause changes in the opening of rock cracks and cause the opening of the cracks to expand. In addition, temperature changes will also affect the physical and chemical properties of the slurry. These factors play an important role in the injection conditions, diffusion distance and diffusion morphology of the slurry. Therefore, conducting thermal-fluid-solid coupled grouting in a dynamic water environment of a three-dimensional fracture network rock mass can better understand the influence of dynamic water conditions, underground temperature and ground stress on the flow of slurry. Summary of the invention

[0005] 1. Technical issues to be resolved

[0006] The invention aims to solve the problem that the existing grouting test device cannot simulate the high-temperature dynamic water environment to have an important influence on the diffusion form and solidification and plugging time of the slurry.

[0007] (II) Technical solution

[0008] In order to solve the above technical problems, the first aspect of the present invention proposes a three-dimensional fracture network rock mass dynamic water environment thermal-fluid-solid coupled grouting test device, which is used to perform an environmental thermal-fluid-solid coupled grouting test on a three-dimensional fracture network rock mass model, including: a grouting system, which is used to simulate grouting on the three-dimensional fracture network rock mass model during the grouting test; a high-temperature dynamic water simulation system, which is used to provide a dynamic water source with a set temperature for the grouting test.

[0009] As a preferred embodiment of the present invention, the high-temperature dynamic water simulation system includes a constant temperature water source and a dynamic water pipe; the constant temperature water source is connected to the dynamic water pipe to provide a water source with a constant temperature for the dynamic water pipe; one end of the dynamic water pipe is connected to the constant temperature water source, and the other end is connected to the dynamic water hole on the three-dimensional fracture network rock model.

[0010] As a preferred embodiment of the present invention, the constant temperature water source is used to simulate the temperature of the dynamic water in the crack before it flows, and is equipped with a heating device and a heat preservation device to achieve the regulation and constant control of the water source temperature.

[0011] As a preferred embodiment of the present invention, the high-temperature dynamic water simulation system also includes a heating wire, which is used to heat the three-dimensional fracture network rock model to a set temperature.

[0012] As a preferred embodiment of the present invention, the test device also includes a 3D printing device for 3D printing the three-dimensional fracture network rock model.

[0013] As a preferred embodiment of the present invention, the test device further comprises a coupled mechanical loading device for applying pressure to the three-dimensional fracture network rock model in multiple directions during the grouting test;

[0014] As a preferred embodiment of the present invention, the test device also includes a data acquisition system for acquiring data detected by the three-dimensional fracture network rock model during the grouting test.

[0015] As a preferred embodiment of the present invention, the data acquisition system includes a pressure and temperature monitoring system, which is arranged inside the three-dimensional fracture network rock model to collect temperature and pressure changes at various locations inside the three-dimensional fracture network rock model.

[0016] As a preferred embodiment of the present invention, the data acquisition system includes an electrical impedance tomography module, which is connected to the three-dimensional fracture network rock model, and includes a signal acquisition unit, a signal excitation unit, a feed end electrode and a plurality of slurry diffusion end electrodes. The electrode is connected to the signal excitation unit and the signal acquisition unit via a wire, and is finally connected to a computer terminal via a data connection line.

[0017] The second aspect of the present invention provides a three-dimensional fracture network rock mass dynamic water environment thermal-fluid-solid coupling grouting test method, using the above-mentioned three-dimensional fracture network rock mass dynamic water environment thermal-fluid-solid coupling grouting test device. The test method comprises the following steps:

[0018] Step S1, obtaining a three-dimensional fracture network rock model using the 3D printing device according to the fracture parameters of the actual fractured rock mass;

[0019] Step S2, uniformly winding heating wires at a certain distance outside the three-dimensional fracture network rock model; starting the high-temperature water-moving simulation system, adjusting the water temperature to meet the test requirements, and injecting water into the three-dimensional fracture network rock model through the water-moving pipe; and simultaneously turning on the heating wires to heat the three-dimensional fracture network rock model to simulate the high-temperature water-moving effect in the actual environment

[0020] Step S3, preparing slurry that meets the performance requirements, and sending the slurry into the three-dimensional fracture network rock model to perform a grouting test;

[0021] Step S4, starting the coupled mechanical loading device to apply stress loading to the three-dimensional fracture network rock model to simulate the formation stress around the three-dimensional fracture network rock model;

[0022] Step S5: using the data acquisition system to acquire data of the three-dimensional fracture network rock model obtained in the grouting test.

[0023] (III) Beneficial effects

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The present invention can be used for high-temperature dynamic water grouting and triaxial loading tests, so that the three-dimensional fracture network rock model is placed in a high-temperature dynamic water and triaxial pressure environment, thereby being able to effectively simulate the heat-fluid-solid multi-field coupling environment in the actual underground rock mass.

[0026] The present invention studies the rock fissure grouting problem of underground rock mass under high temperature environment, dynamic water flow and ground stress, fully considers the actual environment and stress state of the underground rock mass, and can provide a more in-depth and scientific analysis for the study of dynamic water grouting problem of underground rock mass under high ground stress and high temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural schematic diagram of a three-dimensional fracture network rock mass dynamic water environment thermal-fluid-solid coupling grouting test device of the present invention;

[0028] Figure 2 This is a schematic diagram of a 3D printed fracture network rock model according to an embodiment of the present invention;

[0029] Figure 3 It is a schematic diagram of the exterior of a 3D printed fracture network rock model according to an embodiment of the present invention;

[0030] Figure 4 This is a front view of a 3D printed fracture network rock model according to an embodiment of the present invention;

[0031] Figure 5 A regular fracture network rock model containing parallel fractures according to an embodiment of the present invention;

[0032] Figure 6 A random fracture network rock model containing random fractures according to an embodiment of the present invention;

[0033] Figure 7 The present invention is a flowchart of the operation of the thermal-fluid-solid coupled grouting test in a three-dimensional fracture network rock mass dynamic water environment.

[0034] Among them: 1. air compressor, 2. slurry storage tank, 3. grouting pipe, 4. constant temperature water source, 5. dynamic water pipe, 6. column, 7. fracture network rock model, 8. mechanical loading test bench, 9. upper pressure head, 10. bottom plate, 11. top beam, 12. waste liquid collection bucket, 13. electronic balance, 14. data acquisition terminal, 15. grouting hole, 16. fracture, 17. electrical impedance tomography module, 18. combined pressure and temperature sensor, 19. dynamic water hole, 20. signal acquisition unit, 21. signal excitation unit, 22. heating wire. DETAILED DESCRIPTION

[0035] In order to solve the above problems, the present invention proposes a three-dimensional fracture network rock mass dynamic water environment thermal-fluid-solid coupling grouting test device and a corresponding test method. The device can simulate a complex three-dimensional fracture network rock mass in a laboratory environment and monitor the temperature and stress changes of the fractures in real time during the grouting process. In addition, the present invention can simulate the thermal-fluid-solid environment of the actual underground rock mass and effectively study the diffusion characteristics of the slurry in the rock mass fracture network rock mass.

[0036] Specifically, the first aspect of the present invention proposes a three-dimensional fracture network rock mass dynamic water environment thermal-fluid-solid coupled grouting test device, which mainly includes a 3D printing device, a high-temperature dynamic water simulation system, a grouting system, a coupled mechanical loading device and a data acquisition system.

[0037] The 3D printing device is used for 3D printing the three-dimensional fracture network rock model, including dual robotic arms, on which a composite additive printing head and a collaborative subtractive printing head are respectively installed. The dual robotic arms can perform printing operations in coordination, realizing a one-time operation of additive and subtractive molding of a large three-dimensional fracture rock model.

[0038] Furthermore, the high-temperature dynamic water simulation system is used to provide a dynamic water source of a set temperature for the grouting test. The high-temperature dynamic water simulation system includes a constant temperature water source 4, a dynamic water pipe 5 and a heating wire 22. The constant temperature water source 4 is used to simulate the temperature of the dynamic water in the crack before it flows, and is equipped with a heating device and a heat preservation device to achieve the regulation and constant control of the water source temperature. The system is connected to the dynamic water hole on the model through the dynamic water pipe 5 and is sealed with epoxy resin AB glue. The heating wire 22 is evenly arranged in the gap to ensure that the three-dimensional fracture network rock model 7 can be heated evenly and stably. The two ends of the heating wire are respectively connected to electrodes, which are inserted into the base and electrically connected to an external power supply, so that it is powered by the power supply, so that the heating wire 22 heats the entire three-dimensional fracture network rock model 7 to the set temperature.

[0039] Furthermore, the grouting system is used to simulate grouting of the three-dimensional fracture network rock model during the grouting test, and the grouting system includes a grouting unit. The grouting unit consists of a grouting pipe 3, a slurry storage tank and an air compressor 1. The inlet of the slurry storage tank 2 is connected to the pressure regulating valve through a connecting pipeline, and the pressure regulating valve is connected to the air compressor 1 through a pipeline to provide a set constant pressure. The slurry storage tank 2 is connected to the fracture network rock model 7 through the grouting pipe 3, and is sealed with epoxy resin AB glue to ensure that the slurry flows stably in the fracture network rock.

[0040] Furthermore, the coupled mechanical loading device is used to apply pressure to the three-dimensional fracture network rock model in multiple directions during the grouting test. The coupled mechanical loading device includes a servo-controlled triaxial testing machine, including a mechanical loading test bench 8, an upper pressure head 9, a bottom plate 10 and a top beam 11. The test bench 8 is fixed on the bottom plate 10, and the structure between the bottom plate and the top beam is supported by the column 6. In addition, the loading system includes a three-way loading system and a servo control system to load the fracture network rock model 7 and monitor the load and displacement in real time. The loading system is provided with loading devices in the first direction, the second direction and the third direction, and the directions are perpendicular to each other, and the third direction is parallel to the setting direction of the column. The test bench 8 is annular, with a circular outer ring and a square inner ring.

[0041] Further, the data acquisition system includes a pressure and temperature monitoring system (combined pressure and temperature sensor 18), a flow monitoring system (electronic balance 13) and an electrical impedance tomography module 17, wherein the flow monitoring system monitors the flow of the discharged slurry through a discharge port joint and an outlet proportional valve installed on the slurry discharge port at the end of the fracture. An electronic balance 13 is provided under each waste liquid collection barrel 12 for monitoring the flow of the slurry. The temperature and pressure monitoring system installs a combined pressure and temperature sensor 18 at the internal fracture network rock mass position to collect the temperature and pressure changes at various positions inside the three-dimensional fracture network rock mass model. These sensors are pre-buried in the model according to a hierarchical arrangement. In addition, the electrical impedance tomography module is connected to the fracture rock mass model, and includes a signal acquisition unit 20, a signal excitation unit 21, a feed end electrode and a plurality of slurry diffusion end electrodes, which are connected to the signal excitation unit 21 and the signal acquisition unit 20 through wires, and finally connected to a computer terminal through a data connection line.

[0042] A second aspect of the present invention provides a three-dimensional fracture network rock mass dynamic water environment thermal-fluid-solid coupling grouting test method, the test method comprising the following steps:

[0043] Step S1, constructing a fractured rock model 7 according to fracture parameters of an actual fractured rock mass, wherein the fractured rock model is made by using a 3D printing device.

[0044] Step S2, the heating wire 22 is evenly wound at a certain distance outside the prepared model. The high-temperature dynamic water simulation system is started, the temperature of the high-temperature water is adjusted to meet the test requirements, and the high-temperature water is injected into the fracture network rock model 7 through the dynamic water pipe 5. At the same time, the heating wire 22 is turned on to heat the rock mass to simulate the high-temperature dynamic water effect in the actual environment. During the water injection process, the high-temperature dynamic water inside the model will overflow into the water storage space and be discharged through the water outlet, thereby maintaining the high-temperature dynamic water environment inside the model.

[0045] Step S3, prepare grouting materials that meet the performance requirements, and load the slurry into the slurry storage tank 2. According to the test pressure requirements, adjust the slurry storage device to the specified value, connect it to the quick connector at the grouting hole through the grouting pipe 3, open the grouting device, and send the slurry into the fracture network rock model 7 through the grouting pipe 3.

[0046] Step S4, starting the coupled mechanical loading device to apply stress loading to the three-dimensional fracture network rock model to simulate the stratum stress around the grouting model 7.

[0047] Step S5, using the data acquisition system to acquire data of the three-dimensional fracture network rock model obtained in the grouting test.

[0048] After grouting is completed, the slurry diffusion law and mechanism under multiple coupling conditions such as different temperatures, different load stresses, different dynamic water flow rates and different grouting pressures are obtained through data analysis results. By monitoring the temperature field, the relationship between the temperature field and the dynamic water flow rate field is established to capture the flow rate changes during the grouting process and then characterize the grouting effect.

[0049] Optionally, after collecting the visualization surface of the fractured rock mass model after grouting and related data, the method further includes:

[0050] Adjust the grouting parameters and return to the step of "constructing a fractured rock model according to the fracture parameters of the actual fractured rock mass", wherein the grouting parameters include slurry density, slurry ratio and grouting rate;

[0051] Adjust the fracture parameters and return to the step of "constructing a fracture rock model according to the fracture parameters of the actual fracture rock mass"; the fracture parameters include the fracture space strike, inclination, opening and roughness.

[0052] The technical solution of the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments, but the protection scope of the present application is not limited thereto.

[0053] Example 1

[0054] A three-dimensional fracture network rock mass dynamic water environment thermal-fluid-solid coupling grouting test device, such as Figure 1-4 As shown, it includes a 3D printing device, a high-temperature dynamic water simulation system, a grouting system, a coupled mechanical loading device, and a data acquisition system.

[0055] The 3D printing device is used for 3D printing the three-dimensional fracture network rock model, including dual robotic arms, on which a composite additive printing head and a collaborative subtractive printing head are respectively installed. The dual robotic arms can perform printing operations in collaboration, realizing a one-time operation of additive and subtractive molding of a large three-dimensional fracture rock model;

[0056] The high-temperature dynamic water simulation system is used to provide a dynamic water source of a set temperature for the grouting test. The high-temperature dynamic water simulation system includes a constant temperature water source 4, a dynamic water pipe 5 and a heating wire 22. The constant temperature water source 4 is used to simulate the temperature of the dynamic water in the fracture before it flows, and is equipped with a heating device and a heat preservation device to achieve the regulation and constant control of the water source temperature. The system is connected to the dynamic water hole on the model through the dynamic water pipe 5 and is sealed with epoxy resin AB glue. The heating wire 22 is evenly arranged in the gap to ensure that the fracture model can be heated evenly and stably. The two ends of the heating wire are respectively connected to electrodes, which are passed through the base and electrically connected to an external power supply, so that it is powered by the power supply, so that the heating wire 22 heats the entire fracture network rock model 7 to the set temperature;

[0057] The grouting system is used to simulate grouting of the three-dimensional fracture network rock model during the grouting test, and the grouting system includes a grouting unit. The grouting unit consists of a grouting pipe 3, a slurry storage tank and an air compressor 1. The inlet of the slurry storage tank 2 is connected to the pressure regulating valve through a connecting pipeline, and the pressure regulating valve is connected to the air compressor 1 through a pipeline to provide a set constant pressure. The slurry storage tank 2 is connected to the fracture network rock model 7 through the grouting pipe 3 and is sealed with epoxy resin AB glue to ensure that the slurry flows stably in the fracture network rock;

[0058] The coupled mechanical loading device is used to apply pressure to the three-dimensional fracture network rock model in multiple directions during the grouting test. The coupled mechanical loading device includes a servo-controlled triaxial testing machine, including a mechanical loading test bench 8, an upper pressure head 9, a bottom plate 10 and a top beam 11. The test bench 8 is fixed on the bottom plate 10, and the structure between the bottom plate and the top beam is supported by the column 6. In addition, the loading system includes a three-way loading system and a servo control system to load the fracture network rock model 7 and monitor the load and displacement in real time. The loading system is provided with loading devices in the first direction, the second direction and the third direction, and the directions are perpendicular to each other, and the third direction is parallel to the setting direction of the column. The test bench 8 is annular, with a circular outer circle and a square inner circle;

[0059] The data acquisition system is used to collect the data detected by the three-dimensional fracture network rock model during the grouting test. The data acquisition system includes a pressure and temperature detection system (combined pressure and temperature sensor 18), a flow monitoring system (electronic balance 13) and an electrical impedance tomography module 17. The flow monitoring system monitors the flow of the discharged slurry through the outlet joint and the outlet proportional valve installed on the slurry outlet at the end of the fracture. An electronic balance 13 is provided under each waste liquid collection barrel 12 to monitor the flow of the slurry. The temperature and pressure monitoring system installs a combined pressure and temperature sensor 18 at the internal fracture network rock position to collect the temperature and pressure changes at various positions inside the three-dimensional fracture network rock model. These sensors are pre-buried in the model according to the hierarchical arrangement. In addition, the electrical impedance tomography module is connected to the fracture rock model, including a signal acquisition unit 20, a signal excitation unit 21, a feed end electrode and a plurality of slurry diffusion end electrodes, and the electrodes are connected to the signal excitation unit 21 and the signal acquisition unit 20 through a wire, and finally connected to the computer terminal through a data connection line.

[0060] Example 2

[0061] This embodiment is a three-dimensional fracture network rock mass dynamic water environment thermal-fluid-solid coupling grouting test method, specifically including:

[0062] 1. Assemble the composite additive print head and the collaborative subtractive print head and fix them together with the robotic arm. According to the fracture characteristics and rock properties in the fractured rock model, prepare suitable printing materials and introduce them into the pumping equipment;

[0063] 2. According to the location of the slurry diffusion monitoring point on the fracture surface in the model, the additive and subtractive paths are planned according to the fracture occurrence and the geometric dimensions of the rock mass. The planned printing path is imported into the robot arm, and a pre-print is performed to verify the correctness of the path; then the additive-subtractive printing is performed. During the printing process, a combined pressure and temperature sensor is arranged on the fracture surface to complete the preparation of the fracture rock model;

[0064] 3. Turn on the water supply device, adjust the water temperature to the specified temperature, set the water flow rate, and inject water into the fracture network rock model 7. At the same time, set the temperature of the heating wire 22 to simulate the high-temperature water flow effect in the actual environment. During the water injection process, the high-temperature water flow in the model will overflow into the water storage space and be discharged through the water outlet, thereby maintaining the high-temperature water flow environment inside the model;

[0065] 4. Install the grouting unit, connect the grouting control device to the grouting pipe 3, and prepare the grouting material that meets the performance requirements. Load the grouting material into the grouting tank 2, and adjust the grouting control device to the specified pressure or rate value according to the test requirements for standby use. Add sodium chloride to the grouting material to ensure its conductivity. The slurry flows into the fracture network rock model 7 through the grouting pipe 3 and diffuses around the fracture surface;

[0066] 6. Turn on the stress loading device to apply stress loading to the three-dimensional fracture network rock model 7 to simulate the stress environment of the strata around the model;

[0067] 7. The data acquisition system is used to collect the data obtained from the grouting test of the three-dimensional fracture network rock model. After the grouting is completed, the law and mechanism of slurry diffusion under multiple coupling conditions such as different temperatures, different load stresses, different dynamic water flow rates and different grouting rates are obtained through data analysis. By monitoring the temperature field, the relationship between the temperature field and the dynamic water flow rate field is established to obtain the flow rate change during the grouting process, thereby achieving the characterization of the grouting effect.

[0068] In particular, it is crucial to study the effect of fracture distribution on the diffusion characteristics of slurry. Three-dimensional fracture network rock mass can be divided into regular fracture network rock mass and random fracture network rock mass according to the fracture distribution characteristics. In the random fracture network rock mass model, fractures can be established based on normal distribution (such as the center coordinates, length and width of rectangular fractures) and Fisher distribution (such as inclination and inclination direction). For the above fracture network rock mass model, the larger the inclination of the fracture, the larger the diffusion distance of the slurry. This is because the head difference in the fracture with a larger inclination angle increases, resulting in an increase in the flow velocity. In addition, the larger the opening of the fracture, the longer the diffusion distance of the slurry will be.

[0069] As an example, Figure 7 The operation flow chart of a three-dimensional fracture network rock mass dynamic water environment thermal-fluid-solid coupling grouting test is shown, including:

[0070] a) Assemble the composite additive print head and the collaborative subtractive print head and fix them to the robot arm. At the same time, connect the inner nozzle joint, the outer nozzle feed pipe and the filling feed pipe for later use. Prepare suitable printing materials according to the fracture occurrence and rock mass lithology in the fractured rock mass model and introduce them into the pumping equipment;

[0071] b) According to the density of the slurry diffusion monitoring points on the fracture surface in the model, the additive and subtractive paths are planned according to the occurrence of the fractures and the geometric dimensions of the rock mass. The planned printing path is imported into the robot arm, and a pre-print is performed to verify the correctness of the path. Then, additive-subtractive printing is performed, and a combined pressure and temperature sensor 18 is arranged to complete the preparation of the fracture network rock mass model 7;

[0072] c) Start the high-temperature moving water simulation system and adjust the water temperature to the specified temperature according to the test requirements. Inject high-temperature water into the fracture network rock model through the moving water pipe and set it to heat to the required temperature to simulate the high-temperature moving water effect in the actual deep formation environment. During the water injection process, the high-temperature moving water in the model will overflow into the water storage space and be discharged through the outlet to maintain the high-temperature moving water environment inside the model;

[0073] d) Prepare grouting materials that meet the performance requirements and load the slurry into the slurry storage tank 2. According to the test requirements, adjust the stirring slurry storage device to the specified value and connect it to the quick-connect joint of the grouting hole through the grouting pipe 3. Start the grouting device and transport the slurry through the grouting pipe 3 to the fracture network rock model 7;

[0074] e) Apply triaxial stress: Install the sample sealing gasket on the bottom plate 10, control the upper pressure head 9 to move downward, and connect it to the universal sealing joint. Ensure that the upper pressure head 9 fits the upper surface of the sealing gasket of the sample 7. Then, control the movement of the front, rear, left and right pressure heads respectively to apply a predetermined stress value to the sample;

[0075] f) After the test is completed, data processing is performed to obtain the diffusion range, pressure, temperature, flow rate and slurry diffusion distribution results of the slurry in the model fracture space. By simulating the diffusion law of dynamic water grouting slurry in different types of fractured rock masses under real ground stress and high temperature conditions, the slurry diffusion law under fracture conditions such as different fracture network rock mass distribution, fracture inclination, fracture opening and fracture roughness is studied, while considering environmental factors such as temperature, ground stress, dynamic water rate, grouting rate, grouting pressure and different slurry densities and slurry ratios. It can effectively analyze the slurry diffusion law under the multi-field coupling of dynamic water environment in three-dimensional fracture network rock mass.

[0076] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A three-dimensional fracture network rock mass dynamic water environment thermal-fluid-solid coupling grouting test device, used for performing an environmental thermal-fluid-solid coupling grouting test on a three-dimensional fracture network rock mass model, characterized in that: include: A grouting system, used for simulating grouting on the three-dimensional fracture network rock model during the grouting test; The high-temperature dynamic water simulation system is used to provide a dynamic water source with a set temperature for the grouting test.

2. The three-dimensional fracture network rock mass dynamic water environment thermal-fluid-solid coupling grouting test device according to claim 1, characterized in that: The high-temperature dynamic water simulation system comprises a constant temperature water source (4) and a dynamic water pipe (5); The constant temperature water source (4) is connected to the dynamic water pipe (5) to provide a water source with a constant temperature for the dynamic water pipe; One end of the dynamic water pipe (5) is connected to the constant temperature water source, and the other end is connected to the dynamic water hole on the three-dimensional fracture network rock model (7).

3. The three-dimensional fracture network rock mass dynamic water environment thermal-fluid-solid coupling grouting test device according to claim 2, characterized in that: The constant temperature water source (4) is used to simulate the temperature of the dynamic water in the crack before it flows, and is equipped with a heating device and a heat preservation device to achieve the regulation and constant control of the water source temperature.

4. The three-dimensional fracture network rock mass dynamic water environment thermal-fluid-solid coupling grouting test device according to claim 2, characterized in that: The high-temperature dynamic water simulation system also includes an electric heating wire (22) for heating the three-dimensional fracture network rock model (7) to a set temperature.

5. The three-dimensional fracture network rock mass dynamic water environment thermal-fluid-solid coupling grouting test device according to claim 1, characterized in that: It also includes a 3D printing device for 3D printing the three-dimensional fracture network rock model.

6. The three-dimensional fracture network rock mass dynamic water environment thermal-fluid-solid coupling grouting test device according to claim 1, characterized in that: It also includes a coupled mechanical loading device for applying pressure to the three-dimensional fracture network rock model in multiple directions during the grouting test.

7. The three-dimensional fracture network rock mass dynamic water environment thermal-fluid-solid coupling grouting test device according to claim 1, characterized in that: It also includes a data acquisition system for acquiring data detected by the three-dimensional fracture network rock model during the grouting test.

8. The three-dimensional fracture network rock mass dynamic water environment thermal-fluid-solid coupling grouting test device according to claim 7, characterized in that: The data acquisition system includes a pressure and temperature monitoring system, which is arranged inside the three-dimensional fracture network rock model to collect temperature and pressure changes at various positions inside the three-dimensional fracture network rock model.

9. The three-dimensional fracture network rock mass dynamic water environment thermal-fluid-solid coupling grouting test device according to claim 7, characterized in that: The data acquisition system comprises an electrical impedance tomography module, which is connected to the three-dimensional fracture network rock model, and includes a signal acquisition unit (20), a signal excitation unit (21), a feed end electrode and a plurality of slurry diffusion end electrodes, wherein the electrode is connected to the signal excitation unit (21) and the signal acquisition unit (20) via a wire, and is finally connected to a computer terminal via a data connection line.

10. A three-dimensional fracture network rock mass dynamic water environment thermal-fluid-solid coupling grouting test method, characterized by: Using the three-dimensional fracture network rock mass dynamic water environment thermal-fluid-solid coupling grouting test device as claimed in claim 4; The test method comprises the following steps: Step S1, obtaining a three-dimensional fracture network rock model using a 3D printing device according to the fracture parameters of the actual fractured rock mass; Step S2, uniformly winding heating wires (22) at regular intervals outside the three-dimensional fracture network rock model; starting the high-temperature water-moving simulation system, adjusting the water temperature to meet the test requirements, and injecting water into the three-dimensional fracture network rock model through the water-moving pipe (5); and simultaneously turning on the heating wires (22) to heat the three-dimensional fracture network rock model to simulate the high-temperature water-moving effect in an actual environment. Step S3, preparing slurry that meets the performance requirements, and sending the slurry into the three-dimensional fracture network rock model to perform a grouting test; Step S4, starting the coupled mechanical loading device to apply stress loading to the three-dimensional fracture network rock model to simulate the formation stress around the three-dimensional fracture network rock model; Step S5: using a data acquisition system to acquire data of the three-dimensional fracture network rock model obtained in the grouting test.

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