Rock fracture design method, rock fracture model and dynamic water grouting test device

Abstract

This invention discloses a rock fracture design method, a rock fracture model, and a dynamic water grouting test device. It uses the mean and standard deviation parameters of a Gaussian distribution to generate random numbers, and obtains the shape of the rock fracture curve through cumulative summation. The dynamic water grouting test device includes an adjustable network fracture simulation system, a dynamic water system, a grouting system, and a data processing system. The rock fracture model described above is fixedly mounted on the adjustable network fracture simulation system. The fractures on the rock fracture model are equipped with a water inlet end, a grouting end, and several sensing components. The dynamic water system includes a water pump that connects a water source to the water inlet end of the rock fracture model to simulate a dynamic water environment in the rock strata. The grouting system includes a grouting cylinder connected to the grouting end of the rock fracture model to simulate the grouting process of the rock fracture. The data processing system is communicatively connected to the sensing components on the rock fracture model to receive test parameters of the rock fracture model during the grouting process. This invention has a positive reference value for evaluating the effect of rock fracture grouting repair and for subsequent research.

Description

Technical Field

[0001] This invention relates to a rock fracture design method, fracture model, and dynamic water grouting test device, belonging to rock mass grouting repair test technology. Background Technology

[0002] Affected by various natural disasters and factors such as service life, an increasing number of infrastructure projects are suffering from numerous defects. At the same time, underground engineering projects such as mines and tunnels also face a high risk of sudden water inrushes. Repairing these defects is an important and urgent research topic.

[0003] Grouting technology has a wide range of applications and can achieve trenchless repair, playing an irreplaceable role in the repair of infrastructure defects. It is currently widely used in various engineering fields such as tunnels, highways, and dams, mainly for sealing leaks and reinforcing structures. The rock fracture network is a crucial medium environment for grouting repair. Because the diffusion and migration of grout after injection into the injected medium is very complex and difficult to observe, studying the migration mechanism of grout in the fracture network is of great significance and value.

[0004] The current technical challenges in network crack grouting repair, sealing, and reinforcement include:

[0005] (1) The grouting location is highly concealed, and the diffusion and migration of the grout are difficult to observe; (2) The instability and failure mechanism of the water-rich network fractured rock layer under the combined action of tunnel excavation and long-term osmotic pressure is complex, and disasters are difficult to predict and prevent; (3) The risk is high. The water-rich fractured network is under the long-term action of groundwater seepage and groundwater ion erosion, and the rock mass properties are severely deteriorated. The risk of disasters under the action of construction disturbance is high; (4) In the model test for the technical problem of self-expanding polymer grouting repair of rock fractured network under the action of dynamic water, there is also the difficulty of not being able to accurately simulate the real strength of rock fractured network and dynamic water environment.

[0006] Current research focuses primarily on cement grouting tests in horizontal network fractures, while studies on the diffusion mechanism of grout in inclined network fractures under dynamic water conditions are relatively lagging.

[0007] The shortcomings of the current cement grouting test for horizontal network cracks are as follows: (1) The general model test uses a single flat plate crack model, which can only simulate the local planar crack grouting situation, which is quite different from the real cracks; (2) The general model test does not consider the influence of crack opening and crack roughness; (3) The general model test cannot simulate the diffusion and water blocking effect of self-expanding polymer under the dynamic water conditions of network cracks; (4) The general model test does not consider the influence of tilt angle on the grouting repair of network cracks. Summary of the Invention

[0008] The technical problem solved by this invention is to provide a rock fracture design method, fracture model and dynamic water grouting test device, addressing the issue that existing models for repairing rock fractures with polymer grouting cannot realistically simulate the rock stratum environment.

[0009] This invention is achieved using the following technical solution:

[0010] This invention first discloses a method for designing rock strata fractures, comprising the following steps:

[0011] S1. Use the following Gaussian random function to generate a series of random numbers.

[0012]

[0013] Where f(x) is the probability density function of the random variable x, μ is the central location of the distribution, representing the mean of the distribution, and σ is the standard deviation of the distribution, representing the degree of dispersion of the distribution;

[0014] S2. The curve shape is obtained by summing the random numbers obtained in S1 using the following formula.

[0015]

[0016] Where N is the number of points that make up the curve, Γ represents a random number that follows a normal distribution, and the shape of the curve is the designed contour shape of the rock stratum fracture edge.

[0017] S3. Calculate the distance difference between the lower convex hull and the upper convex hull of the curve to obtain the length of each first line segment. Then, sum the lengths of all the first line segments using the following formula to obtain the convex hull length of the curve: convexHullLength.

[0018]

[0019] M represents the number of the first line segment;

[0020] Next, calculate the distance difference between adjacent points on the curve to obtain the length of each second line segment. Then, sum all the lengths of the second line segments using the following formula to obtain the curve length (curveLength).

[0021]

[0022] curve i curve i-1 Let K be two adjacent points on the curve, and K be the number of the second line segment.

[0023] S4. The simulated values ​​of the design rock stratum fracture and roughness coefficient JRC are obtained by calculating using the following formula.

[0024]

[0025] In the rock fracture design method of the present invention, further, after obtaining the JRC simulation value in step S4, it is linearly mapped to the range of 0-20 using the following formula.

[0026] jrcScaled=jrc·(jrcMax-jrcMin)+jrcMin,

[0027] jrcScaled represents the scaled JRC value, which is the result of scaling the jrc value. jrcMax represents the upper limit of the maximum value of the JRC value, and jrcMin represents the lower limit of the minimum value of the JRC value.

[0028] The present invention also discloses a rock stratum fracture model, wherein the model is provided with simulated rock stratum fractures, and the edge contour of the fractures is obtained by the above-mentioned rock stratum fracture design method.

[0029] The present invention also discloses a dynamic water grouting test device, comprising:

[0030] An adjustable network fracture simulation system 1 is fixedly mounted on a rock fracture model 101 as described above. The fractures on the rock fracture model 101 are provided with a water inlet end, a grouting end, and a number of sensing components 110. The sensing components 110 include, but are not limited to, pressure sensors and flow sensors.

[0031] The dynamic water system 2 includes a water pump that connects a water source to the inlet of the rock fracture model 101 to simulate the dynamic water environment of the rock strata.

[0032] Grouting system 3 includes a grouting cylinder connected to the grouting end of rock fracture model 101 to simulate the rock fracture grouting process;

[0033] The data processing system 4 is communicatively connected to the sensing component 110 on the rock fracture model 101 to receive the test parameters of the rock fracture model during the grouting process.

[0034] In the dynamic water grouting test device of the present invention, the adjustable network fracture simulation system further includes an inclination adjustment mechanism 103, on which the rock fracture model 101 is fixed and the inclination angle of the rock fracture can be adjusted for testing.

[0035] In the dynamic water grouting test apparatus of the present invention, the tilt angle adjustment mechanism 103 further includes a fixed base and a tilting platform. The rock fracture model 101 is fixed on the tilting platform, and the tilting platform is rotatably mounted on the fixed base via a rotating shaft and is connected to a servo control motor for transmission, driving the tilting platform and the rock fracture model 101 to rotate and adjust the tilt angle. The servo control motor is connected to the tilting platform through a transmission mechanism, and the tilt angle of the rock fracture model can be precisely controlled by adjusting the tilt angle computer 105, realizing dynamic water grouting tests of the rock fracture at different tilt angles.

[0036] In the dynamic water grouting test device of the present invention, the rock fracture model 101 is a flat plate structure with a fracture network 1011. The fracture network 1011 is located on one side surface of the flat plate, and a transparent upper cover plate 102 is fixedly covered on it to form a closed flow channel for the fracture network 1011. A high-definition camera 111 is also mounted above the upper cover plate 102 to observe and record the flow of grout in the rock fracture during the grouting process.

[0037] In the dynamic water grouting test device of the present invention, further, water guide channels 1012 are provided on the rock fracture models 101 at both ends of the fracture network 1011. One end of the water guide channel is connected to the water inlet pipe 106 as the water inlet end of the rock fracture model 101, and the other end of the water guide channel is connected to the water outlet pipe 107 as the water outlet end of the rock fracture model 101. The fractures in the fracture network 1011 are interconnected and there is at least one through flow channel connecting the water guide channels at both ends of the rock fracture model, ensuring that the water flow entering the fracture from the water inlet end can fill the entire fracture network, fully simulating the dynamic water environment in the rock stratum, and also ensuring that the grout entering the fracture from the grouting end can fill the entire fracture network, fully simulating the process of grouting to repair the rock stratum.

[0038] In the dynamic water grouting test device of the present invention, the dynamic water system 2 further adopts a constant pressure water pump 22. The water pump inlet pipe 224 of the constant pressure water pump 22 is connected to the water tank 21, and the water pump outlet pipe 223 is connected to the water inlet of the rock fracture model. A pressure gauge 221 is provided on it and is connected to the constant pressure controller 222 for feedback, so as to realize that the dynamic water system injects water into the fracture network of the rock fracture model at a constant pressure to form a dynamic water environment.

[0039] In the dynamic water grouting test device of the present invention, the grouting system 3 further adopts a two-component grouting repair method, including a first grouting cylinder 302 and a second grouting cylinder 303 arranged in parallel. The grouting pumps of the first grouting cylinder 302 and the second grouting cylinder 303 are connected to an air compressor 301, and the grouting outlets are connected in parallel to a grout mixer 304. The grout mixer 304 is connected to the grouting end of the rock fracture model.

[0040] The technical solution adopted in this invention firstly discloses a design scheme that can more realistically simulate rock strata fractures through a rock strata fracture design method and a rock strata fracture model, thereby improving the realism of rock strata fractures during grouting tests. Secondly, it discloses an adjustable dynamic water grouting test device that can simulate the inclined network fracture environment under dynamic water conditions, making the relatively complex and invisible rock mass network fractures visible. Furthermore, the device can adjust the inclination angle of the fracture network according to different working conditions, simulating the grouting reinforcement and sealing process, and monitoring the changes in dynamic water pressure and flow rate of the network fractures after polymer grout injection, as well as the water-blocking effect after grout injection. Specific beneficial effects are as follows:

[0041] (1) Over many years of geological movement and groundwater erosion, the actual rock strata fractures have developed into complex media structures. This invention starts from the actual shape of the rock strata fracture network and constructs a rough network fracture model scheme that considers the rock strata roughness, tilt angle and fracture aperture, which can more realistically simulate the grouting repair process of the network of intersecting fractures in the rock strata.

[0042] (2) The pressure of self-expanding polymer slurry in two-component slurry is relatively large during the self-expanding stage. This invention takes into account the pressure of polymer slurry during the self-expanding stage and effectively realizes the simulation of polymer grouting and water blocking effect in rough rock network fractures under the overall coupling effect of dynamic water pressure, grouting pressure and slurry self-expanding stage pressure.

[0043] (3) The present invention provides an inclination adjustment mechanism for rock fracture models, which can automatically control the inclination angle of the network fracture model by computer, so as to study the diffusion morphology and sealing effect of grout in the grouting repair process of network fractures under different inclination conditions.

[0044] (4) This invention provides a simulation method for fracture networks with different roughness, different fracture opening and different pressure water flow, which can provide an effective grouting simulation method for fracture network rock strata in major projects such as tunnel surrounding rock, and has a positive and beneficial effect on the optimization and improvement of actual projects.

[0045] (5) In the dynamic water grouting test device provided by the present invention, the traditional grouting machine is combined with an air compressor, so that the automated grouting machine no longer needs an additional air compression device and can directly realize air compression to provide grouting power.

[0046] In summary, the present invention, using the above-mentioned technical solution, can simulate the grouting repair of fracture networks under invisible dynamic water conditions in tunnels and mines. Throughout the process, the diffusion morphology of the grout in the fracture network can be observed intuitively, realizing the visualization of the diffusion process of fractures in the inclined rock mass under grouting repair and the evaluation of the sealing effect of grouting repair under dynamic water conditions. It has a positive reference value for the effect evaluation of rock mass fracture grouting repair and subsequent research.

[0047] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0048] Figure 1 This is a flowchart of the rock fracture design method of the present invention.

[0049] Figure 2 This is a schematic diagram of the overall structure of the dynamic water grouting test device for an example.

[0050] Figure 3 This is a schematic diagram of the adjustable network crack simulation system in the embodiment.

[0051] Figure 4 This is a schematic diagram of the upper cover plate in the embodiment.

[0052] Figure 5 This is a schematic diagram of a rock fracture model in the embodiment.

[0053] Figure 6 This is a magnified schematic diagram of a portion of the network gap in the embodiment.

[0054] Figure 7 This is a schematic diagram of the water injection system in the embodiment.

[0055] Figure 8 This is a schematic diagram of the grouting system structure in the embodiment.

[0056] The diagram is labeled as follows: 1-Adjustable network fracture simulation system, 101-Rock fracture model, 1011-Fractured network, 1012-Water channel, 102-Upper cover plate, 1021-Grouting hole, 1022-Sensor mounting hole, 103-Tilting adjustment mechanism, 104-Water bucket, 105-Tilting adjustment computer, 106-Water inlet pipe, 107-Water outlet pipe, 108-Grouting pipe, 109-Fixing component, 110-Sensing component, 111-High-definition camera, 112-Weighing balance;

[0057] 2-Dynamic water system, 21-Water tank, 22-Constant pressure water pump, 221-Pressure gauge, 222-Constant pressure controller, 223-Water pump outlet pipe, 224-Water pump inlet pipe;

[0058] 3-Grouting system, 301-Air compressor, 302-First grouting cylinder, 303-Second grouting cylinder, 304-Grouting mixer;

[0059] 4-Data Processing System. Detailed Implementation

[0060] Example

[0061] To make the technical problems, technical solutions and advantages of the present invention clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0062] It should be understood that the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0063] See Figure 1 The rock fracture design method of this invention uses actual rock fractures and roughness coefficient JRC as the standard, and generates curves using a Gaussian random function in MATLAB. When generating curves using the Gaussian random function, the generated curves can be correlated with JRC to generate a new curve. Specifically, it includes the following steps.

[0064] S1. Use the following Gaussian random function to generate a series of random numbers.

[0065]

[0066] Where f(x) is the probability density function of the random variable x, μ is the central location of the distribution, representing the mean of the distribution, and σ is the standard deviation of the distribution, representing the degree of dispersion of the distribution.

[0067] When generating curves using a Gaussian random function, we first set several parameters, including the number of points (numpoints) to generate the curve (which can be set to 100 or more) to define different curves, the mean μ and standard deviation σ of the Gaussian distribution, and the range of the curvature-length ratio of the rock fracture and roughness coefficient JRC, selected between 0 and 20. Adjusting these parameters controls the shape and irregularity of the generated curves.

[0068] S2. The curve shape is obtained by summing the random numbers obtained in S1 using the following formula.

[0069]

[0070] Where N is the number of points, Γ represents a random number that follows a normal distribution, and the shape of the curve is the designed contour shape of the rock stratum fracture edge.

[0071] In MATLAB, the `randn` function generates random numbers that follow a normal distribution with a length of `numPoints`. Multiplying the generated random numbers by the standard deviation `σ` and adding the mean `μ` produces a curve. By introducing random or irregular interference signals, the curve can be made to have more realistic characteristics and more closely resemble actual observed data. The `cumsum` function is used to accumulate the sums on the curve to obtain its integral form, and finally, the `plot` function is used to plot the curve.

[0072] S3. Calculate the distance difference between the lower convex hull and the upper convex hull of the curve to obtain the length of each first line segment. Then, sum the lengths of all the first line segments using the following formula to obtain the convex hull length of the curve: convexHullLength.

[0073]

[0074] M represents the number of the first line segments.

[0075] In MATLAB, the `diff` function is used to calculate the distance difference between the upper and lower convex hulls to obtain the length of each first segment; the `sqrt` function is used to calculate the square root of the length of each first segment; and the `sum` function is used to add up the lengths of all segments to obtain the convex hull length `convexHullLength`.

[0076] Next, calculate the distance difference between adjacent points on the curve to obtain the length of each second line segment. Then, sum all the lengths of the second line segments using the following formula to obtain the curve length (curveLength).

[0077]

[0078] curve i curve i-1 Let K be two adjacent points on the curve, and K be the number of the second line segment.

[0079] In MATLAB, the `diff` function is used to calculate the distance difference between adjacent points on the curve to obtain the length of each second line segment; the `sqrt` function is used to calculate the square root of the length of each second line segment; and the `sum` function is used to add up the lengths of all second line segments to obtain the curve length `curveLength`.

[0080] S4. Divide the difference between the convex hull length and the curve length by the curve length using the following formula to obtain the simulated values ​​of the design rock layer fracture and roughness coefficient JRC.

[0081]

[0082] Furthermore, to represent the JRC value more intuitively, after obtaining the simulated JRC value in step S4, it is linearly mapped to the range of 0-20 using the following formula:

[0083] jrcScaled=jrc·(jrcMax-jrcMin)+jrcMin,

[0084] jrcScaled represents the scaled JRC value, which is the result of scaling the jrc value. jrcMax represents the upper limit of the maximum value of the JRC value, and jrcMin represents the lower limit of the minimum value of the JRC value.

[0085] The Gaussian random function is used to generate random numbers and construct the curve shape. This function uses the mean and standard deviation parameters of a Gaussian distribution to generate random numbers, and the shape of the rock fracture curve is obtained through cumulative summation. Adjusting the parameters of this function can affect the irregularity and amplitude of the generated curve, producing curves with different shapes and degrees of irregularity, and calculating parameters related to the curve shape. This is of great significance for studying curve characteristics, shape analysis, and quantitatively assessing the degree of curve irregularity. The generated curves are imported into AutoCAD to draw the rock fracture network, so that the rock fracture model can be fabricated using acrylic sheets.

[0086] See also Figure 2-8 The illustration shows a specific embodiment of the dynamic water grouting test device of the present invention, specifically including an adjustable network fracture simulation system 1, a dynamic water system 2, a grouting system 3, and a data processing system 4. The adjustable network fracture simulation system 1 is fixedly equipped with a rock fracture model 101 obtained by the rock fracture design method described above in this embodiment. The rock fracture model 101 has a water inlet end, a grouting end, and an internally processed fracture network 1011. The rock fracture model 101 is also equipped with several sensing components 110 to monitor the experimental parameters of the dynamic water grouting test process. The sensing components 110 include, but are not limited to, pressure sensors and flow sensors. The dynamic water system 2 connects a water source to the water inlet end of the rock fracture model 101 via a water pump to simulate the dynamic water environment inside the rock fracture model. The grouting system 3 includes a grouting cylinder connected to the grouting end of the rock fracture model 101 to simulate the rock fracture grouting process. The data processing system 4 is communicatively connected to the sensing component 110 on the rock fracture model 101, receives the test parameters of the rock fracture model during the grouting process, and finally outputs the experimental data charts.

[0087] Specifically, such as Figure 3 As shown, the adjustable network fracture simulation system 1 in this embodiment includes a rock fracture model 101, an upper cover plate 102, a tilt adjustment mechanism 103, a water tank 104, a tilt adjustment computer 105, a water inlet pipe 106, a water outlet pipe 107, a grouting pipe 108, a fixing component 109, a sensing component 110, a high-definition camera 111, and a weighing balance 112. The rock fracture model 101 is fixed on the tilt adjustment mechanism 103, and the tilt angle of the rock fracture is adjusted by the tilt adjustment mechanism 103 to conduct experiments.

[0088] Specifically, the tilt adjustment mechanism 103 includes a fixed base and a tilting platform. The rock fracture model 101 is fixed on the tilting platform, which is rotatably mounted on the fixed base via a rotating shaft and is connected to a servo control motor. This motor drives the tilting platform and the rock fracture model 101 mounted on it to rotate and adjust the tilt angle. The servo control motor is connected to the tilting platform via a transmission mechanism and is also connected to the tilt adjustment computer 105. By adjusting the tilt angle computer 105, the tilt angle of the rock fracture model can be precisely controlled, enabling dynamic water injection grouting tests of the rock fracture at different tilt angles.

[0089] This embodiment selects a servo motor and encoder with sufficient torque and accuracy based on usage requirements. The encoder provides real-time rotation angle feedback. The servo motor is connected to the rotating shaft of the tilting platform to ensure that the motor can drive the rotation of the platform. Simultaneously, the encoder is correctly mounted on the motor shaft to measure the rotation angle. Then, a suitable digital input / output interface or analog input / output interface and driver are used to connect the servo motor to the computer. Control software is written on the computer for communication and control with the servo motor. The communication protocol between the tilting computer 105 and the servo motor is determined, such as serial communication like RS-232, RS-485, or Ethernet communication like TCP / IP. Based on the required rotation angle control algorithm, control software is written to calculate the motor drive signal. Using the rotation angle feedback provided by the encoder, a real-time feedback control algorithm is implemented in the control software. By comparing the actual measured angle with the target angle, the output signal of the servo motor is adjusted to rotate the rotating platform shaft to the desired angle. The design must ensure that safety and protection mechanisms are considered during the control process, such as limit switches, overload protection, and fault detection, to avoid accidents and equipment damage. After connecting to a power source and adjusting the tilt angle of the computer, the tilt angle of the fracture network grouting model can be automatically controlled by the computer to study the diffusion morphology of grout and water-blocking effect of different fracture networks during the grouting process at different tilt angles.

[0090] See also Figure 4 and Figure 5The rock fracture model 101 is a flat plate structure with a fracture network 1011. The fracture network 1011 and the water guide channel 1012 are located on one side surface of the flat plate and can be machined on the surface of the rock fracture model 101 by milling. A transparent upper cover plate 102 is installed on the rock fracture model 101 to form a closed flow channel for the fracture network 1011. A silicone sealing gasket is provided between the upper cover plate 102 and the flat plate of the rock fracture model 101 to ensure the sealing of the model during water injection and grouting. The rock fracture model 101 and the upper cover plate 102 are fixed by a fastener 109, which can be a threaded connector or a clamping fastener. A high-definition camera 111 is also mounted above the upper cover plate 102 to observe and record the flow of grout in the rock fractures during the grouting process through the transparent upper cover plate 102.

[0091] Water guide channels 1012 are provided on the rock fracture models 101 at both ends of the fracture network 1011. The water guide channels 1012 can be grooves machined together on the flat surface of the rock fracture model and the fracture network 1011. One end of the water guide channel of the rock fracture model 101 is connected to the water inlet pipe 106 as the water inlet end of the rock fracture model 101, and the other end of the water guide channel is connected to the water outlet pipe 107 as the water outlet end of the rock fracture model 101. The fractures in the fracture network 1011 are interconnected and there is at least one through flow channel connecting the water guide channels at both ends of the rock fracture model, ensuring that the water flow entering the fracture from the water inlet end can fill the entire fracture network, fully simulating the dynamic water environment in the rock stratum, and also ensuring that the grout entering the fracture from the grouting end can fill the entire fracture network, fully simulating the process of grouting to repair the rock stratum.

[0092] like Figure 6 As shown, the fracture network 1011 in this embodiment adopts a diamond-shaped grid distribution, and all fractures can be interconnected. Whether grouting or water injection is performed, the entire fracture network 1011 can be quickly filled.

[0093] In this embodiment, the rock fracture model 101 is made of plexiglass sheet as raw material. Based on the realistic simulated rough rock network fracture obtained by the rock fracture design method, the plexiglass sheet is cut and polished to form a rock fracture model. Holes are drilled at both ends of the rock fracture model to connect valves as water inlet and outlet holes, respectively, and water inlet pipe 106 and water outlet pipe 107 are connected. A water guide channel 1012 ensures uniform water flow distribution within the fracture network. An upper cover plate 102, also made of transparent plexiglass, is added above the fracture network to achieve a sealed environment.

[0094] In addition, the water outlet pipe 107 of the rock fracture model in this embodiment is connected to a water bucket 104 with a weight measuring device. The water bucket 104 in this embodiment can be placed on a weighing balance 112 to collect the water flowing out after grouting for statistical flow and to evaluate the water blocking effect after rock fracture grouting.

[0095] The upper cover plate 102 covers the surface of the rock fracture model 101. Grouting holes 1021 and sensor mounting holes 1022 are machined at several positions corresponding to the fracture network 1011. The grouting holes 1021 are connected to the grouting pipe 108, and the sensor mounting holes 1022 are used to install the sensing component 110.

[0096] See Figure 7 In this embodiment, the dynamic water system 2 employs a constant-pressure water pump 22. The water inlet pipe 224 of the constant-pressure water pump 22 is connected to the water tank 21, and the water outlet pipe 223 is connected to the water inlet of the rock fracture model. A pressure gauge 221 is installed on the pump and is connected to the constant-pressure controller 222 for feedback, enabling the dynamic water system 2 to inject water into the fracture network of the rock fracture model at a constant pressure to form a dynamic water environment. The dynamic water system 2 can simulate the water pressure, water flow rate, and the influence of dynamic water on grout diffusion before and after grouting of the rock fracture model 101. The constant-pressure water pump 22 has an adjustable water supply pressure component, which can monitor and adjust parameters such as water pressure in the fracture network to continuously and stably inject water into the rock fracture model 101.

[0097] See Figure 8 In this embodiment, the grouting system 3 employs a two-component grouting repair method, comprising a first grouting cylinder 302 and a second grouting cylinder 303 connected in parallel. The grouting pumps of the first and second grouting cylinders 302 and 303 are connected to an air compressor 301, and their grouting outlets are connected in parallel to a grout mixer 304. The grout mixer 304 is connected to the grouting end of the rock fracture model. The grouting system 3 uses a fully digital host control system, with digital display of raw material proportions and flow rates. Parameters are adjustable as required without shutdown, and modular control of raw material temperature achieves automatic constant temperature and pressure functions. The system delivers raw materials A and B to the first and second grouting cylinders 302 and 303 respectively. After heating in the grouting cylinders, the raw materials are mixed according to the required proportions by the grout mixer 304 and then transported to the grouting pipe 108 through pipelines. Grouting system 3 can achieve two grouting conditions: constant flow and constant pressure. It can directly heat and mix the two components of the two-component grout and inject them into the fracture network for subsequent research on the diffusion pressure, diffusion morphology, and water-blocking effect after grout injection. It does not require manual mixing and control of the two components of the grout, and different grouting rates and pressures can be set to study the grout diffusion under different conditions.

[0098] In this embodiment, the grouting system 3 places the air compressor 301 between two grouting cylinders. Two pressure supply valves are connected to the two grouting cylinders respectively via air pipes. When the grouting pipeline is opened, the air compressor 301 simultaneously supplies pressure to both grouting cylinders, forcing the grout to the grout mixer at a set flow rate or pressure to complete the grouting process. The control panels of the grouting machine and the air compressor are integrated into a shared control panel, and the electrical wiring of the grouting machine and the air compressor is connected to the control panel. Commands are transmitted to the equipment via digital signals or control protocols. Corresponding alarm functions are set in the control system to issue alarms when abnormal conditions occur in the equipment.

[0099] The data processing system 4 places the sensing component 110 in the network crack to monitor the change of grout pressure during the grouting process, and converts the pressure signal into an electrical signal through a dynamic acquisition instrument, and finally performs data analysis through a computer.

[0100] The dynamic water grouting test device in this embodiment can simulate the diffusion of grout in rock fractures under different fracture roughness, fracture aperture, fracture network inclination, and dynamic water pressure conditions. The dynamic water system simulates the dynamic water pressure experienced by the rock mass network fractures in real-world working conditions. Throughout the process, the adjustable network fracture simulation system 1, dynamic water system 2, grouting system 3, and data processing system 4 operate independently without interference, thus more closely resembling real-world working conditions.

[0101] The specific steps of the test method for polymer grouting repair model of rough network cracks under dynamic water conditions using the dynamic water grouting test device of this embodiment are as follows:

[0102] (1) Assemble the adjustable network fracture simulation system: Prepare the rock fracture model 101, place silicone pads around it, place the upper cover plate 102 on it and align it, connect it with the fastener 109 and fix it on the flipping platform of the tilt adjustment mechanism 103, then connect the tilt adjustment computer 105 to control the tilt angle of the model, place the above-assembled structure in the designated test position, connect the grouting hole 1021 and sensor mounting hole 1022 on the upper cover plate 102 to the grouting equipment and pressure sensor, and set up a high-definition camera 111 above the upper cover plate 102.

[0103] (2) Connect the dynamic water system 2, connect the water pump inlet pipe 224 to the water tank 21, and connect the water pump outlet pipe 223 to the inlet pipe 106 of the rock fracture model 101 to simulate the action of flowing water and create dynamic water conditions in the rock stratum. Connect the outlet pipe 107 of the rock fracture model 101 to the water bucket 104, and place a weighing balance in the water bucket 104 to measure the change of water flow during the grouting process.

[0104] (3) Connect the data processing system 4, arrange the sensing component 110 on the rock fracture model 101, connect the sensing component 110 to the computer of the data processing system 4, monitor the pressure change during grouting in the rock fracture model 101, and analyze the grout pressure during the grouting process through the computer.

[0105] (4) Connect the grouting system 3 and add the two components of the grout into the first grouting cylinder 302 and the second grouting cylinder 303 respectively. Set a constant pressure condition, connect the grouting gun of the grout mixer 304 to the grouting pipe 108 of the rock fracture model 101, and heat the raw materials in the grouting cylinder. After mixing, the mixture is injected into the network fracture by the air compressor 301. Observe the changes in the grout and water flow rate in the rock fracture model 101. Stop grouting when the water flow stops or the water flow rate is small.

[0106] (5) After the equipment is assembled, an orthogonal test of polymer grouting repair under the action of dynamic water in the rock rough network fracture is carried out. The four factors of the orthogonal test are grouting pressure, dynamic water flow velocity, fracture roughness and fracture opening.

[0107] (6) After grouting is completed, the water blocking effect of the entire test device is evaluated, and range and variance analysis, single factor influence analysis and interaction factor analysis are performed.

[0108] (7) Open the adjustable network fracture simulation system 1, take a sample of the polymer filled in the rock fracture model 101 after grouting diffusion under the action of dynamic water, and conduct scanning electron microscopy test to study the relevant microscopic properties.

[0109] (8) Replace the network fracture model with different roughness and fracture opening, change the dynamic water pressure and grouting pressure, repeat the grouting process, and study the grouting and sealing effect under different working conditions by analyzing the data.

[0110] In this document, the terms "upper," "lower," "front," "back," "left," "right," "top," "bottom," "inner," "outer," "vertical," and "horizontal," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only used for the clarity of expressing the technical solution and for the convenience of description, and therefore should not be construed as limiting the present invention.

[0111] In this document, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, which includes not only the elements listed but also other elements not expressly listed.

[0112] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for designing rock fractures, characterized in that... Includes the following steps: S1. Use the following Gaussian random function to generate a series of random numbers. ， Where f(x) is the probability density function of the random variable x, μ is the central location of the distribution, representing the mean of the distribution, and σ is the standard deviation of the distribution, representing the degree of dispersion of the distribution; S2. The curve shape is obtained by summing the random numbers obtained in S1 using the following formula. ， Where N is the number of points that make up the curve. This represents a random number that follows a normal distribution; the shape of this curve is the designed profile shape of the rock fracture edge. S3. Calculate the distance difference between the lower convex hull and the upper convex hull of the curve to obtain the length of each first line segment. Then, sum the lengths of all the first line segments using the following formula to obtain the convex hull length of the curve: convexHullLength. ， M represents the number of the first line segment; Next, calculate the distance difference between adjacent points on the curve to obtain the length of each second line segment. Then, sum all the lengths of the second line segments using the following formula to obtain the curve length (curveLength). ， curve i curve i-1 For two adjacent points on the curve, K This refers to the number of the second line segment; S4. The simulated values ​​of the design rock stratum fracture and roughness coefficient JRC are obtained by calculating using the following formula. 。 2. The rock fracture design method according to claim 1, characterized in that, After obtaining the JRC simulation value in step S4, it is linearly mapped to the range of 0-20 using the following formula. ， in, jrcScaled represents the scaled JRC value. jrcMax represents the maximum value of the JRC value. jrcMin represents the minimum value of JRC.

3. A method for establishing a rock stratum fracture model, characterized in that: The model is provided with simulated rock strata fractures, and the edge contours of the fractures are designed using the method in claim 1 or 2.

4. A dynamic water grouting test device, characterized in that... include: An adjustable network fracture simulation system (1) is fixedly installed on which the rock fracture model (101) of claim 3 is provided. The fracture on the rock fracture model (101) is provided with a water inlet end, a grouting end and a number of sensing components (110). The dynamic water system (2) includes a water pump that connects a water source to the inlet of a rock fracture model (101) to simulate a dynamic water environment in the rock strata; The grouting system (3) includes a grouting cylinder connected to the grouting end of the rock fracture model (101) to simulate the rock fracture grouting process; The data processing system (4) is connected in communication with the sensing component (110) on the rock fracture model (101) to receive the test parameters of the rock fracture model during the grouting process.

5. The dynamic water grouting test device according to claim 4, characterized in that, The adjustable network fracture simulation system also includes a tilt adjustment mechanism (103), on which the rock fracture model (101) is fixed.

6. The dynamic water grouting test device according to claim 5, characterized in that, The tilt adjustment mechanism (103) includes a fixed base and a flipping platform. The rock fracture model (101) is fixed on the flipping platform. The flipping platform is mounted on the fixed base by a rotating shaft and is connected to a servo control motor to drive the flipping platform and the rock fracture model (101) to rotate and adjust the tilt angle.

7. The dynamic water grouting test device according to claim 4, characterized in that, The rock fracture model (101) is a flat plate structure with a fracture network (1011). The fracture network (1011) is located on one side surface of the flat plate, and a transparent upper cover plate (102) is fixedly covered on it to form a closed flow channel for the fracture network (1011). A high-definition camera (111) is also mounted above the upper cover plate (102) to observe and record the flow of grout in the rock fracture during the grouting process.

8. The dynamic water grouting test device according to claim 7, characterized in that, Water guide channels (1012) are provided on the rock stratum fracture models (101) at both ends of the fracture network (1011). One end of the water guide channel is connected to the inlet pipe (106) as the water inlet end of the rock stratum fracture model (101), and the other end of the water guide channel is connected to the outlet pipe (107) as the water outlet end of the rock stratum fracture model (101). The fractures in the fracture network (1011) are interconnected and there is at least one through flow channel connecting the water guide channels at both ends of the rock stratum fracture model.

9. The dynamic water grouting test device according to claim 4, characterized in that, The dynamic water system (2) adopts a constant pressure water pump (22). The water pump inlet pipe (224) of the constant pressure water pump (22) is connected to the water tank (21), and the water pump outlet pipe (223) is connected to the water inlet of the rock fracture model. A pressure gauge (221) is provided on it and is connected to the constant pressure controller (222) for feedback.

10. The dynamic water grouting test device according to claim 4, characterized in that, The grouting system (3) adopts a two-component grouting repair method, including a first grouting cylinder (302) and a second grouting cylinder (303) set in parallel. The grouting pumps of the first grouting cylinder (302) and the second grouting cylinder (303) are connected to an air compressor (301), and the grouting outlets are connected in parallel to a grout mixer (304). The grout mixer (304) is connected to the grouting end of the rock fracture model.

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