A Visualized Test Device and Method for Dynamic Water Grouting in Cross-Fractions

Abstract

This invention relates to the field of rock grouting reinforcement technology, specifically a visual experimental device and method for cross-fracture dynamic water grouting. It utilizes a transparent soil material with soil and hydraulic properties similar to those of natural soil, such as internal friction angle, deformation characteristics, and flow boundary effects. This allows for realistic simulation of water flow and grout flow in actual strata, significantly improving the accuracy of experimental results. Through a layered water injection design in the backfill box, comprehensive observation of the grouting behavior in cross-fractures under different water-saturated states is achieved, effectively reproducing the influence of complex hydrological conditions on grouting effects. The introduction of a tracer with observational advantages during the grouting process greatly enhances the visualization and observation capabilities of grout diffusion paths, ranges, and velocity changes. This invention enables intuitive observation of the grout diffusion path, expansion range, and grouting effect in deeper fractures and larger models, significantly improving grouting efficiency and providing a scientific basis for optimizing grouting processes and predicting grouting effects.

Description

Technical Field

[0001] This invention belongs to the field of rock grouting reinforcement technology, and particularly relates to a visual cross-crack dynamic water grouting test device and method. Background Technology

[0002] The presence of intersecting fractures in rock masses can significantly increase the permeability and hydraulic conductivity of the rock mass, while weakening the stability of the surrounding rock. Especially near these fractures, stress concentration can easily lead to the formation of dominant water-conducting channels under water-rich conditions, potentially triggering geological hazards such as sudden water inrush. Grouting reinforcement is an effective measure for sealing fractures in surrounding rock. Visualized grouting test devices and methods can clearly demonstrate the diffusion process of grout in fractures and formations under various working conditions through intuitive visualization. Combined with pressure and displacement changes, the dynamic characteristics of grout flow path, diffusion range, and velocity under different grouting environments can be analyzed in detail, providing a scientific basis for optimizing grouting process parameters and predicting grouting effects.

[0003] Existing visualization devices for cross-fracture grouting typically use transparent materials (such as plexiglass) as the main body of the experimental setup. Different cross-fracture models are manually sculpted, or the fracture replication film and silicone strips are adjusted to simulate different types of cross-fracture states. Combined with cameras, pressure sensors, and flow meters, the flow behavior of the grout within the cross-fractures is visualized and monitored. This approach has the following limitations: First, it primarily focuses on the flow behavior of the grout, neglecting the interaction between the grout and the soil or rock mass. Furthermore, the grouting process is usually non-in-situ testing, lacking the influence of geostress, which may lead to discrepancies between the experimental results and actual engineering conditions. Second, while transparent materials can visualize the grouting process, insufficient transparency makes it difficult to clearly observe the grout expansion process in deeper fractures or large-scale models. Third, existing devices cannot accurately monitor the grouting behavior of cross-fractures in strata with different water saturation states. Patent CN103411751B discloses a visual cross-crack dynamic water grouting test device, including a grout collection device and a cross-crack platform. The cross-crack platform includes a support frame, a cross-crack test chamber mounted on the support frame, cross-cracks disposed on the inner wall of the cross-crack test chamber, a flow rate sensor disposed within the cross-crack test chamber, and a pressure sensor disposed within the cross-crack test chamber. It also includes a dynamic water supply device for injecting water into the cross-crack test chamber and a pneumatic grouting device for injecting grout into the cross-crack test chamber. The cross-crack test chamber is connected to the grout collection device. The transparent cavity of this patented device is made of glass, which suffers from the same drawbacks as existing technologies.

[0004] Therefore, how to provide a method that allows for intuitive and clear observation of the diffusion path and range of the grout, thereby improving the grouting effect, is a problem that urgently needs to be solved by those in this technical field. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the purpose of this invention is to provide a visual cross-fracture dynamic water grouting test device to solve the problem of poor grouting effect in rock mass cross-fractures in existing technologies; in addition, this invention also provides a visual cross-fracture dynamic water grouting test method.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a visual cross-crack dynamic water injection grouting test device, comprising:

[0008] The system comprises a simulation system, a water injection system, and a grouting system. The simulation system includes a backfill box, a permeable plate, and several cylinders. The backfill box includes a first backfill section and a second backfill section. The permeable plate and several cylinders are disposed within the second backfill section, with the cylinders positioned above the permeable plate. The water injection system includes a first water tank, a first pressure pump, a first frequency converter, a second water tank, a second pressure pump, a second frequency converter, a monitoring terminal, and a moisture sensor. The first water tank, first pressure pump, first frequency converter, and monitoring terminal are sequentially and communicatively connected. The first water tank is also connected to both the first and second backfill sections. The second water tank, second pressure pump, second frequency converter, and monitoring terminal are sequentially and communicatively connected. The second water tank is also connected to the first backfill section, and the monitoring terminal is also communicatively connected to the moisture sensor, which is installed on the permeable plate. The grouting system includes a first grout storage tank, a second grout storage tank, a tracer storage tank, a controller, an automatic mixing tank, and a third pressure pump. The first and second grout storage tanks are both connected to one end of the automatic mixing tank, and both are communicatively connected to the controller. The tracer storage tank is connected to one end of the automatic mixing tank and is communicatively connected to the controller. The other end of the automatic mixing tank is connected to the grouting hole on the permeable plate, and the automatic mixing tank is also communicatively connected to the third pressure pump.

[0009] Furthermore, the simulation system also includes a waste liquid tank, which is connected to the bottom of the first backfill section.

[0010] Furthermore, the water injection system also includes a water distributor, which is disposed on the permeable plate and communicates with the first water tank.

[0011] Furthermore, it also includes a first stop valve, a second stop valve, a third stop valve, a fourth stop valve, a fifth stop valve, a sixth stop valve, and a seventh stop valve. The first stop valve is located between the first water tank and the first backfill section; the second stop valve is located between the first water tank and the second backfill section; the third stop valve is located between the first slurry storage tank and the automatic mixing tank; the fourth stop valve is located between the tracer storage tank and the automatic mixing tank; the fifth stop valve is located between the second slurry storage tank and the automatic mixing tank; the sixth stop valve is located between the second water tank and the first backfill section; and the seventh stop valve is located between the waste liquid tank and the first backfill section.

[0012] Furthermore, it also includes a first electromagnetic flow meter, a second electromagnetic flow meter, a third electromagnetic flow meter, and a fourth electromagnetic flow meter. The first electromagnetic flow meter is disposed between the first water tank and the first backfill section, the second electromagnetic flow meter is disposed between the first water tank and the second backfill section, the third electromagnetic flow meter is disposed between the automatic mixing tank and the permeable plate, and the fourth flow meter is disposed between the second water tank and the first backfill section.

[0013] Furthermore, the simulation system also includes a DAQ data collection card, one end of which is communicatively connected to the permeable plate, and the other end of which is communicatively connected to the monitoring terminal.

[0014] Furthermore, the simulation system also includes a high-precision camera, which is mounted on one side of the backfill box.

[0015] Furthermore, the simulation system also includes a test platform on which the soil filling box is placed.

[0016] Furthermore, the filling material used in the filling box is one or more of silica gel transparent soil and polyacrylate transparent soil.

[0017] Secondly, the present invention also provides a method for visualizing cross-crack dynamic water injection grouting test, comprising the following steps:

[0018] S10. Pre-preparation: Apply lubricating and anti-adhesion materials evenly around and to the bottom of the filling box, and smooth the surface of the filling box. The first and second water tanks are pre-filled with calcium bromide solution with the same refractive index as the selected transparent soil material. The first and second slurry storage tanks store the corresponding test slurry raw materials. The tracer storage tank stores the prepared tracer solution.

[0019] S20. Soil filling steps: First, lay a layer of transparent soil at the bottom of the first soil filling section and compact the soil. Then, place the 3D printed cross-crack model horizontally on top of the bottom transparent soil and fill the transparent soil layer by layer until the cross-crack model is completely covered by transparent soil and the soil filling height reaches the requirements of the first soil filling section.

[0020] S30. Continue to place and fill the second unsaturated zone model according to step S20. Then install a permeable plate on top of the soil in the first fill section and close the fill box. Install cylinders evenly on top to simulate the ground stress in the actual strata.

[0021] S40. Water Injection Procedure: The monitoring terminal, in conjunction with the first frequency converter, adjusts the water flow rate and pressure to simulate the recharge status of groundwater under different seasons or geological conditions. The first pressure pump is started, and simultaneously the switch built into the first water tank is opened, opening the first stop valve while keeping the second stop valve closed. Water is then transported through the pipeline to the left inlet of the first backfill section. The pressure and flow rate of the injected water are monitored by the first electromagnetic flowmeter. The same operation is repeated, using the second water tank, second pressure pump, and second frequency converter to inject water into the right inlet of the first backfill section. The flow rate and pressure are monitored by the fourth electromagnetic flowmeter. The rise in water level is observed during the injection process until the first... When the transparent soil layer in the fill section is saturated, the second water tank, the second pressure pump, and the sixth stop valve are closed, and the first stop valve is closed to stop water injection into the first fill section. The second stop valve is opened to start water injection into the second fill section to simulate the infiltration of surface water. Water is evenly infiltrated through a water distributor and a permeable plate. The pressure and flow rate are monitored by a second electromagnetic flowmeter, and the saturation state of the transparent soil in the second fill section is monitored by a moisture sensor. When the experimental design requirements are met, the second stop valve is kept open, and the first stop valve is opened. At the same time, the second water tank, the second pressure pump, and the second frequency converter are opened to inject water into the first fill section again and start grouting.

[0022] S50. Grouting Steps: Based on the properties of the grout material and the test requirements, the grout is injected into the automatic mixing tank through the controller and monitoring terminal, and the flow rate and velocity are controlled. At the same time, the tracer in the tracer storage tank is added and uniformly mixed in the automatic mixing tank. The third pressure pump is turned on, and the grout containing the tracer is injected into the top soil of the second fill section according to the set pressure. The seventh water stop valve is opened to simulate groundwater discharge conditions under different conditions. The pressure and flow rate during the grouting process are monitored by the third electromagnetic flow meter. The entire grouting process is recorded by a high-precision camera. The DAQ data collection card is connected to multiple sensors deployed on the cross fractures to collect the grout pressure and flow rate at the inlet, intersection, and outlet of the cross fractures and feed them back to the monitoring terminal. When the tracer diffuses to the preset range or the grout reaches the predetermined saturation, the third pressure pump is turned off, and the high-precision camera is turned off, ending the grouting process.

[0023] S60. Stone removal: Fully open the seventh water stop valve at the bottom of the device, close all other water stop valves and the water tank, completely drain the water and waste liquid in the backfill tank into the waste liquid bucket, remove the stone, and ensure that it is not damaged, so as to facilitate subsequent observation of soil structure changes and verification of grouting effect.

[0024] S70: By recording key parameters during the grouting process with a high-precision camera and combining them with subsequent data analysis, the diffusion behavior of grout in fractured media can be accurately restored.

[0025] Compared with the prior art, the visual cross-crack dynamic water injection grouting test device and method provided by the present invention have at least the following advantages:

[0026] Existing visualization devices and methods for cross-fracture grouting have the following limitations: First, they mainly focus on the flow behavior of the grout, ignoring the interaction between the grout and the soil or rock mass. Moreover, the grouting process is usually a non-in-situ test, lacking the influence of geostress, which may lead to deviations between the test results and actual engineering conditions. Second, although transparent materials can visualize the grouting process, in deeper fractures or large-scale models, the insufficient transparency makes it difficult to clearly observe the grout expansion process. Third, existing devices cannot accurately monitor the grouting behavior of cross-fractures in strata with different water saturation states. This invention utilizes a transparent soil material with soil and hydraulic properties similar to those of natural soil, such as internal friction angle, deformation characteristics, and flow boundary effects. This material can realistically simulate water flow and grout flow in actual strata, significantly improving the accuracy of experimental results. Through a layered water injection design of the backfill box, comprehensive observation of the grouting behavior in cross-fractures under different water-saturated states is achieved, effectively reproducing the influence of complex hydrological conditions on grouting effects. The introduction of a tracer with observational advantages during the grouting process greatly enhances the visualization and observation capabilities of grout diffusion paths, ranges, and velocity changes. This invention allows for intuitive observation of the grout diffusion path, expansion range, and grouting effect in deeper fractures and larger models, significantly improving grouting efficiency and providing a scientific basis for optimizing grouting processes and predicting grouting effects. Attached Figure Description

[0027] To more clearly illustrate the solution of the present invention, a brief introduction will be given to the drawings used in the description of the embodiments below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0028] Figure 1 A structural diagram of a visual cross-crack dynamic water injection test device provided in an embodiment of the present invention;

[0029] Figure 2A schematic diagram of the distribution of grouting ports and water inlets on the permeable plate of a visual cross-crack dynamic water grouting test device provided in an embodiment of the present invention;

[0030] Figure 3 A cross-crack model and sensor distribution diagram of a visual cross-crack dynamic water grouting test device provided in this embodiment of the invention;

[0031] Figure 4 A schematic diagram of a cross-crack model 2 and sensor distribution of a visual cross-crack dynamic water grouting test device provided in an embodiment of the present invention;

[0032] Figure 5 A schematic diagram of the cross-section of the backfill box of a visual cross-crack dynamic water grouting test device provided in an embodiment of the present invention;

[0033] Figure 6 A flowchart of a visual cross-crack dynamic water injection test method is provided for an embodiment of the present invention;

[0034] Attached markings: 101-Soil filling box; 1011-First soil filling section; 1012-Second soil filling section; 102-Permeable plate; 1021-Water injection hole; 1022-Grouting hole; 103-Cylinder; 104-Waste liquid tank; 105-DAQ data collection card; 106-High-precision camera; 107-Test base; 108-Cross fracture model one; 109-Cross fracture model two; 110-Sensor; 201-First water tank; 202-First pressure pump; 203-First frequency converter; 204-Second water tank; 205-Second pressure pump; 206-Second frequency converter; 20 7-Monitoring terminal; 208-Moisture sensor; 209-Water distributor; 301-First slurry storage tank; 302-Second slurry storage tank; 303-Tracer storage tank; 304-Controller; 305-Automatic mixing tank; 306-Third pressure pump; 401-First stop valve; 402-Second stop valve; 403-Third stop valve; 404-Fourth stop valve; 405-Fifth stop valve; 406-Sixth stop valve; 407-Seventh stop valve; 501-First electromagnetic flowmeter; 502-Second electromagnetic flowmeter; 503-Third electromagnetic flowmeter; 504-Fourth electromagnetic flowmeter. Detailed Implementation

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. For example, terms such as “length,” “width,” “upper,” “lower,” “left,” “right,” “front,” “rear,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” and “outer” indicate orientations or positions based on the orientations or positions shown in the accompanying drawings and are for ease of description only, and should not be construed as limiting the technical solution.

[0036] The terms "comprising" and "having," and any variations thereof, in the specification, claims, and accompanying drawings of this invention are intended to cover non-exclusive inclusion; the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish different objects, not to describe a particular order. In the specification, claims, and accompanying drawings of this invention, when an element is referred to as "fixed to," "mounted to," "disposed of," or "connected to" another element, it may be directly or indirectly located on that other element. For example, when an element is referred to as "connected to" another element, it may be directly or indirectly connected to that other element.

[0037] Furthermore, the reference to "embodiment" herein means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0038] This invention provides a visual cross-fracture dynamic water injection grouting test device, which is applied to the grouting reinforcement construction process for sealing surrounding rock fractures. The visual cross-fracture dynamic water injection test device includes:

[0039] The system comprises a simulation system, a water injection system, and a grouting system. The simulation system includes a backfill box, a permeable plate, and several cylinders. The backfill box consists of a first backfill section and a second backfill section. The permeable plate and several cylinders are located within the second backfill section, with the cylinders positioned above the permeable plate. The water injection system includes a first water tank, a first pressure pump, a first frequency converter, a second water tank, a second pressure pump, a second frequency converter, a monitoring terminal, and a moisture sensor. The first water tank, first pressure pump, first frequency converter, and monitoring terminal are sequentially and communicatively connected. The first water tank is also connected to both the first and second backfill sections. The second water tank, second pressure pump, second frequency converter, and monitoring terminal are also connected. The terminals are connected in sequence, the second water tank is also connected to the first backfill section, and the monitoring terminal is also connected to the moisture sensor, which is installed on the permeable plate; the grouting system includes a first grout storage tank, a second grout storage tank, a tracer storage tank, a controller, an automatic mixing tank, and a third pressure pump. The first and second grout storage tanks are both connected to one end of the automatic mixing tank, and both are also connected to the controller. The tracer storage tank is connected to one end of the automatic mixing tank, and is also connected to the controller. The other end of the automatic mixing tank is connected to the grouting hole on the permeable plate, and the automatic mixing tank is also connected to the third pressure pump.

[0040] This invention allows for direct observation of the diffusion path, expansion range, and grouting effect of grout in deeper cracks and larger models, greatly improving the grouting effect and providing a scientific basis for optimizing the grouting process and predicting the grouting effect.

[0041] To enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0042] This invention provides a visual cross-fracture dynamic water grouting test device, which is applied in the grouting reinforcement construction process of sealing surrounding rock fractures, combined with... Figures 1 to 5 In this embodiment, the visualized cross-crack dynamic water injection grouting test device includes:

[0043] The system comprises a simulation system, a water injection system, and a grouting system. The simulation system includes a backfill box 101, a permeable plate 102, and four cylinders 103. The permeable plate 102 and the four cylinders 103 are located within the second backfill section 1012. The four cylinders 103 are positioned above the permeable plate 102 and are used to control and adjust the loading of in-situ stress during the experiment. The control of the cylinders 103 simulates the state of the soil and rock mass under different in-situ stress conditions, thereby observing the behavior of the grouting process under different pressure conditions. This provides a realistic experimental environment for studying the grouting diffusion law under different in-situ stresses. The backfill box 101 is made of high-strength transparent plexiglass, facilitating observation of the grout flow behavior inside the entire model. Capable of accommodating fissures and transparent soil layers, the filling box is equipped with high-efficiency sealing materials, such as silicone sealing rings or rubber gaskets, to prevent fluid leakage and ensure no water leakage during the test. The filling box 101 includes a first filling section 1011 and a second filling section 1012, used to simulate saturated soil and unsaturated soil conditions. After filling, a permeable plate 102 is first installed. The permeable plate 102 is evenly provided with water injection holes 1021 and a grouting hole 1022 in the center to ensure uniform water injection and avoid excessive water concentration that could damage the soil. The stability of the permeable plate 102 is ensured by a fixing device. Finally, the filling box 101 is closed.The water injection system includes a first water tank 201, a first pressure pump 202, a first frequency converter 203, a second water tank 204, a second pressure pump 205, a second frequency converter 206, a monitoring terminal 207, and a moisture sensor 208. The first water tank 201, first pressure pump 202, first frequency converter 203, and monitoring terminal 207 are sequentially and communicatively connected. The first water tank 201 is also connected to the first backfill section 1011 and the second backfill section 1012, respectively. The second water tank 204, second pressure pump 205, second frequency converter 206, and monitoring terminal 207 are sequentially and communicatively connected. The first frequency converter 203 and second frequency converter 206 achieve precise control of the water flow rate by adjusting the rotational speeds of the first pressure pump 202 and the second pressure pump 205, respectively, to meet experimental requirements. The first frequency converter 203 and second frequency converter 206 can adjust the water flow speed and pressure. The system accurately simulates water flow behavior and infiltration rate under different hydrological conditions. Based on real-time data from sensor 110 (such as water pressure and flow rate), it automatically adjusts the water flow to ensure the stability of the water flow during the experiment and avoid the impact of water flow fluctuations on the test results, thereby improving the automation and accuracy of the experiment. The second water tank 204 is also connected to the first backfill section 1011, and the monitoring terminal 207 is also connected to the moisture sensor 208. The moisture sensor 208 is set on the permeable plate 102 and is used to measure the moisture content of the transparent soil in the second backfill section 1012 and compare it with the saturated moisture content. Once the value displayed by the moisture sensor 208 is close to or reaches the saturated moisture content of the soil, it indicates that the soil is close to saturation and the data can be fed back to the monitoring terminal 207 to monitor the moisture content during the water injection process to meet different test requirements.The grouting system includes a first grout storage tank 301, a second grout storage tank 302, a tracer storage tank 303, a controller 304, an automatic mixing tank 305, and a third pressure pump 306. Both the first and second grout storage tanks 301 and 302 are connected to one end of the automatic mixing tank 305 and are also communicatively connected to the controller 304. The tracer storage tank 303 is connected to one end of the automatic mixing tank 305 and is also communicatively connected to the controller 304. The other end of the automatic mixing tank 305 is connected to the grouting hole 1022 on the permeable plate 102 and is also communicatively connected to the third pressure pump 306. The controller 304 includes two control zones: the first zone is used to adjust the flow rate and volume of the grout, and the second zone is used to adjust the flow rate and volume of the tracer. When the grouting material is a single component, the first and second grout storage tanks 301 and 302 store the same grout. When using a two-component grouting material, the first grout storage tank 301 and the second grout storage tank 302 store different grouts respectively. The controller 304 is connected to the monitoring terminal 207, which can adjust the flow rate and velocity according to the characteristics of the grout and the experimental requirements. The tracer storage tank 303 is used to store grout tracers. For colorless grouts, sodium fluorescein or rhodamine B can be selected as tracers. Sodium fluorescein emits bright green fluorescence under ultraviolet light, while rhodamine B emits red fluorescence. These two tracers have strong fluorescence characteristics and can clearly mark the flow trajectory of the grout. When using sodium fluorescein and rhodamine B, it is necessary to select an appropriate concentration according to the experimental conditions to ensure that they provide sufficient tracer effect without interfering with the flow behavior of the grout. For colored grouts, the fluorescence characteristics of sodium fluorescein or rhodamine B can be used for tracer under ultraviolet light: sodium fluorescein emits green fluorescence, and rhodamine B emits red or orange-red fluorescence.

[0044] In this embodiment, the dimensions of the backfill box 101 are 50cm×30cm×50cm (length×width×height), wherein the first backfill section 1011 is 30cm high and the second backfill layer is 20cm high; in other embodiments, the dimensions of the backfill box 101 can be adjusted according to the actual needs of the site.

[0045] In this embodiment, there are two slurry storage tanks; in other embodiments, if there are multiple types of slurry, multiple slurry storage tanks can be set according to the actual situation.

[0046] In this embodiment, the monitoring terminal 207 is a computer; in other embodiments, the monitoring terminal 207 may also be a tablet, mobile phone or other communication device depending on the test site environment.

[0047] Furthermore, in this embodiment, as Figure 1As shown, the simulation system also includes a waste liquid tank 104, which is connected to the bottom of the first backfill section 1011 via a pipe for collecting test waste liquid.

[0048] Furthermore, in this embodiment, as Figure 1 As shown, the water injection system also includes a water distributor 209, which is installed on the permeable plate 102 and connected to the first water tank 201. It is used to cooperate with the permeable plate 102 to ensure that water infiltrates evenly and to avoid excessive flow rate.

[0049] Furthermore, in this embodiment, as Figure 1 As shown, the test apparatus also includes a first stop valve 401, a second stop valve 402, a third stop valve 403, a fourth stop valve 404, a fifth stop valve 405, a sixth stop valve 406, and a seventh stop valve 407 for controlling the opening and closing of water flow. The first stop valve 401 is located between the first water tank 201 and the first backfill section 1011; the second stop valve 402 is located between the first water tank 201 and the second backfill section 1012; the third stop valve 403 is located between the first slurry storage tank 301 and the automatic mixing tank 305; the fourth stop valve 404 is located between the tracer storage tank 303 and the automatic mixing tank 305; the fifth stop valve 405 is located between the second slurry storage tank 302 and the automatic mixing tank 305; the sixth stop valve 406 is located between the second water tank 204 and the first backfill section 1011; and the seventh stop valve 407 is located between the waste liquid tank 104 and the first backfill section 1011.

[0050] Furthermore, in this embodiment, as Figure 1 As shown, the test apparatus also includes a first electromagnetic flowmeter 501, a second electromagnetic flowmeter 502, a third electromagnetic flowmeter 503, and a fourth electromagnetic flowmeter 504 for monitoring pressure and flow rate during the grouting process. The first electromagnetic flowmeter 501 is located between the first water tank 201 and the first backfill section 1011, the second electromagnetic flowmeter 502 is located between the first water tank 201 and the second backfill section 1012, the third electromagnetic flowmeter 503 is located between the automatic mixing tank 305 and the permeable plate 102, and the fourth flowmeter 504 is located between the second water tank 204 and the first backfill section 1011.

[0051] Furthermore, in this embodiment, combined with Figures 1 to 5The simulation system also includes a DAQ data collection card 105. One end of the DAQ data collection card 105 is connected to the permeable plate 102, and the other end is connected to the monitoring terminal 207. It can collect data such as flow rate and pressure transmitted by various sensors 110 arranged on the cross-crack model 1 108 and cross-crack model 2 109 in real time during the test, and transmit these data to the monitoring terminal 207. The DAQ data collection card 105 supports multi-channel data synchronous acquisition and has high sampling rate and low latency characteristics, which can ensure accurate recording of real-time data during the test. Through seamless connection with the sensors 110, the system can process signals from different sensors 110 and effectively avoid signal interference.

[0052] Furthermore, in this embodiment, combined with Figures 1 to 5 The simulation system also includes a high-precision camera 106, which is set on one side of the backfill box 101. It can clearly capture the flow behavior of the grout in the cracks, ensuring the visualization of the dynamic process. It can be combined with the data of the sensor 110 to provide real-time feedback on the test situation, help observe the grout diffusion path and flow velocity, and optimize the grouting process. The high-precision camera 106 overcomes the limitation of insufficient transparency, especially in deep cracks or large models, to ensure the accuracy of the test results.

[0053] Furthermore, in this embodiment, as Figure 1 As shown, the simulation system also includes a test platform 107, on which a soil filling box 101 is placed to ensure the stability of the entire test device during the test.

[0054] Furthermore, in this embodiment, the fill material is selected as transparent soil, which has similar soil and hydraulic properties to natural soil, such as internal friction angle, deformation characteristics, and flow boundary effects. By artificially configuring different porosities and permeabilities of transparent soil, the hydraulic properties of natural soil in different states can be simulated. At the same time, the mechanical properties of transparent soil, such as compressibility and strength, can also be matched with those of natural soil, especially in saturated or partially saturated states. The commonly used transparent soil types are mainly of two categories: silica gel transparent soil and polyacrylate transparent soil. Silica gel transparent soil is suitable for simulating sandy soil or coarse-grained soil, while polyacrylate transparent soil is suitable for... To simulate clay or dense soil layers, in order to avoid observation errors caused by the difference in refractive index at the interface between the liquid and solid phases, the water in the water injection system in this embodiment is replaced with calcium bromide solutions of different concentrations (which need to be determined according to the material of the transparent soil selected, mainly to ensure that the refractive index of the calcium bromide solution is the same as that of the transparent soil). During the experiment, the above-mentioned transparent soil type can be selected according to the needs of different strata simulated in the experiment, and the soil particle size, permeability and other parameters can be adjusted according to the test parameters to ensure the uniformity and stability of the filling, thereby providing a reliable test basis for grouting tests under different fracture conditions.

[0055] Furthermore, in this embodiment, combined with Figures 1 to 5 In 3D modeling software, parameters such as the size, angle, intersection, opening, and shape of the cracks are precisely set according to experimental requirements. By selecting transparent materials, high-precision 3D printing technology is used to generate cross-crack model 108 and cross-crack model 209 to simulate the characteristics of cracks under different geological conditions. To ensure clear observation of the grouting behavior within the cross-cracks, the size of the cracks is usually 30%-50% of the size of the backfill box 101. However, the size, opening, and shape of the cracks can be flexibly adjusted according to experimental requirements. The transparent materials used have high mechanical strength and stability, and can simulate the complexity of cracks in real rock masses. By precisely controlling the geometric parameters of the cracks, the influence of different crack openings and intersection angles on grout flow can be effectively studied, providing more accurate experimental data for the analysis of grouting behavior.

[0056] Secondly, embodiments of the present invention also provide a method for visualizing cross-crack dynamic water injection grouting tests, applied in a visualizing cross-crack dynamic water injection grouting test device, combined with... Figures 1 to 6 The visual cross-crack dynamic water injection grouting test method includes the following steps:

[0057] S10. Pre-preparation: To facilitate the removal of the stones after the test, lubricating and anti-adhesion materials can be evenly applied around and to the bottom of the filling box 101 to lubricate and prevent adhesion. When applying the material, ensure that the petroleum jelly covers the surface evenly, avoiding excessive thickness or thinness to ensure uniform lubrication. The coating should be completely dry or fixed before the test to avoid affecting the slurry flow or data accuracy during the test. If conditions permit, the surface of the filling box 101 can also be smoothed to reduce the adhesion between the stones and the box, thus facilitating the smooth removal of the stones after the test. The first water tank 201 and the second water tank 204 are pre-filled with calcium bromide solution with the same refractive index as the selected transparent soil material. The first slurry storage tank 301 and the second slurry storage tank 302 store the corresponding test slurry raw materials, and the tracer storage tank 303 stores the prepared tracer solution.

[0058] S20. Soil Filling Steps: First, lay a layer of transparent soil about 4cm to 6cm thick at the bottom of the first soil filling section 1011, and gently compact the soil to provide a stable base for the fracture model and prevent the model from shifting during the soil filling process. Use a plastic board to gently compact each layer of soil. After each filling, ensure that the soil layer is uniform and dense to ensure its stability and uniformity. Place the 3D printed cross fracture model horizontally on top of the bottom transparent soil layer, ensuring that the angle and position of the fracture meet the experimental design requirements. Slowly fill the transparent soil layer by layer until the cross fracture model is completely covered by transparent soil. Each layer of soil is 2cm to 3cm thick. After each layer is filled, it should be lightly compacted to ensure that each layer of soil is uniform and stable, and that the filling height meets the requirements of the first soil filling section 1011.

[0059] S30. After completing the first layer of backfill, continue with step S20 to place and backfill the second layer of unsaturated zone model, ensuring that each layer of soil is uniformly compacted to maintain the stability and uniformity of the entire test model. Then, install a permeable plate 102 on top of the soil in the first backfill section 1011 and ensure that it is firmly fixed to ensure uniform water injection. After the backfill is completed, close the backfill box 101 and evenly install cylinders 102 on top. Fix the cylinders 102 with threads to simulate the in-situ stress in the actual strata and ensure that the stress environment during the test meets expectations.

[0060] S40. Water Injection Procedure: Monitoring terminal 207, in conjunction with the first frequency converter 203, adjusts the water flow rate and pressure to simulate the replenishment state of groundwater under different seasons or geological conditions. The first pressure pump 202 is started, and the built-in switch in the first water tank 201 is opened, opening the first stop valve 401 while keeping the second stop valve 402 closed. Water is then transported through the pipeline to the left inlet of the first backfill section 1011. The pressure and flow rate of the injected water are monitored by the first electromagnetic flowmeter 501. The same operation is repeated, using the second water tank 204, the second pressure pump 205, and the second frequency converter 206 to inject water into the right inlet of the first backfill section 1011. The flow rate and pressure are monitored by the fourth electromagnetic flowmeter 504. The water level rise is observed during the injection process until the transparent soil layer of the first backfill section 1011 is saturated. The second water tank 204 is then closed. 04. The second pressure pump 205 and the sixth stop valve 406 are connected, and the first stop valve 401 is closed to stop water injection into the first fill section 1011. The second stop valve 402 is opened to start water injection into the second fill section 1012 to simulate the infiltration of surface water. The water is evenly infiltrated through the water distributor 209 and the permeable plate 102 to avoid excessive flow rate. The pressure and flow rate are monitored by the second electromagnetic flowmeter 502, and the water saturation state of the transparent soil in the second fill section 1012 is monitored by the moisture sensor 208. When the test design requirements are met, the second stop valve 402 is kept open, and the first stop valve 401 is opened. At the same time, the second water tank 204, the second pressure pump 205 and the second frequency converter 206 are opened to inject water into the first fill section 1011 again. Note that the water flow rate should not be too fast at the beginning. Then, grouting begins.

[0061] S50. Grouting Procedure: Based on the properties of the grout material and experimental requirements, the grout is injected into the automatic mixing tank 304 via the controller 304 and monitoring terminal 207, with flow rate and velocity controlled. Simultaneously, tracer from the tracer storage tank 303 is added and uniformly mixed in the automatic mixing tank 304. After uniform mixing according to the grout properties, the third pressure pump 306 is activated, injecting the tracer-containing grout into the top soil of the second fill section 1012 at the set pressure. Simultaneously, according to the experimental design requirements, the seventh stop valve 407 is opened to simulate groundwater discharge conditions under different conditions, via the third electromagnetic current... The meter 503 monitors the pressure and flow rate during the grouting process to ensure that the grout is injected into the top evenly and slowly, avoiding excessive pressure that could lead to uneven diffusion. The entire grouting process is recorded by a high-precision camera 106. The DAQ data collection card 105 is connected to multiple sensors 110 deployed on the cross fractures to collect the grout pressure and flow rate at the inlet, intersection, and outlet of the cross fractures and feeds it back to the monitoring terminal 207. When the tracer diffuses to the preset range or the grout reaches the predetermined saturation, the third pressure pump 306 is turned off, and the high-precision camera 106 is also turned off, ending the grouting process.

[0062] S60. Stone Removal: Fully open the seventh stop valve at the bottom of the device, close all other stop valves and the water tank, and completely drain the water and waste liquid in the backfill tank into the waste liquid bucket. Carefully remove the stone using pliers or other tools, ensuring that it is not damaged, so as to facilitate subsequent observation of soil structure changes and verification of grouting effect.

[0063] S70. Key parameters during the grouting process, including flow rate, pressure, and tracer diffusion path, are recorded by a high-precision camera 106. Combined with subsequent data analysis, the diffusion behavior of the grout in the fractured medium is accurately reconstructed. Based on the diffusion trajectory of the tracer, the flow and diffusion patterns of the grout inside the transparent soil are visualized, thereby enabling a quantitative assessment of the grouting effect. By analyzing the influence of fracture structure characteristics on the flow and diffusion laws of the grout, a scientific basis is provided for optimizing grouting design and construction technology.

[0064] Compared with existing technologies, the visualization devices and methods for cross-fracture grouting described in the above embodiments have the following limitations: First, they mainly focus on the flow behavior of the grout, ignoring the interaction between the grout and the soil or rock mass. Moreover, the grouting process is usually a non-in-situ test, lacking the influence of geostress, which may lead to deviations between the test results and actual engineering conditions. Second, although transparent materials can visualize the grouting process, in deeper fractures or large-scale models, the insufficient transparency makes it difficult to clearly observe the grout expansion process. Third, existing devices cannot accurately monitor the grouting behavior of cross-fractures in strata with different water saturation states. This invention utilizes a transparent soil material with soil and hydraulic properties similar to those of natural soil, such as internal friction angle, deformation characteristics, and flow boundary effects. This material can realistically simulate water flow and grout flow in actual strata, significantly improving the accuracy of experimental results. Through a layered water injection design of the backfill box, comprehensive observation of the grouting behavior in cross-fractures under different water-saturated states is achieved, effectively reproducing the influence of complex hydrological conditions on grouting effects. The introduction of a tracer with observational advantages during the grouting process greatly enhances the visualization and observation capabilities of grout diffusion paths, ranges, and velocity changes. This invention allows for intuitive observation of the grout diffusion path, expansion range, and grouting effect in deeper fractures and larger models, significantly improving grouting efficiency and providing a scientific basis for optimizing grouting processes and predicting grouting effects.

[0065] Obviously, the embodiments described above are merely preferred embodiments of the present invention, and not all embodiments. The accompanying drawings illustrate preferred embodiments of the present invention, but do not limit the scope of the patent. The present invention can be implemented in many different forms; rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing specific embodiments, or make equivalent substitutions for some of the technical features. Any equivalent structures made using the content of this specification and drawings, directly or indirectly applied to other related technical fields, are similarly within the scope of patent protection of this invention.

Claims

1. A visual cross-crack dynamic water injection grouting test device, characterized in that, include: Simulation system, water injection system, and grouting system; The simulation system includes a soil filling box, a permeable plate, and several cylinders. The soil filling box includes a first soil filling section and a second soil filling section. The permeable plate and several cylinders are disposed inside the second soil filling section, and the several cylinders are disposed above the permeable plate. The water injection system includes a first water tank, a first pressure pump, a first frequency converter, a second water tank, a second pressure pump, a second frequency converter, a monitoring terminal, and a moisture sensor. The first water tank, the first pressure pump, the first frequency converter, and the monitoring terminal are sequentially and communicatively connected. The first water tank is also connected to the first backfill section and the second backfill section respectively. The second water tank, the second pressure pump, the second frequency converter, and the monitoring terminal are sequentially and communicatively connected. The second water tank is also connected to the first backfill section. The monitoring terminal is also communicatively connected to the moisture sensor, which is installed on the permeable plate. The grouting system includes a first grout storage tank, a second grout storage tank, a tracer storage tank, a controller, an automatic mixing tank, and a third pressure pump. The first and second grout storage tanks are both connected to one end of the automatic mixing tank, and are also communicatively connected to the controller. The tracer storage tank is connected to one end of the automatic mixing tank, and is also communicatively connected to the controller. The other end of the automatic mixing tank is connected to the grouting hole on the permeable plate, and is also communicatively connected to the third pressure pump. The water injection system further includes a first stop valve, a second stop valve, a third stop valve, a fourth stop valve, a fifth stop valve, a sixth stop valve, and a seventh stop valve. The first stop valve is located between the first water tank and the first backfill section; the second stop valve is located between the first water tank and the second backfill section; the third stop valve is located between the first slurry storage tank and the automatic mixing tank; the fourth stop valve is located between the tracer storage tank and the automatic mixing tank; the fifth stop valve is located between the second slurry storage tank and the automatic mixing tank; the sixth stop valve is located between the second water tank and the first backfill section; and the seventh stop valve is located between the waste liquid tank and the first backfill section. The simulation system also includes a waste liquid tank, which is connected to the bottom of the first backfill section; it also includes a first electromagnetic flow meter, a second electromagnetic flow meter, a third electromagnetic flow meter, and a fourth electromagnetic flow meter. The first electromagnetic flow meter is disposed between the first water tank and the first backfill section, the second electromagnetic flow meter is disposed between the first water tank and the second backfill section, the third electromagnetic flow meter is disposed between the automatic mixing tank and the permeable plate, and the fourth electromagnetic flow meter is disposed between the second water tank and the first backfill section.

2. The visual cross-crack dynamic water injection grouting test device according to claim 1, characterized in that, The water injection system also includes a water distributor, which is installed on the permeable plate and communicates with the first water tank.

3. The visual cross-crack dynamic water injection grouting test device according to claim 1, characterized in that, The simulation system also includes a DAQ data collection card, one end of which is communicatively connected to the permeable plate, and the other end of which is communicatively connected to the monitoring terminal.

4. The visual cross-crack dynamic water injection grouting test device according to claim 1, characterized in that, The simulation system also includes a high-precision camera, which is mounted on one side of the backfill box.

5. The visual cross-crack dynamic water injection grouting test device according to claim 1, characterized in that, The simulation system also includes a test platform on which the soil filling box is placed.

6. The visual cross-crack dynamic water injection grouting test device according to claim 1, characterized in that, The filling material used in the filling box is one or more of silica gel transparent soil and polyacrylate transparent soil.

7. The method of the apparatus according to any one of claims 1 to 6, characterized in that, Includes the following steps: S10. Pre-preparation: Apply lubricating and anti-adhesion materials evenly around and to the bottom of the filling box, and smooth the surface of the filling box. The first and second water tanks are pre-filled with calcium bromide solution with the same refractive index as the selected transparent soil material. The first and second slurry storage tanks store the corresponding test slurry raw materials. The tracer storage tank stores the prepared tracer solution. S20. Soil filling steps: First, lay a layer of transparent soil at the bottom of the first soil filling section and compact the soil. Then, place the 3D printed cross-crack model horizontally on top of the bottom transparent soil and fill the transparent soil layer by layer until the cross-crack model is completely covered by transparent soil and the soil filling height reaches the requirements of the first soil filling section. S30. Continue to place and fill the second unsaturated zone model according to step S20. Then install a permeable plate on top of the soil in the first fill section and close the fill box. Install cylinders evenly on top to simulate the ground stress in the actual strata. S40. Water Injection Procedure: The monitoring terminal, in conjunction with the first frequency converter, adjusts the water flow rate and pressure to simulate the recharge status of groundwater under different seasons or geological conditions. The first pressure pump is started, and simultaneously the switch built into the first water tank is opened, opening the first stop valve while keeping the second stop valve closed. Water is then transported through the pipeline to the left inlet of the first backfill section. The pressure and flow rate of the injected water are monitored by the first electromagnetic flowmeter. The same operation is repeated, using the second water tank, second pressure pump, and second frequency converter to inject water into the right inlet of the first backfill section. The flow rate and pressure are monitored by the fourth electromagnetic flowmeter. The rise in water level is observed during the injection process until the first... When the transparent soil layer in the fill section is saturated, the second water tank, the second pressure pump, and the sixth stop valve are closed, and the first stop valve is closed to stop water injection into the first fill section. The second stop valve is opened to start water injection into the second fill section to simulate the infiltration of surface water. Water is evenly infiltrated through a water distributor and a permeable plate. The pressure and flow rate are monitored by a second electromagnetic flowmeter, and the saturation state of the transparent soil in the second fill section is monitored by a moisture sensor. When the experimental design requirements are met, the second stop valve is kept open, and the first stop valve is opened. At the same time, the second water tank, the second pressure pump, and the second frequency converter are opened to inject water into the first fill section again and start grouting. S50. Grouting Steps: Based on the properties of the grout material and the test requirements, the grout is injected into the automatic mixing tank through the controller and monitoring terminal, and the flow rate and velocity are controlled. At the same time, the tracer in the tracer storage tank is added and uniformly mixed in the automatic mixing tank. The third pressure pump is turned on, and the grout containing the tracer is injected into the top soil of the second fill section according to the set pressure. The seventh water stop valve is opened to simulate groundwater discharge conditions under different conditions. The pressure and flow rate during the grouting process are monitored by the third electromagnetic flow meter. The entire grouting process is recorded by a high-precision camera. The DAQ data collection card is connected to multiple sensors deployed on the cross fractures to collect the grout pressure and flow rate at the inlet, intersection, and outlet of the cross fractures and feed them back to the monitoring terminal. When the tracer diffuses to the preset range or the grout reaches the predetermined saturation, the third pressure pump is turned off, and the high-precision camera is turned off, ending the grouting process. S60. Stone removal: Fully open the seventh water stop valve at the bottom of the device, close all other water stop valves and the water tank, completely drain the water and waste liquid in the backfill tank into the waste liquid bucket, remove the stone, and ensure that it is not damaged, so as to facilitate subsequent observation of soil structure changes and verification of grouting effect. S70: By recording key parameters during the grouting process with a high-precision camera and combining them with subsequent data analysis, the diffusion behavior of grout in fractured media can be accurately restored.

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