Slurry diffusion visualization test system applied to rock and soil grouting

Abstract

The utility model provides a slurry diffusion visualization test system applied to rock and soil grouting, and particularly relates to the technical field of geotechnical engineering test equipment. The test system comprises a control cabinet, a simulation box, a thermal infrared imager, a heating mechanism, a cooling liquid storage tank and a liquid cooling pipe, the thermal infrared imager is arranged right above the simulation box; the heating mechanism is laid on the top of the simulation box; a simulation tunnel is arranged in the inner cavity of the simulation box along the length direction; a plurality of high-frequency induction coils are arranged on the outer surface of the simulation box corresponding to the simulation tunnel; a plurality of thermocouples are arranged in the simulation box at equal intervals; a stratum grouting mechanism is arranged along the periphery of the simulation tunnel; a plurality of electromagnets distributed in a matrix are arranged in an inner cavity of the simulation box; the residual space of the inner cavity of the simulation box is filled with a simulation soil layer. According to the utility model, the traditional transparent box body and soil body are replaced, the planning and visualization of the slurry path and the control of the solidification time can be realized at the same time, and the slurry diffusion dynamic three-dimensional map generated in real time is more visual.

Description

Technical Field

[0001] This utility model patent relates to the field of geotechnical engineering testing equipment technology, specifically to a grout diffusion visualization testing system applied to geotechnical grouting. Background Technology

[0002] In the field of geotechnical engineering, grouting technology is widely used in foundation reinforcement, tunnel sealing, and geological disaster prevention. Existing grouting testing equipment and patented technologies mainly simulate the grout diffusion process through physical models, but they have significant shortcomings in terms of complex environment simulation capabilities, multi-field coupling control accuracy, and dynamic monitoring methods.

[0003] The following are common shortcomings of existing technologies: 1. Lack of realism in simulation: The current visualization of grout diffusion in soil and rock grouting mainly relies on transparent boxes and transparent similar materials to simulate soil. However, traditional transparent model boxes cannot simulate the non-transparent characteristics of real strata, and are limited by the fact that transparent similar materials cannot replace all the mechanical properties of soil; 2. Uncontrollable path: Traditional grouting tests rely on fixed pressure and flow parameters, which cannot correct the grout diffusion path in real time, resulting in the penetration range exceeding the design area; 3. Material limitations: Conventional grouts lack the ability to respond to external physical fields, making it difficult to achieve dynamic rheological property adjustment; 4. Insufficient monitoring accuracy: Existing systems mostly use a single pressure sensor and lack the ability to fuse and analyze multi-dimensional data, making it impossible to obtain three-dimensional grout diffusion data. Utility Model Content

[0004] To overcome the shortcomings of the prior art, this utility model provides a grout diffusion visualization test system for rock and soil grouting, the specific technical solution of which is as follows:

[0005] A visualization test system for grout diffusion in rock and soil grouting includes a control cabinet, a simulation chamber, an infrared thermal imager, a heating mechanism, a coolant storage tank, and liquid cooling pipes. The control cabinet houses a PID control system, a data processing and analysis system, a magnetic induction tomography system, a lock-in amplifier, a magnetic field controller, a distributed fiber optic temperature measurement system, and a temperature controller. The simulation chamber contains a simulated tunnel along its length. The infrared thermal imager is positioned directly above the top of the simulation chamber. The heating mechanism is installed on the top of the simulation chamber. Several high-frequency induction coils are evenly spaced on the left and right outer walls, front and rear outer walls, and the top wall of the heating mechanism, corresponding to the simulated tunnel. Above and below the simulated tunnel along its length within the simulation chamber... Several thermocouples are evenly spaced at the location; a grouting mechanism is installed along the periphery of the simulated tunnel; several electromagnets are arranged in a matrix along the X, Y, and Z axes inside the simulation chamber; several electromagnets are fixed to pre-set anchor points on the inner sidewall of the simulation chamber by several fixing brackets; the electromagnets are connected to the fixing brackets by bolts; a copper foil layer is pasted on the outer surface of each electromagnet, avoiding the bolt connection points; the liquid cooling pipe is sequentially fixed to one side of several bolts by several clips, with a gap between it and the copper foil layer on the surface of the electromagnet; the inlet of the liquid cooling pipe is connected to the outlet of the coolant storage tank through an outlet pipe; the outlet of the liquid cooling pipe is connected to the inlet of the coolant storage tank through an inlet pipe; the remaining space inside the simulation chamber is filled with simulated soil.

[0006] Preferably, the distance between the lens of the infrared thermal imager and the top of the simulation box is 0.5 to 1 m.

[0007] Preferably, the magnetic induction intensity of each electromagnet is in the range of 0.1 to 1.5T; and the thickness of the copper foil layer is 0.5 mm.

[0008] Preferably, the heating mechanism comprises several heating plates with a thickness of 25-30mm spliced ​​together, each heating plate forming an independent temperature control area; a heat insulation layer with a width of 5mm and a thickness of 25-30mm is provided between two adjacent heating plates; the heating temperature range of the heating plate is room temperature to 150℃, the power is 1.8-3.75KW, and the accuracy is ±0.5℃; the heating plate includes a heating layer and a heat-conducting layer from top to bottom; nickel-chromium alloy wires are distributed in a grid pattern in the heating layer; the heat-conducting layer is made of aluminum nitride ceramic material.

[0009] Preferably, the grouting mechanism includes several grouting unit components arranged at equal intervals along the length of the simulated tunnel; each of the grouting unit components is divided into an upper grouting section and a lower grouting section with identical structures; each of the upper or lower grouting sections includes a grout delivery pipe connected to the outlet of a micro-injection pump outside the model box; the end of the grout delivery pipe near the simulated tunnel is provided with an arc-shaped pipe adapted to the outer surface of the simulated tunnel; several grouting perforated pipes are connected in series at equal intervals on the arc-shaped pipe; several grout outlet holes are opened on the surface of the grout outlet holes; a layer of foam rubber is fixed to the surface of the several grout outlet holes by rubber nylon filaments; an independent valve is provided at the end of the grout delivery pipe away from the model box; fiber optic grating sensors are spirally wound on the surface of each of the grouting unit components; the grout delivery pipe, the arc-shaped pipe, and the grouting perforated pipes are all connected to each other.

[0010] Preferably, the fiber Bragg grating sensor has a spatial resolution of 0.1m and a temperature accuracy of ±0.1℃.

[0011] More preferably, the grout in the grouting pipe contains 5%–8% magnetite nanoparticles with a particle size of 10–30 nm, accounting for 10%–8% of the total grout mass, and 3%–5% thermosensitive microcapsules with a diameter of 10–50 μm, accounting for 10%–5% of the total grout mass. The magnetite nanoparticles are coated with silanol groups generated by the hydrolysis of a silane coupling agent, forming a physical barrier with the particle surface. The thermosensitive microcapsules consist of an outer shell and a core material, from the outside in. The outer shell is made of polyurethane material. The core material is made of paraffin stearic acid composite phase change material, and the core material has a dissolution temperature of 40–80°C. The core material is filled with a coagulation catalyst made of sulfoaluminate material.

[0012] Furthermore, preferably, the gap between the liquid cooling pipe and the copper foil layer on the electromagnet surface is 1 mm wide, and four layers of ceramic fiber pads are stacked within the gap; the density of each layer of ceramic fiber pads is ≥128 kg / m³. 3 The thickness is 0.25mm; adjacent ceramic fiber pads are stacked with a left-right offset of ≥5mm; the copper foil layer and the electromagnet, and the ceramic fiber pads near the copper foil layer and the surface of the copper foil layer are all bonded with conductive adhesive; the remaining ceramic fiber pads are bonded and fixed with high-temperature resistant silicone with a working temperature of -60 to 300℃.

[0013] More preferably, the infrared thermal imager, temperature controller, heating mechanism, several thermocouples, lock-in amplifier, several high-frequency induction coils, magnetic induction tomography system, magnetic field controller, several electromagnets, distributed fiber optic temperature measurement system, fiber optic grating sensor, and data processing and analysis system are all electrically connected to the PID control system.

[0014] The beneficial effects of this utility model are:

[0015] 1. This utility model can effectively control the diffusion path of slurry by changing the current, magnetic field strength and direction of the electromagnet coil, in conjunction with the magnetic nanoparticles of iron oxide in the slurry;

[0016] 2. This utility model can ensure that the field of view covers the entire heating area by using an infrared thermal imager, and monitor temperature changes in real time;

[0017] 3. By setting up a high-frequency induction coil combined with a lock-in amplifier, this utility model enables the magnetic induction tomography system to acquire the induced voltage signal generated by the high-frequency induction coil during the slurry diffusion process without affecting the magnetic field control, thereby realizing the visualization imaging of the slurry diffusion process;

[0018] 4. By setting a heating plate connected to a temperature controller in conjunction with a thermocouple, this utility model can effectively monitor and regulate the temperature, thereby controlling the solidification rate of the slurry in the target area. Attached Figure Description

[0019] The accompanying drawings constituting this utility model are provided to further understand this application and do not constitute an undue limitation on this application.

[0020] Figure 1 This is a schematic diagram of the overall structure of this utility model (some box panels are omitted);

[0021] Figure 2 A front view of the internal structure of the simulation box after the formation grouting mechanism has been removed;

[0022] Figure 3 A side view of the internal structure of the simulation box after the formation grouting mechanism has been removed;

[0023] Figure 4 This is a side view of the grouting mechanism.

[0024] In the diagram, 1-simulation box; 2-simulation tunnel; 3-grout delivery pipe; 301-grouting pipe; 4-control cabinet; 5-infrared thermal imager; 6-heating plate; 7-insulation layer; 8-electromagnet; 9-fixed frame; 10-liquid cooling pipe; 11-coolant storage tank; 1101-liquid outlet pipe; 1102-liquid inlet pipe; 12-high frequency induction coil; 13-thermocouple. Detailed Implementation

[0025] The specific implementation of the grout diffusion visualization test system for rock and soil grouting provided by this utility model will be further described with reference to the accompanying drawings and embodiments.

[0026] like Figure 1As shown, a grout diffusion visualization test system for rock and soil grouting includes a simulation box 1, a control cabinet 4, an infrared thermal imager 5, a heating mechanism, a liquid cooling pipe 10, and a coolant storage tank 11.

[0027] Preferably, the control cabinet 4 is equipped with a PID control system, a data processing and analysis system, a magnetic induction tomography (MIT) system, a lock-in amplifier, a magnetic field controller, a distributed fiber optic temperature measurement system, and a temperature controller.

[0028] Preferably, the inner cavity of the simulation box 1 is provided with a simulation tunnel 2 along its length; the infrared thermal imager 5 is set directly above the top of the simulation box 1 and at a distance of 0.5 to 1m from the top of the simulation box, to ensure that the field of view can cover the entire heating mechanism, monitor the temperature field distribution on the surface of the model box, and calibrate the heat conduction uniformity of the heating plate 6.

[0029] Preferably, the heating mechanism is laid on top of the simulation chamber 1 and divided into several independent temperature control zones according to the length of the simulation chamber 1, facilitating zoned grouting observation. Specifically, the heating mechanism comprises several heating plates 6 with a thickness of 25-30mm spliced ​​together; a heat insulation layer 7 with a width of 5mm and a thickness of 25-30mm is provided between adjacent heating plates 6 to block lateral heat conduction interference between the heating plates 6. The heating temperature range of the heating plate 6 is room temperature to 150℃, the power is 1.8-3.75KW, and the accuracy is ±0.5℃.

[0030] Preferably, in order to improve the thermal conductivity of the heating mechanism, the heating plate 6 includes a heating layer and a heat-conducting layer from top to bottom; the heating layer has nickel-chromium alloy wires distributed in a grid pattern to improve heating uniformity; the heat-conducting layer is made of aluminum nitride ceramic material with high thermal conductivity.

[0031] Preferably, the left and right outer walls, front and rear outer walls, and top wall of the heating mechanism of the simulation box 1 are provided with several high-frequency induction coils 12 at equal intervals corresponding to the location of the simulated tunnel 2. These coils are used to excite the magnetite nanoparticles in the slurry, obtain slurry diffusion information, and collect the amplitude and phase difference of the induced voltage signal generated by the high-frequency induction coils 12 during the slurry diffusion process through a lock-in amplifier to eliminate environmental electromagnetic noise. These signals are then transmitted to the magnetic induction tomography (MIT) system, and the Landweber iterative method is used to generate a dynamic three-dimensional image of the slurry diffusion, thereby realizing the visualization of the slurry diffusion process.

[0032] Preferably, a number of thermocouples 13 are equally spaced above and below the simulated tunnel 2 inside the simulation box 1 to monitor the temperature changes of the simulated strata surrounding the simulated tunnel 2.

[0033] Preferably, a grouting mechanism is also provided along the periphery of the simulated tunnel 2 to reinforce the gaps between the simulated strata.

[0034] like Figure 2-3 As shown, the simulation chamber 1 has several electromagnets 8 arranged in a matrix along the X, Y, and Z axes. Preferably, the magnetic induction intensity of each electromagnet 8 is 0.1 to 1.5 T. The electromagnets 8 are fixed to pre-set anchor points on the inner wall of the simulation chamber 1 by several brackets 9 made of aluminum alloy. Preferably, each electromagnet 8 is connected to the bracket 9 by bolts; a 0.5 mm thick copper foil layer is pasted on the outer surface of each electromagnet 8, avoiding the bolt connection points; liquid cooling pipes 10 are sequentially fixed to one side of several bolts by several clips, ensuring that each electromagnet 8 has a liquid cooling pipe 10 passing through it. There is a 1 mm gap between the installation position of the liquid cooling pipe 10 and the copper foil layer on the surface of each electromagnet 8; four layers of ceramic fiber pads are stacked within the gap; the density of each layer of ceramic fiber pads is ≥128 kg / m³. 3 The thickness is 0.25mm; adjacent ceramic fiber pads are staggered left and right with an offset of ≥5mm to avoid thermal bridging due to overlapping seams. The copper foil layer and the electromagnet 8, as well as the ceramic fiber pads near the copper foil layer and the surface of the copper foil layer (ensuring tight contact between the ceramic fiber pads and the copper foil layer surface, and pressing to release air), are all bonded with conductive adhesive; the remaining ceramic fiber pads are bonded and fixed with high-temperature resistant silicone with a working temperature of -60~300℃. It is worth noting that the copper foil layer, through its high conductivity, forms a closed shielding layer, effectively attenuating electromagnetic interference to surrounding circuits, achieving ≥70% magnetic field strength suppression in the core magnetic field region; the double-layer shielding design of the copper foil layer combined with the staggered ceramic fiber pads further reduces eddy current effects, ensuring system electromagnetic compatibility.

[0035] Preferably, the inlet of the liquid cooling pipe 10 is connected to the outlet of the coolant storage tank 11 via the outlet pipe 1101; the outlet of the liquid cooling pipe 10 is connected to the inlet of the coolant storage tank 11 via the inlet pipe 1102, thereby completing the circulation of the cooling system, which can effectively dissipate heat from the surface of the electromagnet and avoid affecting the magnetic field strength and system stability due to overheating of the electromagnet surface.

[0036] After installing all the above components, fill the remaining space inside the simulation chamber 1 with simulated soil. When filling, ensure that the soil is uniform and in close contact with the inner wall of the simulation chamber 1 to ensure the accuracy of the test results.

[0037] like Figure 4As shown, the grouting mechanism includes several grouting unit components arranged at equal intervals along the length of the simulated tunnel 2; each grouting unit component is divided into an upper grouting section and a lower grouting section with identical structures. Each upper or lower grouting section includes a grout delivery pipe 3 connected to the outlet of a micro-injection pump outside the model box 1. An arc-shaped pipe adapted to the outer surface of the simulated tunnel 2 is provided at one end of the grout delivery pipe 3 near the simulated tunnel 2. Several grouting perforated pipes 301 are connected in series at equal intervals on the arc-shaped pipe. The grout delivery pipe, the arc-shaped pipe, and the grouting perforated pipes are all interconnected. Several grout outlet holes are formed on the surface of each grout outlet hole, and a foam rubber layer is fixed to the surface of each grout outlet hole by rubber nylon filaments. During grouting, the grout pressure compresses the foam rubber layer outwards, opening the grout outlet channel. After grouting, the foam rubber layer retracts due to elastic recovery force to conform to the skeleton surface of the arc-shaped pipe 301, sealing the grout outlet holes and preventing grout backflow.

[0038] It is worth noting that, in order to observe the slurry diffusion process in several heating zones separately, each slurry delivery pipe 3 is equipped with an independent valve at the end away from the model box 1, which facilitates targeted slurry injection.

[0039] Preferably, each of the grouting unit components has a fiber Bragg grating sensor with a spatial resolution of 0.1m and a temperature accuracy of ±0.1℃ spirally wound on its surface, with a winding interval of 5cm. The fiber Bragg grating sensor is electrically connected to the PID control system through a distributed fiber optic temperature measurement system to monitor the temperature change of the grout in each grouting unit component.

[0040] To achieve controllable slurry diffusion path, the slurry used in the slurry delivery pipe 3 is composed of 5%–8% magnetite nanoparticles with a particle size of 10–30 nm (by mass of the total slurry) and 3%–5% thermosensitive microcapsules with a diameter of 10–50 μm (by mass of the total slurry). The magnetite nanoparticles are coated with silanol groups generated from the hydrolysis of a silane coupling agent, forming a physical barrier that effectively reduces agglomeration between the magnetite nanoparticles, improves their dispersibility in the slurry, and inhibits particle sedimentation or aggregation. Furthermore, the thermosensitive microcapsules consist of an outer shell and a core material, from the outside in. The outer shell is made of polyurethane; the core material is made of a paraffin-stearic acid composite phase change material with a dissolution temperature of 40–80°C; and the core material is filled with a coagulation catalyst made of sulfoaluminate. When the temperature rises to the core material's melting temperature, the core material's molten volume expands, causing the outer shell to crack. At this time, the coagulation catalyst inside the core material will flow into the slurry through the cracks in the outer shell and undergo a hydrolysis reaction with the sodium silicate in the slurry, consuming OH- ions and lowering the pH value, thereby shortening the local coagulation time of the slurry.

[0041] More preferably, the infrared thermal imager 5, temperature controller, heating mechanism, several thermocouples 13, lock-in amplifier, several high-frequency induction coils 12, magnetic induction tomography system, magnetic field controller, several electromagnets 8, distributed fiber optic temperature measurement system, fiber optic grating sensor, and data processing and analysis system are all electrically connected to the PID control system.

[0042] A method for using a grout diffusion visualization test system applied to rock and soil grouting, specifically including the following steps:

[0043] S1. Preparation Phase:

[0044] S1.1 Install and connect all components and equipment, set test parameters, and complete the filling of the simulated strata inside the simulation chamber to ensure that the soil is uniform and in close contact with the inner wall of the simulation chamber.

[0045] S1.2 Prepare the grouting slurry and mix it thoroughly to ensure that the slurry is mixed evenly;

[0046] S2. Experimental Phase:

[0047] S2.1 Divide the heating mechanism into several independent temperature control zones according to the length of the simulation box, and divide the simulated formation into several grouting zones according to the number of temperature control zones. Turn on the micro-injection pump and start grouting in the first zone.

[0048] S2.2 Start the magnetic field controller. According to the preset slurry diffusion path, the coil current, magnetic field strength and direction of each electromagnet in the first area are dynamically adjusted by the PID algorithm to form a magnetic field gradient in the first area, thereby guiding the slurry to migrate in a specific direction.

[0049] S2.3 The distribution of magnetite nanoparticles in the slurry is monitored by electromagnetic coupling using a high-frequency induction coil located in the first region.

[0050] S2.4 The amplitude and phase difference of the high-frequency induction coil voltage signal located in the first region are monitored by the lock-in amplifier, and the data is transmitted to the magnetic induction tomography system. The Landweber iterative method is used to construct a three-dimensional image of the concentration distribution of ferric oxide magnetic nanoparticles in the slurry, so as to realize the three-dimensional visualization of slurry diffusion.

[0051] S2.5 When the magnetic induction tomography imaging system shows that the slurry has reached the designated area, the temperature controller raises the temperature of the designated area until the core material of the thermosensitive microcapsule melts, causing the outer shell to expand and crack. The coagulation catalyst located in the core material is released into the slurry, which accelerates the slurry coagulation speed, shortens the local coagulation time of the slurry, and achieves coagulation control.

[0052] S2.6 The temperature change data of the grout-soil contact surface is detected by thermocouples and fiber optic grating sensors located in the first area, and a temperature field cloud map is generated; the temperature field distribution is monitored by an infrared thermal imager; and a dynamic three-dimensional image of grout diffusion in the first area is generated in real time using a magnetic induction tomography system, thus completing the test in the first area and ending the grouting in that area.

[0053] S2.7 Complete the slurry visualization test in other areas in sequence;

[0054] S3. Data Processing:

[0055] The collected data were comprehensively analyzed to evaluate the slurry diffusion path, solidification time and state, and temperature distribution. The results were compared with the preset targets, and the test system was improved and optimized by changing the size of the electromagnet, optimizing the grouting system, and updating the PID algorithm.

[0056] Example:

[0057] Taking a simulation chamber with dimensions of 3m×2m×2m as an example, the internal cavity electromagnets are arranged in 4 layers along the Y-axis direction of the simulation chamber, 6 electromagnets are evenly spaced in each layer along the X-axis direction, and 4 electromagnets are evenly spaced in each layer along the Z-axis direction. The dimensions of a single electromagnet are 0.1m×0.05m×0.03m, and the magnetic field strength of a single electromagnet in the central region is 1.5T. The liquid cooling pipe is made of stainless steel corrugated pipe with an outer diameter of 5mm and a bending radius of ≥25mm. The heating mechanism is divided into 5 heating plates, which are divided into 5 independent temperature control zones (each zone is 60cm long).

[0058] During the experiment, grouting was performed separately in each independent temperature control zone. The coil current (0-100A) in each electromagnet was independently adjusted using a PID algorithm to create a magnetic field gradient (0.1-1.5T / m) within the current grouting zone. If the grout needed to deflect to the left, the current of the right electromagnet group was increased (magnetic field strength 1.2T), and the current of the left electromagnet group was decreased (0.8T), thus creating a magnetic field gradient from right to left. The Fe3O4 nanoparticles in the grout generated magnetization force under the magnetic field gradient, driving the grout to migrate towards the region with high magnetic field strength. When the magnetic induction tomography (MIT) system detected that the grout deviated from the preset path (deviation > 5mm), the current of the adjacent electromagnets was dynamically adjusted in time to correct the grout direction with a gradient increment of 0.1T / m, thereby achieving control of the grout diffusion path (the specific process of controlling the grout to deflect to the right will not be elaborated here).

[0059] Once the grout reaches the designated area, it enters the thermal triggering stage (causing the rupture of the thermosensitive microcapsules): the frequency of the electromagnet assembly in the current grouting area is reduced to 500Hz (i.e., the power is reduced by 50%), and the heating plate is heated at full power to above 60℃ at a rate of 10℃ / min (the power of the temperature zone is dynamically adjusted using a PID algorithm, and the temperature difference can be controlled within ±1℃ with real-time feedback from thermocouples). After the coagulation catalyst in the core material enters the grout, it undergoes a hydrolysis reaction with the sodium silicate in the grout, consuming OH- ions, reducing the pH value, and shortening the local coagulation time of the grout by 30%-70%.

[0060] A magnetic induction tomography (MIT) system controls a high-frequency induction coil to sequentially emit alternating magnetic fields. A lock-in amplifier is used to extract the voltage amplitude ΔV and phase difference Δφ (sensitivity 1 μV / °) generated by the high-frequency induction coil during slurry diffusion. Environmental electromagnetic noise is eliminated, and the data is transmitted to the MIT system. The Landweber iterative algorithm is then used to generate a dynamic 3D image of slurry diffusion in the grouting area, magnetic field intensity contour lines (displaying the magnetic field gradient distribution and identifying the driving direction and intensity differences of the electromagnet array on the slurry; areas of strong magnetic fields, i.e., dense contour lines, correspond to the main migration path of the slurry, i.e., the diffusion path), and temperature field cloud map (generated using data collected by thermocouples and fiber optic sensors, processed by a data processing and analysis system; the displayed temperature color scale distinguishes the slurry state between the solidified / high-temperature zone and the fluid / low-temperature zone). The collected data is comprehensively analyzed to evaluate the slurry diffusion path, solidification time and state, temperature changes and distribution, and is compared with preset targets for optimization and improvement.

[0061] This invention replaces the traditional transparent box and soil, and can simultaneously realize the planning, visualization and control of slurry path and setting time. It also provides a more intuitive view by using the real-time generated dynamic three-dimensional map of slurry diffusion.

[0062] In this utility model, terms such as "upper," "lower," "bottom," and "top" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are merely used to facilitate the description of the structural relationships of the various components or elements of this utility model and do not specifically refer to any component or element in this utility model, nor should they be construed as limiting the utility model. Terms such as "connected" and "linked" should be interpreted broadly, indicating a fixed connection, an integral connection, or a detachable connection; a direct connection or an indirect connection through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in this utility model can be determined according to the specific circumstances, and they should not be construed as limiting the utility model.

[0063] Of course, the above description is not intended to limit the present utility model, and the present utility model is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present utility model should also fall within the protection scope of the present utility model.

Claims

1. A grout diffusion visualization test system applied to rock and soil grouting, characterized in that, Includes control cabinet, simulation box, infrared thermal imager, heating mechanism, coolant storage tank and liquid cooling pipe; The control cabinet is equipped with a PID control system, a data processing and analysis system, a magnetic induction tomography system, a lock-in amplifier, a magnetic field controller, a distributed fiber optic temperature measurement system, and a temperature controller. The simulation box has a simulated tunnel arranged along its length; The infrared thermal imager is positioned directly above the top of the simulation box; the heating mechanism is installed on the top of the simulation box; several high-frequency induction coils are evenly spaced on the left and right outer walls, front and rear outer walls, and the top wall of the heating mechanism corresponding to the simulated tunnel. Several thermocouples are evenly spaced at positions directly above and below the simulated tunnel along its length inside the simulation chamber; a grouting mechanism is installed around the perimeter of the simulated tunnel. The simulation chamber has a matrix of electromagnets arranged in the X, Y, and Z axes. Each electromagnet is fixed to a pre-set anchor point on the inner side wall of the simulation chamber by a number of fixing brackets. The electromagnets are connected to the fixing brackets by bolts. A copper foil layer is pasted on the outer surface of each electromagnet, avoiding the bolt connection. The liquid cooling pipe is sequentially fixed to one side of several bolts by several clips and there is a gap between it and the copper foil layer on the surface of the electromagnet; the inlet of the liquid cooling pipe is connected to the outlet of the coolant storage tank through the outlet pipe; the outlet of the liquid cooling pipe is connected to the inlet of the coolant storage tank through the inlet pipe. The remaining space inside the simulation chamber is filled with simulated soil.

2. The grout diffusion visualization test system for rock and soil grouting according to claim 1, characterized in that, The distance between the lens of the infrared thermal imager and the top of the simulation box is 0.5 to 1 m.

3. The grout diffusion visualization test system for rock and soil grouting according to claim 2, characterized in that, The magnetic induction intensity of each electromagnet ranges from 0.1 to 1.5 T; the thickness of the copper foil layer is 0.5 mm.

4. The grout diffusion visualization test system for rock and soil grouting according to claim 3, characterized in that, The heating mechanism comprises several heating plates with a thickness of 25-30mm spliced ​​together, each heating plate forming an independent temperature control area; a heat insulation layer with a width of 5mm and a thickness of 25-30mm is provided between two adjacent heating plates; The heating plate has a heating temperature range of room temperature to 150℃, a power of 1.8 to 3.75KW, and an accuracy of ±0.5℃. The heating plate comprises a heating layer and a heat-conducting layer from top to bottom; the heating layer contains nickel-chromium alloy wires distributed in a grid pattern; the heat-conducting layer is made of aluminum nitride ceramic material.

5. The grout diffusion visualization test system for rock and soil grouting according to claim 4, characterized in that, The grouting mechanism includes several grouting unit components arranged at equal intervals along the length of the simulated tunnel; each of the grouting unit components is divided into an upper grouting section and a lower grouting section with the same structure. The upper or lower grouting section includes a grout delivery pipe connected to the outlet of a micro-injection pump outside the model box. The end of the grout delivery pipe near the simulated tunnel is provided with an arc-shaped pipe adapted to the outer surface of the simulated tunnel. Several grouting perforated pipes are connected in series at equal intervals on the arc-shaped pipe. Several grout outlet holes are opened on the surface of the grout outlet holes, and a foam rubber layer is fixed on the surface of the several grout outlet holes by rubber nylon filaments. Each of the slurry delivery pipes is equipped with an independent valve at the end furthest from the model box; Several of the grouting unit components have fiber optic grating sensors spirally wound on their surfaces; The grout delivery pipe, the arc-shaped pipe, and the grouting flower pipe are all connected.

6. The grout diffusion visualization test system for rock and soil grouting according to claim 5, characterized in that, The fiber Bragg grating sensor has a spatial resolution of 0.1m and a temperature accuracy of ±0.1℃.

7. The grout diffusion visualization test system for rock and soil grouting according to claim 5, characterized in that, The grouting liquid in the grouting pipe contains 5% to 8% of magnetic nanoparticles of iron oxide with a particle size of 10 to 30 nm, and 3% to 5% of thermally sensitive microcapsules with a diameter of 10 to 50 μm. The magnetic nanoparticles of iron oxide are coated with silanol groups generated by the hydrolysis of silane coupling agent, which combine with the particle surface to form a physical barrier. The thermosensitive microcapsule comprises, from the outside to the inside, an outer shell and a core material. The outer shell is made of polyurethane material; the core material is made of paraffin stearic acid composite phase change material, and the melting temperature of the core material is 40–80°C. The core material is filled with a solidified catalyst made of sulfoaluminate material.

8. The grout diffusion visualization test system for rock and soil grouting according to claim 1, characterized in that, The gap between the liquid cooling pipe and the copper foil layer on the surface of the electromagnet is 1 mm, and four layers of ceramic fiber pads are stacked in the gap. The density of each layer of ceramic fiber pads is ≥128 kg / m³. 3 The thickness is 0.25mm; adjacent ceramic fiber gaskets are stacked with a left-right offset of ≥5mm; The copper foil layer and the electromagnet, as well as the ceramic fiber gasket near the copper foil layer and the surface of the copper foil layer, are all bonded together with conductive adhesive; the remaining ceramic fiber gaskets are all bonded and fixed together with high-temperature resistant silicone with a working temperature of -60 to 300℃.

9. The grout diffusion visualization test system for rock and soil grouting according to claim 6, characterized in that, The infrared thermal imager, temperature controller, heating mechanism, several thermocouples, lock-in amplifier, several high-frequency induction coils, magnetic induction tomography system, magnetic field controller, several electromagnets, distributed fiber optic temperature measurement system, fiber optic grating sensor, and data processing and analysis system are all electrically connected to the PID control system.

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