Calcium-based material mineralization pulping and visual grouting experiment system and method

Abstract

The invention discloses a calcium-based material mineralization pulping and visual grouting experiment system and method, and relates to the technical field of grouting experiments. The system comprises a calcium-based material mineralization pulping module, a visual grouting experiment module and a controller, the calcium-based material mineralization pulping module comprises a stirring device, a gas supply device, a monitoring sensor and a discharging device; the visual grouting experiment module comprises a grouting experiment table, a grouting module, a circulating water injection module and a high-speed camera. According to the invention, convenient mineralization pulping and process monitoring of the grouting material can be realized, and the problems of low automation degree, unclear process, incapability of data quantification and the like of a traditional pulping mode are solved; meanwhile, mineralization slurrying and grouting experimental devices are integrated, material research, development and preparation and performance testing are integrated, slurry transfer and storage problems are avoided, and experiments are closer to actual working conditions.

Description

Technical Field

[0001] The invention relates to the technical field of grouting experiments, and in particular to a calcium-based material mineralization pulping and visual grouting experiment system and method. Background Art

[0002] Grouting technology is widely used to improve the structural performance of rock mass in projects such as rock reinforcement, tunnel construction and mining. By injecting slurry into rock cracks and joints, the strength and stability of the rock mass can be effectively improved, the permeability can be reduced, and the rock mass can be prevented from deformation or collapse. With the expansion of the scale of underground engineering projects and the complexity of geological conditions, the requirements for grouting technology are also increasing. In particular, in scenarios involving complex geological conditions, deep rock formations and the influence of various external factors, traditional grouting technology is difficult to fully meet engineering needs. Therefore, in-depth research on material research and development, diffusion laws and consolidation effects in the grouting process has become the key to ensuring engineering safety and stability.

[0003] In order to further study the effects of grouting materials, researchers have developed various types of grouting experimental equipment. These devices are designed to simulate the grouting process in actual engineering in order to analyze the diffusion, penetration and consolidation behavior of slurries under different geological conditions. Through these experimental equipment, researchers can observe and evaluate the performance of grouting materials, optimize the grouting process, and thus improve the effectiveness and safety of rock reinforcement. The main function of grouting experimental equipment is to provide a controllable experimental environment, so that the complex grouting process can be accurately reproduced under laboratory conditions, providing reliable data support for theoretical research.

[0004] Existing grouting experimental equipment still has deficiencies in many key aspects. First, most of the existing equipment lacks an efficient and convenient mineralized pulping system, which makes the material preparation process complicated and time-consuming; second, most equipment is difficult to truly simulate the three-dimensional fractured rock mass under complex working conditions, and cannot accurately reproduce the diffusion and consolidation process of the slurry in the fracture network, which limits the in-depth study of the slurry diffusion law. In addition, the visual monitoring capability of existing equipment is limited, and it is impossible to fully capture the flow path of the slurry under different geological conditions and its consolidation effect. This limitation affects the accuracy and reliability of the research results. More importantly, the current experimental system has significant deficiencies in the secondary flow and consolidation experiments of the slurry under the dynamic water conditions after simulating grouting, and cannot fully evaluate the long-term stability and durability of the material. Therefore, it is urgent to develop an advanced experimental system that integrates mineralized pulping, visual monitoring, multi-condition experiments, and secondary flow and consolidation experiments under dynamic water conditions to make up for the shortcomings of existing technologies and promote the further development of grouting technology. Summary of the invention

[0005] In view of the above problems, the present invention discloses a calcium-based material mineralization pulping and visualized grouting experimental system and method, which solves the problems existing in the prior art of convenient mineralization pulping and process monitoring of grouting materials, integration of material research and development, preparation and performance testing, three-dimensional fractured rock grouting experiments under multiple working conditions, and secondary flow and consolidation effect experiments of slurry under dynamic water conditions after grouting.

[0006] According to the purpose of the present invention, a calcium-based material mineralization pulping and visual grouting experimental system is proposed, which includes a calcium-based material mineralization pulping module, a visual grouting experimental module and a controller.

[0007] The calcium-based material mineralization pulping module includes a stirring device, an air supply device, a monitoring sensor and a discharging device; the stirring device includes a stirring barrel, a stirring element arranged in the stirring barrel, a servo motor installed on the stirring barrel for driving the stirring element and an ultrasonic generator; the air supply device includes a CO 2 Gas tank, waste gas barrel, connection CO 2 An air intake pipe between the gas tank and the mixing barrel, a pressure reducing valve arranged on the air intake pipe, a first flow meter and a first non-return valve, an exhaust pipe connecting the mixing barrel and the waste gas barrel, and a pipe fan and a second flow meter arranged on the exhaust pipe; the monitoring sensor includes a torque sensor and a resistivity sensor arranged in the mixing barrel; the discharging device includes a liquid storage barrel, a liquid outlet pipe connecting the mixing barrel and the liquid storage barrel, and a first electronic valve and a centrifugal pump arranged on the liquid outlet pipe.

[0008] The visualized grouting experiment module comprises a grouting experiment platform, a grouting module, a circulating water injection module and a high-speed camera; the grouting experiment platform comprises a specimen fixing frame, a fractured rock specimen fixedly mounted in the specimen fixing frame and a liquid storage tank; the fractured rock specimen is obtained by 3D printing using a transparent resin, and is provided with fractures, a grouting channel and a water injection channel inside; the liquid storage tank is fixedly mounted at the outlet of the grouting channel; the grouting module comprises a liquid storage barrel, a first air compressor, a grouting pipeline for connecting the liquid storage barrel and the grouting channel on the grouting experiment platform, and a third flowmeter, a first pressure gauge and a second electronic valve arranged on the grouting pipeline; the circulating water injection module comprises a water storage barrel, a second air compressor, a water injection pipeline for connecting the water storage barrel and the water inlet of the water injection channel on the grouting experiment platform, a water outlet pipeline for connecting the water storage barrel and the water outlet of the water injection channel on the grouting experiment platform, a fifth flowmeter, a second pressure gauge and a third electronic valve arranged on the water injection pipeline, and a fourth flowmeter and a second one-way valve arranged on the water outlet pipeline.

[0009] Preferably, the mixing barrel comprises a barrel body and a barrel cover, the barrel cover is a semi-open structure, connected to the barrel body by a snap, and three holes are provided on the barrel cover for installing a servo motor, an ultrasonic generator and a resistivity sensor respectively; the stirring element is installed on the servo motor, including a hollow shaft, stirring blades and spiral blades, and the torque sensor is installed on the top of the hollow shaft; an air inlet for connecting to an air inlet pipe is provided on the side of the bottom of the barrel body, a discharge port for connecting to a liquid discharge pipe is provided on the bottom, and an exhaust port for connecting to an exhaust pipe is provided on the upper side, and a filter is installed at the air inlet.

[0010] Preferably, the barrel body and the barrel cover are sealed with a buckle and an "O"-ring, the connection between the barrel cover is sealed with a toothed sealing strip, and each opening connection is additionally sealed with an "O"-ring.

[0011] The present invention further discloses a method for conducting calcium-based material mineralization pulping and visual grouting experiments using the above system, comprising the following steps: Step 1: Mineralization and pulping of calcium-based materials.

[0012] S11. Install the stirring device, gas supply device, monitoring sensor and discharging device, turn on each device to make sure it can work normally, and turn on the CO 2 A small amount of gas is introduced into the gas cylinder and recovered, and its sealing is tested by reading the first flow meter and the second flow meter.

[0013] S12. Use calcium-based materials and mineralization promoters to prepare grouting materials in a ratio of 1.2-2.5, and obtain the content of alkaline components therein by X-ray powder diffraction analysis.

[0014] S13. According to the weight and proportion of the grouting materials required for the experiment, weigh the calcium-based material and the mineralization accelerator and put them into the mixing bucket; calculate the CO required for the reaction based on the content of the alkaline components in the grouting material obtained by analysis. 2 Measure and add water into the mixing barrel, the water-cement ratio is y, and the value range of y is 0.5-3.

[0015] S14. Close the barrel cover and fasten the buckle to ensure sealing. Start the servo motor through the controller to control the rotation of the stirring element and observe the values ​​of the torque sensor and resistivity sensor.

[0016] S15. When the values ​​of the torque sensor and resistivity sensor gradually decrease and remain stable, turn on the ultrasonic generator and CO 2 The gas tank valve introduces CO into the mixing tank 2 , observe the resistivity sensor value.

[0017] S16. When the resistivity sensor value gradually increases and remains stable, turn off the ultrasonic generator and CO 2Open the gas tank valve and turn on the pipeline fan to extract the exhaust gas into the exhaust gas barrel.

[0018] S17, lower the speed of the servo motor, open the first electronic valve, and the slurry is pumped into the liquid storage barrel by the centrifugal pump for experiment. The remaining slurry is left in the barrel and continues to be stirred to avoid solidification, and the slurry in the liquid storage barrel is replenished in real time.

[0019] Step 2: Visual grouting experiment.

[0020] S21. Take rock samples from the area to be grouting, perform CT scanning and three-dimensional reconstruction to obtain rock fracture characteristics and parameters, use a 3D printer to print transparent fractured rock specimens based on the obtained data, and leave grouting channels and water injection channels.

[0021] S22. Place the fractured rock specimen at the center of the specimen holder, rotate and tighten the bolts to fix it, connect the grouting pipe, water injection pipe and water outlet pipe, and perform a pressure test on the liquid storage tank and water storage tank to verify their sealing properties; S23, start the second air compressor to increase pressure, and after reaching the set water injection pressure, open the third electronic valve, and water flows into the fractured rock specimen and flows back through the second one-way valve into the water storage tank to form a circulating water injection; S24, start the first air compressor to increase pressure, and after reaching the set grouting pressure, open the second electronic valve, and inject slurry into the fractured rock specimen to fill the fractures through the grouting channel under a dynamic water environment.

[0022] S25. Use a high-speed camera to shoot the slurry flow and grouting effect during the grouting process under dynamic water conditions.

[0023] Preferably, after the grouting experiment in step 2 is completed, a liquid storage tank is installed at the outlet of the grouting channel, and the slurry enters the liquid storage tank after being injected into the fractured rock specimen. When the fractures and the liquid storage tank are full, the slurry can no longer be injected, and a high-speed camera is used to capture the rock fracture filling conditions and the slurry consolidation conditions under dynamic water conditions.

[0024] Compared with the prior art, the advantages of the calcium-based material mineralization pulping and visual grouting experimental system and method disclosed in the present invention are: 1. The present invention can realize convenient mineralization pulping and process monitoring of grouting materials, solving the problems of low automation, unclear process and inability to quantify data in traditional pulping methods.

[0025] 2. The present invention integrates the mineralization pulping and grouting experimental equipment, realizes the integration of material research and development preparation and performance testing, avoids the problems of slurry transfer and storage, and the experiment is closer to the actual working conditions.

[0026] 3. The present invention designs a grouting test bench and a fractured rock specimen, which can realize grouting experiments on multi-sized three-dimensional rock specimens under multiple parameters (grouting pressure, dynamic water pressure, fracture density, etc.).

[0027] 4. The present invention can conduct secondary flow and consolidation experiments of slurry under dynamic water conditions after grouting is completed, and further evaluate the grouting effect of the developed grouting material under actual working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions of the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 This is a schematic diagram of the structure of the calcium-based material mineralization pulping and visual grouting experimental system.

[0030] Figure 2 This is a top view of the grouting test bench.

[0031] Figure 3 This is a schematic diagram of the three-dimensional structure of the grouting test bench.

[0032] In the picture: 1-CO 2 Gas tank; 2-first one-way valve; 3-barrel body; 4-first electronic valve; 5-resistivity sensor; 6-centrifugal pump; 7-first air compressor; 8-liquid storage barrel; 9-first pressure gauge; 10-third flow meter; 11-second electronic valve; 12-fracture rock specimen; 13-fourth flow meter; 14-second one-way valve; 15-water storage barrel; 16-second air compressor; 17-second pressure gauge; 18-fifth flow meter; 19-third electronic valve; 20-specimen fixing frame; 21-controller; 22-waste gas barrel; 23-first Second flow meter; 24-pipeline fan; 25-ultrasonic generator; 26-torque sensor; 27-servo motor; 28-stirring element; 29-barrel cover; 30-first flow meter; 31-pressure reducing valve; 32-fastening bolts; 33-water injection channel; 34-grouting channel; 35-liquid storage tank; 36-secondary cracks; 37-high-speed camera; 38-air inlet pipe; 39-exhaust pipe; 40-liquid outlet pipe; 41-grouting pipe; 42-water injection pipe; 43-water outlet pipe; 44-stirring blade; 45-spiral blade. DETAILED DESCRIPTION

[0033] The specific implementation of the present invention is briefly described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] Figure 1-Figure 3 The preferred embodiments of the present invention are shown and analyzed in detail.

[0035] like Figure 1 A calcium-based material mineralization pulping and visual grouting experimental system is shown, comprising a calcium-based material mineralization pulping module, a visual grouting experimental module and a controller 21.

[0036] The calcium-based material mineralization pulping module comprises a stirring device, an air supply device, a monitoring sensor and a discharging device.

[0037] The stirring device includes a stirring barrel, a stirring element 28 disposed in the stirring barrel, a servo motor 27 installed on the stirring barrel for driving the stirring element 28, and an ultrasonic generator 25. The stirring barrel includes a barrel body 3 and a barrel cover 29. The barrel cover 29 is a semi-open structure connected to the barrel body 3 by a buckle. The barrel cover 29 is provided with three holes for installing the servo motor 27, the ultrasonic generator 25 and the resistivity sensor 5 respectively. An air inlet for connecting to an air inlet pipe 38 is provided on the side of the bottom of the barrel body 3 of the stirring barrel. A filter screen is installed at the air inlet to prevent the slurry from blocking the air inlet; an exhaust port for connecting to an exhaust pipe 39 is provided on the side of the upper part of the barrel body 3; and a discharge port for connecting to a liquid outlet pipe 40 is provided at the bottom of the barrel body 3. The stirring element 28 is installed on the servo motor 27, and includes a hollow rotating shaft, a stirring blade 44 and a spiral blade 45. Buckles and O-rings are used to seal the barrel body 3 and the barrel cover 29. The connection of the barrel cover 29 is sealed with a toothed sealing strip, and each opening connection is sealed with an O-ring. The ultrasonic generator can generate ultrasonic waves to achieve ultrasonic-assisted stirring.

[0038] Gas supply includes CO 2 Gas tank 1, waste gas barrel 22, connect CO 2 The gas supply device consists of a CO2-type air supply device and a gas supply device. The gas supply device includes an air supply pipe 38 between the gas tank 1 and the mixing barrel, a pressure reducing valve 31 disposed on the air supply pipe 38, a first flow meter 30 and a first check valve 2, an exhaust pipe 39 connecting the mixing barrel and the waste gas barrel 22, and a pipe fan 24 and a second flow meter 23 disposed on the exhaust pipe 39. 2 The gas tank 1 provides high-pressure gas, which enters the barrel body 3 through the pressure reducing valve 31, the first flow meter 30 and the first one-way valve 2 through the air inlet pipe 38. A filter is installed at the inlet to prevent the slurry from blocking the air inlet. After the slurry is prepared, the remaining gas is drawn into the waste gas barrel 22 from the exhaust port through the exhaust pipe 39 and the pipeline fan 24.

[0039] The monitoring sensors include a torque sensor 26 and a resistivity sensor 5 which are arranged in the mixing barrel. The torque sensor 26 is installed at the top of the hollow shaft of the mixing element 28, and is used to monitor the torque change to determine whether the mixing is complete. The resistivity sensor 5 is placed at the bottom of the mixing barrel through a steel pipe, and the reaction progress is determined by monitoring the resistivity change. The reason for the change in torque is: after adding calcium-based materials and mineralization promoters to the mixing barrel and injecting water, the material is not in sufficient contact with water, and a consolidated block is easily formed, which makes the torque larger in the initial stage of stirring. As the stirring proceeds, the material and water are fully mixed to form a slurry, and the torque gradually decreases and remains stable. The reason for the change in resistivity is: after water is injected into the calcium-based material and the mineralization promoter and mixed, Ca 2+ The alkaline components are ionized, which increases the free ions in the slurry, causing the resistivity to decrease and stabilize. 2 Injected and reacted with calcium-based materials to form CaCO 3 , CaCO 3 Insolubility in water causes the free ions in the system to gradually decrease and the resistivity to gradually increase. Finally, when the mineralization reaction is completed, the ion concentration in the system reaches the lowest point, and the resistivity reaches the highest point and remains stable.

[0040] The discharging device includes a liquid storage barrel 8, a liquid outlet pipe 40 connecting the mixing barrel and the liquid storage barrel 8, and a first electronic valve 4 and a centrifugal pump 6 arranged on the liquid outlet pipe 40. When the slurry is prepared, the first electronic valve 4 and the centrifugal pump 6 are controlled to open, and the slurry enters the liquid storage barrel 8 from the discharging port through the liquid outlet pipe 40 for grouting experiments.

[0041] The visual grouting experiment module includes a grouting experiment table, a grouting module, a circulating water injection module and a high-speed camera 37.

[0042] like Figure 2 and Figure 3As shown, the grouting test bench includes a specimen fixing frame 20, a fractured rock specimen 12 fixedly installed in the specimen fixing frame 20, and a liquid storage tank 35. The specimen fixing frame 20 is made of a transparent acrylic plate, which wraps the fractured rock specimen 12 on all sides, and each side is provided with fastening bolts 32 for fixing the fractured rock specimen 12. The fractured rock specimen 12 is obtained by 3D printing using transparent resin, and is provided with fractures, grouting channels 34 and water injection channels 33 inside. The fractured rock specimen 12 is provided with grouting channels 34 and water injection channels 33 to simulate the oblique main fractures. According to the obtained rock parameters, secondary fractures 36 of different sizes and orientations are distributed along the main fractures, and there are through fractures between the secondary fractures 36 to form a fracture network. Irregular protrusions are printed on the surfaces of the main fractures and the secondary fractures 36 to simulate the influence of actual rock fractures on the slurry flow rate. The grouting channel 34 and the water injection channel 33 can be changed according to different working conditions, but the two will not intersect directly, but are connected through cracks. The liquid storage tank 35 is installed at the outlet of the grouting channel 34, and is installed and fixed with the specimen through the groove slide rail set on the specimen. After the slurry is injected, it enters the liquid storage tank 35. After it is full, the slurry cannot be injected further, which can simulate the filling of rock cracks after the grouting space is full and the consolidation of slurry under dynamic water conditions after the grouting is completed.

[0043] The grouting module includes a liquid storage tank 8, a first air compressor 7, a grouting pipe 41 for connecting the liquid storage tank 8 and the grouting channel 34 on the grouting test platform, and a third flow meter 10, a first pressure gauge 9, and a second electronic valve 11 arranged on the grouting pipe 41. The grouting module uses the first air compressor 7 to pressurize the slurry in the liquid storage tank 8, and opens the second electronic valve 11 when the pressure meter value reaches the experimental requirement, and the slurry is injected into the fractured rock specimen 12 through the steel grouting pipe 41.

[0044] The circulating water injection module includes a water storage barrel 15, a second air compressor 16, a water injection pipe 42 for connecting the water storage barrel 15 and the water inlet of the water injection channel 33 on the grouting test bench, a water outlet pipe 43 for connecting the water storage barrel 15 and the water outlet of the water injection channel 33 on the grouting test bench, a fifth flowmeter 18, a second pressure gauge 17 and a third electronic valve 19 arranged on the water injection pipe 42, and a fourth flowmeter 13 and a second check valve 14 arranged on the water outlet pipe 43. The circulating water injection module uses the second air compressor 16 to pressurize the water in the water storage barrel 15, and opens the third electronic valve 19 when the pressure meter value reaches the experimental requirement, and the water flows back into the water storage barrel 15 through the water injection channel 33 on the fractured rock specimen 12 for recycling. The fifth flowmeter 18 and the second pressure gauge 17 are installed at the water inlet end of the water injection pipe 42, and the fourth flowmeter 13 and the second check valve 14 are installed at the return water end.

[0045] There is one high-speed camera 37 placed on the side of the grouting channel 34 outside the grouting experimental table.

[0046] The controller 21 includes an input end, an output end and a visual interface. The input end is connected to the torque sensor 26 and the resistivity sensor 5 through wires, and the output end is connected to the servo motor 27, the ultrasonic transmitter and the air compressor through wires, and is wirelessly connected to the electronic valve to control the start and stop of each equipment. The visual interface can display the torque and resistivity data and the start and stop status of each device. The controller 21 is equipped with physical buttons to realize the output function.

[0047] The present invention further discloses a method for conducting calcium-based material mineralization pulping and visual grouting experiments using the above system, comprising the following steps: Step 1: Mineralization and pulping of calcium-based materials: Wet mineralization CO 2 The process involves dissolving calcium-based materials such as fly ash and mining waste in water and introducing CO 2 , due to Ca 2+ Alkaline components such as CO will dissolve into water, and 2 Ionizes to CO in water 3 2- The two react to form carbonate minerals that precipitate and fix CO 2 , and carbonate is a stable mineral with good mechanical properties and can be used as grouting material. The specific slurry preparation steps are: S11. Install the stirring device, gas supply device, monitoring sensor and discharging device, turn on each device to make sure it can work normally, and turn on the CO 2 A small amount of gas is introduced into the gas cylinder 1 and recovered, and the sealing performance is checked by reading the first flow meter 30 and the second flow meter 23 .

[0048] S12. Use calcium-based materials and mineralization accelerators to prepare grouting materials, with a ratio of 1.5, and obtain the content of alkaline components through X-ray powder diffraction analysis. The main components of calcium-based materials are limestone, calcium hydroxide, etc., and the main components of mineralization accelerators are silicate minerals, bauxite, etc.

[0049] S13. According to the weight and proportion of the grouting materials required for the experiment, weigh the calcium-based material and the mineralization accelerator and put them into the mixing bucket; calculate the CO required for the reaction based on the content of the alkaline components in the grouting material obtained by analysis. 2 The basic principle of mineralization pulping is that Ca+, Mg+ ions and CO 2 The reaction can be calculated by detecting the Ca+, Mg+ and other ion contents in the material and then calculating the required CO according to the reaction formula. 2 quantity.

[0050] S14, close the barrel cover 29 and fasten the buckle to ensure sealing, start the servo motor 27 through the controller 21 to control the stirring element 28 to rotate, and observe the values ​​of the torque sensor 26 and the resistivity sensor 5.

[0051] S15. After adding calcium-based materials and mineralization accelerators to the mixing barrel and injecting water, the materials are not in sufficient contact with water, and a consolidated block is easily formed, resulting in a large torque at the initial stage of mixing. As the mixing progresses, the materials and water are fully mixed to form a slurry, and the torque gradually decreases and remains stable. Ca 2+ The alkaline components are ionized, which increases the free ions in the slurry and reduces and stabilizes the resistivity. Therefore, when the values ​​of the torque sensor 26 and the resistivity sensor 5 gradually decrease and remain stable, it means that the calcium-based material and the mineralization promoter are fully mixed with water and the alkaline components are fully ionized. Turn on the ultrasonic generator 25 and CO 2 Valve 1 of gas tank introduces CO into the mixing tank 2 , observe the resistivity sensor 5 value.

[0052] S16, with CO 2 Injected and reacted with calcium-based materials to form CaCO 3 , CaCO 3 Insolubility in water causes the free ions in the system to gradually decrease, and the resistivity to gradually increase. Finally, when the mineralization reaction is completed, the ion concentration in the system reaches the lowest point, and the resistivity reaches the highest point and remains stable. Therefore, when the resistivity sensor 5 value gradually increases and remains stable, it indicates that the calcium-based material and CO 2 The reaction is complete, turn off the ultrasonic generator 25 and CO 2 Open the valve of gas tank 1 and turn on the pipeline fan 24 to extract the exhaust gas into the exhaust gas barrel 22.

[0053] S17, lower the speed of the servo motor 27, open the first electronic valve 4, and the slurry is pumped into the liquid storage barrel 8 by the centrifugal pump 6 for experiment. The remaining slurry is left in the barrel and continues to be stirred to avoid solidification, and the slurry in the liquid storage barrel 8 is replenished in real time.

[0054] Step 2: Visual grouting experiment; S21, taking rock samples from the area to be grouted, performing CT scanning and three-dimensional reconstruction, obtaining rock fracture characteristics and parameters, using a 3D printer to print a transparent fractured rock specimen 12 according to the obtained data, and leaving a grouting channel 34 and a water injection channel 33.

[0055] S22. Place the fractured rock specimen 12 at the center of the specimen holder 20, rotate the fastening bolts 32 to fix it, connect the grouting pipe 41, the water injection pipe 42 and the water outlet pipe 43, and perform a pressure test on the liquid storage barrel 8 and the water storage barrel 15 to verify their sealing properties.

[0056] S23, start the second air compressor 16 to increase pressure, and after reaching the set water injection pressure, open the third electronic valve 19, and water flows into the fractured rock specimen 12 and flows back through the second one-way valve 14 into the water storage tank 15 to form a circulating water injection.

[0057] S24, start the first air compressor 7 to increase pressure, and after reaching the set grouting pressure, open the second electronic valve 11, and inject slurry into the fractured rock specimen 12 through the grouting channel 34 to fill the fractures under the dynamic water environment.

[0058] S25. Using a high-speed camera 37 to shoot the slurry flow and grouting effect during the grouting process under dynamic water conditions, the influence of dynamic water on the slurry flow is studied.

[0059] Furthermore, after the grouting experiment in step 2 is completed, the liquid storage tank 35 is installed at the outlet of the grouting channel 34, and the slurry is injected into the fractured rock specimen 12 and then enters the liquid storage tank 35. When the fractures and the liquid storage tank 35 are full, the slurry can no longer be injected. The high-speed camera 37 is used to shoot the filling conditions of the rock fractures and the consolidation of the slurry under dynamic water conditions, which can simulate the filling conditions of the rock fractures after the grouting space is filled and the consolidation conditions of the slurry under dynamic water conditions after the grouting is completed.

[0060] The above description of the disclosed embodiments enables those skilled in the art to implement and use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit and scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest range consistent with the principles and novel features disclosed herein.

Claims

1. A calcium-based material mineralization pulping and visual grouting experimental system, characterized in that: It includes a calcium-based material mineralization pulping module, a visual grouting experiment module and a controller (21); The calcium-based material mineralization pulping module comprises a stirring device, an air supply device, a monitoring sensor and a discharging device; the stirring device comprises a stirring barrel, a stirring element (28) arranged in the stirring barrel, a servo motor (27) installed on the stirring barrel for driving the stirring element (28), and an ultrasonic generator (25); the air supply device comprises a CO2 gas tank (1), an exhaust gas tank (22), an air intake pipe (38) connecting the CO2 gas tank (1) and the stirring barrel, a pressure reducing valve (31) arranged on the air intake pipe (38), a first A flow meter (30) and a first one-way valve (2), an exhaust pipe (39) connecting the mixing barrel and the waste gas barrel (22), and a pipe fan (24) and a second flow meter (23) arranged on the exhaust pipe (39); the monitoring sensor comprises a torque sensor (26) and a resistivity sensor (5) arranged in the mixing barrel; the discharge device comprises a liquid storage barrel (8), a liquid outlet pipe (40) connecting the mixing barrel and the liquid storage barrel (8), and a first electronic valve (4) and a centrifugal pump (6) arranged on the liquid outlet pipe (40); The visual grouting experiment module comprises a grouting experiment platform, a grouting module, a circulating water injection module and a high-speed camera (37); the grouting experiment platform comprises a specimen fixing frame (20), a fractured rock specimen (12) fixedly mounted in the specimen fixing frame (20) and a liquid storage tank (35); the fractured rock specimen (12) is obtained by 3D printing using a transparent resin and is provided with fractures, a grouting channel (34) and a water injection channel (33) inside; the liquid storage tank (35) is fixedly mounted at the outlet of the grouting channel (34); the grouting module comprises a liquid storage barrel (8), a first air compressor (7), a grouting pipeline (35) for connecting the liquid storage barrel (8) and the grouting channel (34) on the grouting experiment platform 41) and a third flowmeter (10), a first pressure gauge (9) and a second electronic valve (11) arranged on the grouting pipeline (41); the circulating water injection module comprises a water storage bucket (15), a second air compressor (16), a water injection pipeline (42) used to connect the water storage bucket (15) and a water inlet of a water injection channel (33) on the grouting experimental platform, a water outlet pipeline (43) used to connect the water storage bucket (15) and a water outlet of the water injection channel (33) on the grouting experimental platform, a fifth flowmeter (18), a second pressure gauge (17) and a third electronic valve (19) arranged on the water injection pipeline (42), and a fourth flowmeter (13) and a second one-way valve (14) arranged on the water outlet pipeline (43).

2. The calcium-based material mineralization pulping and visual grouting experimental system according to claim 1 is characterized in that: The stirring barrel comprises a barrel body (3) and a barrel cover (29); the barrel cover (29) is a semi-open structure connected to the barrel body (3) by a buckle; the barrel cover (29) is provided with three holes for installing a servo motor (27), an ultrasonic generator (25) and a resistivity sensor (5) respectively; the stirring element (28) is installed on the servo motor (27) and comprises a hollow rotating shaft, stirring blades (44) and spiral blades (45); the torque sensor (26) is installed on the top of the hollow rotating shaft; the barrel body (3) is provided with an air inlet for connecting to an air inlet pipeline (38) on the bottom side thereof, a material outlet for connecting to a liquid outlet pipeline (40) on the bottom thereof, and an exhaust port for connecting to an exhaust pipeline (39) on the upper side thereof; a filter screen is installed at the air inlet.

3. The calcium-based material mineralization pulping and visual grouting experimental system according to claim 2 is characterized in that: The barrel body (3) and the barrel cover (29) are sealed by means of a buckle and an "O"-shaped sealing ring, the connection of the barrel cover (29) is sealed by means of a toothed sealing strip, and each opening connection is additionally provided with an "O"-shaped sealing ring for sealing.

4. A method for conducting calcium-based material mineralization pulping and visual grouting experiments using the system of claim 1, characterized in that: The following steps are involved: Step 1: Mineralization and pulping of calcium-based materials; S11, complete the installation of the stirring device, the gas supply device, the monitoring sensor and the discharging device, start each device to ensure that it can work normally, open the CO2 gas cylinder (1) to pass a small amount of gas and recover it, and check its sealing performance by reading the first flow meter (30) and the second flow meter (23); S12, using calcium-based materials and mineralization promoters to prepare grouting materials, the ratio of the two is 1.2-2.5, and obtaining the content of alkaline components therein by X-ray powder diffraction analysis; S13. According to the weight and proportion of the grouting materials required for the experiment, weigh the calcium-based material and the mineralization accelerator and put them into a mixing bucket; calculate the amount of CO2 required for the reaction according to the content of the alkaline components in the grouting material obtained by analysis, and add water into the mixing bucket. The water-cement ratio is y, and the value range of y is 0.5-3; S14, closing the barrel cover (29) and fastening the buckle to ensure sealing, starting the servo motor (27) through the controller (21) to control the rotation of the stirring element (28), and observing the values ​​of the torque sensor (26) and the resistivity sensor (5); S15. When the values ​​of the torque sensor (26) and the resistivity sensor (5) gradually decrease and remain stable, open the valves of the ultrasonic generator (25) and the CO2 gas tank (1) to introduce CO2 into the mixing barrel, and observe the value of the resistivity sensor (5); S16. When the value of the resistivity sensor (5) gradually increases and remains stable, the ultrasonic generator (25) and the valve of the CO2 gas tank (1) are closed, and the pipeline fan (24) is turned on to extract the exhaust gas into the exhaust gas barrel (22); S17, lowering the speed of the servo motor (27), opening the first electronic valve (4), and pumping the slurry by the centrifugal pump (6) into the liquid storage tank (8) for use in the experiment, while the remaining slurry is left in the stirring tank and continues to be stirred to avoid solidification, and the slurry in the liquid storage tank (8) is replenished in real time; Step 2: Visual grouting experiment; S21, taking rock samples from the area to be grouted, performing CT scanning and three-dimensional reconstruction, obtaining rock fracture characteristics and parameters, and printing a transparent fractured rock specimen (12) using a 3D printer based on the obtained data, and leaving a grouting channel (34) and a water injection channel (33); S22, placing the fractured rock specimen (12) at the center of the specimen fixing frame (20), rotating the fastening bolts (32) to fix it, connecting the grouting pipe (41), the water injection pipe (42) and the water outlet pipe (43), and performing a pressure test on the liquid storage barrel (8) and the water storage barrel (15) to verify their sealing properties; S23, start the second air compressor (16) to increase pressure, and after reaching the set water injection pressure, open the third electronic valve (19), so that water flows into the fractured rock specimen (12) and flows back through the second one-way valve (14) into the water storage tank (15) to form a circulating water injection; S24, starting the first air compressor (7) to increase pressure, and after reaching a set grouting pressure, opening the second electronic valve (11), injecting slurry into the fractured rock specimen (12) to fill the fractures through the grouting channel (34) under a dynamic water environment; S25. Using a high-speed camera (37), the grout flow and grouting effect during the grouting process under dynamic water conditions are photographed.

5. The method according to claim 4, characterized in that After the visual grouting experiment in step 2 is completed, the liquid storage tank (35) is installed at the outlet of the grouting channel (34), and the slurry is injected into the fractured rock specimen (12) and then enters the liquid storage tank (35). When the fractures and the liquid storage tank (35) are filled and the slurry can no longer be injected, the filling conditions of the rock fractures and the consolidation conditions of the slurry under dynamic water conditions are photographed by a high-speed camera (37).

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