A test device and method for grouting reinforcement under high-pressure water environment

Abstract

The application is a kind of test device and method for grouting reinforcement under high pressure and water environment. It includes water injection and pressure system, sample loading system, grouting system, constant temperature control system and recording system. The sample to be grouted is placed in the sample loading system, and the sample loading system applies pressure to the sample during grouting to simulate the overburden pressure. The water injection and pressure system is nested outside the sample loading system and is sealed. The water injection and pressure system adjusts the water pressure, changes the water flow speed and direction to simulate the influence of water flow on the grouting effect of the sample under the dynamic water environment. The grouting system is connected to the sample loading system and is used for injecting grout. The constant temperature control system is used to simulate the influence of temperature change on the grouting effect. The recording system is used to record the trend of grout escaping with water flow during grouting. The application can highly restore the high pressure and water environment under complex geological conditions, and significantly improve the accuracy and reliability of the grouting reinforcement simulation test.

Description

Technical Field

[0001] This invention belongs to the field of grouting reinforcement testing technology, specifically relating to a test device and method for grouting reinforcement under high pressure dynamic water environment. Background Technology

[0002] Grouting technology, as a fast, efficient, and economical engineering method, has been widely used globally and plays a crucial role in improving the integrity and safety of target structures. It is particularly important in the reinforcement of underground soil and rock environments. With the acceleration of urbanization in recent years, the development and utilization of underground space has become increasingly frequent, leading to a series of new challenges requiring the reinforcement of underground soil. Especially in coastal areas and areas rich in groundwater, changes in groundwater conditions have a significant impact on the effectiveness of grouting reinforcement. Fluctuations in groundwater levels, changes in water flow velocity, and differences in water quality can all affect the permeability, curing effect, and overall reinforcement performance of grouting materials. Therefore, accurate testing and determination of the performance of the grout before implementing grouting reinforcement projects is particularly important. This is not only related to the control of construction quality but also directly relates to the long-term safety and stability of the engineering structure.

[0003] Currently, there are many types of indoor grouting reinforcement testing equipment, most of which are designed for specific engineering projects. The existing grouting reinforcement testing equipment mainly has the following shortcomings:

[0004] (1) At present, most grouting reinforcement test equipment has a single sample environment, which fails to truly reflect the evaluation of grouting effect under the coupled interaction of multiple fields such as groundwater pressure, water flow, temperature, and soil pressure.

[0005] (2) Most of the existing grouting reinforcement test equipment still require the sample to be taken out of the grouting equipment after grouting, which causes great disturbance to the sample and cannot complete the curing and effect measurement in the original grouting environment.

[0006] (3) The existing grouting sleeve has a simple grouting hole, the size of the seepage hole is fixed and cannot be adjusted according to the sample condition, and the hole is not sealed. Sand samples will be lost under grouting disturbance. Summary of the Invention

[0007] The purpose of this invention is to provide a test device and method for grouting reinforcement under high pressure dynamic water conditions, which can simulate the real situation of grouting reinforcement under real high pressure dynamic water conditions to a great extent, and can provide a theoretical basis for practical engineering applications.

[0008] The technical solution to achieve the purpose of this invention is: a test device for grouting reinforcement under high pressure dynamic water environment, including a water injection pressurization system, a sample loading system, a grouting system, a constant temperature control system and a recording system;

[0009] The specimen to be grouted is placed in the specimen loading system. When the specimen loading system is grouting, pressure is applied to the specimen to simulate the pressure of the upper soil layer.

[0010] The water injection and pressurization system is nested outside the sample loading system and sealed. The water injection and pressurization system simulates the effect of water flow on the grouting effect of the sample in a dynamic water environment by adjusting the water pressure and changing the water flow speed and direction.

[0011] The grouting system is connected to the sample loading system and is used to inject grout.

[0012] The constant temperature control system is used to simulate the effect of temperature changes on grouting effect;

[0013] The recording system is used to record the trend of grout escaping with the water flow during the grouting process.

[0014] Furthermore, the water injection and pressurization system includes a clean water tank, a servo pressurization pump, a water guide pipe, a transparent pressurization sleeve, an upper cover, a lower cover, a waste water tank, a stop valve, and a flow and pressure sensor;

[0015] The pressure sleeve is sealed to the upper and lower caps. The pressure sleeve is circumferentially equipped with a set of water injection holes, a set of drainage holes and a set of water guide holes. By opening and closing different water injection holes, drainage holes and water guide holes, the servo pressure pump, water stop valve and flow and pressure sensor realize the change of water pressure, water flow speed and direction in the grouting environment inside the pressure sleeve.

[0016] Furthermore, the constant temperature control system includes a heating rod and a temperature controller; the heating rod is installed inside the clean water tank, and the temperature controller precisely controls the water temperature inside the clean water tank.

[0017] Furthermore, a set of water injection holes and a set of drainage holes are arranged at 180° to each other on the circumferential direction of the pressure sleeve, and a set of water guide holes are arranged at 90° to the set of water injection holes and the set of drainage holes respectively; the set of water injection holes includes multiple water injection holes evenly arranged vertically along the pressure sleeve, and each water injection hole is equipped with a three-way valve; the set of drainage holes includes multiple drainage holes evenly arranged vertically along the pressure sleeve, and each drainage hole is equipped with a three-way valve; the set of water guide holes is used for water injection or drainage as needed, and the set of water guide holes includes multiple water guide holes evenly arranged vertically along the pressure sleeve, and each water guide hole is equipped with a three-way valve.

[0018] Furthermore, the pressure sleeve is sealed to the upper and lower caps with sealing rings, and the upper and lower caps are fastened with tie rods and bolts at the four corners; the pressure sleeve is made of transparent acrylic or transparent plexiglass.

[0019] Furthermore, the sample loading system includes a permeable sleeve, a permeable nut, a confining pressure hose clamp, a confining pressure adjusting rod, an upper pressure rod, a lower pad, and a confining pressure testing device;

[0020] The permeable sleeve has threaded openings on its side wall, and different specifications of permeable nuts can be matched according to the requirements;

[0021] The lower pad is placed inside the permeable sleeve at the bottom of the sample, and the upper pressure rod is provided with grouting channels, and the sample is pressurized through the upper pressure rod;

[0022] The grouting pressure is controlled by a confining pressure hose clamp on the outside of the permeable sleeve. The strain gauge of the confining pressure testing device is attached between the permeable sleeve and the confining pressure hose clamp. The confining pressure of the confining pressure hose clamp is controlled by the confining pressure adjusting rod.

[0023] Furthermore, the permeable sleeve is a splicing component composed of multiple sleeve petals. The sleeve petals are made of transparent acrylic material or transparent plexiglass material. One end of the adjacent sleeve petals is set as a concave surface and the other end is set as a convex surface. The inner wall of the concave surface of the sleeve petal is chamfered inward. The splicing of the sleeve petals is achieved through the cooperation of the concave and convex surfaces.

[0024] The confining hose clamp is made of spring steel and clamps the permeable sleeve from the outside.

[0025] The upper pressure bar is made of spring steel and is located on the upper side of the sample. The upper soil pressure under the actual grouting condition is simulated by a single-axis hydraulic press.

[0026] The lower pad is made of permeable stone material, and excess grout is discharged from the bottom of the grouting material;

[0027] A permeable nut consists of an outer ring and an inner ring. The volume occupied by the inner ring varies depending on the specifications of the permeable nut.

[0028] The outer ring of the permeable nut is made of acrylic or plexiglass, while the inner ring is made of permeable stone.

[0029] Furthermore, the grouting system includes a grout tank, an air compressor, a rotary motor, and stirring blades;

[0030] The slurry tank is used to load the uniformly mixed grouting material. The air compressor injects compressed air into the slurry tank to form a pressure of up to 10 MPa, which pushes the slurry at the bottom of the slurry tank to be injected into the sample through the water guide pipe, thus realizing pressurized grouting. The rotary motor drives the stirring blades to stir the grouting material.

[0031] Furthermore, the recording system is a high-speed camera, which uses a transparent pressure sleeve and a water-permeable sleeve to record the trend of grout escaping with the water flow during the grouting process.

[0032] A method for conducting grouting reinforcement tests using the above-mentioned testing apparatus includes the following steps:

[0033] S1: Select the permeable nut and screw it into the corresponding position of the permeable sleeve. Install the confining pressure hose clamp to the fixed position on the outside of the permeable sleeve. Attach the strain gauge to the fixed position.

[0034] S2: The sample to be grouted is placed into the permeable sleeve, the upper pressure rod is installed on the upper part of the sample, placed into the pressure sleeve, the upper cover is put on, and the fixing bolts are tightened; the upper pressure rod is pressurized using a single-axis hydraulic press to achieve the preset upper pressure;

[0035] S3: Turn on the servo booster pump to continuously inject water into the clean water tank, open the valve of the corresponding water injection hole to achieve the preset water pressure and flow rate; turn on the constant temperature control system to heat the clean water tank so that the water injection temperature reaches the preset temperature;

[0036] S4: Pour the set ratio of grouting material and water into the grout tank. After the grout is mixed, turn on the air compressor to inject compressed air into the grout tank. Use the pressure gauge above the grout tank to control the grouting pressure. When the preset grouting pressure is reached, open the grouting valve to perform grouting. The grout is injected into the center of the sample through the grouting hole in the upper pressure rod.

[0037] S5: Observe the loss of grout from each permeable hole after grouting through the transparent pressure sleeve; stop grouting the sample after it reaches a stable state.

[0038] S6: Different curing methods are adopted for the samples according to different actual working conditions;

[0039] S7: After curing is completed, mechanical property tests and permeability tests are conducted on the sample in situ according to the working conditions.

[0040] Compared with the prior art, the significant advantages of this invention are:

[0041] 1. This invention designs a grouting reinforcement test device that can realistically simulate the coupled and interactive effects of multiple fields such as groundwater pressure, water flow, temperature, and soil pressure. It also allows the specimens to be cured and their effects tested directly in the original grouting environment, effectively avoiding interference that may occur during the specimen removal process, and providing a more reliable basis for engineering practice.

[0042] 2. This invention designs an adjustable grouting sleeve with perforated opening. The size of the seepage hole in the sleeve can be flexibly adjusted according to the sample conditions, and a sealing device is provided inside the hole. This invention can effectively prevent the sand sample from being lost under grouting disturbance, which not only improves the controllability of the grouting process, but also further ensures the accuracy and stability of the test results.

[0043] 3. This invention innovatively proposes a novel grouting effect evaluation technology. This technology can accurately reflect the grouting process in complex geological environments, calculate the effective grouting volume, and observe the seepage of grouting materials through a transparent sleeve, thereby more intuitively and accurately evaluating the grouting effect through multiple factors. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of the overall structure of the experimental device of the present invention;

[0045] Figure 2 This is a three-dimensional structural diagram of the grouting part of the present invention;

[0046] Figure 3 This is a cross-sectional view of the pressure sleeve of the present invention;

[0047] Figure 4 This is a cross-sectional view of the permeable sleeve of the present invention;

[0048] Figure 5 This is a three-dimensional schematic diagram of the permeable sleeve flap of the present invention;

[0049] Figure 6 This is a schematic diagram of the permeable nut of the present invention;

[0050] Figure 7 This is a schematic diagram of a series of permeable nuts according to the present invention.

[0051] Explanation of reference numerals in the attached figures:

[0052] 1-1-Clear water tank, 1-2-Servo pressurized water pump, 1-3-Water guide pipe, 1-4-Pressure sleeve, 1-5-Upper cover, 1-6-Lower cover, 1-7-Waste water tank, 1-8-Stop valve, 1-9-Flow and pressure sensor, 2-1-Permeable sleeve, 2-2-Permeable nut, 2-3-Containing pressure hose clamp, 2-4-Containing pressure adjusting rod, 2-5-Upper pressure rod, 2-6-Lower pad, 2-7-Containing pressure testing device, 2-8-Outer ring of permeable nut, 2-9-Inner ring of permeable nut 2-10- Grouting channel, 2-11- First water injection hole, 2-12- Second water injection hole, 2-13- Third water injection hole, 2-14- First water guide hole, 2-15- Second water guide hole, 2-16- Third water guide hole, 2-17- First drainage hole, 2-18- Second drainage hole, 2-19- Third drainage hole, 3-1- Grout tank, 3-2- Air compressor, 3-3- Rotary motor, 3-4- Stirring blade, 4-1- Heating rod, 4-2- Temperature controller, 5- Sample. Detailed Implementation

[0053] The technical solutions will be described in detail and clearly below with reference to the accompanying drawings of the embodiments of this application. It should be noted that the embodiments described are only some examples of this application, and not all of it. All other implementation methods that can be derived by those skilled in the art based on these embodiments without creative effort are considered to fall within the protection scope of this application.

[0054] In this document, the term "embodiment" is used to indicate that a particular feature, structure, or property described in connection with examples thereof may be embodied in at least one embodiment of this application. The appearance of this phrase in different places throughout the document does not necessarily refer to the same embodiment, nor is it intended to refer to instances that are mutually exclusive, independent, or alternative to other embodiments. Those skilled in the art will clearly understand that the embodiments described herein can be flexibly combined with other embodiments.

[0055] Example 1:

[0056] Please see Figure 1-6 This invention provides a test device for grouting reinforcement under high-pressure dynamic water environment, including a water injection pressurization system, a sample loading system, a grouting system, and a constant temperature control system. The water injection pressurization system mainly simulates the influence of water flow on the grouting effect of the sample under dynamic water environment by increasing water pressure and changing water flow velocity and direction; it also simulates the influence of deep soil pressure environment on the grouting effect of the sample. The grouting system uses an air compressor to increase pressure and pump grouting material through a water pipe to grout the sample. The constant temperature control system mainly uses a temperature controller to control heating elements to simulate the influence of temperature changes on the grouting effect.

[0057] The water injection and pressurization system includes a clean water tank 1-1, a servo pressurization water pump 1-2, a water guide pipe 1-3, a pressurization sleeve 1-4, an upper cover 1-5, a lower cover 1-6, a wastewater tank 1-7, a water stop valve 1-8, and a flow and pressure sensor 1-9.

[0058] The sample loading system includes a permeable sleeve 2-1, a permeable nut 2-2, a confining pressure hose clamp 2-3, a confining pressure adjusting rod 2-4, an upper pressure rod 2-5, a lower pad block 2-6, and a confining pressure testing device 2-7;

[0059] The grouting system includes a grout tank 3-1, an air compressor 3-2, a rotary motor 3-3, and a stirring blade 3-4;

[0060] The constant temperature control system includes a heating rod 4-1 and a temperature controller 4-2.

[0061] The clean water tank 1-1 is continuously supplied with water by the servo-driven pressurized water pump 1-2 to increase its internal pressure. When the preset water pressure value is reached, the stop valve 1-8 opens, allowing water to flow into the pressurized sleeve 1-4. The water then flows through the sample loading system and finally flows into the waste water tank 1-7. All water supply pipes in the entire water injection and pressurization system are equipped with stop valves 1-8 and flow and pressure sensors 1-9 to achieve precise control and real-time monitoring of the water flow status.

[0062] The permeable sleeve 2-1 is located inside the pressure sleeve 1-4; the upper cover 1-5 and the lower cover 1-6 are located outside the pressure sleeve 1-4 and are tightened with bolts, and the connection is sealed with a sealing ring.

[0063] The pressure sleeve 1-4 is equipped with multiple water injection holes, drainage holes and water guide holes. By precisely controlling the opening and closing of the corresponding valves, the direction of water flow can be flexibly controlled.

[0064] The permeable sleeve 2-1 is constructed as a splicable structure composed of multiple sleeve petals. One end of each sleeve petal is designed as a concave interface, and the other end is designed as a matching convex interface. The inner wall of the concave interface is provided with an inward chamfer so that the sleeve can achieve a certain degree of radial contraction through the tight fit between the petals when confining pressure is applied.

[0065] The grouting pressure is controlled by the confining pressure hose 2-3 on the outside of the permeable sleeve 2-1, and the strain gauge of the confining pressure testing device 2-7 is attached between the permeable sleeve 2-1 and the confining pressure hose 2-3.

[0066] The permeable sleeve 2-1 has a threaded opening and is fitted with a corresponding permeable nut.

[0067] The outer ring 2-8 of the permeable nut is made of transparent material, while the inner ring 2-9 is made of permeable stone material. In addition, the permeable nut is designed in various specifications to adapt to and match the permeability requirements under different actual working conditions.

[0068] The grouting system is equipped with a sealed grout tank 3-1, which is used to load uniformly mixed grouting material; it also includes an air compressor 3-2, which injects compressed air into the grout tank 3-1 to form a pressure of up to 10 MPa, thereby forcibly injecting the grout in the lower part of the grout tank into the sample 5 through the water pipe, thus realizing the process of pressurized grouting.

[0069] To prevent segregation of the grouting material, the device is equipped with a rotary motor 3-3, which drives the stirring blades 3-4 through a transmission shaft to effectively stir the grouting material.

[0070] The constant temperature control system includes a heating rod 4-1 and a temperature controller 4-2;

[0071] Heating rods 4-1 are evenly arranged in the clean water tank to maintain the temperature of the injected water medium.

[0072] Temperature controller 4-2 is responsible for accurately monitoring and adjusting the working status of the heating rods to ensure that the dynamic water environment in which the grouting sample is located can reach the preset constant temperature conditions throughout the entire test.

[0073] When assembling the test apparatus of the present invention, the permeable stones of the lower pad 2-6 are properly placed at the bottom of the permeable sleeve 2-1. The pre-grouted reinforced sample 5 is placed on the lower pad 2-6 and tightly fixed to the periphery of the permeable sleeve 2-1 using the confining clamp 2-3 to ensure stability and sealing during the test.

[0074] The strain gauges of the confining pressure testing device 2-7 are precisely attached between the permeable sleeve 2-1 and the confining pressure hose 2-3, and the corresponding signal transmission lines are carefully connected to monitor and record the strain changes during the test in real time.

[0075] Make sure the upper pressure rod 2-5 is in contact with the sample 5, and then put the pressure sleeve 1-4 on the outside of the permeable sleeve 2-1. To ensure the sealing and stability of the device, sealing rings should be placed at the upper and lower connection points of the upper cover 1-5 and the lower cover 1-6 with the pressure sleeve 1-4, and the bolts at the four feet of the device should be used to tighten and fix it evenly.

[0076] The upper pressure bar 2-5 can be used to counteract the upper part with a hydraulic press, which can provide axial pressure to simulate the upper soil pressure during the grouting process.

[0077] Water is injected into the clear water tank 1-1 by the servo pressurized water pump 1-2, which can raise the water pressure in the clear water tank 1-1 to a maximum of 10MPa. The corresponding control valves are opened and closed according to the settings of the test control group to simulate the flow direction of water.

[0078] Pressurized water first flows through the permeable sleeve 2-1, and then this water flows through specially designed drainage holes. During this process, it mixes with any grouting fluid that may escape. The mixed wastewater is then effectively discharged and eventually collected in the wastewater tank 1-7.

[0079] Specifically, the water injection and pressurization system can inject water into the pressurization sleeve 1-4 through the first water injection hole 2-11, the second water injection hole 2-12, the third water injection hole 2-13, the first water guide hole 2-14, the second water guide hole 2-15, and the third water guide hole 2-16; and can drain water into the wastewater tank 1-7 through the first drain hole 2-17, the second drain hole 2-18, the third drain hole 2-19, the first water guide hole 2-14, the second water guide hole 2-15, and the third water guide hole 2-16.

[0080] By selecting different combinations of channels for water injection and drainage operations, the flow direction of water within the pressure sleeve can be flexibly adjusted. This flexibility not only simulates the impact of different water flow directions on the grouting effect but also allows for in-depth analysis under specific water flow conditions.

[0081] Each water inlet is equipped with a three-way valve on its outer side. These valves not only control the inflow and outflow of water but also precisely adjust the path and state of the water flow. By adjusting the direction of the valve, the water flow path can be easily opened, closed, or changed, thus achieving precise control over the direction of the water flow.

[0082] The temperature controller 4-2 enables precise temperature regulation of the heating rod 4-1 and constant temperature control of the clear water tank 1-1. Through precise temperature setting and maintenance, this device can simulate grouting environments under different temperature conditions, thereby comprehensively evaluating the performance of grouting materials and grouting effects at different temperatures.

[0083] Add the grouting material with a preset water-cement ratio into the grout tank 3-1, start the rotary motor 3-3 to drive the stirring blades 3-4 through the transmission shaft to stir and mix the grout, and prevent the grout from bleeding or segregating.

[0084] Start the air compressor 3-2 to inject high-pressure air into the grout tank 3-1, which can drive a grouting pressure of up to 10MPa, and drive the grouting liquid mixed in the grout tank 3-1 to perform grouting.

[0085] Example 2:

[0086] This invention provides a technical solution: a test method for grouting reinforcement under high pressure dynamic water environment, and Example 2 is an optimization based on Example 1;

[0087] The grout loss during the grouting process can be observed through the transparent pressure sleeve 1-4 and the water-permeable sleeve 2-1. A high-speed camera can be used to record the trend of grout escaping with the water flow and to study the influence of the water flow direction on the grout escaping.

[0088] The effect of the grouting sample is evaluated based on the output of the clear water tank 1-1 and the grout tank 3-1, and the increase of the wastewater tank 1-7 and the sample 5.

[0089] During the sample curing stage, the present invention adopts a strategy of conducting the process in the original grouting environment. By continuously injecting pressurized dynamic water into the pressurized sleeve 1-4 and maintaining the axial pressure applied by the upper pressure rod 2-5, the curing conditions are made closer to the actual environment after grouting, thereby enabling more accurate simulation and evaluation of the curing effect after grouting.

[0090] After the curing process is completed, this equipment supports direct in-situ pressure testing of the mechanical properties of sample 5. The specific operation involves adjusting the confining hose 2-3 to a loose state using the adjusting rod, and then applying gradually increasing pressure to sample 5 until sample 5 reaches its breaking strength, thereby accurately determining its strength after grouting reinforcement in the original environment.

[0091] It should be noted that the structural layout, proportions, dimensions, and specifications shown in the accompanying drawings are intended to assist in the explanation and facilitate understanding and analysis by those skilled in the art, and do not constitute a strict limitation on the embodiments of the present invention. Therefore, any minor adjustments to the structure, reasonable changes in proportions, or appropriate expansions or contractions in the dimensional range, as long as they do not weaken the functional effect of the present invention or hinder the achievement of the intended goal, should be considered to fall within the protection scope defined by the technical solution of the present invention. Furthermore, the directional expressions such as "upper," "lower," "left," "right," "center," and "single" used in the specification are only for clarity of explanation and are not intended to define the application boundaries of the present invention. While maintaining the core technology unchanged, relative changes or adaptive adjustments to the above directional descriptions should also be considered reasonable extensions of the embodiments of the present invention.

Claims

1. A test device for grouting reinforcement under high-pressure dynamic water environment, characterized in that, It includes a water injection and pressurization system, a sample loading system, a grouting system, a constant temperature control system, and a recording system; The specimen to be grouted is placed in the specimen loading system. When the specimen loading system is grouting, pressure is applied to the specimen to simulate the pressure of the upper soil layer. The water injection and pressurization system is nested outside the sample loading system and sealed. The water injection and pressurization system simulates the effect of water flow on the grouting effect of the sample in a dynamic water environment by adjusting the water pressure and changing the water flow speed and direction. The grouting system is connected to the sample loading system and is used to inject grout. The constant temperature control system is used to simulate the effect of temperature changes on grouting effect; The recording system is used to record the trend of grout escaping with the water flow during the grouting process; The water injection and pressurization system includes a clean water tank (1-1), a servo pressurization pump (1-2), a water guide pipe (1-3), a transparent pressurization sleeve (1-4), an upper cover (1-5), a lower cover (1-6), a wastewater tank (1-7), a water stop valve (1-8), and a flow and pressure sensor (1-9). The pressure sleeve (1-4) is sealed to the upper cover (1-5) and the lower cover (1-6). The pressure sleeve (1-4) is circumferentially provided with a set of water injection holes, a set of drainage holes and a set of water guide holes. By opening and closing different water injection holes, drainage holes and water guide holes, the servo pressure pump (1-2), the water stop valve (1-8) and the flow and pressure sensor (1-9) realize the change of water pressure, water flow speed and direction in the grouting environment inside the pressure sleeve (1-4). A set of water injection holes and a set of water drainage holes are arranged at 180° along the circumference of the pressure sleeve (1-4), and a set of water guide holes are arranged at 90° with the set of water injection holes and the set of water drainage holes respectively; the set of water injection holes includes multiple water injection holes evenly arranged vertically along the pressure sleeve (1-4), and each water injection hole is equipped with a three-way valve; the set of water drainage holes includes multiple water drainage holes evenly arranged vertically along the pressure sleeve (1-4), and each water drainage hole is equipped with a three-way valve; the set of water guide holes is used for water injection or drainage as needed, and the set of water guide holes includes multiple water guide holes evenly arranged vertically along the pressure sleeve (1-4), and each water guide hole is equipped with a three-way valve; The sample loading system includes a permeable sleeve (2-1), a permeable nut (2-2), a confining pressure hose clamp (2-3), a confining pressure adjusting rod (2-4), an upper pressure rod (2-5), a lower pad (2-6), and a confining pressure testing device (2-7); The permeable sleeve (2-1) has threaded openings on its side wall, and different specifications of permeable nuts can be matched according to the requirements; The lower pad (2-6) is set inside the permeable sleeve (2-1) at the bottom of the sample (5), and the upper pressure rod (2-5) is provided with grouting channel (2-10), and the sample is pressurized through the upper pressure rod (2-5); The grouting confining pressure is controlled by the confining pressure hose (2-3) on the outside of the permeable sleeve (2-1). The strain gauge of the confining pressure testing device (2-7) is attached between the permeable sleeve (2-1) and the confining pressure hose (2-3). The confining pressure of the confining pressure hose (2-3) is controlled by the confining pressure adjusting rod (2-4).

2. The experimental apparatus according to claim 1, characterized in that, The constant temperature control system includes a heating rod (4-1) and a temperature controller (4-2); the heating rod (4-1) is evenly arranged in the clean water tank (1-1), and the temperature controller (4-2) is used to control the water temperature in the clean water tank (1-1).

3. The experimental apparatus according to claim 2, characterized in that, The pressure sleeve (1-4) is sealed to the upper cover (1-5) and the lower cover (1-6) by a sealing ring. The upper cover (1-5) and the lower cover (1-6) are fastened by the pull rods and bolts at the four corners. The pressure sleeve (1-4) is made of transparent acrylic or transparent plexiglass.

4. The experimental apparatus according to claim 3, characterized in that, The permeable sleeve (2-1) is a splicing component composed of multiple sleeve petals. The sleeve petals are made of transparent acrylic material or transparent plexiglass material. One end of the adjacent sleeve petals is set as a concave surface and the other end is set as a convex surface. The inner wall of the concave surface of the sleeve petal is chamfered inward. The splicing of the sleeve petals is achieved by the cooperation of the concave and convex surfaces. The confining hose clamp (2-3) is made of spring steel and clamps the permeable sleeve (2-1) from the outside. The upper pressure bar (2-5) is made of spring steel and is located on the upper side of the sample. The upper soil pressure under the actual grouting condition is simulated by a single-axis servo hydraulic press. The lower pad blocks (2-6) are made of permeable stone material, and excess grout is discharged from the bottom of the grouting material; The permeable nut (2-2) includes a permeable nut outer ring (2-8) and a permeable nut inner ring (2-9). The volume occupied by the permeable nut inner ring (2-9) varies for different specifications of permeable nuts (2-2). The outer ring (2-8) of the permeable nut is made of acrylic or plexiglass, and the inner ring (2-9) of the permeable nut is made of permeable stone.

5. The test apparatus according to claim 4, characterized in that, The grouting system includes a grout tank (3-1), an air compressor (3-2), a rotary motor (3-3), and stirring blades (3-4); The grout tank (3-1) is used to load the uniformly mixed grouting material. The air compressor (3-2) injects compressed air into the grout tank (3-1) to form a pressure of up to 10 MPa, which pushes the grout in the lower part of the grout tank to be injected into the sample (5) through the water guide pipe, thus realizing pressurized grouting. The rotary motor (3-3) drives the stirring blades (3-4) to stir the grouting material.

6. The experimental apparatus according to claim 5, characterized in that, The recording system is a high-speed camera. The high-speed camera records the trend of grout escaping with the water flow during the grouting process through the transparent pressure sleeve (1-4) and the water-permeable sleeve (2-1).

7. A method for conducting grouting reinforcement tests using the test apparatus described in claim 6, characterized in that, Includes the following steps: S1: Select the permeable nut and screw it into the corresponding position of the permeable sleeve. Install the confining pressure hose clamp to the fixed position on the outside of the permeable sleeve. Attach the strain gauge to the fixed position. S2: The sample to be grouted is placed into the permeable sleeve, the upper pressure rod is installed on the upper part of the sample, placed into the pressure sleeve, the upper cover is put on, and the fixing bolts are tightened; the upper pressure rod is pressurized using a single-axis hydraulic press to achieve the preset upper pressure; S3: Turn on the servo booster pump to continuously inject water into the clean water tank, open the valve of the corresponding water injection hole to achieve the preset water pressure and flow rate; turn on the constant temperature control system to heat the clean water tank so that the water injection temperature reaches the preset temperature; S4: Pour the set ratio of grouting material and water into the grout tank. After the grout is mixed, turn on the air compressor to inject compressed air into the grout tank. Use the pressure gauge above the grout tank to control the grouting pressure. When the preset grouting pressure is reached, open the grouting valve to perform grouting. The grout is injected into the center of the sample through the grouting hole in the upper pressure rod. S5: Observe the loss of grout from each permeable hole after grouting through the transparent pressure sleeve; stop grouting the sample after it reaches a stable state. S6: Different curing methods are adopted for the samples according to different actual working conditions; S7: After curing is completed, mechanical property tests and permeability tests are conducted on the sample in situ according to the working conditions.

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