Circulating slurry dipping device based on MICP solidified soil body and using method

Abstract

The invention belongs to the technical field of calcium carbonate crystallization induced by microorganisms, and particularly relates to a circulating slurry dipping device based on MICP solidified soil and a using method.The circulating slurry dipping device comprises a slurry dipping reaction system, a circulating system and a cementing liquid treatment and determination system; and the cementing liquid in the cementing liquid treatment and determination system is conveyed into the dipping reaction system by utilizing the circulating system, and is conveyed back to the cementing liquid treatment and determination system after reaction. Through the cooperation of the slurry soaking reaction system, the circulating system and the cementing liquid treatment and determination system, the application range of the MICP technology is expanded to more types of soil bodies, a good solidification effect can be achieved even in the soil body with an extremely low permeability coefficient, and the application field of the MICP technology is widened. Meanwhile, the device can efficiently recycle the cementing fluid consumed in a large amount in the reaction process, so that the cost is remarkably reduced, the overall economy is improved, and the MICP technology is promoted to show better practicability and application potential in the field of engineering practice.

Description

Technical Field

[0001] The invention belongs to the technical field of microbial induced calcium carbonate crystallization, and particularly relates to a circulating slurry immersion device based on MICP solidified soil and a use method thereof. Background Art

[0002] Microbial Induced Calcite Precipitation (MICP) is an eco-friendly, green and environmentally friendly microbial solidification technology. In the application of MICP technology in the field of soil treatment, the highly active urease continuously produced by bacteria in the life process promotes the hydrolysis of urea and combines with calcium ions. The induced carbonate mineral crystals can fill pores and cement in the soil, increase the density of the soil, and effectively improve the strength of the soil. MICP has achieved a series of practical applications in solidifying the surface of tailings, degrading heavy metal contaminated soil, anti-seepage treatment of soil, and repair of rock cracks.

[0003] At present, there have been many new developments in the research of MICP technology. Studies have found that MICP technology has shown significant solidification effects in solidifying different types of soil. However, most related studies still face key problems such as limited reinforcement depth and low nutrient solution utilization efficiency. Such problems have caused many obstacles to the practical application of microbial soil reinforcement. In the existing indoor test equipment, the utilization rate of nutrient solution is low during the treatment of soil samples with bacterial solution. When the nutrients in the nutrient solution are not fully utilized by the bacteria, they are discharged as waste liquid, resulting in a waste of resources. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention proposes a circulating slurry device and a method for using MICP-solidified soil. With the help of a circulation system and a binder concentration detector, this device can realize the recycling of binder at a constant concentration, while improving the accuracy of MICP laboratory research, and effectively solving the problem of resource waste in traditional microbial induced calcium carbonate precipitation technology. In addition, the slurry reaction system of the device can allow the soil sample to be completely immersed in the slurry, so that the soil can fully react, effectively improving the problem of limited soil reinforcement depth in traditional microbial induced calcium carbonate precipitation technology.

[0005] The embodiment of the present invention first discloses a circulating grouting device based on MICP solidified soil, including a grouting reaction system, a circulation system and a cementing liquid treatment and measurement system, wherein:

[0006] The slurry dipping reaction system comprises a reaction chamber, a hatch cover is provided at the upper end of the reaction chamber, a placing rack is provided in the reaction chamber, a liquid inlet hole and a liquid outlet hole are opened on the hatch cover, and a liquid infusion hose is respectively passed through the liquid inlet hole and the liquid outlet hole, and the lower end of the liquid infusion hose passing through the liquid outlet hole is located on the upper side of the inner cavity of the reaction chamber;

[0007] The cementing liquid treatment and measurement system includes a storage cabin, which is arranged on a magnetic stirrer, and a gas pipe with one end extending into the lower side of the storage cabin is arranged in the storage cabin, and an oxygen pump is connected to the other end of the gas pipe, and a density tester is also arranged in the storage cabin;

[0008] The circulation system includes a peristaltic pump A and a peristaltic pump B; two infusion hoses are connected to the peristaltic pump A, one of which is connected to the infusion hose passing through the liquid inlet hole, and the other infusion hose extends into the lower side of the storage compartment cavity; two infusion hoses are also connected to the peristaltic pump B, one of which is connected to the infusion hose passing through the liquid outlet hole, and the other infusion hose extends into the lower side of the storage compartment cavity.

[0009] As preferred in some embodiments of the present invention, a filter countersunk head A is installed at one end of the infusion hose passing through the liquid inlet hole located in the reaction chamber, and a filter countersunk head B is installed at one end of the infusion hose passing through the liquid outlet hole located in the reaction chamber.

[0010] As some embodiments of the present invention, one of the infusion hoses on the peristaltic pump A is connected to the infusion hose passing through the liquid inlet hole via a hose docking joint A, and one of the infusion hoses on the peristaltic pump B is connected to the infusion hose passing through the liquid outlet hole via a hose docking joint B.

[0011] As a preference of some embodiments of the present invention, hose joint A is installed on the liquid inlet hole of the hatch cover, and is provided with a sealing gasket A to seal the remaining gap in the liquid inlet hole; hose joint B is installed on the liquid outlet hole of the hatch cover, and is provided with a sealing gasket B to seal the remaining gap in the liquid outlet hole.

[0012] As some embodiments of the present invention, the sensor of the density tester extends into the side wall of the inner cavity of the storage compartment, and the main body of the density tester is located above the storage compartment.

[0013] As preferred in some embodiments of the present invention, the main body of the density tester is installed on the upper end of the housing of the oxygen pump through a bracket, and the height of the density tester can be adjusted by the bracket.

[0014] As preferred in some embodiments of the present invention, the reaction chamber is in the form of a cylindrical hollow dome made of transparent tempered glass, and the cabin cover is in the form of a dome made of tempered glass, and the reaction chamber and the cabin cover match in size and shape.

[0015] As preferred in some embodiments of the present invention, four cylindrical supporting feet are arranged at the bottom of the reaction chamber.

[0016] As preferred in some embodiments of the present invention, the shape of the placement rack matches the inner cavity of the reaction chamber, and is placed at the bottom of the inner cavity of the reaction chamber;

[0017] As preferred in some embodiments of the present invention, the peristaltic pump A and the peristaltic pump B are movable.

[0018] As preferred in some embodiments of the present invention, the flow rate range of the peristaltic pump A and the peristaltic pump B is 0.5 mL / min to 10 mL / min.

[0019] As preferred in some embodiments of the present invention, the storage cabin is made of cylindrical transparent tempered glass, and the bottom of the storage cabin is flat.

[0020] As preferred in some embodiments of the present invention, the magnetic stirring bar of the magnetic stirrer is placed at the bottom of the inner cavity of the storage compartment.

[0021] As a preference in some embodiments of the present invention, the density tester is of tuning fork type.

[0022] Some embodiments of the present invention further include an air outlet stone, which is placed on the side wall of the inner cavity of the storage compartment and is connected to the air supply pipe.

[0023] As preferred in some embodiments of the present invention, the filter sink A and the filter sink B have the same shape and the same filter aperture.

[0024] As preferred in some embodiments of the present invention, the pore size of the filter area of ​​the filter sink A and the filter sink B is ≤0.1 mm.

[0025] As preferred in some embodiments of the present invention, the hose butt joint A and the hose butt joint B are both of two-joint type.

[0026] As preferred in some embodiments of the present invention, the sealing pad A and the sealing pad B are both made of annular silicone material.

[0027] The embodiment of the present invention further discloses a method for using any of the above-mentioned circulating grouting devices based on MICP solidified soil, comprising the following steps:

[0028] Step 1: Take the soil sample mixed with the bacterial solution out of the mold and place it in a pre-made flexible mold, and adjust the position;

[0029] Step 2: The flexible mold is tightly attached to the soil sample and sewed together to obtain a cylindrical sample containing the soil sample;

[0030] Step 3: Open the hatch, place the cylindrical specimen steadily on the rack, and adjust the position;

[0031] Step 4: Put the hatch cover back on the reaction chamber body, so that the lower end of the infusion hose passing through the liquid inlet hole is lower than the cylindrical sample, and the lower end of the infusion hose passing through the liquid outlet hole is higher than the cylindrical sample;

[0032] Step 5: Fill the storage tank with cementing liquid;

[0033] Step 6: Turn on the peristaltic pump A and the peristaltic pump B, and set the infusion speed to achieve smooth and stable circulation of the cementing liquid in the reaction chamber and the storage chamber;

[0034] Step 7: Turn on the magnetic stirrer, oxygen pump and density tester to achieve real-time detection of the oxygenation and stirring of the cementing fluid and the concentration of chemical substances;

[0035] Step 8. After the immersion time reaches the preset 7 days, let it stand for 24 hours, take out the cylindrical sample from the reaction chamber, and soak it in pure water for 24 hours. Then remove the flexible mold and dry it before carrying out subsequent tests.

[0036] As preferred in some embodiments of the present invention, the flexible mold is made of geotextile material with good water permeability and certain supporting capacity due to its own fiber structure, and its shape is a cylindrical unfolded style with a size of Ф39.4mm×83mm; the size of the manufactured cylindrical sample is Ф39.4mm×83mm.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] The present invention provides a circulating grouting device for MICP solidified soil. Through the coordinated cooperation of the grouting reaction system, the circulation system and the cementing liquid treatment and measurement system, the application scope of the MICP technology can be expanded to more types of soils, and even in soils with extremely low permeability coefficients, a good solidification effect is shown, which broadens the applicable field of the MICP technology. At the same time, the device enables the cementing liquid consumed in large quantities during the reaction process to be efficiently recycled, significantly reducing cost expenditure, improving overall economic efficiency, and promoting MICP technology to show better practicality and application potential in the field of engineering practice.

[0039] Through the slurry reaction system, the sample is fully immersed in the cementing liquid, the reaction is sufficient, and the curing effect is good, which effectively overcomes the technical obstacles of traditional curing devices for curing low permeability soils and limited curing depth. At the same time, a concentration detection instrument is set in the cementing liquid storage tank to detect the concentration change of the cementing liquid in the device in real time. According to the change of the measured value of the cementing liquid concentration, new solutes can be added to the cementing liquid in time to ensure that the cementing liquid is recycled at a constant concentration. While effectively saving resources, it also realizes the precision of the experiment and simplifies the steps of MICP technology for soil treatment.

[0040] In the cementing liquid treatment and measurement system, an air outlet stone of an oxygen pump is arranged on the side wall of the inner cavity of the storage chamber, and a rotor of a magnetic stirrer is arranged at the bottom of the inner cavity. By running the oxygen pump and the magnetic stirrer, the chemical substances of the cementing liquid in the chamber are evenly distributed and rich in oxygen, and then directly transported to the slurry reaction system through the peristaltic pump of the circulation system to immerse the soil samples. Compared with the traditional immersion method in which the stirring and oxygen supply systems are directly placed in the immersion container, this method significantly reduces the disturbance to the soil samples, and effectively improves the problem that for unreinforced and low-strength soil samples, the use of the immersion scheme during the initial reinforcement will have an adverse effect on the integrity of the soil sample specimens. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the specific implementation of the present invention or the technical solution in the prior art, the drawings required for describing the specific implementation or the prior art will be briefly introduced below. Obviously, the drawings described below are only one implementation of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0042] Figure 1 A schematic structural diagram of a circulating grouting device based on MICP solidified soil provided in an embodiment of the present invention;

[0043] Figure 2 An operation schematic diagram of step 1 in a method for using a circulating grouting device based on MICP solidified soil provided in an embodiment of the present invention;

[0044] Figure 3 A schematic diagram of a cylindrical sample being solidified by a grouting reaction system of a circulating grouting device based on MICP solidified soil provided in an embodiment of the present invention.

[0045] The markings in the accompanying drawings are: 1. reaction chamber; 2. hatch; 3. placement rack; 4. hose joint A; 5. hose joint B; 6. sealing gasket A; 7. sealing gasket B; 8. liquid inlet; 9. liquid outlet; 10. infusion hose; 11. infusion hose; 12. filter sink A; 13. filter sink B; 14. peristaltic pump A; 15. peristaltic pump B; 16. infusion hose; 17. infusion hose; 18. infusion hose; 19. infusion hose; 20. storage chamber; 21. magnetic stirrer; 22. oxygen pump; 221. gas pipe; 23. density tester; 24. soil sample; 25. flexible mold; 26. cylindrical sample. DETAILED DESCRIPTION

[0046] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the technical scheme in the specific implementation mode of the present invention is clearly and completely described below to further illustrate the present invention. Obviously, the specific implementation mode described is only a part of the implementation mode of the present invention, rather than all styles.

[0047] This embodiment is a circulating grouting device and a method of using the MICP solidified soil. Figure 1 As shown, a circulating grouting device based on MICP solidified soil includes a grouting reaction system, a circulation system and a cementing liquid treatment and measurement system, wherein:

[0048] The slurry dipping reaction system comprises a reaction chamber 1, a hatch 2 is provided at the upper end of the reaction chamber 1, a placing rack 3 is provided in the reaction chamber 1, a liquid inlet 8 and a liquid outlet 9 are provided on the hatch 2, a liquid infusion hose 10 is passed through the liquid inlet 8, a liquid infusion hose 11 is passed through the liquid outlet 9, and the lower end of the liquid infusion hose 11 is located on the upper side of the inner cavity of the reaction chamber 1; a filter sink A12 is installed at one end of the liquid infusion hose 10 located in the reaction chamber 1, and a filter sink B13 is installed at one end of the liquid infusion hose 11 located in the reaction chamber 1; the shape and size of the reaction chamber 1 can be adjusted accordingly according to the number of cylindrical samples 26, for example, a cylindrical hollow The reaction chamber 1 is in the form of a dome, and in order to facilitate the observation of the curing status of the cylindrical sample 26 on the placement rack during the reaction process, the side walls of the reaction chamber 1 can be made of transparent material, such as transparent tempered glass. The cover 2 is also in the form of a dome made of tempered glass. The size and shape of the reaction chamber 1 and the cover 2 match, and four cylindrical feet are set at the bottom of the reaction chamber 1. In order to facilitate the placement and stability of the cylindrical sample 26, the table of the placement rack 3 placed at the bottom of the inner cavity of the reaction chamber 1 can adopt a flat structure, and the shape and size of the placement rack 3 should be consistent with the shape and size of the inner cavity of the reaction chamber 1 to ensure that the two match.

[0049] The cementing liquid treatment and measurement system includes a storage cabin 20, which is arranged on a magnetic stirrer 21. An air pipe 221 with one end extending into the lower side of the storage cabin 20 is provided in the storage cabin 20, and the other end of the air pipe 221 is connected to an oxygen pump 22. A density tester 23 is also provided in the storage cabin 20; the storage cabin 20 is made of cylindrical transparent tempered glass, and the bottom of the storage cabin 20 is a plane; the magnetic stirrer of the magnetic stirrer 21 is placed at the bottom of the inner cavity of the storage cabin 20; the density tester 23 is a tuning fork type; it also includes an air outlet stone, which is placed on the side wall of the inner cavity of the storage cabin 20 and is connected to the air pipe 221; the sensor of the density tester 23 extends into the side wall of the inner cavity of the storage cabin 20, and the main body of the density tester 23 is located above the storage cabin 20; the main body of the density tester 23 is installed on the upper end of the outer shell of the oxygen pump 22 through a bracket, and the height of the density tester 23 can be adjusted by the bracket.

[0050] The circulation system includes a peristaltic pump A14 and a peristaltic pump B15; the peristaltic pump A14 is connected with an infusion hose 16 and an infusion hose 18, the infusion hose 16 is connected with the infusion hose 10, and the infusion hose 18 extends into the lower side of the storage compartment 20; the peristaltic pump B15 is connected with an infusion hose 17 and an infusion hose 19, the infusion hose 17 is connected with the infusion hose 11, and the infusion hose 19 extends into the lower side of the storage compartment 20; the peristaltic pump A14 and the peristaltic pump B15 are movable, and the flow range is 0.5mL / min to 10mL / min.

[0051] The infusion hose 16 is connected to the infusion hose 10 via a hose joint A4, and the infusion hose 17 is connected to the infusion hose 11 via a hose joint B5; the hose joint A4 is installed on the liquid inlet hole 8 of the hatch cover 2, and a sealing gasket A6 is provided to seal the remaining gap in the liquid inlet hole 8; the hose joint B5 is installed on the liquid outlet hole 9 of the hatch cover 2, and a sealing gasket B7 is provided to seal the remaining gap in the liquid outlet hole 9.

[0052] In this embodiment, the filter sink A12 and the filter sink B13 have the same shape, and the filter aperture is ≤0.1 mm;

[0053] The hose butt joint A4 and the hose butt joint B5 are both two-joint type, and the sealing gasket A6 and the sealing gasket B7 are both made of annular silicone material.

[0054] The method of using the above-mentioned circulating grouting device based on MICP solidified soil comprises the following steps:

[0055] Step 1: Figure 2 As shown, the soil sample 24 mixed with the bacterial solution is removed from the mold and placed in the pre-made flexible mold 25, and the position is adjusted; in this embodiment, the flexible mold 25 is made of geotextile material with good water permeability and certain support capacity due to its own fiber structure, and the shape is a cylindrical unfolded style with a size of Ф39.4mm×83mm;

[0056] Step 2: The flexible mold 25 is tightly fitted to the soil sample 24 and sewed together to obtain a cylindrical sample 26 with a size of Φ39.4 mm×83 mm containing the soil sample 24.

[0057] Step 3: Open the hatch 2, place the cylindrical sample 26 on the placement rack 3 stably, and adjust the position;

[0058] Step 4: Put the hatch cover 2 back onto the reaction chamber 1, so that the lower end of the infusion hose 10 is lower than the cylindrical sample 26, and the lower end of the infusion hose 11 is higher than the cylindrical sample 26;

[0059] Step 5: Fill the storage compartment 20 with the cementing liquid;

[0060] Step 6: Turn on the peristaltic pump A14 and the peristaltic pump B15, and set the infusion speed to achieve smooth and stable circulation of the cementing liquid in the reaction chamber 1 and the storage chamber 20;

[0061] Step 7: Turn on the magnetic stirrer 21, the oxygen pump 22 and the density tester 23 to achieve real-time detection of the oxygenation and stirring of the cementing liquid and the concentration of the chemical substances;

[0062] Step 8. After the immersion time reaches the preset 7d immersion time, it can be observed that a significant layer of calcium carbonate deposits has been formed on the surface of the cylindrical sample 26, which means that the reaction has been fully carried out. Then let it stand for 24 hours, take the cylindrical sample 26 out of the reaction chamber 1, and soak it in pure water for 24 hours. Then remove the flexible mold 25 and dry it before carrying out subsequent experiments.

[0063] Before use, it is necessary to first connect the hatch cover 2 with the infusion hose 16 and the infusion hose 17 through the hose joints A4 and B5 located at the liquid inlet hole 8 and the liquid outlet hole 9, and respectively set sealing gaskets A6 and B7 at the connected joints to ensure that the infusion hoses 16 and 17 in the circulation system can be tightly connected to the reaction chamber body 1.

[0064] The function of the peristaltic pump A14 and the peristaltic pump B15 in the circulation system is to first transport the cementing liquid (nutrient solution) in the storage chamber 20 to the reaction chamber 1 through the peristaltic pump A14 to transport the calcium source and nutrients required for the MICP reaction. Then, the reacted cementing liquid is transported back to the storage chamber 20 through the peristaltic pump B15 to complete a slurry transport cycle. Therefore, any existing liquid transport pump can be used, for example, the portable small peristaltic pump used in this embodiment can be used.

[0065] The effect of the density tester 23 in the cementing liquid treatment measuring system is to measure the solute (nutrient required for MICP reaction) concentration of the cementing liquid in the storage tank 20, to ensure that the solute in the cementing liquid can be replenished in time and recycled with a constant concentration. Therefore, any existing liquid concentration detector can be adopted, for example, the tuning fork density tester used in the present embodiment can be adopted. The effect of the magnetic stirrer 21 is to make the nutrients of the cementing liquid in the storage tank 20 evenly distributed, so any existing liquid stirring instrument can be adopted, for example, the laboratory magnetic stirrer used in the present embodiment can be adopted. The effect of the oxygenation pump 22 is to enrich the cementing liquid in the storage tank 20 with oxygen.

[0066] The present invention provides a cyclic slurry immersion test device and a method for using the MICP technology to solidify soil. This method not only overcomes the technical obstacles of traditional solidification devices for solidifying low permeability soils and limited solidification depth, but also effectively improves the adverse effects of using immersion schemes on the integrity of soil specimens in the initial reinforcement of unreinforced, low-strength soil samples pointed out by some scholars. In addition, this device, with the help of a circulation system and a nutrient solution concentration detector, can ensure that the nutrient solution is recycled at a constant concentration, effectively solving the problem of resource waste in traditional microbial-induced calcium carbonate precipitation technology.

[0067] The above describes the main technical features and basic principles of the present invention and the related advantages. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the concept or basic features of the present invention. Therefore, no matter from which point of view, the above specific embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the attached claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention.

[0068] In addition, it should be understood that although the present specification is described according to various implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each implementation method may also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A circulating grouting device based on MICP solidified soil, comprising a grouting reaction system, a circulation system and a cementing liquid treatment and measurement system, characterized in that: The slurry dipping reaction system comprises a reaction chamber (1), a chamber cover (2) is provided at the upper end of the reaction chamber (1), a placement rack (3) is provided in the reaction chamber (1), a liquid inlet hole (8) and a liquid outlet hole (9) are provided on the chamber cover (2), a liquid infusion hose (10) is passed through the liquid inlet hole (8), a liquid infusion hose (11) is passed through the liquid outlet hole (9), and the lower end of the liquid infusion hose (11) is located on the upper side of the inner cavity of the reaction chamber (1); The cementing liquid treatment and measurement system comprises a storage cabin (20), the storage cabin (20) is arranged on a magnetic stirrer (21), an air delivery pipe (221) is arranged in the storage cabin (20) and one end of the air delivery pipe (221) extends into the lower side of the storage cabin (20), the other end of the air delivery pipe (221) is connected to an oxygen pump (22), and a density tester (23) is also arranged in the storage cabin (20); The circulation system comprises a peristaltic pump A (14) and a peristaltic pump B (15); the peristaltic pump A (14) is connected to an infusion hose (16) and an infusion hose (18); the infusion hose (16) is in communication with the infusion hose (10), and the infusion hose (18) extends into the lower side of the storage compartment (20); the peristaltic pump B (15) is connected to an infusion hose (17) and an infusion hose (19); the infusion hose (17) is in communication with the infusion hose (11), and the infusion hose (19) extends into the lower side of the storage compartment (20).

2. The circulating grouting device based on MICP solidified soil according to claim 1 is characterized in that: A filter countersunk head A (12) is installed at one end of the infusion hose (10) located in the reaction chamber (1), and a filter countersunk head B (13) is installed at one end of the infusion hose (11) located in the reaction chamber (1).

3. The circulating grouting device based on MICP solidified soil according to claim 1 is characterized in that: The infusion hose (16) is connected to the infusion hose (10) via a hose butt joint A (4), and the infusion hose (17) is connected to the infusion hose (11) via a hose butt joint B (5); The hose butt joint A (4) is installed on the liquid inlet hole (8) of the hatch cover (2), and is provided with a sealing gasket A (6) to seal the remaining gap of the liquid inlet hole (8); the hose butt joint B (5) is installed on the liquid outlet hole (9) of the hatch cover (2), and is provided with a sealing gasket B (7) to seal the remaining gap of the liquid outlet hole (9).

4. The circulating grouting device based on MICP solidified soil according to claim 1 is characterized in that: The sensor of the density tester (23) extends into the side wall of the inner cavity of the storage compartment (20), and the main body of the density tester (23) is located above the storage compartment (20); The main body of the density tester (23) is installed on the upper end of the housing of the oxygenation pump (22) through a bracket, and the height of the density tester (23) can be adjusted through the bracket.

5. The circulating grouting device based on MICP solidified soil according to claim 1 is characterized in that: The reaction chamber (1) is a cylindrical hollow dome made of transparent tempered glass, the chamber cover (2) is a dome made of tempered glass, the reaction chamber (1) and the chamber cover (2) match in size and shape, and four cylindrical supporting feet are arranged at the bottom of the reaction chamber (1); The shape of the placement rack (3) matches the inner cavity of the reaction chamber (1) and is placed at the bottom of the inner cavity of the reaction chamber (1); The peristaltic pump A (14) and the peristaltic pump B (15) are movable, and the flow rate range is 0.5 mL / min to 10 mL / min; The storage compartment (20) is made of cylindrical transparent tempered glass, and the bottom of the storage compartment (20) is a flat surface; The magnetic stirrer (21) is placed at the bottom of the inner cavity of the storage compartment (20); The density tester (23) is of tuning fork type; It also includes an air outlet stone, which is placed on the side wall of the inner cavity of the storage cabin (20) and is connected to the air delivery pipe (221).

6. The circulating grouting device based on MICP solidified soil according to claim 2, characterized in that: The filter sink A (12) and the filter sink B (13) have the same shape and the same filter aperture.

7. The circulating grouting device based on MICP solidified soil according to claim 6, characterized in that: The pore size of the filter area of ​​the filter sink A (12) and the filter sink B (13) is ≤0.1 mm.

8. The circulating grouting device based on MICP solidified soil according to claim 3 is characterized in that: The hose butt joint A (4) and the hose butt joint B (5) are both two-joint type, and the sealing pad A (6) and the sealing pad B (7) are both made of circular silicone material.

9. A method for using the circulating grouting device based on MICP solidified soil as claimed in any one of claims 1 to 8, characterized in that: The following steps are involved: Step 1: Take the soil sample (24) mixed with the bacterial solution out of the mold and place it in a pre-made flexible mold (25), and adjust the position; Step 2: The flexible mold (25) is tightly attached to the soil sample (24), and after sewing, a cylindrical sample (26) containing the soil sample (24) is obtained; Step 3: Open the hatch (2), place the cylindrical sample (26) on the placement rack (3) stably, and adjust the position; Step 4: Put the hatch cover (2) back onto the reaction chamber (1) so that the lower end of the infusion hose (10) is lower than the cylindrical sample (26) and the lower end of the infusion hose (11) is higher than the cylindrical sample (26); Step 5: Fill the storage chamber (20) with the cementing liquid; Step 6: Turn on the peristaltic pump A (14) and the peristaltic pump B (15), and set the infusion speed to achieve smooth and stable circulation of the cementing liquid in the reaction chamber (1) and the storage chamber (20); Step 7: Turn on the magnetic stirrer (21), the oxygen pump (22) and the density tester (23) to achieve real-time detection of the oxygenation and stirring of the cementing fluid and the concentration of the chemical substances; Step 8: After the immersion time reaches 7 days, let it stand for 24 hours, take out the cylindrical sample (26) from the reaction chamber (1), and soak it in pure water for 24 hours, then remove the flexible mold (25) and dry it, and then carry out subsequent tests.

10. The method for using the circulating grouting device based on MICP solidified soil as claimed in claim 9, characterized in that: The flexible mold (25) is made of geotextile material with good water permeability and certain support capacity due to its own fiber structure, and is in the shape of a cylindrical unfolded style with a size of Ф39.4mm×83mm; the size of the manufactured cylindrical sample (26) is Ф39.4mm×83mm.

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