A peristaltic pump combined with ultrasonic vibration experimental device for microbial reinforcement of clay and its usage method

Abstract

This invention discloses a peristaltic pump combined with ultrasonic vibration testing device and its method of use for microbial-reinforced clay. The device includes a lifting platform, a fixed support rod, an ultrasonic generator, an ultrasonic vibrating rod, a mold barrel, a temperature control device, and a peristaltic pump. The lifting platform is installed at the top center of the fixed support rod, with the ultrasonic generator located at the bottom of the support rod. A disc is located on the upper part of the lifting platform, and the ultrasonic vibrating rod is bolted to the bottom of the disc. A first peristaltic pump and a second peristaltic pump are installed on the left and right sides of the fixed support rod, respectively. The mold barrel is mounted on a support frame, with symmetrical inlet and outlet ports on its side walls. This invention employs a peristaltic pump combined with ultrasonic vibration grouting to achieve multi-round treatment of microbial-reinforced clay by cross-grouting a mixed solution of bacterial solution and cementing solution at low temperature. This effectively improves the strength of microbially solidified clay and ensures the uniformity and integrity of the samples.

Description

Technical Field

[0001] This invention relates to the field of civil engineering testing technology, and in particular to a peristaltic pump combined with ultrasonic vibration for microbial reinforcement of clay and its usage method. Background Technology

[0002] Numerous microorganisms exist within soil and rock masses, and their activities significantly influence the physical and mechanical properties of these materials. Microbial reinforcement technology utilizes the metabolic processes of widely distributed microorganisms to generate calcium carbonate crystals that cement the soil, thereby improving its mechanical properties. This technology offers advantages such as environmental friendliness and low carbon footprint. However, when existing Microbial Concrete-Based Polymerization (MICP) techniques are applied to clay solidification, the small pore size between clay particles leads to uneven and insufficient reinforcement. Furthermore, with increasing reinforcement cycles, the pores in the clay gradually become filled and blocked by calcium carbonate, making the infiltration of the microbial cementing solution increasingly difficult and negatively impacting the effective reinforcement depth of the soil sample. Therefore, existing microbial reinforcement techniques for clay solidification often result in samples with poor uniformity and low strength.

[0003] Prior to this invention, the patent “An indoor test device and method for uniform solidification of clay by microorganisms (publication CN109342135A)” disclosed a device that can solve the problem of poor uniformity of clay solidification treatment by microorganisms. This device can quickly and uniformly solidify the clay body by stirring the clay body and applying pressure to perform microbial grouting. However, this device will disturb and damage the clay body during the stirring process, and it cannot carry out multiple rounds of grouting, resulting in limited reinforcement strength. The patent "A device and construction method for microbial ultrasonic grouting to reinforce the foundation (publication CN112813953A)" discloses a device and construction method for reinforcing the foundation using microbial ultrasonic grouting. This invention utilizes grout to diffuse outwards from a grouting pipe with holes in the pipe wall in conjunction with ultrasonic waves, which can expand the reinforcement range and improve the uniformity of reinforcement. It is also applicable to a wide range of soil types and can reinforce deeper soil layers. However, the device requires a traditional step-by-step grouting method during the grouting process. That is, the bacterial solution is injected first, and after the bacteria in the bacterial solution are fully adsorbed onto the surface of the soil particles, the cementing solution is injected. This method is inefficient, affects the progress, has many steps, and has a long construction period. It may also reduce the utilization rate of the reaction solution to a certain extent. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing a peristaltic pump combined with ultrasonic vibration for microbial reinforcement of clay and its usage method.

[0005] To achieve the above objectives, the present invention provides a microbial reinforced clay testing device combining a peristaltic pump and ultrasonic vibration, comprising a lifting platform, an ultrasonic generator, an ultrasonic vibrating rod, a fixed support rod, a mold barrel, a constant temperature device, and a peristaltic pump. The lifting platform is installed at the top center of the front of the fixed support rod. The ultrasonic generator is located at the bottom side of the fixed support rod. A disc is located on the upper part of the lifting platform. The ultrasonic vibrating rod is fixedly installed at the bottom of the disc by bolts. A circular turntable is located in the base of the fixed support rod. A mold barrel is fixedly installed on the circular turntable. The side wall of the mold barrel is provided with a slurry inlet and a slurry outlet. A first peristaltic pump and a second peristaltic pump are respectively installed on the left and right sides of the fixed support rod. One end of the first peristaltic pump is connected to a slurry inlet barrel through a first slurry inlet pipe, and the other end of the first peristaltic pump is connected to the slurry inlet through a second slurry inlet pipe. One end of the second peristaltic pump is connected to an slurry outlet barrel through a second slurry outlet pipe, and the other end of the second peristaltic pump is connected to the slurry outlet through a first slurry outlet pipe. A constant temperature device is fixedly installed in front of the first peristaltic pump, and the lower part of the slurry inlet barrel is immersed in the constant temperature device.

[0006] Preferably, the fixed support rod is a stainless steel bracket with a height of 15cm and a width of 10cm. The bottom of the fixed support rod is a stainless steel base with a length of 10cm and a width of 10cm. The stainless steel base is provided with a circular turntable with a diameter of 8cm. The circular turntable can rotate freely and can be fixed at 0° and 180°. The circular turntable is provided with two cube protrusions with a side length of 0.5cm.

[0007] Preferably, the maximum extension of the lifting platform is 7cm, the lifting platform is installed on the upper part of the fixed support rod, the lifting platform switch is installed on the side of the fixed support rod, and the disc is a stainless steel disc with a diameter of 10cm.

[0008] Preferably, the ultrasonic generator is connected to the ultrasonic vibrating rod via an electric wire.

[0009] Preferably, the lower end of the ultrasonic vibrator extends into the mold barrel by no more than 2 cm.

[0010] Preferably, the mold barrel is a transparent PVC container with an open top, a height of 12cm, a diameter of 5cm, and a thickness of 0.5cm. The bottom of the mold barrel has a groove that matches the cubic protrusion of the circular turntable. The mold barrel is fixed to the circular turntable by the cubic protrusion. The mold barrel has two slurry inlets and two slurry outlets symmetrically arranged on its side wall. The two slurry inlets are the first slurry inlet and the second slurry inlet, and the two slurry outlets are the first slurry outlet and the second slurry outlet, respectively. The slurry inlets are located at the bottom of the mold barrel, and the slurry outlets are located at the top of the mold barrel. From bottom to top on the left, the first slurry inlet and the second slurry outlet are arranged, and from bottom to top on the right, the second slurry inlet and the first slurry outlet are arranged. Valves and filter screens are installed at both the slurry inlets and the slurry outlets. The valves are installed on the outside of the slurry inlets and the slurry outlets, and the filter screens are installed inside the slurry inlets and the slurry outlets. The filter screens have a pore size of 10μm. The mold barrel contains a clay sample.

[0011] Preferably, the first slurry inlet pipe, the second slurry inlet pipe, the second slurry outlet pipe, and the first slurry outlet pipe are all rubber pressure hoses.

[0012] Preferably, the temperature of the constant temperature device is set to 4°C, and the liquid level inside the constant temperature device exceeds the liquid level of the slurry.

[0013] Preferably, the feed solution is a mixture of bacterial solution and cementing solution at 4°C in a 1:4 ratio, wherein the bacterial solution is *Bacillus pasteurellii* bacterial solution, and its OD... 600 The cementing solution is between 0.8 and 1.2, and is a mixture of urea and calcium chloride of equal concentrations of 0.5 to 1 mol / L.

[0014] A method for using a peristaltic pump combined with ultrasonic vibration for testing microbial-reinforced clay is also provided, including the following steps:

[0015] Step 1: Prepare OD separately 600 The bacterial suspension of Bacillus pasteurellii with a concentration between 0.8 and 1.2 and a mixture of urea and calcium chloride at a concentration of 0.5 to 1 mol / L were placed in a refrigerator at 4°C for cooling.

[0016] Step 2: Install an ultrasonic generator on the bottom side of the fixed support rod, install a fixed lifting platform at the top center of the fixed support rod, and install the lifting platform switch on the side of the fixed support rod. The upper part of the lifting platform is equipped with a disc, and an ultrasonic vibrating rod is installed at the bottom of the fixed disc. Connect the ultrasonic vibrating rod to the ultrasonic generator with a wire.

[0017] Step 3: Prepare clay samples and load them into the mold barrel. Fix the mold barrel onto the circular turntable using the cube protrusions.

[0018] Step 4: Install the first peristaltic pump and the second peristaltic pump on both sides of the fixed support rod respectively. Install a constant temperature device in front of the first peristaltic pump and install the slurry outlet tank in front of the second peristaltic pump. Connect the slurry inlet tank, the first peristaltic pump, the mold tank, the second peristaltic pump, and the slurry outlet tank in sequence with the first slurry inlet pipe, the second slurry inlet pipe, the first slurry outlet pipe, and the second slurry outlet pipe.

[0019] Step 5: Turn on the thermostat switch and set the thermostat temperature to 4℃. After taking the prepared bacterial solution and cementing solution out of the refrigerator, pour them into the slurry tank at a ratio of 1:4 to prepare the slurry. Place the slurry tank into the thermostat so that the liquid level in the thermostat is higher than the slurry level.

[0020] Step 6: Connect the second grout inlet pipe to the first grout inlet, open the valve of the first grout inlet, use the first peristaltic pump to inject the grout, inject the grout to 1.5 times the pore volume of the clay sample, close the valve of the first grout inlet after grouting is completed, remove the second grout inlet pipe, and turn off the thermostat switch;

[0021] Step 7: Operate the lifting platform to lower the ultrasonic vibrating rod to the liquid surface inside the mold barrel, 3mm above the surface of the clay sample. Turn on the ultrasonic generator and adjust the vibration frequency. Use ultrasonic vibration to make the slurry evenly distributed in the pores of the clay sample. Then turn off the ultrasonic generator and raise the ultrasonic vibrating rod above the liquid surface.

[0022] Step 8: Let stand for six hours to allow the grout to react fully as the temperature gradually rises to room temperature, generating calcium carbonate crystals to reinforce the soil. After the reaction is complete, connect the first grout pipe to the first grout outlet, open the first grout outlet valve, use the second peristaltic pump to extract the remaining grout, close the first grout outlet valve after pumping is complete, and remove the first grout pipe.

[0023] Step 9: Operate the circular turntable to rotate the mold barrel horizontally by 180°. Use the second grout inlet and outlet to inject and pump grout, forming a cross-grouting pattern. Repeat steps 5 to 8 until reinforcement is complete.

[0024] Beneficial effects: 1) The present invention uses a peristaltic pump combined with ultrasonic vibration grouting, which makes the bacterial solution and cementing solution more evenly distributed in the clay sample, and the resulting solidified sample is more uniform and has high overall mechanical strength.

[0025] 2) This invention utilizes the dormancy of bacteria at low temperatures to delay the reaction between the bacterial solution and the cementing solution. The mixed solution is injected into the sample under low temperature conditions. This method allows the clay particles, bacterial solution, and cementing solution to be fully mixed before the microbial reaction occurs, thereby improving the uniformity of the clay-reinforced sample and saving curing time.

[0026] 3) This invention utilizes a peristaltic pump to achieve a cross-grouting method, which can further improve the uniformity of the cured sample;

[0027] 4) This invention uses a peristaltic pump combined with ultrasonic vibration grouting instead of grouting methods such as stirring, which minimizes soil disturbance and ensures the integrity of the sample to the greatest extent. Attached Figure Description

[0028] Figure 1 This is a front structural design diagram of the microbial reinforced clay test device combining a peristaltic pump and ultrasonic vibration according to an embodiment of the present invention;

[0029] Figure 2 This is a schematic diagram of the structure of the mold barrel according to an embodiment of the present invention;

[0030] Figure 3 This is a schematic diagram of the structure of the circular turntable according to an embodiment of the present invention;

[0031] Figure 4 This is a schematic diagram of the filter structure according to an embodiment of the present invention.

[0032] In the diagram: 1. Lifting platform; 2. Ultrasonic generator; 3. Ultrasonic vibrator; 4. Fixed support rod; 5. Mold barrel; 6. Temperature control device; 7. Peristaltic pump; 7-A. First peristaltic pump; 7-B. Second peristaltic pump; 8. Lifting platform switch; 9. Bolt; 10. Disc; 11. Circular turntable; 12. Wire; 13-A. First slurry inlet; 13-B. Second slurry inlet; 13-C. First slurry outlet; 13-D. Second slurry outlet 14. Valve; 14-A. First slurry inlet valve; 14-B. Second slurry inlet valve; 14-C. First slurry outlet valve; 14-D. Second slurry outlet valve; 15. Filter screen; 16. Slurry inlet tank; 17. Slurry inlet; 18-A. First slurry inlet pipe; 18-B. Second slurry inlet pipe; 18-C. First slurry outlet pipe; 18-D. Second slurry outlet pipe; 19. Slurry outlet tank; 20. Clay sample; 21. Cube protrusion. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] Please see Figures 1 to 4This invention provides a microbial grouting reinforcement clay test device using a peristaltic pump combined with ultrasonic vibration, comprising a lifting platform 1, an ultrasonic generator 2, an ultrasonic vibrating rod 3, a fixed support rod 4, a mold barrel 5, a constant temperature device 6, and a peristaltic pump 7. The peristaltic pump 7 includes a first peristaltic pump 7-A and a second peristaltic pump 7-B. The lifting platform 1 is installed at the top center of the front of the fixed support rod 4. The fixed support rod 4 is a stainless steel bracket 15cm high and 10cm wide, with a stainless steel base 10cm long and 10cm wide at its bottom. A circular turntable 11 with a diameter of 8cm is provided inside the stainless steel base. The circular turntable 11 can rotate freely and can be fixed at 0° and 180°. Two cubic protrusions 21 with a side length of 0.5cm are provided on the circular turntable 11, which are used to fix the mold barrel 5. The mold barrel 5 is a transparent PVC container with an open top, a height of 12cm, a diameter of 5cm, and a thickness of 0.5cm. Figure 3 As shown, the bottom of the mold barrel 5 is provided with a groove that matches the cube protrusion 21 on the circular turntable 11. The mold barrel 5 is installed and fixed on the circular turntable 11 through the cube protrusion 21.

[0035] like Figure 2 The mold barrel 5 has a first slurry inlet 13-A, a second slurry inlet 13-B, a first slurry outlet 13-C, and a second slurry outlet 13-D symmetrically arranged on its side wall, located at the bottom and top of the mold barrel 5 respectively. From bottom to top on the left, the first slurry inlet 13-A and the second slurry outlet 13-D are respectively located at the bottom and top on the right. The second slurry inlet 13-B and the first slurry outlet 13-C are respectively located at the bottom and top on the right. Both the slurry inlet and outlet are equipped with valves 14 and filter screens 15. The filter screens 15 are as follows: Figure 4The valves 14 corresponding to the first slurry inlet 13-A, the second slurry inlet 13-B, the first slurry outlet 13-C, and the second slurry outlet 13-D are respectively the first slurry inlet valve 14-A, the second slurry inlet valve 14-B, the first slurry outlet valve 14-C, and the second slurry outlet valve 14-D. The valves 14 are installed on the outside of the slurry inlet and outlet. Opening the valves 14 allows slurry to enter and exit, while closing the valves 14 keeps the slurry inlet and outlet sealed. The filter screen 15 is installed inside the slurry inlet and outlet. The filter screen 15 has a pore size of 10μm and can prevent soil particles from entering the second slurry inlet pipe 18-B and the first slurry outlet pipe 18-C during the slurry inlet and outlet process. The mold barrel 5 contains a clay sample 20. The maximum extension of the lifting platform 1 is 7cm. The lifting platform switch 8 is installed on the side of the fixed support rod 4. The ultrasonic generator 2 is placed at the bottom of the side of the fixed support rod 4. The ultrasonic generator 2 and the ultrasonic vibrating rod 3 are connected by an electric wire 1. 2. The ultrasonic generator 2 can control the vibration frequency of the ultrasonic vibrating rod 3. The upper part of the lifting platform 1 is equipped with a disc 10, which is a stainless steel disc with a diameter of 10cm. The ultrasonic vibrating rod 3 is installed and fixed to the bottom of the disc 10 by bolts 9. The ultrasonic vibrating rod 3 can move up and down with the disc 10. The lower end of the ultrasonic vibrating rod 3 can extend into the mold barrel 5 by up to 2cm. The first peristaltic pump 7-A and the second peristaltic pump 7-B are respectively installed on the left and right sides of the fixed support rod 4. The first peristaltic pump 7-A is connected to the slurry inlet tank 16 through the first slurry inlet pipe 18-A. The second peristaltic pump 7-B is connected to the slurry outlet tank 19 through the second slurry outlet pipe 18-D. A constant temperature device 6 is installed and fixed in front of the first peristaltic pump 7-A. The constant temperature device 6 can be set as a constant temperature water bath, constant temperature box or other equipment. The lower part of the slurry inlet tank 16 is immersed in the constant temperature device 6. The liquid level in the constant temperature device 6 is higher than the liquid level of the slurry inlet 17. The constant temperature device 6 maintains the temperature below 4℃.

[0036] The inlet and outlet pipes 18 used in this embodiment of the invention are rubber pressure hoses.

[0037] The bacterial suspension used in this embodiment of the invention is a Bacillus pasteurellus suspension, whose OD... 600 The pH should be between 0.8 and 1.2. The bacterial culture can be prepared as follows: the liquid culture medium consists of 20 g / L yeast extract, 10 g / L ammonium chloride, 10 mg / L manganese sulfate monohydrate, and 24 mg / L nickel chloride hexahydrate, adjusted to pH 9.0. The culture temperature is 30℃, and the shaking speed is 200 rpm. After 24 hours of constant temperature and shaking culture, the OD... 600 The bacterial culture solution, with a concentration between 0.8 and 1.2, is stored at 4°C until use. The preferred cementing solution is a mixture of 0.5–1 mol / L urea and calcium chloride, with a urea-to-calcium chloride concentration ratio of 1:1. After preparation, it is stored at 4°C until use.

[0038] Based on the above embodiments, those skilled in the art will understand that the present invention also provides a method for using a peristaltic pump combined with ultrasonic vibration for testing microbial-reinforced clay, comprising the following steps:

[0039] Step 1: Prepare OD separately 600 The bacterial suspension of Bacillus pasteurellii with a concentration between 0.8 and 1.2 and a mixture of urea and calcium chloride at a concentration of 0.5 to 1 mol / L were placed in a refrigerator at 4°C for cooling.

[0040] Step 2: Install the ultrasonic generator 2 at the bottom side of the fixed support rod 4, install the fixed lifting platform 1 at the top middle position of the fixed support rod 4, and install the lifting platform switch 8 on the side of the fixed support rod 4. The upper part of the lifting platform 1 is provided with a disc 10, and an ultrasonic vibrating rod 3 is installed at the bottom of the fixed disc 10. Connect the ultrasonic vibrating rod 3 to the ultrasonic generator 2 with a wire 12.

[0041] Step 3: Prepare clay sample 20 and put it into mold barrel 5. Fix mold barrel 5 on circular turntable 11 through cube protrusion 21.

[0042] Step 4: Install the first peristaltic pump 7-A and the second peristaltic pump 7-B on both sides of the fixed support rod 4 respectively. Install the constant temperature device 6 in front of the first peristaltic pump 7-A and the slurry outlet tank 19 in front of the second peristaltic pump 7-B. Connect the slurry inlet tank 16, the first peristaltic pump 7-A, the mold tank 5, the second peristaltic pump 7-B, and the slurry outlet tank 19 in sequence with the first slurry inlet pipe 18-A, the second slurry inlet pipe 18-B, the first slurry outlet pipe 18-C, and the second slurry outlet pipe 18-D.

[0043] Step 5: Turn on the thermostat 6 and set the temperature of the thermostat 6 to 4℃. After taking the prepared bacterial solution and cementing solution out of the refrigerator, pour them into the slurry tank 16 at a ratio of 1:4 to prepare the slurry 17. Place the slurry tank 16 into the thermostat 6 so that the liquid level in the thermostat 6 is higher than the liquid level in the slurry 17.

[0044] Step 6: Connect the second grout inlet pipe 18-B to the first grout inlet 13-A, open the first grout inlet valve 14-A, use the first peristaltic pump 7-A to inject grout 17, inject grout 17 to 1.5 times the pore volume of clay sample 20, close the first grout inlet valve 14-A after grouting is completed, remove the second grout inlet pipe 18-B, and turn off the thermostat 6 switch;

[0045] Step 7: Operate the lifting platform 1, lower the ultrasonic vibrating rod 3 to the liquid surface inside the mold barrel 5, 3mm above the surface of the clay sample, turn on the ultrasonic generator 2, adjust the vibration frequency, and use ultrasonic vibration to make the slurry evenly distributed in the pores of the clay sample 20. Then turn off the ultrasonic generator 2 and raise the ultrasonic vibrating rod 3 above the liquid surface.

[0046] Step 8: Let stand for six hours to allow the grout 17 to fully react and generate calcium carbonate crystals to reinforce the soil as the temperature gradually rises to room temperature. After the reaction is complete, connect the first grout outlet pipe 18-C to the first grout outlet 13-C, open the first grout outlet valve 14-C, and use the second peristaltic pump 7-B to extract the remaining grout. After the pumping is completed, close the first grout outlet valve 14-C and remove the first grout outlet pipe 18-C.

[0047] Step 9: Operate the circular turntable 11 to rotate the mold barrel 5 horizontally by 180°. Use the other second grout inlet 13-B and second grout outlet 13-D to inject and pump grout, forming a cross-grouting pattern. Repeat steps 5 to 8 until reinforcement is completed.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method of using a peristaltic pump combined with ultrasonic vibration microbial reinforced clay testing device, characterized in that, The experimental device comprises a lifting platform (1), an ultrasonic generator (2), an ultrasonic vibration rod (3), a fixed support rod (4), a mold barrel (5), a constant temperature device (6) and a peristaltic pump (7), the lifting platform (1) is installed at the middle position of the top of the front side of the fixed support rod (4), the fixed support rod (4) is provided with the ultrasonic generator (2) at the bottom of the side, the upper part of the lifting platform (1) is provided with a disc (10), the ultrasonic vibration rod (3) is fixedly installed at the bottom of the disc (10) through bolts (9), a circular turntable (11) is arranged in the base of the fixed support rod (4), the mold barrel (5) is fixedly installed on the circular turntable (11), the side wall of the mold barrel (5) is provided with pulp inlets and pulp outlets, first and second peristaltic pumps (7-A) and (7-B) are respectively installed on the left and right sides of the fixed support rod (4), one end of the first peristaltic pump (7-A) is connected with a pulp inlet barrel (16) through a first pulp inlet pipe (18-A), the other end of the first peristaltic pump (7-A) is connected with the pulp inlet through a second pulp inlet pipe (18-B), one end of the second peristaltic pump (7-B) is connected with a pulp outlet barrel (19) through a second pulp outlet pipe (18-D), the other end of the second peristaltic pump (7-B) is connected with the pulp outlet through a first pulp outlet pipe (18-C), the constant temperature device (6) is fixedly installed in front of the first peristaltic pump (7-A), and the pulp inlet barrel (16) is immersed in the constant temperature device (6); The mold barrel (5) is provided with two pulp inlets and two pulp outlets on the side wall, the two pulp inlets are a first pulp inlet (13-A) and a second pulp inlet (13-B), and the two pulp outlets are a first pulp outlet (13-C) and a second pulp outlet (13-D); The method comprises the following steps: Step one: prepare a bacillus pasteurii bacterial solution with OD600 of 0.8-1.2 and a mixed solution of 0.5-1 mol / L urea and calcium chloride with the same concentration, and place them in a 4℃ refrigerator for cooling; Step two: install the ultrasonic generator (2) on the side bottom of the fixed support rod (4), install the fixed lifting platform (1) at the middle position of the top of the fixed support rod (4), and install the lifting platform switch (8) on the side of the fixed support rod (4), the upper part of the lifting platform (1) is provided with a disc (10), the ultrasonic vibration rod (3) is installed at the bottom of the fixed disc (10), and the ultrasonic vibration rod (3) is connected with the ultrasonic generator (2) through an electric wire (12); Step three: prepare a clay sample (20) and load it into the mold barrel (5), and install the mold barrel (5) on the circular turntable (11) through the cube protrusion (21). Step four: install the first peristaltic pump (7-A) and the second peristaltic pump (7-B) on both sides of the fixed support rod (4), install the thermostat device (6) in front of the first peristaltic pump (7-A), install the slurry barrel (19) in front of the second peristaltic pump (7-B), and connect the slurry barrel (16), the first peristaltic pump (7-A), the mold barrel (5), the second peristaltic pump (7-B), and the slurry barrel (19) in sequence by using the first slurry inlet pipe (18-A), the second slurry inlet pipe (18-B), the first slurry outlet pipe (18-C), and the second slurry outlet pipe (18-D); Step five: turn on the thermostat device (6) switch and set the temperature to 4℃, then take the prepared bacteria solution and cementing fluid out of the refrigerator, mix them in the slurry barrel (16) at a ratio of 1:4 to prepare the slurry solution (17), and place the slurry barrel (16) in the thermostat device (6) so that the liquid level in the thermostat device (6) is higher than that in the slurry solution (17); Step six: connect the second slurry inlet pipe (18-B) with the first slurry inlet (13-A), open the first slurry inlet valve (14-A), use the first peristaltic pump (7-A) to inject the slurry solution (17), inject the slurry solution (17) to 1.5 times the pore volume of the clay sample (20), close the first slurry inlet valve (14-A) after the grouting is completed, remove the second slurry inlet pipe (18-B), and turn off the thermostat device (6) switch; Step seven: operate the lifting platform (1), lower the ultrasonic vibration rod (3) to the liquid level in the mold barrel (5), 3mm above the surface of the clay sample (20), turn on the ultrasonic generator (2), adjust the vibration frequency, make the slurry solution uniformly distributed in the pores of the clay sample (20) through ultrasonic vibration, then turn off the ultrasonic generator (2), and raise the ultrasonic vibration rod (3) above the liquid level; Step eight: stand for six hours, let the slurry solution (17) fully react to generate calcium carbonate crystals to reinforce the soil during the process of gradually increasing the temperature to room temperature, connect the first slurry outlet pipe (18-C) with the first slurry outlet (13-C) after the reaction is completed, open the first slurry outlet valve (14-C), use the second peristaltic pump (7-B) to extract the remaining slurry, close the first slurry outlet valve (14-C) after the grouting is completed, and remove the first slurry outlet pipe (18-C); Step nine: operate the circular turntable (11), rotate the mold barrel (5) horizontally by 180°, use the other second slurry inlet (13-B) and the second slurry outlet (13-D) for grouting and pumping, form a cross grouting mode, repeat steps five to eight until reinforcement is completed.

2. The method of claim 1, wherein the method further comprises: The fixed support rod (4) is a stainless steel support with a height of 15cm and a width of 10cm, the bottom of the fixed support rod (4) is a stainless steel base with a length of 10cm and a width of 10cm, a circular turntable (11) with a diameter of 8cm is arranged in the stainless steel base, and two square protrusions (21) with a side length of 0.5cm are arranged on the circular turntable (11).

3. The method of claim 1, wherein the method further comprises: The maximum extension of the lifting platform (1) is 7 cm, the lifting platform (1) is installed on the upper part of the fixed support rod (4), the lifting platform switch (8) is installed on the side of the fixed support rod (4), and the disc (10) is a stainless steel disc with a diameter of 10 cm.

4. The method of claim 1, wherein the method further comprises: The ultrasonic generator (2) is connected with the ultrasonic vibration rod (3) through the wire (12).

5. The method of claim 1, wherein the method further comprises: The lower end of the ultrasonic vibration rod (3) extends into the mold barrel (5) by not more than 2 cm.

6. The method of claim 1, wherein the method further comprises: The mold barrel (5) is a transparent PVC container with an open top, a height of 12 cm, a diameter of 5 cm and a thickness of 0.5 cm, the bottom of the mold barrel (5) is provided with a groove matched with the cube protrusion (21) of the circular turntable (11), and the mold barrel (5) is installed and fixed on the circular turntable (11) through the cube protrusion (21); the pulp inlet is located at the bottom of the mold barrel (5), the pulp outlet is located at the top of the mold barrel (5), the left side is sequentially provided with the first pulp inlet (13-A) and the second pulp outlet (13-D) from bottom to top, and the right side is sequentially provided with the second pulp inlet (13-B) and the first pulp outlet (13-C) from bottom to top, the pulp inlet and the pulp outlet are both provided with a valve (14) and a filter screen (15), the valve (14) is installed outside the pulp inlet and the pulp outlet, and the filter screen (15) is installed inside the pulp inlet and the pulp outlet, the pore size of the filter screen (15) is 10 μm, and the mold barrel (5) is provided with a clay sample (20).

7. The method of claim 1, wherein the method further comprises: The first pulp inlet pipe (18-A), the second pulp inlet pipe (18-B), the second pulp outlet pipe (18-D) and the first pulp outlet pipe (18-C) are all rubber pressure hoses.

8. The method of claim 1, wherein the method further comprises: The temperature of the constant temperature device (6) is set to 4℃, and the liquid level in the constant temperature device (6) is higher than that of the pulp liquid (17).

9. The method of claim 1, wherein the method further comprises: The feeding liquid (17) is a mixed solution of bacteria liquid and cementing liquid at 1:4 at 4℃, the bacteria liquid is Pasteur's Bacillus liquid, and the OD 600 The cementing liquid is a mixed solution of 0.5-1 mol / L urea and calcium chloride at the same concentration, and the concentration of the cementing liquid is between 0.8-1.2.

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