Device and method for biologically reinforcing soft soil foundation by using microorganism-induced cemented ground pile

Abstract

The invention discloses a device and a method for biologically reinforcing a soft soil foundation by a microorganism-induced cemented ground pile, the device is provided with a grouting assembly capable of spraying slurry and an induction assembly arranged around the grouting assembly, and a permeation space is formed between the induction assembly and the grouting assembly; the grouting assembly comprises a supporting body, an anode bar is arranged on the supporting body in a surrounding mode, and a slurry spraying channel capable of spraying slurry outwards is formed in the supporting body. The induction assembly comprises a cathode bar; the anode bar is electrically connected with a positive pole input end of a control module, and the cathode bar is electrically connected with a negative pole input end of the control module, so that electroosmosis is performed in the osmosis space to form a uniform overlapping channel in a three-dimensional space for slurry to permeate and fill. The problem that in the prior art, even diffusion in a three-dimensional space cannot be achieved in a microorganism grouting foundation consolidation mode is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of foundation reinforcement, and in particular to a device and method for biologically reinforcing a soft soil foundation using microbial-induced cemented piles. Background Art

[0002] In the field of civil engineering, the foundation is the root of the building, and its stability and bearing capacity are directly related to the safety and service life of the entire building structure. With the acceleration of urbanization and the advancement of large-scale infrastructure construction, the requirements for foundation reinforcement technology are becoming increasingly stringent. Traditional foundation reinforcement methods, such as replacement, dynamic compaction, and grouting, although they can meet engineering needs to a certain extent, have disadvantages such as environmental pollution, high construction costs, and a large impact on the surrounding environment. In recent years, microbial grouting reinforcement technology has become a research hotspot and development direction in the field of foundation treatment due to its green and environmentally friendly nature, small disturbance to the soil, and ability to precisely reinforce specific areas.

[0003] Microbial grouting reinforcement technology centers on microbial mineralization. By injecting a bacterial solution containing specific microorganisms and a nutrient solution into the soil, the enzymes produced during microbial metabolism catalyze the hydrolysis of urea, thereby promoting the combination of calcium ions and carbonate ions, forming calcium carbonate crystals between the pores of soil particles. These calcium carbonate crystals act as a natural "cementing agent," tightly connecting loose soil particles, significantly enhancing the cohesion and internal friction angle of the soil, and greatly increasing the strength and stiffness of the soil, ultimately achieving the goal of foundation reinforcement. This technology has demonstrated unique advantages in projects such as soft soil foundation treatment, historical building foundation reinforcement, and dam anti-seepage. It is particularly suitable for environmentally sensitive areas and complex geological conditions that are difficult to handle with traditional methods.

[0004] However, microbial grouting reinforcement technology currently faces numerous bottlenecks in practical engineering applications. The primary issue is the uneven and limited distribution of microbial biomass and nutrients within the foundation soil. Existing conventional grouting methods, such as single-point grouting and tube-well grouting, struggle to achieve uniform grout distribution in three dimensions due to factors such as varying soil permeability and insufficient grouting pressure control precision. For example, in a soft soil foundation reinforcement project in a coastal area, testing using traditional grouting revealed that calcium carbonate deposition in areas 0.5 meters from the injection hole was less than 30% of that in the core area, resulting in a significant "gradient attenuation" of the reinforcement effect. Furthermore, microbial growth and metabolic processes are extremely sensitive to environmental conditions. Even small fluctuations in temperature, pH, and dissolved oxygen levels can inhibit microbial activity and prolong the formation cycle of calcium carbonate crystals. In a tunnel foundation reinforcement project, fluctuations in the groundwater level led to localized hypoxia in the grouting area, reducing microbial metabolic efficiency by over 50%. The originally planned 30-day reinforcement period was extended to 60 days, increasing project costs and significantly impacting construction progress. Summary of the Invention

[0005] The purpose of the present invention is to solve the problem that the microbial grouting reinforcement method in the prior art cannot spread evenly in three-dimensional space, and to provide a microbial induced cemented pile biological reinforcement device and method for soft soil foundation.

[0006] In order to solve the above-mentioned technical problems, the present invention adopts the following technical solutions: a microbial-induced cemented pile bioreinforcement soft soil foundation device, which comprises a grouting component capable of spraying slurry and an induction component arranged around the grouting component, with a permeable space formed between the induction component and the grouting component;

[0007] The grouting assembly includes a support body, an anode rod is arranged around the support body, and a spraying channel is arranged in the support body for spraying slurry outwards;

[0008] The induction assembly includes a cathode rod;

[0009] The anode rod is electrically connected to the positive input terminal of the control module, and the cathode rod is electrically connected to the cathode input terminal of the control module, so as to perform electrical osmosis in the osmotic space to form uniform overlapping channels in the three-dimensional space for slurry to infiltrate and fill.

[0010] As a further optimization of the microbial induced cemented pile biological reinforcement soft soil foundation device of the present invention: the grouting channel is connected to the slurry tank and the nutrient tank through two grouting parts respectively, the slurry tank is used to store microbial slurry, and the nutrient tank is used to store nutrient solution.

[0011] As a further optimization of the microbial induced cemented pile biological reinforcement soft soil foundation device of the present invention: the grouting part includes a grouting pipe connecting the grouting channel and the slurry tank or the nutrient tank, and the grouting pipe is provided with a control valve, a grouting pump and a first pressure gauge in sequence in the direction of the grouting channel.

[0012] As a further optimization of the microbial induced cemented pile biological reinforcement soft soil foundation device of the present invention: the end of the support body away from the input port of the shotcrete channel is provided with a vibration body connected to a shock absorber, and an air supply channel is provided in the vibration body, which is connected to the air pump component provided on the support body to input high-pressure gas into the vibration body.

[0013] As a further optimization of the microbial induced cemented pile biological reinforcement soft soil foundation device of the present invention: a cooling channel is further provided in the excitation body, and the cooling channel is connected to a cold water tank through a cooling member.

[0014] As a further optimization of the microbial induced cemented pile biological reinforcement soft soil foundation device of the present invention: the cooling part includes an inlet pipe and a return pipe connecting the cold water tank and the cooling channel, and a one-way valve, a water pump and a second pressure gauge are sequentially provided on the inlet pipe in the direction toward the cooling channel.

[0015] As a further optimization of the microbial induced cemented pile biological reinforcement soft soil foundation device of the present invention: the cathode rod is arranged in the protective cover, the bottom of the protective cover is conical and is arranged corresponding to the support body.

[0016] As a further optimization of the microbial induced cemented pile biological reinforcement soft soil foundation device of the present invention: a plurality of through holes are opened on the side of the protective cover facing the support body, and shielding nets are provided in the through holes to block the through holes.

[0017] The method of biological reinforcement of soft soil foundation by microbial induced cemented piles uses a microbial induced cemented piles biological reinforcement of soft soil foundation device to perform electroosmosis in the infiltration space to form uniformly overlapping channels in the three-dimensional space for the microbial slurry sprayed from the grouting channel to penetrate and fill.

[0018] As a further optimization of the method for biological reinforcement of soft soil foundation by microbial-induced cemented piles of the present invention, the nutrient solution is sprayed out through the spraying channel before the microbial slurry is sprayed out, so as to cooperate with the electro-osmosis to assist in forming and infiltrating the filling channel.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The present invention employs a grouting assembly connected to the positive pole of a power source, while an induction assembly is connected to the negative pole of the power source. Multiple induction assemblies are arranged around the grouting assembly to form an infiltration space. Upon powering on, electroosmosis occurs within the infiltration space, creating overlapping and complex channels within this three-dimensional space. These complex channels guide the subsequent infusion and growth of biological slurry, ensuring its uniform distribution within the infiltration space, significantly improving the quality and efficiency of foundation reinforcement.

[0021] The present invention establishes a spray channel for ejecting bioslurry, connecting it to a nutrient tank storing nutrient solution. With the aid of electroosmosis, the channel forms complex, overlapping channels in sync with the water in the soil. The nutrient solution seeps into the channel, further optimizing the bioslurry's effectiveness and efficiency in reinforcing the foundation.

[0022] The present invention also realizes the functions of electro-osmosis, nutrient solution injection into the foundation, and microbial slurry injection into the soil by integrating the vibration body, spraying channel and anode rod in the grouting assembly, which greatly simplifies the structure and facilitates the overall transportation and use by operators. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the structure of the present invention in use;

[0024] Figure 2 It is a structural schematic diagram of the grouting assembly of the present invention;

[0025] Figure 3Schematic diagram of the cross-sectional structure of the grouting assembly of the present invention;

[0026] Figure 4 Schematic diagram of the cross-sectional structure of the induction component of the present invention;

[0027] Figure 5 This is a schematic diagram of the top view of the structure of the present invention in use;

[0028] Markings in the figure: 1. Induction component; 101. Protective cover; 102. Through hole; 103. Shielding net; 104. Cathode rod; 2. Negative wire; 3. Slurry tank; 4. Control module; 5. Cold water tank; 6. Nutrient tank; 7. Grouting parts; 701. Grouting pipe; 702. Control valve; 703. Grouting pump; 704. First pressure gauge; 8. Cooling part; 801. Return pipe; 802. Inlet pipe; 803. Second pressure gauge; 804. Water pump; 805. One-way valve; 9. Grouting component; 901. Vibration body; 902. Shock absorber; 903. Spraying channel; 904. Shielding cover; 905. Support body; 906. Anode rod; 907. Air supply channel; 908. Cooling channel; 10. Positive wire; 11. Air pump parts. DETAILED DESCRIPTION

[0029] In order to better understand the present invention, the content of the present invention is further illustrated below in conjunction with examples, but the content of the present invention is not limited to the following examples.

[0030] like Figure 1 and Figure 5 As shown, a device and method for biological reinforcement of soft soil foundation by microbial induced cemented piles comprises a grouting component 9 and a plurality of induction components 1 carefully arranged around the grouting component 9. The grouting component 9 can closely cooperate with the plurality of induction components 1 in the initial stage of the operation to jointly construct an infiltration space between them, and then the electro-osmosis process is carried out in this space. Electro-osmosis is a technology that uses the action of an electric field to directional move water and other mobile substances in the soil. During the electro-osmosis process, the grouting component 9 will accurately inject a pre-prepared nutrient solution. Under the action of the electro-osmosis effect, these nutrient solutions can penetrate into the entire infiltration space relatively evenly and at multiple angles, and then gradually construct multiple complex and overlapping nutrient channels inside the infiltration space.

[0031] Once these complex, overlapping nutrient channels have been stably formed within the infiltration space, the electroosmotic action of the grouting assembly 9 and the induction assembly 1 ceases in due time. Subsequently, the grouting assembly 9 injects the microbial slurry into this now-filled infiltration space. Guided by these meticulously arranged and overlapping nutrient channels, the microorganisms are able to distribute relatively densely and rapidly throughout the infiltration space. This distribution method is not only highly efficient but also ensures uniform microbial diffusion within the infiltration space, thereby successfully completing the task of high-quality foundation reinforcement.

[0032] like Figure 4 As shown, the structure of the induction component 1 is quite ingenious. It includes a protective cover 101 and a cathode rod 104 arranged inside the protective cover 101. The bottom of the protective cover 101 is designed to be conical. This design greatly facilitates the operator to accurately insert the protective cover 101 and the cathode rod 104 into the predetermined position and depth in the foundation soil. The protective cover 101 is cleverly provided with a plurality of through holes 102 on the side facing the grouting component 9. A shielding net 103 is installed inside each through hole 102. The function of the shielding net 103 is to provide necessary protection to the cathode rod 104 during the process of inserting the protective cover 101 into the foundation soil. At the same time, it can also effectively reduce the obstruction encountered when the current passes through the protective cover 101.

[0033] like Figure 2 and Figure 3As shown, the grouting assembly 9 is also very ingeniously designed. It includes a support body 905, and multiple anode rods 906 are evenly arranged on the periphery of the support body 905. Each anode rod 906 is covered with a shielding cover 904 fixed to the support body 905. The function of this shielding cover 904 is to prevent soil particles from eroding the anode rod 906, and it can also further reduce the obstruction encountered when the current passes through. Multiple anode rods 906 are closely connected to the positive power supply interface of the control module 4 through the positive wire 10, while multiple cathode rods 104 are connected to the negative power supply interface of the control module 4 through the negative wire 2. The input end of the control module 4 is electrically connected to the power supply. When the anode rod 906 is connected to the positive pole of the power supply through the control module 4, and the cathode rod 104 is connected to the negative pole of the power supply through the control module 4, the current will drive water and other substances in the infiltration space to move in a directional manner from the anode rod 906 to the cathode rod 104, that is, the electroosmosis phenomenon occurs. At this point, the spray channel 903 within the support body 905 will timely spray out the corresponding nutrient solution. Under the action of the electric current, this nutrient solution will further move from the cathode rod 104 to the anode rod 906, thereby forming multiple nutrient channels that overlap and are evenly distributed in three dimensions within the infiltration space. These nutrient channels provide ideal channel conditions for subsequent microbial grouting, greatly improving the efficiency and quality of microbial foundation reinforcement. The nutrient solution is rich in key nutrients such as carbon, nitrogen, phosphorus, and trace elements required for microbial growth. Under the action of the electric current, these nutrients will further move from the cathode rod 104 to the anode rod 906, achieving directional transport through the electroosmotic effect. Specifically, the carbon source in the nutrient solution provides an energy source for microorganisms, promoting their rapid reproduction; the nitrogen and phosphorus sources are essential elements for microorganisms to synthesize cellular substances and produce cementing materials; and the trace elements play a crucial role in regulating microbial growth and metabolic activity. These nutrients form multiple nutrient channels that overlap and are evenly distributed in three dimensions within the infiltration space, providing ideal channel conditions for the directional migration and reproduction of microorganisms. As microorganisms continue to multiply and produce cementing substances in the nutrient solution, the bond between soil particles gradually strengthens, forming a more compact and stable foundation structure. In this way, microbially induced cemented piles can effectively reinforce soft soil foundations, improving their bearing capacity and resistance to deformation, and providing more reliable foundation support for engineering construction.

[0034] It is worth mentioning that Figure 2 and Figure 3As shown, a vibration body 901 connected by a shock absorber 902 is cleverly provided at the bottom of the support body 905. This vibration body 901 is connected to high-pressure gas through the air pump part 11 provided at the center of the support body 905, and cooperates with the support body 905 and the air supply channel 907 provided in the vibration body 901 to drive the vibration body 901 to vibrate, so that the support body 905 can penetrate deep into the foundation soil. During the movement of the vibration body 901, the shock absorber 902 will effectively reduce the impact on the spraying channel 903 and the anode rod 906. At the same time, the movement of the vibration body 901 will drive the soil in the foundation to vibrate and rub, thereby generating heat to make itself and the vibration body 901 heat up. This heating effect can provide a good temperature environment for the subsequent injection of microbial slurry to a certain extent, thereby further improving the effect and quality of foundation reinforcement.

[0035] In addition, a cooling channel 908 passing through the center of the support body 905 is cleverly provided inside the vibration body 901. This cooling channel 908 is connected to the cold water tank 5 via the cooling element 8, thereby effectively cooling the interior of the vibration body 901 during the process of the vibration body 901 moving and generating heat, thereby reducing the adverse effects of high heat on the vibration body 901 and ensuring the functional stability of the vibration body 901. The cooling element 8 includes a return pipe 801 connected to the cold water tank 5 and a water inlet pipe 802. The water inlet pipe 802 is sequentially provided with a one-way valve 805, a water pump 804, and a second pressure gauge 803 in the direction of connecting to the cooling channel 908, so as to facilitate the operator to operate and control and achieve effective cooling of the vibration body 901.

[0036] Finally, Figure 1 As shown, the grouting channel 903 is connected to the slurry tank 3 and the nutrient tank 6 respectively through two grouting components 7. The main function of the slurry tank 3 is to store microbial slurry, while the nutrient tank 6 is used to store nutrient solution that can penetrate the soil with electric current and provide necessary nutrients for the microbial slurry. The grouting system includes a grouting pipe 701 connecting the grouting channel 903 and the nutrient tank 6 or the slurry tank 3. The grouting pipe 701 is sequentially provided with a control valve 702, a grouting pump, and a first pressure gauge 704 in the direction of the grouting channel 903. This design not only provides the necessary basic conditions for injecting microbial slurry and nutrient solution into the foundation, but also facilitates precise control operations by operators. The integrated structure makes the entire device more compact and portable, making it easier for operators to place and drive the device into the soil of the foundation for efficient use. For example, operators can adjust the opening of the control valve 702 according to actual needs to control the speed and amount of grouting, while monitoring the pressure changes during the grouting process by observing the first pressure gauge 704 to ensure the smooth progress of the entire grouting process.

[0037] After the microbial slurry is injected, the grouting assembly 9 will cease operation at an appropriate time. The entire microbial-induced cementing pile device will remain in the soil for a period of time to allow the microorganisms to fully grow and produce a cementing effect. Nourished by the nutrient solution, these microorganisms will rapidly multiply and secrete cementing substances. These substances gradually fill and solidify the spaces between soil particles, forming a strong and stable pile structure.

[0038] Over time, the microbial cementation effect will become increasingly pronounced, significantly improving the strength and stability of the foundation soil. This microbial-induced cementation pile bioreinforcement method is not only highly efficient, environmentally friendly, and sustainable, but also offers significant reinforcement results, effectively addressing issues such as insufficient bearing capacity and excessive deformation in soft soil foundations.

[0039] Furthermore, operators can flexibly adjust the parameters of the grouting assembly 9 and the induction assembly 1, such as grouting speed, grouting volume, and electroosmotic strength, based on the specific conditions of the foundation soil and reinforcement requirements, to achieve the best reinforcement effect. This system also has good adaptability and scalability, making it suitable for different types of soft soil foundations and reinforcement projects of varying scales.

[0040] The method for biologically reinforcing a soft soil foundation with microbial-induced cemented piles comprises the following steps:

[0041] First, prepare a grouting assembly 9 and a plurality of induction assemblies 1 carefully arranged around the grouting assembly 9. These assemblies need to fit tightly so as to construct a permeable space between them.

[0042] Next, the electroosmosis process takes place within the infiltration space. Electroosmosis is a technology that uses an electric field to directional-move water and other mobile substances in the soil. During this process, the grouting assembly 9 precisely injects a pre-prepared nutrient solution. Under the influence of the electroosmotic effect, this nutrient solution penetrates the infiltration space relatively evenly and at multiple angles, gradually forming multiple complex and overlapping nutrient channels within the infiltration space.

[0043] Once these nutrient channels are stably formed, electroosmosis ceases. Grouting assembly 9 then injects microbial slurry into the now-filled nutrient channel-filled osmotic space. Guided by these carefully arranged and overlapping nutrient channels, the microorganisms are able to distribute relatively densely and rapidly throughout the osmotic space.

[0044] To ensure uniform microbial diffusion and efficient foundation reinforcement, the induction assembly 1 includes a protective cover 101 and a cathode rod 104 disposed within the protective cover 101. The through holes 102 and the shielding mesh 103 on the protective cover 101 provide necessary protection for the cathode rod 104 and reduce obstacles to the passage of current.

[0045] The grouting assembly 9 includes a support body 905, and a plurality of anode rods 906 are evenly arranged on the periphery of the support body 905. Each anode rod 906 is covered with a shielding cover 904 to prevent soil particles from eroding the anode rod 906 and reduce the obstruction when the current passes through. Through the connection between the control module 4 and the power supply, the current will drive the water and other substances in the infiltration space to move from the anode rod 906 to the cathode rod 104 in a directional manner, that is, the electroosmosis phenomenon occurs. At this time, the spraying channel 903 in the support body 905 will spray out the corresponding nutrient solution in a timely manner to form a nutrient channel.

[0046] During the grouting process, attention must also be paid to the protection and maintenance of the equipment. For example, a vibration body 901 connected to a shock absorber 902 is installed at the bottom of the support body 905. Through vibration, the support body 905 can penetrate deep into the foundation soil. Simultaneously, cooling channels 908 within the vibration body 901 effectively cool the interior of the vibration body 901, reducing the adverse effects of high heat on the vibration body 901.

[0047] Finally, the grouting channel 903 is connected to the slurry tank 3 and the nutrient tank 6 respectively through two grouting components 7. The operator can adjust the opening of the control valve 702 according to actual needs to control the speed and amount of grouting. At the same time, the pressure changes during the grouting process are monitored by observing the first pressure gauge 704 to ensure the smooth progress of the entire grouting process.

[0048] In this embodiment, the model structure and operation mode of the control module 4, water pump 804 and grouting pump 703 should be understood as the existing technology, and the detailed principle of electro-osmosis and how to drive the synchronous osmosis of water and other nutrient solutions should be understood as the existing technology.

[0049] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art may make various variations or modifications within the scope of the claims, which do not affect the essence of the present invention.

Claims

1. A microbial-induced cemented pile bioreinforcement device for soft soil foundation, characterized by: It comprises a grouting assembly (9) capable of spraying slurry and an induction assembly (1) arranged around the grouting assembly (9), wherein a permeable space is formed between the induction assembly (1) and the grouting assembly (9); The grouting assembly (9) comprises a support body (905), an anode rod (906) is arranged around the support body (905), and a spraying channel (903) is provided inside the support body (905) for spraying slurry outward; The induction assembly (1) includes a cathode rod (104); The anode rod (906) is electrically connected to the positive input terminal of the control module (4), and the cathode rod (104) is electrically connected to the cathode input terminal of the control module (4), so as to perform electrical osmosis in the osmotic space to form uniform overlapping channels in the three-dimensional space for slurry to infiltrate and fill.

2. The microbial-induced cemented pile bioreinforcement device for soft soil foundation according to claim 1, characterized in that: The spraying channel (903) is connected to the slurry tank (3) and the nutrient tank (6) respectively through two grouting parts (7). The slurry tank (3) is used to store microbial slurry, and the nutrient tank (6) is used to store nutrient solution.

3. The microbial-induced cemented pile bioreinforcement device for soft soil foundation according to claim 2, characterized in that: The grouting member (7) comprises a grouting pipe (701) connecting the grouting channel (903) and the slurry tank (3) or the nutrient tank (6); the grouting pipe (701) is provided with a control valve (702), a grouting pump (703) and a first pressure gauge (704) in sequence in the direction of the grouting channel (903).

4. The microbial-induced cemented pile bioreinforcement device for soft soil foundation according to claim 1, characterized in that: The end of the support body (905) away from the input port of the spraying channel (903) is provided with a vibration body (901) connected to a shock absorber (902), and an air supply channel (907) is provided in the vibration body (901). The air supply channel (907) is connected to an air pump component (11) provided on the support body (905) to input high-pressure air into the vibration body (901).

5. The microbial-induced cemented pile bioreinforcement device for soft soil foundation according to claim 4, characterized in that: A cooling channel (908) is also provided in the vibration body (901), and the cooling channel (908) is connected to a cold water tank (5) through a cooling element (8).

6. The microbial-induced cemented pile bioreinforcement device for soft soil foundation according to claim 5, characterized in that: The cooling element (8) comprises a water inlet pipe (802) and a water return pipe (801) connecting the cold water tank (5) and the cooling channel (908); a one-way valve (805), a water pump (804) and a second pressure gauge (803) are sequentially provided on the water inlet pipe (802) in a direction toward the cooling channel (908).

7. The microbial-induced cemented pile bioreinforcement device for soft soil foundation according to claim 1, characterized in that: The cathode rod (104) is arranged in the protective cover (101), and the bottom of the protective cover (101) is arranged in a conical shape and corresponds to the support body (905).

8. The microbial-induced cemented pile bioreinforcement device for soft soil foundation according to claim 7, characterized in that: The protective cover (101) is provided with a plurality of through holes (102) on one side facing the support body (905), and a shielding net (103) is provided in the through holes (102) to block the through holes (102).

9. A method for bioreinforcement of soft soil foundation using microbial-induced cemented piles, characterized by: The microbial-induced cemented pile bioreinforcement soft soil foundation device as described in any one of claims 1 to 8 is used to perform electroosmosis in the infiltration space to form uniformly overlapping channels in the three-dimensional space for the microbial slurry ejected from the grouting channel (903) to penetrate and fill.

10. The method for bioreinforcement of soft soil foundation by microbial-induced cemented piles according to claim 9, characterized in that: The spraying channel (903) sprays out the nutrient solution before the microbial slurry, so as to cooperate with the electro-osmosis to assist in the formation and infiltration of the filling channel.

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