Composite reinforcement type suction barrel device based on microbial induction and use method of composite reinforcement type suction barrel device

Abstract

The invention discloses a composite reinforcement type suction barrel device based on microorganism induction and a use method thereof. The composite reinforcement type suction barrel device based on microorganism induction comprises a suction barrel model system, a microorganism cement reinforcement system and a test monitoring system. The suction cylinder model system comprises a suction cylinder, a grouting pipeline and hydraulic equipment, and the grouting pipeline is laid on the inner wall of the suction cylinder and used for injecting microorganism cement grout; the hydraulic equipment is connected to the suction barrel and used for controlling lifting and pressing-in of the suction barrel. The microbial cement reinforcement system comprises liquid storage equipment and negative pressure equipment, and the liquid storage equipment is connected to the grouting pipeline and used for storing and providing microbial cement grout for the grouting pipeline; the negative pressure equipment is connected to the suction barrel and used for applying negative pressure to the interior of the suction barrel in the grouting process, and permeation of microorganism cement grout is promoted. The test monitoring system is used for testing mechanical parameters of a soil body, monitoring the suction barrel and carrying out a loading test on the suction barrel.

Description

Technical Field

[0001] The invention relates to a composite reinforced suction cylinder device based on microbial induction and a use method thereof, belonging to the technical field of marine engineering. Background Art

[0002] With the development of offshore wind power and offshore oil and gas, suction cylinders have been widely used as a foundation form that is easy to install and environmentally friendly. However, there is a gap between the traditional suction cylinder and the soil during installation. In order to improve the bearing capacity and stability, low-strength cement is usually needed to be filled in this gap. However, the construction process of this traditional grouting material may affect the environment, and its durability is poor under cyclic loads. It is prone to strength attenuation and performance degradation, and cannot meet long-term service requirements; at the same time, the construction process is complicated, the cost is high, and it is sensitive to environmental conditions, which limits its application in complex marine environments.

[0003] Therefore, a new reinforcement method is urgently needed that can reduce environmental impact, improve the bonding quality between the suction tube and the soil, and enhance the bearing capacity and long-term stability of the foundation. This demand has prompted people to explore more environmentally friendly and effective technical means to solve the problems existing in traditional methods. Summary of the invention

[0004] The main purpose of the present invention is to propose a microbially induced composite reinforced suction cylinder device and its use method, which utilizes microbial induced calcium carbonate deposition (MICP) technology to form a low-strength reinforcement layer in the gap between the suction cylinder and the soil to improve the stability and bearing capacity of the suction cylinder.

[0005] According to one aspect of the present invention, a microbial-induced composite reinforcement suction cylinder device is proposed, comprising: a suction cylinder model system, a microbial cement reinforcement system and a test monitoring system; the suction cylinder model system comprises a suction cylinder, a grouting pipe and a lifting device, wherein the grouting pipe is laid on the inner wall of the suction cylinder for injecting microbial cement slurry; the lifting device is connected to the suction cylinder for controlling the lifting and pressing of the suction cylinder; the microbial cement reinforcement system comprises a liquid storage device and a negative pressure device, wherein the liquid storage device is connected to the grouting pipe for storing and providing the microbial cement slurry to the grouting pipe; the negative pressure device is connected to the suction cylinder for applying negative pressure to the inside of the suction cylinder during the grouting process to promote the penetration of the microbial cement slurry; the test monitoring system is used for soil mechanical parameter testing, suction cylinder monitoring, and loading test on the suction cylinder.

[0006] Furthermore, the lifting equipment includes: a connecting screw, a vertical screw, a hydraulic cylinder, a lifting beam and a wire displacement sensor for recording the displacement of the suction cylinder in real time; one end of the connecting screw is installed on the top of the suction cylinder, and the other end passes through the lifting beam to be connected to the vertical screw, and the lifting beam is connected to the hydraulic cylinder.

[0007] Furthermore, a water outlet hole and a test hole are opened on the top of the suction cylinder; the negative pressure equipment performs negative pressure penetration pumping and negative pressure circulation during grouting through the water outlet hole; and the test monitoring system performs soil mechanical parameter testing through the test hole.

[0008] Furthermore, the grouting pipe is spirally laid from the upper part to the lower part along the inner wall of the suction cylinder, and a plurality of slurry release holes are opened on the pipe wall of the grouting pipe; the microbial cement reinforcement system also includes a conveying pipe, a peristaltic pump is installed on the conveying pipe, one end of the conveying pipe is connected to the liquid storage device, and the other end is connected to the grouting port opened on the upper part of the suction cylinder, and the upper end of the grouting pipe is connected to the grouting port.

[0009] Furthermore, the microbial cement reinforcement system also includes: a nutrient solution tank and a concentrated seawater tank, which are respectively used to store the nutrient solution and concentrated seawater required for culturing the microbial cement slurry.

[0010] Furthermore, the test monitoring system includes: CPT test equipment, LVDT displacement sensor, inclination sensor and loading test equipment, the CPT test equipment is used to test the mechanical parameters of the in-situ soil in the suction cylinder and the soil after micro-cement reinforcement, the LVDT displacement sensor and the inclination sensor are used to monitor the displacement and inclination of the suction cylinder during the loading process, respectively, and the loading test equipment is used to perform a loading test on the suction cylinder to simulate the load-bearing conditions during the service stage.

[0011] Furthermore, the loading test equipment includes: a loading ring, a steel wire rope and a weight. The loading ring is used to be installed on the top of the suction cylinder during the loading test phase. One end of the steel wire rope is connected to the loading ring and the other end is connected to the weight.

[0012] According to another aspect of the present invention, a method for using the aforementioned microbial-induced composite reinforcement suction cylinder device is also proposed, comprising the following steps: S1, pressing the suction cylinder into the soil to a target depth by means of the lifting device; S2, transporting the microbial cement slurry in the liquid storage device to the grouting pipe, grouting at a predetermined rate, and applying negative pressure to the inside of the suction cylinder by means of the negative pressure device to promote the microbial cement slurry to penetrate into the soil; S3, after the grouting is completed to form a reinforcement layer, the suction cylinder is subjected to a loading test by means of the test monitoring system, and the soil mechanical parameter test and the suction cylinder monitoring are performed.

[0013] Furthermore, the microbial cement slurry is prepared by mixing a microbial suspension, a nutrient solution and concentrated seawater in proportion; wherein the microbial suspension is obtained by culturing high urease bacteria to a bacterial liquid concentration OD600 of 1.2 to 1.5; the nutrient solution is used to provide a carbon source, and the concentrated seawater is used to provide a calcium source.

[0014] Furthermore, it also includes: during the grouting process, monitoring the grouting pressure, pH value and temperature, wherein the pH value is controlled at 8.0-8.5 and the temperature is maintained at 25-30°C to ensure the microbial activity and calcium carbonate deposition effect.

[0015] The beneficial effects of the technical solution of the present invention are embodied in:

[0016] 1. Innovation of composite reinforcement technology: This invention combines microbial induced sedimentation technology with traditional suction tube structure, and improves the stability and bearing capacity of soil through microbial cement reinforcement method. This composite reinforcement method not only enhances the reinforcement effect, but also reduces the impact on the environment. Compared with traditional chemical reinforcement methods, it is more environmentally friendly and sustainable.

[0017] 2. Adaptability to various environmental conditions: By using high urease activity microorganisms and nutrient solution formula, the present invention can adapt to the soil reinforcement needs in complex environments such as the ocean. Compared with traditional reinforcement methods, it can more effectively deposit calcium carbonate in marine sediments and sandy soils, thereby enhancing the strength of the reinforcement layer.

[0018] 3. Integrated use of negative pressure equipment: Based on the traditional suction cylinder, the present invention further promotes the uniform penetration of microbial slurry through negative pressure equipment, making the reinforcement layer more uniform and stable. The application of negative pressure technology increases the penetration depth of slurry and solves the problem of slurry being difficult to fully penetrate in the prior art.

[0019] 4. In-situ monitoring and precise control: The present invention integrates CPT test system, LVDT displacement sensor and inclination sensor and other test and monitoring equipment, which can monitor the installation process, displacement, inclination and soil mechanical parameters of the suction cylinder in real time. These functions help to control the reinforcement process more accurately, provide instant feedback and adjustment, and improve the reliability and safety of the project.

[0020] In summary, the present invention can improve the bonding strength between the suction cylinder and the soil through the deposition process of microbial cement, while maintaining its stable performance during long-term use, reducing material degradation and environmental impact; after solidification, the microbial cement can effectively enhance the shear strength and anti-penetration performance of the soil, thereby further improving the overall stability and reliability of the suction cylinder foundation. At the same time, the present invention has the advantages of environmentally friendly materials, simple construction, and improved suction cylinder performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of a composite reinforced suction cylinder device based on microbial induction according to an embodiment of the present invention.

[0022] Figure 2 Schematic diagram of a suction cylinder according to an embodiment of the present invention.

[0023] Figure 3 It is a schematic diagram of a loading test of a composite reinforced suction cylinder device based on microbial induction according to an embodiment of the present invention.

[0024] Figure 4 It is a schematic diagram of a CPT test after grouting of a composite reinforced suction cylinder device induced by microorganisms according to an embodiment of the present invention.

[0025] Explanation of the accompanying drawings: 1-suction cylinder, 2-connecting screw, 3-water outlet, 4-test hole, 5-grouting pipe, 6-grouting port, 7-slurry release hole, 8-vertical screw, 9-pull wire displacement sensor, 10-hydraulic cylinder, 11-microbial solution tank, 12-nutrient solution tank, 13-concentrated seawater tank, 14-peristaltic pump, 15-transport pipeline, 16-vacuum pump, 17-negative pressure tank, 18-negative pressure gauge, 19-negative pressure tank water inlet valve, 20-negative pressure tank water outlet valve, 21-vacuum tube, 22-LVDT displacement sensor, 23-tilt sensor, 24-loading ring, 25-wire rope, 26-weight, 27-CPT connecting screw, 28-CPT probe, 29-soil. DETAILED DESCRIPTION

[0026] The present invention will be further described below in conjunction with the accompanying drawings and specific implementation methods and examples. The purpose of providing the examples is only to illustrate, but not to impose any limitation.

[0027] The embodiment of the present invention provides a composite reinforced suction cylinder device based on microbial induction, including a suction cylinder model system, a microbial cement reinforcement system and a test monitoring system.

[0028] Please refer to Figure 1 and Figure 2The suction cylinder model system includes a suction cylinder 1, a grouting pipe 5 and a lifting device. The suction cylinder 1 is the main structure of the composite reinforced suction cylinder device of the present invention, and a plurality of water outlet holes 3 and CPT (Cone Penetration Test) test holes 4 are opened on the top thereof, and a grouting port 6 is opened on the upper part of the side wall. The grouting pipe 5 is spirally laid from the upper part to the lower part along the inner wall of the suction cylinder, and its upper end is connected to the grouting port 6, and a plurality of slurry release holes 7 are opened on its pipe wall. The lifting device includes a connecting screw 2, a vertical screw 8, a hydraulic cylinder 10, a lifting beam and a wire displacement sensor 9 for real-time recording of the displacement of the suction cylinder. One end of the connecting screw 2 is installed on the top of the suction cylinder, and the other end passes through the lifting beam to be connected to the vertical screw 8, and the lifting beam is connected to the hydraulic cylinder 10.

[0029] Please continue to refer to Figure 1 The microbial cement reinforcement system includes a microbial solution tank 11, a nutrient solution tank 12, a concentrated seawater tank 13, a peristaltic pump 14, a delivery pipeline 15, a vacuum pump 16, a negative pressure tank 17, a negative pressure gauge 18, a negative pressure tank water inlet valve 19, a negative pressure tank water outlet valve 20 and a vacuum tube 21. Among them, the microbial solution tank 11 is used to store the prepared microbial cement slurry, and the nutrient solution tank 12 and the concentrated seawater tank 13 are used to store the nutrient solution and concentrated seawater required for preparing the microbial cement slurry. One end of the delivery pipeline 15 is connected to the microbial solution tank 11, and the other end is connected to the grouting port 6 of the suction cylinder; the peristaltic pump 14 is arranged on the delivery pipeline 15, and is used to inject the microbial cement slurry in the microbial solution tank 11 into the grouting pipeline 5 at a set rate. The vacuum pump 16, the negative pressure tank 17, the negative pressure gauge 18, the negative pressure tank water inlet valve 19, the negative pressure tank water outlet valve 20 and the vacuum tube 21 constitute a negative pressure device, which is used to apply negative pressure to the inside of the suction cylinder during the grouting process to promote the penetration of the microbial cement slurry.

[0030] Please refer to Figure 3 and Figure 4 The test monitoring system includes a CPT test system, an LVDT displacement sensor 22, an inclination sensor 23, a loading ring 24, a steel wire rope 25 and a weight 26. The CPT test system includes a CPT connecting screw 27 and a CPT probe 28, which are used to test the mechanical parameters of the in-situ soil and the soil after microbial reinforcement to evaluate the effect of microbial reinforcement. The LVDT (Linear Variable Displacement Transducer) displacement sensor 22 and the inclination sensor 23 are used to monitor the displacement and inclination of the suction cylinder during the loading process. The loading ring 24, the steel wire rope 25 and the weight 26 are used to perform loading tests on the suction cylinder to simulate the load-bearing conditions during the service stage.

[0031] The embodiment of the present invention also provides a method for using the aforementioned composite reinforced suction cylinder device based on microbial induction, including four steps of suction cylinder installation, microbial cement slurry preparation, grouting and loading test, which are specifically as follows:

[0032] 1) Installation of suction cylinder: Insert the connecting screw 2 at the top of the suction cylinder into the center of the lifting beam and connect it with the vertical screw 8 to ensure a tight fit. After the connection is completed, start the hydraulic cylinder 10, and drive the lifting beam downward through the hydraulic system control. The connecting screw 2 and the vertical screw 8 are pressed down accordingly, and the suction cylinder 1 is gradually pressed into the soil. During this process, the wire displacement sensor 9 records the lifting height in real time to ensure that the suction cylinder is installed to the target position at the expected depth. After the installation is completed, remove the connecting screw 2 from the lifting beam and start the hydraulic cylinder 10 to lift the lifting beam.

[0033] 2) Preparation of microbial cement slurry: Select high urease bacteria adapted to the marine environment, and culture until the bacterial liquid concentration OD600 is 1.2-1.5 to obtain a microbial suspension to ensure microbial activity and calcium carbonate deposition effect. A nutrient solution containing glucose and urea is used to provide a carbon source. In this embodiment, a nutrient solution containing 0.5-1 mol / L glucose and 0.3-1 mol / L urea can be used; protein can also be further added. It should be understood that those skilled in the art can also use other nutrient solution formulas, and the present invention does not limit the specific cultivation of the nutrient solution. Polluted concentrated seawater is used to provide a calcium source. In the embodiment of the present invention, polluted seawater with a concentration ratio of 5-8 times is used. The microbial suspension, nutrient solution and concentrated seawater are mixed in proportion to obtain a uniform microbial cement slurry. In each liter of microbial cement slurry, 100-200 mL of microbial suspension, 400-500 mL of nutrient solution, and 300-400 mL of concentrated seawater are included.

[0034] In some specific embodiments, the screening steps of marine high urease bacteria are as follows: collect soil samples from the marine environment, select sediments in coastal areas or sandy soil samples at the bottom of shallow seas. Add the soil sample to sterile water, dilute it step by step at a ratio of 1:10, and finally dilute it to an appropriate concentration (such as 10^-5 to 10^-7) to ensure that a single colony can be obtained. Add urea (at a concentration of 1.1 mol / L) to the culture medium to promote the growth of microorganisms with high urease activity. The culture medium includes yeast extract and calcium chloride to provide necessary nutrients and calcium sources. Spread the diluted soil sample on a selective culture medium containing urea and place it in a constant temperature incubator at 30°C for 36-48 hours. Observe the change in the color of the culture medium with a phenol red indicator, and screen out the colonies that make the culture medium pink, which are strains with high urease activity. Take the screened colonies and test the urease activity. Mix 3 ml of bacterial solution with 27 ml of urea solution, and use a conductivity meter to measure the conductivity change to determine the urease activity of the strain. The screened high urease bacteria were purified and inoculated into new culture medium for further culture, and the strains with higher activity were stored in a refrigerated (2-8°C) or frozen (-20°C) environment for subsequent experimental use.

[0035] 3) Grouting: Start the peristaltic pump 14, and pump the microbial cement slurry in the microbial solution 11 into the grouting pipe 5 through the delivery pipe 15. The grouting rate is controlled at 3 ml / min to ensure that the slurry is evenly released through the slurry release hole 7 in the grouting pipe 5 and penetrates into the surrounding soil 29 to form a reinforcement layer. During the grouting process, monitor the grouting pressure, pH value (controlled at 8.0-8.5) and temperature (maintained at 25-30°C) to ensure the microbial activity and calcium carbonate deposition effect. After 5-10 minutes of injection, negative pressure is applied to the inside of the suction cylinder 1 through the water outlet 3 using the vacuum pump 16 and the negative pressure tank 17 to further promote the penetration and uniform distribution of the microbial cement slurry in the soil 29. The negative pressure is formed by the negative pressure pump to extract upward, which is parallel to the grouting.

[0036] 4) Loading test: After the microbial cement slurry solidifies in the soil 29 to form a stable reinforcement layer, install the loading ring 24 on the top of the suction cylinder 1, and connect the wire rope 25 and the weight 26. By gradually increasing the weight of the weight, a vertical load is applied to the suction cylinder 1 to simulate the load-bearing conditions in the service stage. During the loading process, the LVDT displacement sensor 22 and the inclination sensor 23 are used to monitor the vertical displacement and inclination angle of the suction cylinder, respectively, to evaluate its stability and load-bearing capacity. At the same time, through the CPT test hole 4, the CPT connecting screw 27 and the CPT probe 28 are used to test the mechanical parameters of the soil to further evaluate the effect of microbial reinforcement.

[0037] The present invention utilizes microbial induced calcium carbonate deposition (MICP) technology to form a low-strength reinforcement layer in the gap between the suction cylinder and the soil by injecting microbial cement slurry, thereby improving the overall performance of the suction cylinder. Microbial cement has the advantages of being environmentally friendly, having strong consolidation strength, and being applicable in marine environments. By adopting microbial cement technology, the problem of strength reduction of traditional low-strength cement due to environmental changes during long-term use can be avoided, and the long-term bearing capacity and anti-liquefaction performance of the suction cylinder foundation can be significantly improved. In addition, the use of microbial cement can also reduce dependence on chemical additives and further reduce potential pollution to the marine environment.

[0038] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art of the present invention, several equivalent substitutions or obvious variations can be made without departing from the concept of the present invention, and the performance or use is the same, which should be regarded as belonging to the protection scope of the present invention.

Claims

1. A composite reinforced suction cylinder device based on microbial induction, characterized in that: include: Suction cylinder model system, microbial cement reinforcement system and test monitoring system; The suction cylinder model system comprises a suction cylinder (1), a grouting pipe (5) and a lifting device, wherein the grouting pipe (5) is laid on the inner wall of the suction cylinder (1) and is used to inject microbial cement slurry; the lifting device is connected to the suction cylinder and is used to control the lifting and pressing of the suction cylinder; The microbial cement reinforcement system comprises a liquid storage device and a negative pressure device, wherein the liquid storage device is connected to the grouting pipeline (5) and is used to store and provide the microbial cement slurry to the grouting pipeline (5); The negative pressure device is connected to the suction cylinder (1) and is used to apply negative pressure to the inside of the suction cylinder during the grouting process to promote the penetration of the microbial cement slurry; The test monitoring system is used for soil mechanical parameter testing, suction cylinder monitoring, and loading testing of the suction cylinder.

2. The microbial-induced composite reinforced suction cylinder device according to claim 1, characterized in that: The lifting device comprises: a connecting screw (2), a vertical screw (8), a hydraulic cylinder (10), a lifting beam and a wire displacement sensor (9) for real-time recording of the displacement of the suction cylinder; one end of the connecting screw (2) is installed on the top of the suction cylinder, and the other end passes through the lifting beam and is connected to the vertical screw (8), and the lifting beam is connected to the hydraulic cylinder.

3. The microbial-induced composite reinforced suction cylinder device according to claim 1, characterized in that: The top of the suction cylinder (1) is provided with a water outlet hole (3) and a test hole (4); the negative pressure equipment performs negative pressure penetration pumping and negative pressure circulation during grouting through the water outlet hole; and the test monitoring system performs soil mechanical parameter testing through the test hole.

4. The microbial-induced composite reinforced suction cylinder device according to claim 1, characterized in that: The grouting pipe (5) is spirally laid from the upper part to the lower part along the inner wall of the suction cylinder, and a plurality of slurry release holes (7) are opened on the pipe wall of the grouting pipe; The microbial cement reinforcement system also includes a delivery pipeline (15) on which a peristaltic pump (14) is installed. One end of the delivery pipeline (15) is connected to the liquid storage device, and the other end is connected to a grouting port (6) opened on the upper part of the suction cylinder. The upper end of the grouting pipeline (5) is connected to the grouting port (6).

5. The microbial-induced composite reinforced suction cylinder device according to claim 1, characterized in that: The microbial cement reinforcement system further comprises: a nutrient solution tank (12) and a concentrated seawater tank (13), which are respectively used to store the nutrient solution and concentrated seawater required for culturing the microbial cement slurry.

6. The microbial-induced composite reinforced suction cylinder device according to claim 1, characterized in that: The test monitoring system comprises: a CPT test device, an LVDT displacement sensor (22), an inclination sensor (23) and a loading test device. The CPT test device is used to test the mechanical parameters of the in-situ soil in the suction cylinder and the soil after micro-cement reinforcement. The LVDT displacement sensor and the inclination sensor are used to monitor the displacement and inclination of the suction cylinder during the loading process. The loading test device is used to perform a loading test on the suction cylinder to simulate the load-bearing condition in the service stage.

7. The microbial-induced composite reinforced suction cylinder device according to claim 6, characterized in that: The loading test equipment comprises: a loading ring (24), a steel wire rope (25) and a weight (26); the loading ring is used to be installed on the top of the suction cylinder during the loading test phase; one end of the steel wire rope is connected to the loading ring and the other end is connected to the weight.

8. The method for using the microbial-induced composite reinforced suction cylinder device according to any one of claims 1 to 7, characterized in that: The steps include: S1. Pressing the suction cylinder into the soil to a target depth by means of the lifting device; S2, transporting the microbial cement slurry in the liquid storage device to the grouting pipeline, performing grouting at a predetermined rate, and applying negative pressure to the inside of the suction cylinder through the negative pressure device to promote the microbial cement slurry to penetrate into the soil; S3. After the grouting is completed to form the reinforcement layer, the suction cylinder is subjected to a loading test using the test monitoring system, and the soil mechanical parameter test and the suction cylinder monitoring are performed.

9. The method for using the microbial-induced composite reinforced suction cylinder device according to claim 8, characterized in that: The microbial cement slurry is prepared by mixing microbial suspension, nutrient solution and concentrated seawater in proportion; wherein the microbial suspension is obtained by culturing high urease bacteria to a bacterial liquid concentration OD600 of 1.2 to 1.5; the nutrient solution is used to provide a carbon source, and the concentrated seawater is used to provide a calcium source.

10. The method for using the microbial-induced composite reinforced suction cylinder device according to claim 8, characterized in that: Also includes: During the grouting process, the injection pressure, pH value and temperature are monitored, among which the pH value is controlled at 8.0-8.5 and the temperature is maintained at 25-30°C to ensure the microbial activity and calcium carbonate deposition effect.

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