Piston type self-expansion seabed slope reinforcing system and method based on microbial grouting

Abstract

The invention relates to the technical field of seabed geotechnical engineering and side slope reinforcement, and discloses a piston type self-expansion seabed side slope reinforcement system and method.The piston type self-expansion seabed side slope reinforcement system based on microbial grouting comprises a sea surface supporting system which comprises a sea surface control ship and a multifunctional control vehicle, and the multifunctional control vehicle is connected with the sea surface control ship through an umbilical cable; the anchoring system comprises an anchoring part and a plurality of anchor rods, the anchor rods are lowered into anchor holes in the seabed stratum through the multifunctional control vehicle, the anchor rods are used for pumping and draining pore water of a soil body, and the anchoring part is installed on the anchor rods through the multifunctional control vehicle; and the microorganism grouting system is arranged on the sea surface control ship and used for injecting microorganism slurry into the anchor holes, an expansion structure is arranged on the anchor rod, and the expansion structure on the anchor rod makes contact with the microorganism slurry. The method effectively solves the problems of surface scouring, deep slippage and interface separation of the seabed slope, and has the advantages of being good in reinforcing effect, environmentally friendly, high in adaptability and high in construction efficiency.

Description

Technical Field

[0001] This invention relates to the field of submarine geotechnical engineering and slope reinforcement technology, and in particular to a piston-type self-expanding submarine slope reinforcement system and method based on microbial grouting. Background Technology

[0002] Submarine slope reinforcement technology is a core challenge in ensuring the safety of marine engineering. Existing technologies face multiple bottlenecks when dealing with high pressure, high salt corrosion and complex geological conditions in the deep sea, specifically manifested in the following four major systemic defects.

[0003] (1) Engineering limitations of traditional grouting technology: Although cement-based grouting has high short-term strength, the diffusion of grout in the deep-sea environment is restricted by high pressure, which easily leads to the formation of local solidification and uneven reinforcement. In addition, traditional grouting relies on gravity infiltration, and the diffusion radius of grout in the soft soil layer of the deep sea is small, requiring dense hole layout, resulting in low construction efficiency. In the construction of deep-water inclined pile foundations, traditional straight pile drilling grouting requires repeated hole cleaning, which prolongs the construction cycle of a single pile, and the grouting effect is significantly affected by water flow disturbance.

[0004] (2) Structural defects of mechanical anchoring technology: Traditional steel anchors have a high annual corrosion rate in seawater with a salt content of 3.5%, which leads to an increased rate of anchoring force decay within 10 years. In addition, gravity anchors have insufficient pull-out resistance in soft seabed soil layers and are prone to borehole wall collapse during construction.

[0005] (3) Functional shortcomings of geosynthetics: After long-term immersion in seawater, the tensile strength of geogrids decreases by 8%-12% per year, and after 5 years it can only maintain 50% of the initial strength. In addition, underwater laying of geosynthetics requires diving operations, which are inefficient and greatly affected by ocean currents.

[0006] (4) The time-related dilemma of drainage consolidation technology: Vacuum preloading method requires 12-18 months to complete consolidation in soft seabed soil, which is far beyond the construction period requirements of marine engineering. In addition, traditional drainage boards are prone to uneven consolidation due to siltation.

[0007] In summary, existing seabed slope reinforcement technologies suffer from systemic deficiencies in terms of material durability, construction efficiency, environmental adaptability, and long-term stability, making it difficult to meet the comprehensive safety, environmental protection, and economic requirements of deep-sea engineering. Therefore, it is essential to develop a more efficient, environmentally friendly, and economical seabed slope reinforcement technology.

[0008] Therefore, there is an urgent need for a piston-type self-expanding seabed slope reinforcement system and method based on microbial grouting to solve the above problems. Summary of the Invention

[0009] The purpose of this invention is to provide a piston-type self-expanding seabed slope reinforcement system and method based on microbial grouting, so as to solve the problems existing in the prior art.

[0010] To achieve the above objectives, the present invention provides the following solution: The present invention provides a piston-type self-expanding seabed slope reinforcement system based on microbial grouting, comprising:

[0011] The surface support system includes a surface control vessel and a multi-functional control vehicle. The surface control vessel is located on the sea surface, and the multi-functional control vehicle operates on the seabed and is connected to the surface control vessel via an umbilical cable.

[0012] An anchoring system, including anchors and multiple anchor rods, wherein the anchor rods are lowered into anchor holes on the seabed strata by the multi-functional control vehicle, the anchor rods are used to pump out pore water from the soil, and the anchors are installed on the anchor rods by the multi-functional control vehicle;

[0013] A microbial grouting system is installed on the surface control vessel. The microbial grouting system is used to inject microbial slurry into the anchor hole. An expansion structure is provided on the anchor bolt, and the expansion structure on the anchor bolt is in contact with the microbial slurry.

[0014] Preferably, a tray is fixedly connected to the top of the anchor rod, a drill bit is fixedly connected to the bottom of the anchor rod, an inner metal rod is provided inside the anchor rod, a piston section limiting block is provided at the bottom of the anchor rod, the bottom end of the inner metal rod extends into the piston section limiting block and is fixedly connected to an inner piston rod body, a piston head is fixedly connected to the bottom end of the inner piston rod body, a sealing device is installed at the bottom end of the piston head, a drainage hole is provided inside the anchor rod, one end of the drainage hole is connected to the piston working section inside the piston section limiting block through a piston section one-way valve, and the other end of the drainage hole extends out of the tray and is equipped with a drainage one-way valve.

[0015] Preferably, the drill bit has a hollow channel, the inlet end of which is equipped with a one-way valve and a filter, and the outlet end of which is connected to the piston working section.

[0016] Preferably, the microbial grouting system includes a multi-stage delivery pipe, one end of which is connected to a tank on the surface control vessel, and the other end of which is connected to a relay chamber via a multi-stage grouting pump. A temporary grout storage tank is installed in the relay chamber, and the temporary grout storage tank is connected to a grouting pipe filter device via a grouting pipe. A flow meter is installed on the grouting pipe, and multiple grouting holes are opened on the tray. The output end of the grouting pipe filter device is connected to the grouting holes.

[0017] Preferably, the anchor includes an integral steel hoop and multiple fixing nuts, the integral steel hoop being installed on the inner metal rod of the anchor rod via the fixing nuts.

[0018] Preferably, the multi-functional control vehicle is equipped with an air compressor / injection device mounting box, a shotcrete material mounting box, and a multi-functional robotic arm. The air compressor / injection device mounting box is connected to an injection pipe, the shotcrete material mounting box is connected to a shotcrete hose, the tray has an injection hole, the injection pipe is connected to the injection hole, and the shotcrete hose is used to spray mortar onto the integrated steel hoop to form a shotcrete surface.

[0019] Preferably, the expansion structure includes an outer rod of the anchor rod, which is installed on the outside of the anchor rod. A hemispherical friction-enhancing structure is provided on the outer wall of the outer rod of the anchor rod. An injection cavity is provided inside the hemispherical friction-enhancing structure, and the injection cavity is connected to the injection hole.

[0020] Preferably, a protective casing is provided inside the anchor hole, and the anchor rod is located inside the protective casing.

[0021] Preferably, the tray is fixedly connected with several barbs.

[0022] A piston-type self-expanding seabed slope reinforcement method based on microbial grouting includes the following steps:

[0023] Anchor holes are drilled on the slope of the seabed strata, and anchor bolts are lowered into the anchor holes;

[0024] The operation involves pumping out pore water from the soil using anchor bolts.

[0025] Microbial grout is injected into the anchor hole using a microbial grouting system;

[0026] Injecting self-heating material into the anchor bolt causes it to expand due to heat.

[0027] Anchors were installed on the slope of the seabed strata and shotcrete material was sprayed.

[0028] Compared with the prior art, the present invention has the following advantages and technical effects:

[0029] This invention provides a piston-type self-expanding seabed slope reinforcement system and method based on microbial grouting. A surface control vessel is connected to a multi-functional control vehicle via an umbilical cable, enabling power transmission, data communication, and physical traction. The multi-functional control vehicle operates underwater, using anchor bolts to depressurize and drain loose, high-moisture-content deep-sea soft soil, increasing its density. A microbial grouting system injects microbial slurry, which diffuses more easily and evenly in the drained soil. An expansion structure ensures close contact between the anchor bolts and the slurry. Finally, anchor bolts rigidly connect multiple anchor bolts, effectively transferring the surface soil load to the deep reinforcement system while simultaneously resisting seawater erosion, corrosion, and biological attack. This invention effectively solves the problems of surface erosion, deep slippage, and interface delamination in seabed slopes, offering advantages such as good reinforcement effect, environmental friendliness, strong adaptability, and high construction efficiency. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly described below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0032] Figure 2 This is a schematic diagram of the anchor bolt distribution of the present invention;

[0033] Figure 3 This is a schematic diagram of the internal structure of the anchor bolt of the present invention;

[0034] Figure 4 This is a schematic diagram of the sprayed anchor surface structure of the present invention;

[0035] Figure 5 This is a cross-sectional view of the anchor bolt of the present invention;

[0036] Figure 6 This is a top view of the anchor bolt of the present invention;

[0037] Figure 7 This is a schematic diagram of the anchor bolt reinforcement state according to the present invention;

[0038] Figure 8 This is a schematic diagram of the integrated steel hoop wire connection of the present invention;

[0039] Figure 9 This is a flowchart illustrating the construction process of this invention.

[0040] The components include: 1. Surface control vessel; 2. Microbial grouting device; 3. Main control computer; 4. Umbilical cable; 5. Multi-stage delivery pipe; 6. Multi-stage grouting pump; 7. Relay compartment; 8. Temporary grout storage tank; 9. Flow meter; 10. Grouting pipe; 11. Grouting pipe filter device; 12. Multi-functional control vehicle; 13. Air compressor / injection device installation box; 14. Injection pipe; 15. Shotcrete and anchor material installation box; 16. Shotcrete and anchor hose; 17. Multi-functional robotic arm; 18. Seabed strata; 19. Anchor bolt; 20. Barb; 21. Tray; 22. Anchor bolt inner metal rod; 23. Drainage one-way valve; 24. Injection hole. 25. Anchor bolt outer rod body; 26. Hemispherical friction-enhancing structure; 27. Sprayed anchor surface; 28. Integrated steel hoop; 29. ​​Fixing nut; 30. Drill bit; 31. Drill bit check valve; 32. Drill bit filter device; 33. Drill bit hollow channel; 34. Piston section check valve; 35. Casing range; 36. Injection chamber; 37. Piston section limit block; 38. Piston working section; 39. Drainage hole; 40. Piston head; 41. Sealing device; 42. Piston inner rod body; 43. Grouting hole; 44. Casing; 45. Microbial grouting area; 46. Drilling range; 47. Pore pressure sensor; 48. Temperature sensor. Detailed Implementation

[0041] 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.

[0042] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0043] Reference Figures 1-9 This invention provides a piston-type self-expanding seabed slope reinforcement system based on microbial grouting, comprising:

[0044] The surface support system includes a surface control vessel 1 and a multi-functional control vehicle 12. The surface control vessel 1 is located on the sea surface, and the multi-functional control vehicle 12 operates on the seabed and is connected to the surface control vessel 1 via an umbilical cable 4.

[0045] The anchoring system includes anchors and multiple anchor bolts 19. The anchor bolts 19 are lowered into anchor holes on the seabed strata 18 by a multi-functional control vehicle 12. The anchor bolts 19 are used to pump out pore water from the soil. The anchors are installed on the anchor bolts 19 by the multi-functional control vehicle 12.

[0046] A microbial grouting system is installed on the surface control vessel 1. The microbial grouting system is used to inject microbial slurry into the anchor hole. An expansion structure is provided on the anchor bolt 19, and the expansion structure on the anchor bolt 19 is in contact with the microbial slurry.

[0047] In one embodiment of the present invention, the surface control vessel 1 is equipped with a main control computer 3, a material storage and preparation unit of the microbial grouting device 2, a power system, etc. The surface control vessel 1 is connected to the multi-functional control vehicle 12 through an armored umbilical cable 4 to realize power transmission, data communication and physical traction. The anchor bolts 19 are set to decompress and drain the loose, high-moisture deep-sea soft soil, thereby increasing its density. The microbial grouting system injects microbial slurry, which is more easily and evenly diffused in the drained soil. The expansion structure ensures that the anchor bolts 19 are in close contact with the slurry. Finally, the anchor bolts are applied to rigidly connect multiple anchor bolts 19, effectively transferring the surface soil load to the deep reinforcement system, while resisting seawater erosion, corrosion and biological erosion.

[0048] In one embodiment of the present invention, a monitoring system is also included, which is installed in the multi-functional control vehicle 12. The monitoring system includes multiple sets of pore pressure sensors, flow monitors, temperature sensors, temperature control modules, and underwater high-definition cameras for monitoring underwater operations.

[0049] In one embodiment of the present invention, the multi-functional control vehicle 12 is a tracked multi-functional control vehicle, which is controlled by an operator on the water surface for movement and operation. It is equipped with a power supply device, a platform heat exchanger, a high-definition camera system, and a lighting system to support complex tasks such as drilling, piston extraction, grouting, steel mesh binding, shotcreting, and maintenance.

[0050] As an optional implementation, a tray 21 is fixedly connected to the top of the anchor rod 19, a drill bit 30 is fixedly connected to the bottom of the anchor rod 19, an inner metal rod 22 is provided inside the anchor rod 19, a piston section limiting block 37 is provided at the bottom of the anchor rod 19, the bottom end of the inner metal rod 22 extends into the piston section limiting block 37 and is fixedly connected to an inner piston rod body 42, a piston head 40 is fixedly connected to the bottom end of the inner piston rod body 42, a sealing device 41 is installed at the bottom end of the piston head 40, a drainage hole 39 is provided inside the anchor rod 19, one end of the drainage hole 39 is connected to the piston working section 38 inside the piston section limiting block 37 through a piston section one-way valve 34, and the other end of the drainage hole 39 extends out of the tray 21 and is equipped with a drainage one-way valve 23.

[0051] In one embodiment of the present invention, by setting a precision piston system consisting of a piston head 40, a sealing device 41, a piston working section 38, and an associated one-way valve, the structure upgrades the traditional passive anchor 19 into a dynamic component with active drainage and consolidation function. It can directly and quickly pump out the surrounding pore water after being implanted into the soil, effectively reduce pore pressure, improve soil density, and create favorable conditions for subsequent microbial slurry infiltration and solidification, fundamentally improving the initial effect and reliability of the reinforcement.

[0052] As an optional implementation, the drill bit 30 has a hollow drill bit channel 33. The inlet end of the hollow drill bit channel 33 is equipped with a drill bit check valve 31 and a drill bit filter device 32. The outlet end of the hollow drill bit channel 33 is connected to the piston working section 38.

[0053] In one embodiment of the present invention, the hollow channel 33 of the drill bit serves as the intake path for pore water, and the one-way valve 31 at its inlet end ensures that the water flow can only flow in one direction to prevent backflow; the drill bit filter device 32 can effectively intercept solid particles in the soil to prevent them from entering the piston working section and causing blockage or wear.

[0054] As an optional implementation, the microbial grouting system includes a multi-stage delivery pipe 5, one end of which is connected to a tank on the surface control vessel 1. The other end of the multi-stage delivery pipe 5 is connected to a relay chamber 7 via a multi-stage grouting pump 6. A temporary grout storage tank 8 is installed in the relay chamber 7. The temporary grout storage tank 8 is connected to a grouting pipe filter device 11 via a grouting pipe 10. A flow meter 9 is installed on the grouting pipe 10. Multiple grouting holes 43 are opened on the tray 21. The output end of the grouting pipe filter device 11 is connected to the grouting holes 43.

[0055] In one embodiment of this invention, a mode of surface storage-multi-stage pump pipeline delivery-subsea relay is adopted to solve the problems of pressure loss and stability during long-distance grout delivery under high-pressure deep-sea conditions. The relay chamber 7 and temporary storage tank enable buffering and localized supply of the grout, the flow meter enables precise control of the grout volume, and the grout pipe filtration device ensures the purity of the grout. Finally, grout is injected through the grouting holes on the tray, ensuring that the grout can be evenly injected into the reinforced area around the anchor bolt, achieving controllable and efficient microbial bonding construction.

[0056] In one embodiment of the invention, the tank on the surface control vessel 1 is a microbial culture storage tank, a double-walled stainless steel vacuum insulated tank, with temperature control at 2-8℃, equipped with a sterile filter membrane and low-speed stirring, to achieve low-temperature sterile storage of Bacillus pasteurellii, suitable for the high-salt environment on board. It also includes a culture medium preparation tank, a stainless steel vertical tank equipped with a low-shear combined stirring, heating sterilization module and pH / concentration monitor, to achieve uniform dissolution and sterile processing of nutrients. The microbial slurry is a mixed slurry of bacterial culture and cementing solution in a 1:1 ratio. The slurry filtration device is a circular filter screen with a unit size of 1mm and a thickness of 10mm. The stirring device consists of a stainless steel static mixer and a Hastelloy alloy shaft dynamic stirrer.

[0057] As an optional implementation, the anchor includes an integral steel hoop 28 and a plurality of fixing nuts 29, the integral steel hoop 28 being mounted on the inner metal rod 22 of the anchor bolt via the fixing nuts 29.

[0058] In one embodiment of the present invention, the integrated steel hoop 28 is rigidly connected to the top of each anchor rod 19 via a fixing nut 29, thereby connecting all the independent anchor rods on the slope surface into a unified force network. This connection method extends the single-point anchoring force into a distributed surface constraint force, greatly enhancing the integrity and tensile strength of the slope surface soil, effectively resisting wave erosion, preventing local spalling, and uniformly transferring the surface load to the deep reinforcement system.

[0059] As an optional implementation, the multi-functional control vehicle 12 is equipped with an air compressor / injection device mounting box 13, a shotcrete material mounting box 15, and a multi-functional robotic arm 17. The air compressor / injection device mounting box 13 is connected to an injection pipe 14, and the shotcrete material mounting box 15 is connected to a shotcrete hose 16. An injection hole 24 is opened on the tray 21, and the injection pipe 14 is connected to the injection hole 24. The shotcrete hose 16 is used to spray mortar onto the integrated steel hoop 28 to form a shotcrete surface 27.

[0060] In one embodiment of the present invention, an air compressor, a mortar injection device, a shotcrete material bin, and a multi-functional robotic arm are integrated onto a single underwater control vehicle, enabling one-stop continuous operation of multiple processes such as drilling, anchoring, mortar injection, and shotcrete. This significantly reduces the number of times and time required for equipment hoisting and replacement in deep-sea environments, substantially improves construction efficiency, and reduces operational risks and complexity, making it a key platform for achieving efficient and automated subsea construction.

[0061] As an optional implementation, the expansion structure includes an outer rod body 25 of the anchor rod, which is installed on the outside of the anchor rod 19. A hemispherical friction-enhancing structure 26 is provided on the outer wall of the outer rod body 25. An injection cavity 36 is provided inside the hemispherical friction-enhancing structure 26, and the injection cavity 36 is connected to the injection hole 24.

[0062] In one embodiment of the present invention, the outer rod body 25 of the anchor bolt is made of a special thermally expandable material. Its internal injection cavity 36 is used to contain the self-heating material. The hemispherical friction-enhancing structure 26 on the outer wall provides initial friction when unexpanded, and after expansion, it can embed more deeply into the surrounding soil or grout. When the self-heating material is activated, the heat causes the outer rod body to expand uniformly, causing the hemispherical structure to generate significant radial compressive force, thereby forming a strong interlocking effect with the soil.

[0063] As an optional implementation, a protective sleeve 44 is provided inside the anchor hole, and the anchor rod 19 is located inside the protective sleeve 44.

[0064] In one embodiment of the present invention, the top of the casing 44 is 0.3m above the surface of the seabed slope, and the diameter of the casing is 1.3 times the diameter of the hole. After drilling is completed, the casing and drilling device are retrieved into the recovery bin of the multi-functional control vehicle by a multi-functional robotic arm. The casing 44 is a casing range 35, and the drilling range 46 set within the casing range 35 is set as a microbial grouting area 45, in which microbial grout is injected.

[0065] As an optional implementation, a plurality of barbs 20 are fixedly connected to the tray 21.

[0066] In one embodiment of the present invention, the barbs 20 on the tray 21 will penetrate 0.3m into the slope to enhance the anchoring ability of the anchor bolt 19.

[0067] In one embodiment of the present invention, a pore pressure sensor 47 is further included for monitoring pore pressure, and a temperature sensor 48 is included for monitoring temperature.

[0068] A piston-type self-expanding seabed slope reinforcement method based on microbial grouting includes the following steps:

[0069] Anchor holes are drilled on the slope of seabed stratum 18, and anchor bolts 19 are lowered into the anchor holes.

[0070] The soil pore water is pumped out using anchor bolt 19;

[0071] Microbial grout is injected into the anchor hole using a microbial grouting system;

[0072] Injecting self-heating material into the anchor bolt 19 causes the anchor bolt 19 to expand due to heat;

[0073] Anchors were installed on the slope of seabed stratum 18 and shotcrete material was sprayed.

[0074] In one embodiment of the present invention, during use:

[0075] Submarine slope site exploration: Sonar technology is used to scan the seabed topography, identify slope gradient, hydrate distribution, and seabed sediment types. Soil samples are obtained using a deep-sea drilling vessel to determine the soil's physical and mechanical parameters (porosity, cohesion, internal friction angle, etc.). Finally, a three-dimensional geological model is established based on the topographic exploration results and physicochemical property analysis to determine the borehole layout.

[0076] Parameter design: Based on the results of seabed topographic exploration and three-dimensional geological model, the spacing and depth of boreholes, as well as the borehole diameter and design elevation, are designed. In addition, the piston pumping frequency and the amount and flow rate of microbial grouting fluid are designed according to certain specifications and construction process requirements.

[0077] Equipment preparation: Prepare high-pressure grouting pumps, temperature-controlled storage tanks, hydraulic power units, etc. on the offshore operation platform, connect the multi-stage delivery hard pipes, multi-stage high-pressure grouting pumps, relay chambers and grouting pipes, and turn on the main control computer.

[0078] The multi-functional control vehicle (the work vehicle is equipped with a pre-designed piston-type self-expanding anchor bolt, laser rangefinder, hydraulic vibratory hammer, steel casing, fixing nut, multiple sensors, air compressor, prepared shotcrete material and shotcrete hose, etc.) is controlled by the marine equipment to install the injection pipe and grouting pipe through the multi-functional robotic arm of the multi-functional control vehicle, and the drilling position is determined by a high-definition camera.

[0079] Materials preparation:

[0080] Preparation and purification of bacterial culture: Prepare LB liquid medium according to the standard formula. Under the aseptic environment of a laminar flow hood, inoculate Bacillus pasteurellii into the LB medium and incubate it in a constant temperature shaking incubator for a certain period of time. Transfer the cultured bacterial culture to a sterile centrifuge tube and centrifuge at a constant speed for 10-20 minutes. Discard the supernatant (retain the bacterial precipitate), resuspend the bacterial cells with sterile physiological saline, and repeat the centrifugation-resuspending operation 2-3 times to purify the bacterial cells. Finally, prepare the bacterial culture to the designed concentration and store it in a corrosion-resistant polyethylene sterile container at a low temperature (4°C) in the dark (storage time not exceeding 24 hours).

[0081] Preparation of cementing solution: Prepare urea and calcium chloride solutions (urea 5 mol / L, calcium chloride 3 mol / L). The urea and calcium chloride solutions should be stored separately to avoid pre-mixing, which could lead to precipitation. III. Preparation of microbial grouting solution: Under aseptic conditions, mix the bacterial solution and cementing solution (urea and calcium chloride solutions mixed in equal volumes beforehand) at a 1:1 volume ratio. Use a sterile magnetic stirrer and keep the stirring time within 5 minutes (to minimize microbial activity loss). The mixed MICP grout should be injected within 4 hours to prevent bacterial activity decay or system precipitation.

[0082] Casing installation and drilling: The casing is vertically positioned to the designed hole location using a multi-functional control vehicle. The laser rangefinder is calibrated, and the casing is slowly and evenly lowered to the designed elevation using a hydraulic vibratory hammer (the top of the casing is 0.3m above the seabed slope surface). The drilling device is then activated, and high-pressure water jets are simultaneously used to break up the rock and soil. The debris inside the hole flows out from the hole in a solid-liquid mixture. The drilling sequence uses a horizontal and vertical alternating hole construction method. Next, the piston-type new anchor bolt is lowered into the hole. The position is calibrated using a laser rangefinder, and the tray is pressed tightly against the seabed slope surface using a hydraulic hammer (the anchor bolt drill bit elevation will be lower than the hole bottom elevation, with the drill bit penetrating 0.3m into the hole bottom).

[0083] Sensor placement: The multi-functional robotic arm of the multi-functional control vehicle vertically places the borehole pressure sensor and temperature sensor in a certain order on the borehole wall, ensuring that the position will not delay the piston extraction and grouting of the anchor bolt. At the same time, the underwater high-definition camera starts working, and the operators of the surface control vessel test whether the sensors and high-definition camera are working properly.

[0084] Piston extraction: The magnetic attraction device in the multi-functional control vehicle attracts the piston metal rod, which reciprocates through the hydraulic power device. When it is lifted, the one-way valve opens to extract pore water from the surrounding soil. When it is pressed down, the one-way valve closes and the pore water is discharged from the drainage hole. When the pore pressure reaches the critical value, the piston extraction stops and all one-way valves are closed.

[0085] Microbial grouting: A multi-stage high-pressure grouting pump, relay chamber, and offshore working platform grouting device are connected via corrosion-resistant and high-pressure-resistant metal delivery pipes. Before starting grouting, the pipeline is flushed with sterile seawater to prevent contamination of the bacterial solution. The grouting platform is then activated and grouting is carried out in layers. During grouting, the monitoring data from the flow monitor and temperature sensor are constantly monitored. Grouting is terminated after the design elevation is reached.

[0086] Anchor bolt self-heating expansion: Self-heating material is injected into the anchor bolt's injection port through the injection pipe connected to the multi-functional control vehicle. The self-heating material causes the anchor bolt shell to expand and contract appropriately due to thermal expansion and contraction, which strengthens the friction and adhesion between the anchor bolt shell and the microbial grout and soil layer.

[0087] Slope spraying and anchoring: The multi-functional robotic arm in the multi-functional control vehicle uses a pre-fabricated integrated steel hoop to fit the top metal anchor head of the metal inner rod in both the vertical and vertical directions, and fixes the integrated steel hoop with a fixing nut. Then, underwater mortar is sprayed onto the surface of the seabed slope using a wet spraying method.

[0088] Maintenance and monitoring: Within 24 hours after grouting, the multi-functional robotic arm of the multi-functional control vehicle adjusts the seawater temperature (20-30℃) through the temperature control module. After maintenance, a core drilling rig is used to collect samples of the reinforced soil to test the calcium carbonate content and unconfined compressive strength.

[0089] This invention relies on a four-pronged mechanism: piston drainage pre-consolidation, thermal expansion of the outer rod for increased friction, MIP deep bonding, and unified stress distribution through slope spraying and anchoring. The pull-out resistance of the anchor bolts is significantly improved compared to traditional anchor bolts. After MIP grouting, a continuous calcium carbonate cementitious body is formed within the soil pores, enhancing the compressive strength of loose seabed soil and improving the slope's anti-slide safety factor, effectively reducing the probability of landslides and other geological disasters. Utilizing Bacillus pasteurellium-induced calcium carbonate deposition (MICP) technology, the grouting fluid is non-toxic and biodegradable, with metabolic products consisting only of calcium carbonate (a natural marine mineral) and ammonia (which dissipates naturally). It avoids the problems of heavy metal leaching, solidification shrinkage cracks, and other issues associated with traditional cement grouting, fully complying with relevant regulations. The marine environmental protection requirements of the Marine Environmental Protection Law for nearshore waters; improved construction efficiency and environmental adaptability: the anchor bolt integrates drainage, thermal expansion injection, and anchoring functions, significantly shortening the single-hole construction cycle compared to traditional processes and reducing the operational risks of switching underwater equipment; the bolt body is made of stainless steel with a polyurea anti-corrosion layer, suitable for highly corrosive seabed environments at depths of 1000-5000m; superior long-term stability and durability: the calcium carbonate cementitious material generated by MIP is a natural mineral, with no risk of aging and degradation in the seabed environment; the mechanical interlocking between the thermally expanded outer bolt body and the soil is a permanent locking structure, avoiding the strength decay after a long period of traditional reinforcement (such as cement grouting), and meeting the long-term stability requirements of marine engineering.

[0090] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0091] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A piston-type self-expanding seabed slope reinforcement system based on microbial grouting, characterized in that, include: The surface support system includes a surface control vessel (1) and a multi-functional control vehicle (12), wherein the surface control vessel (1) is located on the sea surface and the multi-functional control vehicle (12) operates on the seabed and is connected to the surface control vessel (1) via an umbilical cable (4). An anchoring system, including anchors and multiple anchor rods (19), the anchor rods (19) being lowered into anchor holes on the seabed strata (18) by the multi-functional control vehicle (12), the anchor rods (19) being used to pump out pore water from the soil, and the anchors being installed on the anchor rods (19) by the multi-functional control vehicle (12). A microbial grouting system is installed on the surface control vessel (1). The microbial grouting system is used to inject microbial slurry into the anchor hole. An expansion structure is provided on the anchor bolt (19). The expansion structure on the anchor bolt (19) is in contact with the microbial slurry.

2. The piston-type self-expanding seabed slope reinforcement system based on microbial grouting according to claim 1, characterized in that: The top end of the anchor rod (19) is fixedly connected to a tray (21), the bottom end of the anchor rod (19) is fixedly connected to a drill bit (30), the anchor rod (19) is provided with an inner metal rod (22), the bottom end of the anchor rod (19) is provided with a piston section limiting block (37), the bottom end of the inner metal rod (22) extends into the piston section limiting block (37) and is fixedly connected to a piston inner rod body (42), the bottom end of the piston inner rod body (42) is fixedly connected to a piston head (40), the bottom end of the piston head (40) is equipped with a sealing device (41), the anchor rod (19) is provided with a drainage hole (39), one end of the drainage hole (39) is connected to the piston working section (38) inside the piston section limiting block (37) through a piston section one-way valve (34), and the other end of the drainage hole (39) extends out of the tray (21) and is equipped with a drainage one-way valve (23).

3. The piston-type self-expanding seabed slope reinforcement system based on microbial grouting according to claim 2, characterized in that: The drill bit (30) has a hollow channel (33) inside. The inlet end of the hollow channel (33) is equipped with a drill bit check valve (31) and a drill bit filter device (32). The outlet end of the hollow channel (33) is connected to the piston working section (38).

4. The piston-type self-expanding seabed slope reinforcement system based on microbial grouting according to claim 2, characterized in that: The microbial grouting system includes a multi-stage delivery pipe (5), one end of which is connected to a tank on the surface control vessel (1). The other end of the multi-stage delivery pipe (5) is connected to a relay chamber (7) via a multi-stage grouting pump (6). A temporary slurry storage tank (8) is provided in the relay chamber (7). The temporary slurry storage tank (8) is connected to a grouting pipe filter device (11) via a grouting pipe (10). A flow meter (9) is installed on the grouting pipe (10). Multiple grouting holes (43) are opened on the tray (21). The output end of the grouting pipe filter device (11) is connected to the grouting holes (43).

5. The piston-type self-expanding seabed slope reinforcement system based on microbial grouting according to claim 2, characterized in that: The anchor includes an integral steel hoop (28) and multiple fixing nuts (29), the integral steel hoop (28) being installed on the inner metal rod (22) of the anchor rod via the fixing nuts (29).

6. The piston-type self-expanding seabed slope reinforcement system based on microbial grouting according to claim 5, characterized in that: The multi-functional control vehicle (12) is equipped with an air compressor / injection device installation box (13), a spray anchor material installation box (15), and a multi-functional robotic arm (17). The air compressor / injection device installation box (13) is connected to an injection pipe (14), and the spray anchor material installation box (15) is connected to a spray anchor hose (16). The tray (21) is provided with an injection hole (24), and the injection pipe (14) is connected to the injection hole (24). The spray anchor hose (16) is used to spray mortar onto the integrated steel hoop (28) to form a spray anchor surface (27).

7. The piston-type self-expanding seabed slope reinforcement system based on microbial grouting according to claim 6, characterized in that: The expansion structure includes an outer rod body (25) of the anchor rod, which is installed on the outside of the anchor rod (19). A hemispherical friction-enhancing structure (26) is provided on the outer wall of the outer rod body (25). An injection cavity (36) is provided inside the hemispherical friction-enhancing structure (26), and the injection cavity (36) is connected to the injection hole (24).

8. The piston-type self-expanding seabed slope reinforcement system based on microbial grouting according to claim 1, characterized in that: A protective sleeve (44) is provided inside the anchor hole, and the anchor rod (19) is located inside the protective sleeve (44).

9. The piston-type self-expanding seabed slope reinforcement system based on microbial grouting according to claim 2, characterized in that: Several barbs (20) are fixedly connected to the tray (21).

10. A piston-type self-expanding seabed slope reinforcement method based on microbial grouting, applicable to the piston-type self-expanding seabed slope reinforcement system based on microbial grouting as described in claim 1, characterized in that, Includes the following steps: Anchor holes are drilled on the slope of the seabed stratum (18), and anchor rods (19) are lowered into the anchor holes; The soil pore water is pumped out using anchor bolts (19); Microbial grout is injected into the anchor hole using a microbial grouting system; Injecting self-heating material into the anchor rod (19) causes the anchor rod (19) to expand due to heat; Anchors were installed on the slope of the seabed stratum (18) and shotcrete material was sprayed.

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