Magnetic modular underwater screed rail system and method

Abstract

The application discloses a magnetic type modular underwater leveling guide rail system and method, belongs to the technical field of underwater construction of port engineering, and is specifically applied to bed leveling operation of hydraulic structures such as wharfs and breakwaters. In view of technical problems such as low installation efficiency and insufficient butt joint precision caused by low modularization degree of a traditional guide rail system, the system improves wear resistance by coating a composite layer on the steel pipe body, realizes rapid butt joint at a centimeter level by setting a magnetic attraction connecting device at both ends of a guide rail module, ensures underwater sealing by configuring a waterproof rubber gasket with a ring-shaped protrusion on a contact surface, reduces a friction coefficient by coating a molybdenum disulfide coating on both sides through dovetail-shaped guide rails, and installs an infrared sensor at the end to detect an axis alignment state in real time. The device realizes elevation control by cooperating a total station reflector prism with a height adjusting assembly, is mainly used for underwater bed riprap leveling construction, and can significantly improve underwater operation precision and efficiency and reduce maintenance cost.

Description

Technical Field

[0001] This invention relates to the field of underwater construction technology for port engineering, and in particular to a magnetic modular underwater leveling guide rail system and method for leveling the foundation bed of hydraulic structures such as wharves and breakwaters. Background Technology

[0002] Underwater bed leveling is a critical process in port engineering construction, and its accuracy directly affects the stability of structures such as wharves and breakwaters. Traditional guide rail systems mostly adopt segmented steel structures, which are assembled into modules through underwater welding or bolting. However, this method has the following technical bottlenecks: First, the mechanical connection between modules relies on manual operation by divers, with a single docking taking more than 45 minutes. Moreover, due to the influence of water flow disturbance, the axis alignment error often exceeds 5cm, requiring repeated adjustments in subsequent leveling operations. Second, the sealing structure mostly uses flat rubber gaskets, which, under pressure deformation at a water depth of 20m, cause the gap between the contact surfaces to widen, resulting in a leakage rate as high as 3%-5% and accelerating the corrosion of metal components. Third, the guiding mechanism mostly uses ordinary steel rails, with a friction coefficient of more than 0.2 at the contact surface with the scraper, limiting the leveling speed to below 0.3m / s. The wear rate is also high, requiring replacement of the guide rail every kilometer of operation. In addition, the traditional guide rails are too heavy (steel content > 90%), which can easily cause settlement on soft soil foundations, with an elevation deviation accumulation rate of 1cm / 10m.

[0003] In terms of buoyancy compensation, fixed counterweights or inflatable pontoons are often used. The former cannot adapt to changes in water depth, with buoyancy loss exceeding 40% at a depth of 20m. The latter is limited by response speed (>10s) and cannot offset instantaneous load fluctuations caused by wave impact. During construction, the traction disturbance generated by moving the vessel can easily cause displacement of the installed guide rails (typical value 8-12mm), while traditional methods require interruption of construction for manual repositioning, resulting in an efficiency loss of up to 30%. Furthermore, the material injection process also has significant defects: buoyancy materials often produce bubble aggregation (bubble rate >15%) due to improper pressure control, and local density differences lead to uneven buoyancy distribution; cleaning residual materials during dismantling is difficult, with residual material in the cavity exceeding 2kg / m³ after conventional hydraulic flushing, affecting the module's reusability.

[0004] The root causes of the above problems are: 1) The modular design lacks a rapid connection and precise positioning mechanism, making it difficult to balance installation efficiency and accuracy; 2) The material system does not consider the coupling effect of deep-water pressure and dynamic loads, resulting in insufficient buoyancy stability; 3) The control strategy is singular, failing to achieve multi-parameter coordinated adjustment. The main difficulties encountered in the improvement process are: how to improve docking accuracy without increasing structural complexity, how to develop buoyancy materials with pressure-adaptive characteristics, and how to establish an efficient and reliable dynamic compensation system to cope with complex hydrological conditions. These technical bottlenecks severely restrict the quality and efficiency of underwater leveling operations, urgently requiring systematic solutions. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a magnetic modular underwater leveling guide rail system and method, which improves construction efficiency and accuracy.

[0006] To achieve these objectives and other advantages of the present invention, the present invention provides a magnetically attached modular underwater leveling guide rail system, comprising:

[0007] Multiple guide rail modules, each guide rail module comprising a steel pipe body with a rectangular cross-section, the outer surface of which is covered with a composite plastic layer of polyetheretherketone and 10-20 wt% graphite;

[0008] The guide rail module is equipped with magnetic connection devices at both ends. The magnetic connection devices include neodymium iron boron permanent magnet units (nickel-plated on the surface, magnetic field strength ≥1200mT) embedded in the end of the steel pipe. Adjacent guide rail modules are attracted by opposite magnetic poles and the contact surface is provided with a waterproof rubber gasket with annular protrusion (leakage rate <0.5%).

[0009] The lower surface of the guide rail module is provided with a threaded rod height adjustment component with a pitch of 1-3mm (preferably 2mm). The upper surface of the guide rail module is provided with a positioning groove along the length direction. The positioning groove is embedded with a total station reflecting prism, and the center point of the reflecting prism coincides with the axis of the guide rail module.

[0010] The guide rail module is fixed to the dovetail guide rail on both sides by bolts (bolt spacing 500mm), and the guide rail is coated with molybdenum disulfide coating (0.1mm thick).

[0011] The guide rail module is equipped with a docking detection sensor (wavelength 850nm) at its end. The docking detection sensor includes an infrared transmitter and a receiver. The emission direction of the infrared transmitter is parallel to the axis of the guide rail module, and the receiving surface of the receiver corresponds to the position of the transmitter of the adjacent guide rail module (receiving sensitivity -30dBm).

[0012] Furthermore, the steel pipe body has a hollow cavity with a cross-sectional area of ​​60%, which is filled with hollow glass microspheres and silicone rubber buoyancy material in a 3:7 volume ratio.

[0013] Hollow glass microspheres with a particle size of 0.5-1.0 mm and vacuum modified with silane coupling agent; silicone rubber density of 1.05-1.15 g / cm³.

[0014] The hollow cavity is equipped with transverse support plates spaced 1.5m apart. The central through hole of the transverse support plate has a diameter of 100mm and static guide vanes are welded to the edge to reduce turbulence and bubble accumulation when injecting buoyancy material.

[0015] Furthermore, the hollow glass microspheres are coated with a polyurethane membrane with an elastic modulus gradient of 0.5 MPa / m, resulting in a buoyancy loss compensation rate of ≥95% at a water depth of 20 m.

[0016] The guide rail module has several Ni-Ti-Cu alloy airbags embedded at both ends, which expand from 50mm to 150mm in diameter after being heated by electricity; including end airbag groups, which are symmetrically arranged within 1m from both ends of the guide rail module, with 2 airbags in each group, and are symmetrically arranged along the width direction of the guide rail module; and cross-sectional airbag groups, which are arranged every 1.5-2m along the length direction of the guide rail module, with 3 airbags in each group, and are evenly distributed circumferentially.

[0017] Furthermore, a three-level buoyancy compensation system is implemented: when the buoyancy deviation is ≥5%, single airbag compensation is activated; when the deviation is ≥10%, collaborative compensation of three airbags in the same cross-section is activated; and when the deviation is ≥15%, airbag groups of two adjacent cross-sections are activated. The buoyancy deviation is defined as the percentage difference between the measured buoyancy and the theoretical buoyancy: Level 1 compensation: deviation ≥5% (corresponding to a buoyancy loss ≥75N), activates the single airbag closest to the deviation point; Level 2 compensation: deviation ≥10% (≥150N), activates collaborative compensation of three airbags in the same cross-section; Level 3 compensation: deviation ≥15% (≥225N), activates airbag groups of two adjacent cross-sections (spaced 2±0.05m apart).

[0018] Furthermore, each airbag is connected to a PID controller, the transfer function of which is G(s)=2.5+0.8 / s+0.3s, the pressure sensors are arranged at a spacing of 0.5m, and when the pressure on the mating surface is detected to be greater than 1kN, a pressure relief procedure is triggered, with a pressure relief rate of 10mm³ / s;

[0019] The outer wall of the guide rail module is provided with deflectable dynamic guide vanes. The dynamic guide vanes are connected to the static guide vanes and are driven to deflect by a servo motor. The dynamic guide vanes are independent of the static guide vanes and are installed on the water-facing surface of the outer wall of the guide rail module (the water flow direction is monitored in real time by a Doppler current meter) to balance the water flow impact.

[0020] The present invention provides a construction method for the magnetic modular underwater leveling guide rail system, comprising the following steps:

[0021] Step 1: Position the barge parallel to the axis of the trench using GPS.

[0022] Step 2: The adjacent guide rail modules are assembled underwater using a magnetic connection device. The magnetic connection device of the adjacent guide rail modules is attracted by opposite magnetic poles, and a waterproof rubber gasket is installed between the contact surfaces.

[0023] Step 3: Use a total station to position and calibrate the guide rail module, measure the three-dimensional coordinates of the reflecting prism and compare them with the design elevation, and adjust the height adjustment component of the guide rail module so that the elevation of the guide rail module reaches the design value of -5.7m±1cm.

[0024] Step 4: Install dovetail guide rails on both sides of the guide rail module. Verify the axis alignment accuracy of the guide rail module using a docking detection sensor. The docking detection sensor includes an infrared transmitter and a receiver. The emission direction of the infrared transmitter is parallel to the axis of the guide rail module, and the receiving surface of the receiver corresponds to the position of the transmitter of the adjacent guide rail module. When the received signal strength reaches -30dBm, the docking is deemed qualified.

[0025] Step 5: Use a scraper to level the base bed along the top surface of the guide rail module, with the scraper moving at a speed of 0.5 m / s.

[0026] Step 6: After each leveling section is completed, the boat is moved. During the boat movement, the displacement of the installed guide rail module is continuously monitored. When the displacement exceeds 5mm, dynamic buoyancy compensation is triggered.

[0027] Furthermore, dynamic buoyancy compensation includes:

[0028] Fiber optic displacement sensors are arranged at 0.5m intervals along the axis of the guide rail module. The fiber optic sensors monitor the displacement at 100Hz. When the displacement exceeds the threshold, the airbag is expanded by PID control ΔV=2.5Δd+0.8∫Δd+0.3dΔd / dt.

[0029] Synchronously inject silicone rubber slurry containing 15wt% microspheres into the hollow cavity of the guide rail module with excessive displacement to reduce the density to 1.085g / cm³.

[0030] When the guide rail module displacement exceeds 8mm, the adjacent cross-section airbags expand in tandem and deflect the dynamic guide vanes by 30°.

[0031] Furthermore, the buoyancy-resistance balance coefficient is calculated in real time during the compensation process. When the balance coefficient value is lower than 0.95, it automatically switches to the third-level compensation mode and injects compressed air into the hollow cavity of all non-operational guide rail modules. The air pressure is controlled at 0.15MPa and the duration does not exceed 10s.

[0032] After each compensation operation is completed, the axis coordinates of the guide rail module are re-measured using a total station. When the deviation of three consecutive measurements is ≤2mm, the compensation state is released and the airbag reference volume is restored.

[0033] Furthermore, when injecting buoyancy material into the hollow cavity, a three-stage pressure control is adopted: in the first stage, the material is injected at a pressure of 0.2MPa for 30 seconds to fill the middle of the cavity; in the second stage, the pressure is switched to 0.5MPa and maintained for 20 seconds to allow the material to penetrate the through-hole area of ​​the transverse support plate; in the third stage, the pressure is reduced to 0.1MPa and maintained for 60 seconds.

[0034] When the water depth exceeds 15m, a PWM current is applied to the Ni-Ti-Cu alloy airbag through a PID controller to control the airbag volume expansion rate of 0.5-4.5mm³ / s;

[0035] After every 200m of guide rail is laid, the temperature-strain field is detected by the fiber optic grating sensor arranged in the cavity. When the local strain exceeds 0.3%, the PTC heating element on the outer wall is activated to control the temperature uniformity, and the temperature gradient is controlled within ≤2℃ / cm.

[0036] During the dismantling and recycling phase, hot seawater at 60±3℃ is injected into the hollow cavity, while ultrasonic vibration at approximately 28kHz is applied to facilitate the discharge of materials.

[0037] Furthermore, during the guide rail module docking stage, a three-level response is initiated based on the axis deviation value fed back by the total station: when the deviation is ≥5%, single airbag compensation is activated; when the deviation is ≥10%, three airbags in the same section work together; and when the deviation is ≥15%, two adjacent airbag groups are linked. The airbag groups are spaced 2m apart and have a maximum radial expansion of 150mm.

[0038] Furthermore, during the guide rail module docking stage, a three-level response is initiated based on the axis deviation value fed back by the total station, synchronously controlling the deflection angle of the dynamic guide vanes: when the deviation is ≥5%, the vanes deflect 0-10°; when the deviation is ≥10%, the vanes deflect 10-20°; when the deviation is ≥15%, the vanes deflect 20-30°.

[0039] The present invention has at least the following beneficial effects:

[0040] 1. This invention achieves rapid and precise docking (error less than or equal to 2 mm) through neodymium iron boron permanent magnet units, improves sealing performance (leakage rate less than 0.5%) with the design of the gasket with annular protrusion, reduces friction with the dovetail slide rail and molybdenum disulfide coating, and ensures axis alignment accuracy with infrared sensors. It effectively solves the technical problems of traditional underwater guide rail systems, such as low modularity, poor docking accuracy (error > 5 cm), high risk of water leakage due to insufficient sealing, and lack of efficient positioning and guidance mechanisms.

[0041] 2. This invention reduces the weight of the guide rail module by 35% through a hollow cavity design with a cross-sectional area of ​​60%; it is filled with hollow glass microspheres and silicone rubber in a 3:7 volume ratio (microsphere particle size 0.5-1.0mm, silicone rubber density 1.05-1.15g / cm³); and it incorporates transverse support plates and static guide vanes spaced 1.5m apart, with through-hole diameters of 100mm, improving material filling uniformity by 40%. This effectively solves the technical problem of excessive guide rail weight (steel density 7.85g / cm³) and uneven distribution of buoyancy material leading to localized collapse.

[0042] 3. The steel pipe body of the guide rail module is directly exposed to seawater and bears static pressure and dynamic pressure during construction, causing deformation of the steel pipe and compression of the internal hollow cavity, which puts pressure on the microspheres. This invention uses a polyurethane film with an elastic modulus gradient of 0.5MPa / m to coat the hollow glass microspheres, which can effectively disperse and resist these pressures. The buoyancy loss compensation rate is ≥95% at a water depth of 20m, ensuring stable buoyancy performance. Ni-Ti-Cu alloy airbags are embedded, which expand from 50mm to 150mm in diameter after being energized (expansion rate of 300%) to enhance buoyancy, offset impact force, reduce acceleration, and thus suppress displacement. Among them, the end airbag group is 200mm away from the end of the module, which can suppress longitudinal bending deformation. The cross-sectional airbag group has 3 airbags arranged every 2m (circumferentially distributed) to control lateral displacement. A three-level buoyancy compensation is set: deviation ≥5% activates a single airbag, ≥10% activates 3 airbags in synergy, and ≥15% activates adjacent airbag groups, with a response time ≤0.5s. It effectively solves the technical problems of severe buoyancy loss under deep water pressure (loss rate >40% at a water depth of 20m) and slow response to sudden changes in local loads (>10s).

[0043] 4. This invention achieves elevation control accuracy of ±1cm and axis alignment error of ≤2mm through GPS positioning and total station calibration; by setting a dynamic buoyancy compensation contact, airbag linkage compensation is activated when the displacement is >5mm (response time ≤2s), and the leveling efficiency is increased to 20m² / h, effectively solving the problems of large positioning error (>50cm), low leveling efficiency (<10m² / h), and excessive guide rail displacement caused by ship movement disturbance in traditional construction methods.

[0044] 5. This invention achieves graded adjustment of the airbag expansion rate (0.5~4.5mm³ / s) through real-time PID control ΔV=2.5Δd+0.8∫Δd+0.3dΔd / dt; injecting silicone rubber slurry containing 15wt% microspheres reduces the density from 1.25g / cm³ to 1.085g / cm³, achieving dynamic density adjustment; and linking adjacent airbags with dynamic guide vanes to deflect 30°, shortening the recovery time to ≤5min when the displacement exceeds 8mm. The vane deflection guides the water flow to generate a lateral velocity component, reducing the impact on the guide rail module, effectively solving the technical problems of low single compensation efficiency (recovery time>30min) and lag in material density adjustment after displacement exceeds the limit.

[0045] 6. This invention achieves a bubble residue rate of <3% through three-stage pressure control: 0.2MPa→0.5MPa→0.1MPa. It employs a combined hot seawater and ultrasonic removal process, with 60℃ seawater and 28kHz vibration working in tandem, resulting in a residue amount ≤0.5kg / m³, significantly improving efficiency. This effectively solves the technical problems of high bubble residue rate (>15%) and low removal efficiency (residue amount >2kg / m³) in buoyancy material injection.

[0046] 7. Compared with the prior art, the present invention solves the problems of low efficiency (single connection time > 45 minutes) and poor sealing (leakage rate > 3%) of traditional bolt connections by using magnetic connection and three-level buoyancy compensation in a coordinated control.

[0047] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0048] Figure 1 This is a schematic diagram of the magnetic modular underwater leveling guide rail system of the present invention during the construction of the foundation bed;

[0049] Figure 2 This is a schematic diagram of the guide rail module of the present invention;

[0050] Figure 3 This is a schematic diagram of the internal structure of the hollow cavity of the guide rail module of the present invention;

[0051] Figure 4 This is a schematic diagram of the cross-sectional structure of the hollow cavity of the guide rail module of the present invention;

[0052] Figure 5 This is a schematic diagram of the airbag arrangement structure of the present invention.

[0053] The components include: guide rail module 10, steel pipe body 101, composite material layer 102, height adjustment component 103, positioning groove 104, reflective prism 105, magnetic connection device 106, waterproof rubber gasket 107, guide slide rail 108, fixing bolt 109, hollow cavity 110, transverse support plate 111, central through hole 112, static guide vane 113, injection port 114, control valve 115, exhaust pipe 116, end airbag assembly 117, cross-section airbag assembly 118, dynamic guide vane 119, servo motor 120, base bed 20, barge 30, and scraper 40. Detailed Implementation

[0054] The present invention will be further described in detail below with reference to embodiments, so that those skilled in the art can implement it based on the description.

[0055] As shown in Figures 1-5, a magnetic modular underwater leveling guide rail system of the present invention includes:

[0056] Multiple guide rail modules, each guide rail module comprising a steel pipe body with a rectangular cross-section, the outer surface of which is covered with a composite plastic layer of polyetheretherketone and 15wt% graphite;

[0057] The guide rail module is equipped with magnetic connection devices at both ends. The magnetic connection devices include neodymium iron boron permanent magnet units embedded in the ends of steel pipes. Adjacent guide rail modules are attracted by opposite magnetic poles and the contact surface is provided with a waterproof rubber gasket with annular protrusions.

[0058] The lower surface of the guide rail module is provided with a threaded rod height adjustment component with a pitch of 2mm. The upper surface of the guide rail module is provided with a positioning groove along the length direction. The positioning groove is embedded with a total station reflecting prism. The center point of the reflecting prism coincides with the axis of the guide rail module. The installation position of the total station reflecting prism is provided with a calibration mark. The calibration mark is a laser-etched crosshair with a line width of 0.1mm and perpendicular to the axis of the guide rail module.

[0059] The guide rail module is fixed to dovetail-shaped guide rails on both sides by bolts spaced 500mm apart. The guide rails are coated with a 0.1mm thick molybdenum disulfide coating.

[0060] The guide rail module is equipped with an 850nm wavelength docking detection sensor at its end. The sensor includes an infrared transmitter and a receiver. The infrared transmitter's emission direction is parallel to the axis of the guide rail module, and the receiver's receiving surface corresponds to the transmitter position of the adjacent guide rail module. The receiving sensitivity is -30dBm. The signal output terminal of the docking detection sensor is connected to a control unit, which determines the docking accuracy of adjacent guide rail modules based on the received signal strength.

[0061] Specifically, the guide rail module uses Q345B grade rectangular steel pipe with a cross-sectional dimension of 200mm × 150mm. The composite plastic layer covering the outer surface of the steel pipe is made by melt blending polyetheretherketone powder (particle size 50-80μm) and flake graphite (particle size 20-40μm) using a twin-screw extruder. The density of the polyetheretherketone and graphite mixture is 1.45g / cm³, and the surface roughness Ra of the composite plastic layer is ≤0.8μm. The graphite content can be selected in the range of 10-20wt%, preferably 15wt%. This composite material can be made from PEEK type finished sheet with a thickness of 3mm, bonded to the surface of the steel pipe using epoxy structural adhesive. The inner wall of the steel pipe is coated with epoxy anti-corrosion primer with a dry film thickness ≥200μm.

[0062] The permanent magnet unit uses N42H grade neodymium iron boron magnets, measuring 50mm×50mm×10mm, with a nickel-plated surface. It is embedded in a groove at the end of a steel pipe (groove depth 11±0.1mm), with a single-sided gap of 0.5mm, and an adsorption force ≥1.5kN (tested at a water depth of 20m and a flow rate of 1m / s). The magnet groove is machined at the center of the steel pipe end face and fixed with structural adhesive. A waterproof rubber gasket has an outer diameter of 110mm, an inner diameter of 60mm, and a thickness of 5mm. The gasket's edge has an annular protrusion height of 2.0±0.1mm, forming a 0.2-0.3mm gap with the adjacent module groove. Temporary positioning is achieved using spray adhesive during installation. The threaded rod is a 300mm long, 45# steel M36×2 trapezoidal threaded rod with a Dacromet coating. The base is a 180mm diameter ductile iron disc with a 1mm deep radial anti-slip texture on the bottom, with a texture spacing of 10mm. The total station's reflecting prism is installed in a positioning groove 1.5m from the end of the module. The groove is 10±0.1mm wide and 5±0.2mm deep, and the deviation of the prism's central axis is ≤0.5mm.

[0063] The dovetail-shaped guide rail is cold-bent from Q235B steel plate, with a rail surface angle of 60±0.5° and a rail height of 15mm. M16×60 stainless steel hex bolts are used for fixing, with a preload torque of 80±5 N·m. The molybdenum disulfide coating is applied by spraying, and the coating thickness is controlled to be within 0.1±0.02mm. The docking detection sensor is an Omron E3Z-T61 photoelectric sensor, with the transmitter installed 50mm from the module end face, and the parallelism error between the receiver and transmitter axes ≤0.1°.

[0064] Finite element analysis of the guide rail system in this embodiment shows that, under a water depth of 20m, the maximum equivalent stress of the guide rail module is 185MPa (safety factor 2.3), and the maximum deformation is 2.1mm (less than the design allowable value of 3mm). Vibration testing shows that at a ship movement speed of 0.5m / s, the system's natural frequency is 12.5Hz, avoiding the peak frequency range of common wave energy spectra (0.1-0.3Hz). Neodymium iron boron permanent magnet units enable rapid and precise docking (error ≤2cm); the gasket design with annular protrusions improves sealing (leakage rate <0.5%); the dovetail-shaped slide rail and molybdenum disulfide coating reduce friction (coefficient ≤0.15); infrared sensors ensure axis alignment accuracy (sensitivity -30dBm), with an axis alignment accuracy of ±1mm / m.

[0065] Preferably, in the above embodiments, the steel pipe is pre-treated by sandblasting to Sa2.5 grade, with a surface roughness Ra=50-70μm to ensure bonding strength. After magnet installation, the surface magnetic field strength must be measured with a gaussmeter to be ≥1200mT. Molybdenum disulfide grease is applied during the assembly of the height adjustment assembly. After guide rail installation, the straightness of the rail surface must be checked with a feeler gauge to be ≤0.5mm / m. When debugging the docking sensor, a clamp must be used to ensure the coaxiality of the transmitting / receiving ends.

[0066] Furthermore, in another embodiment, the steel pipe body has a hollow cavity with a cross-sectional area of ​​60%, and the hollow cavity is filled with hollow glass microspheres and silicone rubber buoyancy material in a volume ratio of 3:7.

[0067] Hollow glass microspheres with a particle size of 0.5-1.0 mm and vacuum modified with silane coupling agent; silicone rubber density of 1.05-1.15 g / cm³.

[0068] The hollow cavity is equipped with transverse support plates spaced 1.5m apart. The central through hole of the transverse support plate has a diameter of 100mm and static guide vanes are welded to the edge.

[0069] Specifically, a hollow cavity accounting for 60% of the cross-sectional area is machined within the main body of the steel pipe. For a 200mm × 150mm rectangular steel pipe, the hollow cavity size can be set to 150mm × 100mm. Injection ports and control valves are installed at both ends of the main body of the steel pipe. The injection ports have a diameter of 20mm and are threaded internally. The control valves are electromagnetically driven ball valves, with the valve diameter matching the injection port diameter. The control valves are connected to the surface control console via a waterproof cable. The outlet end of the control valve is connected to an exhaust pipe, which uses a 2mm thick stainless steel corrugated pipe, extending 500mm above the top of the guide rail module.

[0070] The buoyancy material is composed of 3M's K15 hollow glass microspheres and Wacker's ELASTOSIL® LR 3003 / 50 silicone rubber, mixed at a volume ratio of 3:7. The particle sizes of the microspheres can be selected from three specifications: 0.5mm, 0.8mm, and 1.0mm for mixed use. The density of the silicone rubber can be controlled within the range of 1.05 - 1.15 g / cm³ by adjusting the addition amount of the curing agent, preferably 1.10 ± 0.02 g / cm³. A double planetary mixer can be selected as the mixing equipment, with a vacuum degree maintained at -0.08 MPa and a mixing time of 30 ± 5 minutes. After adding 15wt% hollow glass microspheres to modify the silicone rubber (Wacker ELASTOSIL® LR3003 / 50), the density is reduced to 1.085 ± 0.02 g / cm³ (test standard: ISO2781-2008).

[0071] The microspheres are pretreated with KH-550 silane coupling agent to prepare a 3wt% ethanol solution. A vacuum impregnation tank can be selected as the treatment equipment, with the vacuum degree controlled at 1×10⁻² Pa and an impregnation time of 30 minutes. The drying process is carried out in a hot air circulation oven at a temperature of 80 ± 5℃ for 2 hours. The treated microspheres are detected by a particle size analyzer, and the surface contact angle ≥ 120° is the qualified standard.

[0072] The transverse support plate is laser cut from a Q235B steel plate with a thickness of 5mm, the plate spacing is 1.5m, and the allowable tolerance is ±10mm. The central through-hole is machined to a diameter of 100 ± 0.5mm, and 6 static flow guiding blades are welded circumferentially at the edge of the central through-hole. The blade material is 304 stainless steel, with a thickness of 1.2mm, an installation angle of 45 ± 1° (the angle with the axis of the through-hole), and a blade height of 20mm (covering 20% of the through-hole height). When the buoyancy material (hollow glass microspheres + silicone rubber) is injected, the blades decompose the axial flow into a tangential component through a 45° inclination angle, generating a swirling effect, accelerating the circumferential distribution of the material, and improving the uniformity; and decompose it into a radial component, suppressing the aggregation of the material towards the center of the through-hole, reducing the density gradient; at the same time, the blades reduce the Reynolds number of the through-hole cross-section, suppressing turbulence. The centrifugal force generated by the swirling effect causes the bubbles to migrate towards the center of the through-hole and be discharged through the top swirling separator, reducing the bubble residue rate. The static flow guiding blades are welded under argon protection, and the welding machine current is set at 90 - 110A. During assembly, double-sided fillet welds are used between the support plate and the inner wall of the steel pipe, with a fillet weld height of 3mm, and it is qualified after magnetic particle flaw detection.

[0073] The hydrodynamic simulation of this embodiment shows that: at an injection pressure of 0.5 MPa, the static flow guiding blades improve the uniformity of the material flow velocity distribution by 35% and reduce the pressure loss by 22%. The transverse support plate is at 10 6Under cyclic loading (±20kN), the maximum stress amplitude is <100MPa, meeting the design requirements for unlimited life. By designing a hollow cavity with a cross-sectional area of ​​60%, the weight of the guide rail is reduced by 35%. The hollow cavity is filled with hollow glass microspheres (density 0.6g / cm³) and silicone rubber (density 1.25g / cm³) in a 3:7 volume ratio, and the overall density after mixing is 1.085g / cm³ (calculation formula: ρ=0.3×0.6 + 0.7×1.25=1.085g / cm³). Horizontal support plates with a spacing of 1.5m and static guide vanes are set, with a through-hole diameter of 100mm, improving the material filling uniformity by 40%.

[0074] Preferably, in the above embodiments, the microspheres should be added to the silicone rubber matrix in three stages, with a 5-minute interval between each addition, to avoid agglomeration. After welding, the static guide vanes require electrolytic polishing to achieve a surface roughness Ra ≤ 0.8 μm. Before injection into the hollow cavity, Dow Corning DC-1200 release agent should be pre-coated for later maintenance and cleaning. Custom-made fixtures should be used during support plate installation to ensure spacing tolerances, with a cumulative error ≤ 1.5 mm / 10 m.

[0075] Furthermore, in another embodiment, the hollow glass microspheres are coated with a polyurethane membrane with an elastic modulus gradient of 0.5 MPa / m, resulting in a buoyancy loss compensation rate of ≥95% at a water depth of 20 m.

[0076] The guide rail module has a 1m range at both ends embedded with an electrically controlled variable buoyancy unit made of shape memory alloy (SMA). The unit contains 3 sets of Ni-Ti-Cu alloy airbags, which expand from 50mm to 150mm in diameter after being heated by electricity.

[0077] Furthermore, a three-level buoyancy compensation system is implemented: when the buoyancy deviation is ≥5%, single airbag compensation is activated; when the deviation is ≥10%, collaborative compensation of three airbags in the same cross-section is activated; and when the deviation is ≥15%, airbag groups of two adjacent cross-sections are activated. The buoyancy deviation is defined as the percentage difference between the measured buoyancy and the theoretical buoyancy: Level 1 compensation: deviation ≥5% (corresponding to a buoyancy loss ≥75N), activates the single airbag closest to the deviation point; Level 2 compensation: deviation ≥10% (≥150N), activates collaborative compensation of three airbags in the same cross-section; Level 3 compensation: deviation ≥15% (≥225N), activates airbag groups of two adjacent cross-sections (spaced 2±0.05m apart).

[0078] The dynamic guide vane is rotated and positioned on the water-facing side of the outer wall of the guide rail module (such as the side, where the water flow direction can be monitored in real time by a Doppler current meter). It can be positioned 500mm from the end airbag assembly. The dynamic guide vane is connected to a servo motor (IP68 protection rating), which drives the dynamic guide vane to deflect. The reduction ratio between the servo motor and the dynamic guide vane is 30:1, the repeatability is ±0.2°, and the deflection range is 0°~45°.

[0079] Specifically, the polyurethane film can be made of Covestro Desmopan® 385E material, applied using high-pressure airless spraying equipment. The spraying pressure is set at 8-12 MPa, and the film thickness is controlled at 10±2 μm. The elastic modulus gradient is achieved through layered curing: the bottom layer is pre-cured at 50℃ for 30 minutes after spraying, with a modulus of 0.3 MPa; the middle layer adds 5 wt% nano-silica filler, with a modulus of 0.5 MPa; the top layer is sprayed with pure polyurethane solution, with a modulus of 0.7 MPa. The curing oven temperature is controlled in three stages: 60℃ / 2h → 80℃ / 4h → room temperature standing for 24h. The coated microspheres are pressure tested, and the compression deformation under 0.5 MPa water pressure is ≤15%.

[0080] In the shape memory alloy airbag structure, the airbag uses a Ni-Ti-Cu alloy tube with a wall thickness of 0.3±0.02mm. The inner diameter in the cold-worked state is 50mm, and it undergoes 3% axial pre-compression during installation. The heating element can be made of 0.5mm diameter nickel-chromium alloy wire with a resistance of 2Ω / m and a winding spacing of 5mm. When energized for heating, the temperature is controlled at 60±2℃, and the outer diameter reaches 150±3mm after thermal expansion. The airbag end connector uses a 316L stainless steel flange, and the sealing gasket is made of DuPont Kalrez® 6375 material with a pressure resistance rating of 1.6MPa.

[0081] In the three-stage buoyancy compensation control strategy, during the first-stage compensation (deviation 5-10%), a single airbag (such as the nearest end airbag) is activated and inflated at a rate of 0.5 L / min. The pressure sensor used is the Honeywell TruStability® TSC series, with a range of 0-2 kPa and a sampling frequency of 100 Hz. For the second-stage compensation (deviation 10-15%), three airbags at the same cross-section are activated for coordinated compensation, increasing the inflation rate to 1.5 L / min, and simultaneously opening the dynamic guide vanes to deflect by 30°. For the third-stage compensation (deviation > 15%), two sets of airbags at adjacent cross-sections are linked, with an inflation rate of 2.5 L / min, and simultaneously injecting compensation slurry with a density of 1.05 g / cm³. The control command delay is ≤200 ms, and mode switching is implemented through a state machine program developed using LabVIEW.

[0082] In this embodiment, the airbag assembly showed no corrosion or leakage after 1000 hours in a 5% NaCl solution. The airbag... 5 After one charge-discharge cycle, the diameter change rate is <0.5%. The burst pressure test reaches 2.4MPa (1.5 times the design pressure). By coating hollow glass microspheres with a polyurethane membrane with an elastic modulus gradient of 0.5MPa / m, the buoyancy loss compensation rate at a water depth of 20m is ≥95%; embedded Ni-Ti-Cu alloy airbags expand from 50mm to 150mm in diameter after being energized (expansion rate 300%); three-stage buoyancy compensation is set: deviation ≥5% activates the single airbag closest to the deviation point, ≥10% activates 3 airbags in synergy, and ≥15% activates adjacent airbag groups, with a response time ≤0.5s.

[0083] In the above embodiments, preferably, the microbead coating operation must be carried out in a cleanroom (ISO Class 8) with a relative humidity ≤40%. The airbag is embedded in the guide rail module without protruding from the guide rail surface. During installation, the pre-tightening bolts should be tightened in three stages to 15 N·m, with an interval of 120°. The dynamic guide vane deflection mechanism is driven by a micro servo motor with a reduction ratio of 30:1 and a repeatability accuracy of ±0.1°. The compensation slurry must be pre-treated with a 200-mesh filter before injection to prevent microbeads from clogging the pipeline.

[0084] Furthermore, in another embodiment, each airbag is connected to a PID controller. The PID controller has a transfer function G(s) = 2.5 + 0.8 / s + 0.3s, and the pressure sensors are spaced 0.5m apart. When the pressure at the docking surface is detected to be greater than 1kN, a pressure relief procedure is triggered at a rate of 10mm³ / s. In the PID controller, the transfer function G(s) = Kp + Ki / s + Kds controls the airbag through the synergistic action of the proportional, integral, and derivative components. Its working principle is as follows: Proportional component (P): Quickly responds to pressure deviations, outputting a value proportional to the current error, directly suppressing pressure fluctuations (such as instantaneous pressure increases caused by water flow impact). Integral component (I): Eliminates steady-state errors, accumulates historical errors and gradually corrects them, compensating for long-term pressure deviations (such as buoyancy loss caused by slow water absorption by buoyancy materials). Derivative component (D): Predicts future error trends, suppresses system oscillations, and prevents over-inflation / de-inflation of the airbags (such as pressure surges caused by ship movement disturbances).

[0085] Specifically, the volume expansion ΔV of the airbag assembly is calculated using the following formula: ΔV = Kp·Δd + Ki·∫Δd·dt + Kd·d(Δd) / dt, where the proportional coefficient Kp = 2.5 N / mm, the integral coefficient Ki = 0.8 N / (mm·s), the derivative coefficient Kd = 0.3 N·s / mm, and Δd is the real-time displacement deviation. An Omron E5CC-TQX3ASM-800 PID controller can be used, with a proportional coefficient setting range of 0.1-25.0, preferably 2.5±0.1; the integral time is set to 1.25s (corresponding to Ki = 0.8), and the derivative time is set to 3.33s (corresponding to Kd = 0.3). Parameter tuning is achieved through the step response method: a 10% step current input is applied to the airbag, the pressure response curve is recorded, and the parameters are adjusted to ensure overshoot ≤ 5% and steady-state time ≤ 2s. The control signal output is 4-20mA, corresponding to an airbag volume change of 0-150mm³.

[0086] The pressure sensor can be a Honeywell TSCDANN015PGUCV model, with a range of 0-1.5kN and an accuracy of ±0.25%FS. One set should be installed every 0.5m along the length of the guide rail module, at a distance of 200±10mm from the magnetic connection surface. The sensor is fixed to the groove on the side wall of the guide rail module via an M5 threaded interface, and the cable uses a waterproof connector. The data acquisition card has a sampling rate of 1kHz and a noise suppression bandwidth set to 50Hz.

[0087] The pressure relief valve uses an ASCO 8262G054 solenoid valve with a 4mm diameter and a response time ≤15ms. When the pressure sensor detects a value >1.00±0.05kN for three consecutive sampling cycles, the controller outputs a 24V pulse signal to trigger pressure relief. The pressure relief rate is controlled via a closed-loop flow meter, which can be a KEYENCE FD-Q50C model with a range of 0-20mm³ / s. Adjusting the pressure relief valve opening stabilizes the flow rate at 10±0.5mm³ / s. The pressure relief pipeline uses a 6mm outer diameter polyurethane flexible hose with a pressure rating of 1MPa.

[0088] This implementation uses a PID controller (transfer function G(s)=2.5+0.8 / s+0.3s), pressure sensor spacing of 0.5m, and control accuracy of ±0.1kPa; it triggers a pressure relief program (starts when pressure > 1kN), and the pressure relief rate is stabilized at 10mm³ / s (error ±0.5mm³ / s).

[0089] A construction method for the magnetic modular underwater leveling guide rail system of the present invention includes the following steps:

[0090] Step 1: Position the barge parallel to the axis of the trench using GPS.

[0091] Step 2: The adjacent guide rail modules are assembled underwater using a magnetic connection device. The magnetic connection device of the adjacent guide rail modules is attracted by opposite magnetic poles, and a waterproof rubber gasket is installed between the contact surfaces.

[0092] Step 3: Use a total station to position and calibrate the guide rail module, measure the three-dimensional coordinates of the reflecting prism and compare them with the design elevation, and adjust the height adjustment component of the guide rail module so that the elevation of the guide rail module reaches the design value of -5.7m±1cm.

[0093] Step 4: Install dovetail guide rails on both sides of the guide rail module. Verify the axis alignment accuracy of the guide rail module using a docking detection sensor. The docking detection sensor includes an infrared transmitter and a receiver. The emission direction of the infrared transmitter is parallel to the axis of the guide rail module, and the receiving surface of the receiver corresponds to the position of the transmitter of the adjacent guide rail module. When the received signal strength reaches -30dBm, the docking is deemed qualified.

[0094] Step 5: Use a scraper to level the base bed along the top surface of the guide rail module, with the scraper moving at a speed of 0.5 m / s.

[0095] Step 6: After each leveling section is completed, the boat is moved. During the boat movement, the displacement of the installed guide rail module is continuously monitored. When the displacement exceeds 5mm, dynamic buoyancy compensation is triggered.

[0096] Specifically, the barge is equipped with GPS receivers installed at both ends of the hull's longitudinal axis, with a positioning accuracy of ±10mm horizontally and ±20mm vertically. Underwater assembly of the magnetic connection device requires a diver to operate the clamps for assisted positioning. Before installation, the waterproof rubber gaskets must be soaked in silicone grease lubricant, with the installation pressure controlled at 0.1-0.2MPa, ensuring a gap of 0.2±0.05mm between the annular protrusion and the groove. After assembly, a watertightness test is required, involving pressurizing with 0.15MPa compressed air for 5 minutes; the leakage rate should be ≤0.5%.

[0097] The total station should be set 30-50m away from the guide rail module, and the 3D coordinate acquisition frequency of the reflecting prism should be 1Hz. For the height adjustment component, each 90° rotation of the threaded rod corresponds to a 0.5mm change in elevation. After adjustment, it must be locked with a lock nut; the torque value is 45±5N·m. When installing the dovetail guide rail, a positioning template must be used to ensure bolt hole alignment. Bolt pre-tightening should be done in two stages: the initial torque is 50N·m, and after the second calibration, it is increased to 80N·m. When debugging the docking detection sensor, a laser calibrator must be used to ensure that the coaxiality of the transmitter / receiver ends is ≤0.1mm.

[0098] The scraper bar is made of 10cm×10cm Q345B square steel, with a dovetail groove structure at the bottom matching the dovetail-shaped guide rail, forming a sliding pair guide to ensure that the scraper moves linearly along the axis of the guide rail module. A hard alloy wear-resistant strip with a hardness ≥HRC60 can also be welded to the bottom. The leveling speed is controlled by a variable frequency motor. The conversion formula between motor speed and scraper bar movement speed is: v=0.0167×n (v: m / s, n: rpm). The displacement monitoring system can use a laser displacement meter with a sampling frequency of 200Hz. An audible and visual alarm is triggered when the displacement at three consecutive sampling points is >5.0±0.2mm. The ship-moving winch's step distance error is controlled within ±0.5m, and the anchor chain tension difference is ≤5%.

[0099] In this implementation, the assembly time for a single guide rail module is reduced from the traditional 45 minutes to 18 minutes, the single-point calibration time is ≤3 minutes, and the percentage of points with an elevation deviation >1cm in a continuous 100m section is ≤3%. Through GPS positioning and total station calibration, the elevation control accuracy is ±1cm, and the axis alignment error is ≤2mm. By setting a dynamic buoyancy compensation contact, airbag linkage compensation is activated when the displacement is >5mm (response time ≤2s), and the leveling efficiency is increased to 20m² / h.

[0100] Furthermore, in another implementation, dynamic buoyancy compensation includes:

[0101] Fiber optic displacement sensors are arranged at 0.5m intervals along the axis of the guide rail module. The fiber optic sensors monitor the displacement at 100Hz. When the displacement exceeds the threshold, the airbag is expanded by PID control ΔV=2.5Δd+0.8∫Δd+0.3dΔd / dt.

[0102] Synchronously inject a silicone rubber slurry containing 15wt% microspheres into the hollow cavity of the guide rail module with excessive displacement to reduce the density to 1.085g / cm³; for example, inject a silicone rubber mixed slurry containing 15wt% hollow glass microspheres into the hollow cavity of the module with excessive displacement at a flow rate of 0.3L / s through a control valve to reduce the material density from 1.25g / cm³ to about 1.085g / cm³, while maintaining the injection pressure at 0.35±0.02MPa, to achieve the purpose of synchronously adjusting the density distribution of the buoyancy compensation material;

[0103] When the guide rail module is displaced by more than 8mm, the adjacent airbags expand in coordination and the dynamic guide vanes deflect by 30°.

[0104] Specifically, the fiber optic displacement sensor has a wavelength resolution of 1 pm, corresponding to a displacement resolution of 0.1 mm. The sensor is arranged along the groove on the top of the guide rail module, with a spacing of 0.5 ± 0.02 m, and is fixed with UV adhesive. The monitoring system collects data at a frequency of 100 Hz. When the relative displacement of adjacent modules exceeds 5.0 ± 0.2 mm for three consecutive samples, a yellow warning signal is triggered. After exceeding the limit for 2 seconds, a compensation program is initiated. The displacement threshold is dynamically adjusted according to the guide rail length, using the formula ΔLmax = 0.05% × L (where L is the total length of the guide rail).

[0105] The airbag inflation is controlled using a proportional-integral-derivative (PID) algorithm, with a proportional gain set at 2.5 N / mm, an integral time constant of 1.25 seconds, and a derivative time constant of 0.33 seconds. A PLC can be used to execute the calculations, outputting a 4-20mA signal to drive the proportional valve. The inflation rate is adjustable in three levels: primary compensation 0.5-1.0 mm³ / s, secondary 1.5-2.5 mm³ / s, and tertiary 3.0-4.5 mm³ / s. The silicone rubber slurry uses ELASTOSIL N10 with 15wt% microspheres, injected via a screw pump at a flow rate of 0.3 ± 0.05 L / s. Density is measured using an online density meter, with a control accuracy of ±0.005 g / cm³.

[0106] When the displacement is greater than 8.0 ± 0.3 mm, all six airbags in the two adjacent guide rail modules activate synchronously, increasing the inflation rate to 200% of the nominal value. The dynamic guide vane deflection mechanism is driven by a micro servo motor with a reduction ratio of 30:1 and a repeatability of ±0.2°, enabling it to work in tandem with the airbags. The vane surface can be coated with a polytetrafluoroethylene coating with a thickness of 50 ± 5 μm and a friction coefficient ≤0.05. The linkage control signal is transmitted via an underwater CAN bus with a delay ≤50 ms.

[0107] In this embodiment, under test conditions with a wave height of 0.5m, the displacement over-limit incidence rate is as low as 6%. Real-time PID control (ΔV = 2.5Δd + 0.8∫Δd + 0.3dΔd / dt) enables graded adjustment of the airbag inflation rate (0.5~4.5mm³ / s). Injection of a silicone rubber slurry containing 15wt% microspheres reduces the density from 1.25g / cm³ to 1.085g / cm³, achieving dynamic density adjustment. Linking adjacent airbags with a 30° deflection of the dynamic guide vanes shortens the recovery time to ≤5min when the displacement exceeds 8mm.

[0108] Furthermore, in another implementation, the buoyancy-resistance balance coefficient η=ΣFbuoy / (Fcurrent + Fanchor) is calculated in real time during the compensation process. When the balance coefficient value is lower than 0.95, it automatically switches to the third-level compensation mode and injects compressed air into the hollow cavity of all unoperated guide rail modules. The air pressure is controlled at 0.15MPa and the duration does not exceed 10s.

[0109] After each compensation operation is completed, the axis coordinates of the guide rail module are re-measured using a total station. When the deviation of three consecutive measurements is ≤2mm, the compensation state is released and the airbag reference volume is restored.

[0110] Specifically, the total buoyancy (ΣFbuoy) is acquired in real time using a pressure sensor array with a range of 0-10 kN and a sampling frequency of 100 Hz. The current resistance (Fcurrent) is measured using a Doppler current meter with a range of 0-3 m / s and an accuracy of ±0.05 m / s. The anchor resistance (Fanchor) is obtained using an anchor chain tension meter with a range of 0-50 kN. The balance coefficient η = ΣFbuoy / (Fcurrent + Fanchor) is calculated by an embedded industrial computer, updating 10 times per second. Level 3 compensation is triggered when the calculated value of η is <0.95 ± 0.02 for five consecutive calculations. In the balance coefficient formula η = ΣFbuoy / (Fcurrent + Fanchor), both the numerator and denominator are in N, and η is a dimensionless ratio.

[0111] After the three-level compensation mode is activated, the air compressor outputs a pressure of 0.15±0.01MPa, which is used to inject air into the non-operating module cavity through an 8mm polyurethane tube. The injection rate is controlled in two stages: rapid filling at 10L / min for the first 5 seconds, followed by a pressure maintenance rate of 5L / min. The compressed air dew point temperature is ≤-40℃. After being buffered by the air tank, the compressed air is distributed to the target guide rail module through a solenoid valve.

[0112] After compensation, the total station performs three consecutive remeasurements with a 30-second interval. Coordinate deviation is calculated using least squares fitting; a deviation of ≤2.0±0.3mm for the X / Y / Z axes is considered acceptable. The status reset procedure includes: closing the airbag supply valve, resetting the dynamic guide vanes to the 0° position, and restoring the buoyancy material density to 1.25g / cm³. The reset operation record is saved to the database, including the timestamp, operator code, and sensor calibration values.

[0113] In this implementation, under low flow velocity conditions (0.2 m / s), the compensation trigger frequency is reduced to 0.8 times per hour. Under high turbulence conditions (1.5 m / s), the fluctuation range of the η value is controlled within ±0.03. After a sudden load test (10 kN step force), the system's recovery time to steady state is ≤30 seconds.

[0114] Furthermore, in another embodiment, when injecting buoyancy material into the hollow cavity, a three-stage pressure control is adopted: in the first stage, the cavity is filled with 0.2MPa pressure for 30 seconds; in the second stage, the pressure is switched to 0.5MPa and maintained for 20 seconds to allow the material to penetrate the through-hole area of ​​the transverse support plate; and in the third stage, the pressure is reduced to 0.1MPa and maintained for 60 seconds.

[0115] When the water depth exceeds 15m, a PWM current is applied to the Ni-Ti-Cu alloy airbag through a PID controller to control the airbag volume expansion rate of 0.5-4.5mm³ / s;

[0116] After every 200m of guide rail is laid, the temperature-strain field is detected by the fiber optic grating sensor arranged in the cavity. When the local strain exceeds 0.3%, the PTC heating element on the outer wall is activated to control the temperature uniformity, and the temperature gradient is controlled within ≤2℃ / cm.

[0117] During the dismantling and recycling phase, 60°C hot seawater is injected into the hollow cavity, while 28kHz ultrasonic vibration is applied to help discharge the material.

[0118] Specifically, the buoyancy material injection system can be a hydraulic station equipped with three pressure control modules. The first stage involves injection at 0.2±0.02MPa for 30 seconds, filling the center of the cavity through a φ20mm injection port. The second stage switches to 0.5±0.05MPa and maintains it for 20 seconds, allowing the material to penetrate the through-hole area of ​​the transverse support plate, with the flow velocity controlled at 0.8-1.2m / s. The third stage reduces the pressure to 0.1±0.01MPa and maintains it for 60 seconds, during which gas can be discharged through a cyclone separator with a cone angle of 15° and an inlet tangential velocity of 8±0.5m / s.

[0119] The relationship between the duty cycle of the PWM signal output by the PID controller and the airbag expansion rate is as follows: for every 10% increase in duty cycle, the rate increases by 0.5 mm³ / s. An Omron E5CN-HTV2Q controller can be used, with set parameters Kp=2.8, Ki=0.6, and Kd=0.4. The current output range is 4-20mA, corresponding to a heating power of 0-500W. A PT100 platinum resistance temperature sensor with an accuracy of ±0.5℃ is used. When the water depth is >15m, the preset program group P03 is activated to control the expansion rate in stages within the range of 0.5-4.5 mm³ / s.

[0120] The fiber optic grating sensors are spirally arranged along the outer wall of the guide rail module, with a spacing of 200±10mm. The temperature measurement range is -20℃ to 120℃, and the strain measurement range is ±5000με. When a local strain > 0.3% is detected, the outer wall PTC heating element is activated. The heating element power density is 0.8±0.1W / cm², and a PID algorithm is used to control the temperature gradient to ≤2℃ / cm. The heating area is divided into a 50mm×50mm grid; when the temperature difference between adjacent grids exceeds the limit, an equalization compensation program is triggered.

[0121] The hot seawater injection system can use a centrifugal pump with a flow rate of 3±0.5 m³ / h and a water temperature of 60±2℃. The ultrasonic transducer frequency is 28±1 kHz, and the power density is 0.5±0.05 W / cm². The vibrating head is inserted into the discharge port at a 45° angle, and the amplitude is set to 50±5 μm. The material discharge efficiency was determined experimentally: 8 m³ / h without heating, and increased to 12 m³ / h with the combined heating and ultrasonic operation.

[0122] In this embodiment, the buoyancy material injection efficiency reaches 1.2 hours per guide rail module, the airbag expansion adjustment efficiency reaches 5 minutes per cycle, and the material removal and recovery efficiency is 4.5 hours per 100 meters. Furthermore, the three-stage pressure control (0.2 MPa → 0.5 MPa → 0.1 MPa) ensures a bubble residue rate of <3%. The use of hot seawater and ultrasonic combined removal, with 60°C seawater and 28kHz vibration working in tandem, results in a residue amount of ≤0.5 kg / m³, significantly improving efficiency.

[0123] Furthermore, in another embodiment, during the guide rail module docking stage, a three-level response is initiated based on the axis deviation value fed back by the total station: when the deviation is ≥5%, single airbag compensation is activated; when the deviation is ≥10%, three airbags in the same section work together; when the deviation is ≥15%, two adjacent sections of airbag groups are linked. The airbag groups are spaced 2m apart and have a maximum radial expansion of 150mm.

[0124] The total station measurement frequency is set to 2Hz, with a horizontal angle accuracy of ±1″ and a distance measurement accuracy of ±(0.6mm + 1ppm). Axis deviation is calculated using least squares fitting, with the deviation percentage δ = (measured axis offset / designed axis length) × 100%. Thresholds are set as follows: δ ≥ 5% corresponds to an offset ≥ 75mm (design axis length 1.5m), δ ≥ 10% corresponds to ≥ 150mm, and δ ≥ 15% corresponds to ≥ 225mm. Axis deviation δ is the percentage of the maximum offset distance between the measured axis and the designed axis relative to the design length, calculated using the formula δ = ΔL / Ldesign × 100%.

[0125] Upon triggering the first-level response, the airbag closest to the deviation point is activated at an inflation rate of 0.5 ± 0.1 L / min, corresponding to a radial expansion rate of 2 mm / s. The second-level response activates three airbags in the same section, increasing the inflation rate to 1.5 L / min, and simultaneously deflecting the dynamic guide vanes by 15°. The third-level response activates six airbags in two adjacent sections, with an inflation rate of 3.0 L / min and increasing the deflection of the dynamic guide vanes to 30°.

[0126] The airbags are spaced 2.0±0.05m apart and symmetrically distributed along the axis of the guide rail module. Each airbag uses a 0.3mm thick Ni-Ti-Cu alloy tube with a cold-state outer diameter of 50±0.5mm and a maximum working outer diameter of 150±2mm. The mounting flange is made of 316L stainless steel and is fixed to the reinforcing ribs on the inner wall of the guide rail module with 8 sets of M8 bolts. The 5mm thick EPDM rubber insulating layer between the airbag and the buoyancy material has a Shore hardness of 60±5HA.

[0127] In this implementation, under the δ=15% deviation condition, the system recovers to δ≤3% within 8 minutes. Under the maximum expansion condition, the module stress concentration factor is ≤1.8. Example

[0128] In a deep-water port breakwater project, a 500m long foundation leveling operation needs to be completed under complex hydrological conditions with a water depth of 18-22m and a flow velocity of 0.8-1.2m / s. Traditional guide rail systems cannot meet the project schedule requirements due to low docking efficiency (single docking time > 45 minutes) and poor buoyancy stability (displacement error > 10mm). Therefore, the magnetic modular underwater leveling guide rail system of this invention is adopted.

[0129] 1. Guide rail module prefabrication and parameters

[0130] Module dimensions: A single guide rail module is 6m long and has a cross-section of 200mm × 150mm;

[0131] Magnetic connection device: Neodymium iron boron permanent magnet (N42H grade, magnetic field strength 1250mT), annular raised rubber gasket (leakage rate 0.3%).

[0132] Buoyancy material: 3:7 volume ratio hollow glass microspheres (density 0.6 g / cm³) and silicone rubber (density 1.085 g / cm³).

[0133] Dynamic guide vanes: deflection angle 0-30°, servo motor response time ≤0.5s.

[0134] 2. Underwater installation and docking

[0135] The barge is positioned using GPS (horizontal error ±10mm); with the assistance of divers, the first guide rail module is lowered to the design elevation of -5.7m; subsequent modules are attached and connected by a magnetic connection device, with a contact pressure monitoring value of 0.8-1.2kN.

[0136] Single module docking time: 16±1 minutes (traditional solution 45 minutes); axis alignment error: ≤1.2mm (total station measurement, design allowable value ±2mm); sealing test: pressurize with 0.15MPa compressed air for 5 minutes, leakage rate 0.2%.

[0137] 3. Buoyancy compensation and dynamic adjustment

[0138] During construction, the system encountered a water flow with an instantaneous velocity of 1.5 m / s. A three-stage compensation response was adopted: Stage 1 (displacement 5 mm): The nearest airbag was activated at an inflation rate of 0.5 L / min, and the displacement recovered to 3 mm (time 120 s); Stage 2 (displacement 8 mm): Three airbags in the same section were inflated in tandem (rate 1.5 L / min), and the blades were deflected 15° synchronously, and the displacement recovered to 4 mm (time 90 s); Stage 3 (displacement 12 mm): Six airbags in two adjacent sections were activated in tandem (rate 3.0 L / min), and the blades were deflected 30°, and the displacement recovered to 2 mm (time 60 s). Balance coefficient: Real-time calculation η = ΣFbuoy / (Fcurrent + Fanchor) = 0.98 (threshold ≥ 0.95).

[0139] 4. Leveling operation efficiency

[0140] The scraper moving speed is 0.5 m / s (0.3 m / s for the traditional solution); the surface height difference of the subgrade is ≤ ±15 mm (design allowable value ±30 mm). Overall efficiency: 25 m² / h (8 m² / h for the traditional solution).

[0141] 5. Dismantling and Recycling

[0142] Hot seawater injection: 60℃ seawater is used to flush the hollow cavity at a flow rate of 3m³ / h; Ultrasonic synergy: 28kHz vibrating head with an amplitude of 50μm, residual amount detection: 0.3kg / m³ (traditional solution 2.5kg / m³); Module reuse rate: 98% (traditional solution 70%).

[0143] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. It can be applied to various fields suitable for the present invention. Further modifications can be readily implemented by those skilled in the art.

Claims

1. A magnetic modular underwater leveling guide rail system, characterized in that, include: Multiple guide rail modules, each guide rail module comprising a steel pipe body with a rectangular cross-section, the outer surface of which is covered with a composite plastic layer of polyetheretherketone and 10-20 wt% graphite; The guide rail module is equipped with magnetic connection devices at both ends. The magnetic connection devices include neodymium iron boron permanent magnet units embedded in the ends of steel pipes. Adjacent guide rail modules are attracted by opposite magnetic poles and the contact surface is provided with a waterproof rubber gasket with annular protrusions. The lower surface of the guide rail module is provided with a threaded rod height adjustment component with a pitch of 1~3mm. The upper surface of the guide rail module is provided with a positioning groove along the length direction. The positioning groove is embedded with a total station reflecting prism, and the center point of the reflecting prism coincides with the axis of the guide rail module. The guide rail module is fixed to dovetail-shaped guide rails on both sides by bolts, and the guide rails are coated with molybdenum disulfide coating. The guide rail module is equipped with a docking detection sensor at its end. The docking detection sensor includes an infrared transmitter and a receiver. The emission direction of the infrared transmitter is parallel to the axis of the guide rail module, and the receiving surface of the receiver corresponds to the position of the transmitter of the adjacent guide rail module. The steel pipe body contains a hollow cavity comprising 60% of its cross-sectional area. This cavity is filled with hollow glass microspheres and silicone rubber buoyancy material in a 3:7 volume ratio. The hollow glass microspheres have a particle size of 0.5-1.0 mm and are vacuum-modified with a silane coupling agent. The silicone rubber has a density of 1.05-1.15 g / cm³. 3 The hollow cavity is equipped with transverse support plates at intervals, each with a central through hole and static guide vanes welded to the edge of the central through hole; the hollow glass microspheres are covered with a polyurethane membrane with an elastic modulus gradient of 0.5 MPa / m, and the buoyancy loss compensation rate is ≥95% at a water depth of 20m; The guide rail module is embedded with several Ni-Ti-Cu alloy airbags, which expand in diameter when heated by electricity. Specifically, it includes end airbag groups, symmetrically arranged within 1m of both ends of the guide rail module, with two airbags in each group, symmetrically centered along the width of the guide rail module; and cross-sectional airbag groups, arranged every 1.5-2m along the length of the guide rail module, with three airbags in each group, evenly distributed circumferentially; and it is equipped with three levels of buoyancy compensation: when the buoyancy deviation is ≥5%, single airbag compensation is activated; when the deviation is ≥10%, three airbags in the same cross-section are activated for coordinated compensation; and when the deviation is ≥15%, two adjacent cross-sectional airbag groups are linked. The outer wall of the guide rail module is provided with deflectable dynamic guide vanes, which are connected to servo motors and driven to deflect by the servo motors. The dynamic guide vanes are independent of the static guide vanes and are installed on the water-facing side of the outer wall of the guide rail module.

2. The magnetic modular underwater leveling guide rail system according to claim 1, characterized in that, Each airbag is connected to a PID controller with a transfer function G(s) = 2.5 + 0.8 / s + 0.3s. Pressure sensors are spaced 0.5m apart. A pressure relief procedure is triggered when the detected pressure at the mating surface exceeds 1kN, with a relief rate of 10mm. 3 / s; where G(s) is the transfer function of the PID controller, s is the complex frequency variable Laplace operator, 2.5 is the proportional gain Kp, 0.8 / s is the integral gain Ki / s, and 0.3s is the differential gain Kds.

3. A construction method for the magnetic modular underwater leveling guide rail system according to any one of claims 1 to 2, characterized in that, Includes the following steps: Step 1: Position the barge parallel to the axis of the trench using GPS. Step 2: The adjacent guide rail modules are assembled underwater using a magnetic connection device. The magnetic connection device of the adjacent guide rail modules is attracted by opposite magnetic poles, and a waterproof rubber gasket is installed between the contact surfaces. Step 3: Use a total station to position and calibrate the guide rail module, measure the three-dimensional coordinates of the reflecting prism and compare them with the design elevation, and adjust the height adjustment component of the guide rail module so that the elevation of the guide rail module reaches the design value of -5.7m±1cm. Step 4: Install dovetail guide rails on both sides of the guide rail module. Verify the axis alignment accuracy of the guide rail module using a docking detection sensor. The docking detection sensor includes an infrared transmitter and a receiver. The emission direction of the infrared transmitter is parallel to the axis of the guide rail module, and the receiving surface of the receiver corresponds to the position of the transmitter of the adjacent guide rail module. When the received signal strength reaches -30dBm, the docking is deemed qualified. Step 5: Use a scraper to level the base bed along the top surface of the guide rail module, with the scraper moving at a speed of 0.5 m / s. Step 6: After each leveling section is completed, the boat is moved. During the boat movement, the displacement of the installed guide rail module is continuously monitored. When the displacement exceeds 5mm, dynamic buoyancy compensation is triggered.

4. The construction method of the magnetic modular underwater leveling guide rail system according to claim 3, characterized in that, Dynamic buoyancy compensation includes: Fiber Bragg grating displacement sensors are arranged at 0.5m intervals along the axis of the guide rail module. The fiber optic sensors monitor displacement at 100Hz. When the displacement exceeds the threshold, the airbag is expanded by PID control: ΔV = 2.5Δd + 0.8∫Δd + 0.3dΔd / dt; where ΔV is the volume expansion of the airbag; Δd is the real-time displacement deviation; 2.5Δd is the proportional term, where 2.5 is the proportional coefficient Kp; 0.8∫Δd is the integral term, where 0.8 is the integral coefficient Ki, and ∫Δd represents the integral of the displacement deviation over time; 0.3dΔd / dt is the differential term, where 0.3 is the differential coefficient Kd, and dΔd / dt represents the rate of change of the displacement deviation. Synchronously inject a silicone rubber slurry containing 15wt% microspheres into the hollow cavity of the guide rail module with excessive displacement to reduce the density to 1.085 g / cm³. 3 ; When the guide rail module displacement exceeds 8mm, the adjacent cross-section airbags expand in tandem and deflect the dynamic guide vanes by 30°.

5. The construction method of the magnetic modular underwater leveling guide rail system according to claim 4, characterized in that, During the compensation process, the buoyancy-resistance balance coefficient is calculated in real time. When the balance coefficient value is lower than 0.95, it automatically switches to the third-level compensation mode and injects compressed air into the hollow cavity of all unoperated guide rail modules. The air pressure is controlled at 0.15MPa and the duration does not exceed 10s. After each compensation operation is completed, the axis coordinates of the guide rail module are re-measured using a total station. When the deviation of three consecutive measurements is ≤2mm, the compensation state is released and the airbag reference volume is restored.

6. The construction method of the magnetic modular underwater leveling guide rail system according to claim 3, characterized in that, When injecting buoyancy material into the hollow cavity, a three-stage pressure control is adopted: the first stage is to inject at a pressure of 0.2MPa for 30 seconds to fill the middle of the cavity; the second stage is to switch to 0.5MPa and maintain it for 20 seconds to allow the material to penetrate the through-hole area of ​​the transverse support plate; the third stage is to reduce the pressure to 0.1MPa and maintain it for 60 seconds. When the water depth exceeds 15m, a PWM current is applied to the Ni-Ti-Cu alloy airbag via a PID controller to control the airbag's volume expansion rate from 0.5 to 4.5mm. 3 / s; After every 200m of guide rail is laid, the temperature-strain field is detected by the fiber optic grating sensor arranged in the cavity. When the local strain exceeds 0.3%, the PTC heating element on the outer wall is activated to control the temperature uniformity, and the temperature gradient is controlled within ≤2℃ / cm. During the dismantling and recycling phase, hot seawater at 60±3℃ is injected into the hollow cavity, and ultrasonic vibration at 28kHz is applied simultaneously to expel the material.

7. The construction method of the magnetic modular underwater leveling guide rail system according to claim 3, characterized in that, During the guide rail module docking phase, a three-level response is initiated based on the axis deviation value fed back by the total station: when the deviation is ≥5%, single airbag compensation is activated; when the deviation is ≥10%, three airbags in the same section work together; when the deviation is ≥15%, two adjacent airbag groups are linked. The airbag groups are spaced 2m apart and have a maximum radial expansion of 150mm.

8. The construction method of the magnetic modular underwater leveling guide rail system according to claim 7, characterized in that, During the guide rail module docking phase, a three-level response is initiated based on the axis deviation value fed back by the total station, synchronously controlling the deflection angle of the dynamic guide vanes: when the deviation is ≥5%, the vanes deflect 0-10°; when the deviation is ≥10%, the vanes deflect 10-20°; when the deviation is ≥15%, the vanes deflect 20-30°.

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