Round caisson independent pier assembly type omnidirectional wave energy capturing structure and construction method

Abstract

This invention relates to a prefabricated omnidirectional wave energy capture structure and construction method for a circular caisson independent pier, belonging to the field of port hydraulic structures and marine renewable energy utilization technology. The structure is a fully integrated structure of an oscillating water column wave energy device and a circular caisson, including a modular circular caisson energy capture unit, a sealing and anti-corrosion unit, and a top connection and confluence unit. This invention employs a four-chamber annular symmetrical independent sealing layout to achieve 360° omnidirectional energy capture without blind spots; it uses a prefabricated energy-concentrating guide sill to concentrate wave energy and amplify the water column oscillation amplitude; the epoxy-modified cement-based sealing material of this invention can be directly applied to high-humidity surfaces; through secondary connections of water-stop rubber, prefabricated cover plates, and wet joints, it achieves overall structural stability and long-term sealing of the air chambers; the four independent flanges share a single turbine unit, with each chamber having independent air intake without cross-flow or backflow. This invention is convenient to construct, has reliable sealing, stable structure, and high energy capture efficiency, demonstrating significant engineering and industrialization promotion value.

Description

Technical Field

[0001] This invention belongs to the field of port hydraulic structures and marine renewable energy utilization technology, specifically relating to a prefabricated omnidirectional wave energy capture structure and construction method for circular caisson independent piers, which is specifically used for energy integration construction projects of circular caisson independent pier structures. Background Technology

[0002] Circular caissons are widely used gravity hydraulic structures in nearshore port, wharf, and breakwater projects, especially in caisson-type independent pier structures. Integrating wave energy capture functionality with the caisson body represents an important technological direction for the green and low-carbon development of port engineering. Currently, related structures and construction techniques have many limitations in practical applications. 1. Wave energy capture devices are mostly externally mounted, requiring secondary drilling, rebar installation, and cutting modifications after the caisson is formed. This can easily damage the main reinforcement of the caisson and the overall stress system, weakening the core hydraulic performance such as structural load-bearing capacity, anti-tipping ability, and anti-collision capability. It cannot meet the requirements of waterway engineering specifications, and is especially unsuitable for the safety and stability control standards of circular caisson-type independent piers. A search of similar technologies reveals that existing externally mounted OWC devices all have common defects such as large additional structural stiffness, eccentric stress on the caisson, and reduced seismic performance.

[0003] 2. Construction conditions for sealing concrete substrates are limited. Conventional epoxy and cement-based sealing materials must be applied to dry substrates. However, after the caisson is installed at sea, the chamber is constantly exposed to high humidity due to tides and sea fog, making it impossible to dry and cure, which prolongs the construction period. At the same time, in the marine environment of high salt spray and alternating dry and wet conditions, the sealing layer is prone to cracking, peeling, and leakage, resulting in poor structural durability. In existing publicly available technologies, three-component epoxy-modified cement-based materials are mainly used for leveling and protecting building concrete, and have not broken through the application bottleneck in the field of full-section airtight and watertight sealing of wave energy capture chambers. The service life of the sealing system is generally insufficient, and the operation and maintenance costs are high.

[0004] 3. The wave-focusing structure is unreasonable. Existing structures are mostly monolithic cast-in-place or complex prefabricated structures, making formwork erection difficult, modular assembly construction impossible, on-site installation quality difficult to control, structural stability poor, and subsequent maintenance and replacement inconvenient. Research shows that existing wave-focusing structures mostly use fixed guide vanes and irregularly shaped folded plates, resulting in high flow resistance and inability to adapt to rapid assembly within the caisson cavity. Furthermore, existing guide structures have not optimized slope parameters for the omnidirectional wave characteristics of the four-chamber annular symmetrical air chamber, resulting in low wave-focusing efficiency and significant differences in wave performance from different directions.

[0005] 4. There are defects in the layout and connection of the energy-capturing air chambers. Single-sided and double-sided air chamber layouts have blind spots in the energy-capturing direction, making it difficult to adapt to the changing wave conditions in the sea area. Multi-chamber series connection structures are prone to air leakage, backflow, and pressure cancellation, resulting in large wave energy loss and low capture efficiency. Similar four-chamber caisson technologies generally adopt a series connection of cavities or a shared air channel design, which has serious air leakage and extremely poor omnidirectional energy capture stability.

[0006] In summary, existing technologies cannot achieve the integrated fusion of the caisson body, the prefabricated wave energy capture unit, and the high-humidity adaptable sealing system. They cannot simultaneously ensure the safety of the circular caisson independent pier structure and the efficient capture of wave energy. There is an urgent need for a circular caisson wave energy capture technology solution that is prefabricated in the factory, easy to assemble, adaptable to high humidity, structurally reliable, and omnidirectional without gas leakage. Summary of the Invention

[0007] This invention addresses a series of problems in existing technologies for integrating caissons and wave energy harvesting devices, including structural modifications that damage the main structure, reliance on dry substrates for sealing materials leading to extended construction periods, complex and poorly assembled energy-concentrating structures, easy air leakage due to multi-cavity air passages, low energy harvesting efficiency due to directional blind spots in the energy-harvesting chamber, and the difficulty in balancing top sealing and structural stability. It innovatively proposes a technical approach combining prefabrication of the caisson main body with assembly of the energy-harvesting components. This achieves an integrated design of the circular caisson-type independent pier structure and the wave energy harvesting unit, avoiding damage to the caisson main body caused by later drilling and rebar installation, and fully preserving the caisson's core hydraulic performance of load-bearing, anti-tipping, and anti-collision. Utilizing a mature, high-moisture substrate-compatible three-component epoxy-modified cement-based sealing system, this invention is the first to apply it to the full-section airtight and watertight sealing of the wave energy harvesting chamber, allowing for direct sealing in relatively dry substrates. Construction on damp surfaces with humidity >90% and newly poured concrete surfaces significantly shortens the construction cycle. A modular, prefabricated energy-concentrating structure is adopted, with an optimized wavefront slope of 1:2 to 1:4. The height difference between the top and the bottom plate of the caisson cavity is 1 / 3 to 1 / 2 of the design tidal range. This parameter matches common wave conditions in nearshore waters and the four-chamber structure of this invention, amplifying the amplitude of water column oscillation within the chamber by 1.4 to 1.6 times, significantly improving wave energy capture efficiency, simplifying construction procedures, enhancing structural stability, and reducing maintenance difficulty. The optimized independent sealing layout of the four chambers completely eliminates blind spots in the energy capture direction, prevents backflow of air, and improves energy capture efficiency under varying wave conditions. A dual sealing system of water-stop rubber and wet joints is constructed, simultaneously achieving structural integrity and long-term sealing of the chambers. A standardized prefabricated construction method is formed to meet the needs of mass prefabrication in factories.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: a circular caisson independent pier assembled omnidirectional wave energy capture structure, wherein the structure is a fully integrated structure of an oscillating water column wave energy device and a circular caisson, including a modular circular caisson energy capture unit, a sealing and anti-corrosion unit, and a top connection and confluence unit; The modular circular caisson energy capture unit uses the circular caisson wall as the base. The interior of the caisson is integrally cast with a cross-shaped radial partition wall, which divides and forms four independent and non-interconnected 90° annular centrally symmetrical sealed energy capture chambers. The working area of ​​the chambers covers the designed tidal range. The underwater sidewall of the energy capture chamber has a water inlet, and the bottom plate of the caisson cavity inside the water inlet is equipped with a prefabricated energy-concentrating guide sill. The sealing and anti-corrosion unit includes a three-component epoxy-modified cement-based sealing and protective layer installed on the concrete base surface of the energy capture chamber, and a water-stop rubber installed on the top surface of the caisson partition wall. A prefabricated cover plate is installed on the upper part of the water-stop rubber. The prefabricated cover plate and the caisson are connected to each other through a wet joint to form a sealed and stable whole. The top connection and manifold unit includes an independent flange interface and a load-embedded component set on the top of each energy-capturing gas chamber. The four flange interfaces are connected to a parallel gas collection and manifold device, and the outlet of the manifold device is connected to a bidirectional self-rectifying impulse air turbine-generator integrated module.

[0009] The cross-shaped radial partition wall is coaxially and symmetrically arranged with the circular caisson, equally dividing it into four independent fan-shaped energy-capturing chambers. Each chamber is completely isolated and the air paths are not interconnected. The prefabricated energy-concentrating guide sill is an independently prefabricated sloping gradually changing cross-section component with a wave-facing slope of 1:2 to 1:4. It is designed according to the internal streamline of the chamber, and the height difference between the top and the bottom plate of the caisson cavity is 0.3 to 0.8m. After the caisson is formed, it is assembled and fixed to the bottom plate of the cavity. By constraining energy concentration, raising the wave water level, and amplifying the water column oscillation amplitude through the slope, it is used to gather wave energy, constrain the water flow path, and increase the oscillation amplitude of the water column in the chamber, so that at least two chambers can work independently in any direction of wave arrival, without energy-capturing blind spots.

[0010] The three-component epoxy-modified cement-based sealing and protective layer uses existing mature high-humidity substrate-compatible sealing materials to fully cover the inner wall of the air chamber, the side of the partition wall, and the joint surface of the top of the caisson. The construction thickness is controlled at 0.5~3.0mm, which is suitable for the sealing requirements of the entire cross section of the air chamber, forming a continuous and closed airtight and watertight barrier. This sealing and protective layer can be directly impregnated and bonded to form a film on a high-humidity substrate with relative humidity >90% and without standing water. It works in synergy with the thermal expansion coefficient of concrete, adapting to marine salt spray and alternating dry and wet conditions, and preventing peeling, cracking and leakage.

[0011] The water-stop rubber is a continuous sealing element that is embedded in the positioning groove on the top surface of the partition wall and compressed and sealed between the caisson and the precast cover plate. The compression amount is controlled to be ≥10mm by the positioning tool. The precast cover plate is rigidly connected to the caisson through an annular wet joint, and together with the water-stop rubber, it forms a double sealing system at the top, simultaneously achieving structural integrity and long-term sealing of the air chamber.

[0012] Each independent flange interface is embedded in the prefabricated cover plate. The parallel gas collection and confluence device is equipped with four independent check flow channels that are isolated from each other. Each channel has a single chamber for independent air intake and only the outlet end merges to drive the turbine unit, with no gas leakage, no backflow, and no pressure cancellation.

[0013] A construction method for a prefabricated omnidirectional wave energy capture structure with independent caisson piers, the specific steps of which are as follows: S1. Prefabrication of the caisson body and assembly installation of the energy-concentrating diversion sill; Specifically, it includes: S11. Prefabrication of caisson structure: In the prefabrication yard, standard steel templates are used for steel bar binding and concrete pouring to complete the integrated prefabrication of the circular caisson body and the cross radial partition wall, forming four independent and non-connected fan-shaped energy-capturing chambers. The chamber outline, top connection structure and bottom assembly positioning base are precisely reserved to ensure that the dimensional accuracy and load-bearing performance of the caisson structure meet the requirements of independent pier hydraulic engineering. S12. Precast Energy Concentration Diversion Sill: The precast assembly energy concentration diversion sill is designed according to the internal flow line of the air chamber. It is made of reinforced concrete with a concrete strength grade of not less than C30. The slope of the wave-facing surface is controlled at 1:2~1:4. The height difference between the top and the bottom plate of the caisson cavity is controlled at 0.3~0.8m. The slope is smooth and the dimensions are accurate. The positioning deviation of the structural dimensions is controlled at ≤±5mm. It has the structural functions of energy concentration, flow stabilization and lifting water column oscillation. S13. Assembly inside the caisson cavity: After the main body of the fixed caisson is prefabricated and reaches the design strength, the assembled energy-concentrating caisson is hoisted to the inside of the inlet of each energy-capturing gas chamber, and precisely installed on the bottom plate of the caisson cavity according to the design position and fixed in a limited position. The installation plane deviation is ≤±3mm, forming an independent and stable energy-concentrating structure, and achieving a non-damaged assembly and combination with the main body of the caisson.

[0014] S2. Offshore installation of caissons and sealing of high-humidity substrates; Specifically, it includes: S21. Caisson transport and offshore installation: The assembled circular caisson-type independent piers are transported and floated to the designed sea area. The GPS-RTK system is used for sinking, fine adjustment and positioning, controlling the plane positioning deviation to ≤±50mm and the tilt angle to ≤1 / 1000, and the offshore installation is completed. After installation, the chamber is affected by seawater tides and environmental humidity, and is in a high humidity state with a relative humidity of >90% for a long time. S22. High Moisture Substrate Treatment and Sealing Construction: No drying treatment is required for the chamber substrate. Simply use an angle grinder to mechanically grind and clean the substrate of any floating slurry and stains, ensuring the substrate is free of standing water, loose particles, and has a surface roughness that meets bonding requirements before construction. Use a three-component epoxy-modified cement-based sealant, mixed in a weight ratio of A:B:C=1:2.5:(14~15). Use a low-speed mixer at 300~400 rpm for 3 minutes until homogeneous. Apply two full coats to the high-moisture concrete substrate. The first coat is 0.3~1.5mm thick, the second coat is 0.2~1.5mm thick, and the total thickness is controlled at 0.5~3.0mm. Completely cover the chamber walls, partition walls, and top surfaces, adapting to marine salt spray and alternating wet and dry environments, preventing leakage and gas flow.

[0015] S3. The water-stop sealing structure is installed and integrally connected with the top structure; Specifically, it includes: S31. Water-stop rubber positioning and installation: After the sealing layer has been cured and formed, water-stop rubber is laid in the positioning groove on the top surface of the cross radial partition wall of the caisson. It is fixed with positioning clamps to ensure that the position is centered and the line is straight. The joint is connected by hot vulcanization. The joint strength is not less than 80% of the strength of the parent material, forming the first flexible sealing barrier at the top. S32. Precast cover plate hoisting and positioning: The precast reinforced concrete cover plate is hoisted using lifting equipment and precisely positioned on the top of the caisson using the guide pins embedded at the four corners of the cover plate. This ensures that the bottom surface of the cover plate is evenly pressed against the water-stop rubber to form a compression seal. The compression amount is controlled to be ≥10mm and the deviation is ≤±1mm to ensure that the top of each air chamber is independently sealed. S33. Wet Joint Casting and Structural Forming: A ring-shaped wet joint concrete is cast at the junction of the cover plate and the top surface of the caisson. Micro-expansion concrete is used, with a strength grade one level higher than the caisson body. The slump is controlled at 120-160mm. The concrete is vibrated to ensure compaction and cured. The wet joint achieves a rigid secondary connection between the precast cover plate and the caisson body. This process simultaneously achieves two major functions: first, it forms an integral load-bearing structure, ensuring the stability, impact resistance, and overturning resistance of the independent pier structure; second, it works in conjunction with the water-stop rubber to form a rigid + flexible dual-sealing system, ensuring long-term airtightness and independent airflow prevention in each air chamber.

[0016] S4. Integration and overall acceptance and commissioning of the combined generation system; Specifically, it includes: S41. Installation of Independent Flanges and Combination Devices: Install independent flange interfaces at the corresponding positions of each air chamber on the prefabricated cover plate. Use 3mm thick nitrile rubber gaskets to seal the flange surfaces. Tighten bolts symmetrically in a diagonal sequence, ensuring that the tightening torque meets the standard requirements and guarantees independent ventilation for each chamber. Connect the four flanges to the parallel gas collection and combination device. The internal flow channels of the device are isolated from each other, and only the outlet ends merge, achieving independent air intake, no cross-flow, and no backflow. S42. Integration of power generation module and control system: Install an integrated impulse air turbine-generator module at the outlet of the combiner device to complete the connection of power line and control line, perform insulation resistance test ≥0.5MΩ and grounding resistance test ≤4Ω, and complete parameter setting and single-unit function debugging. S43. Performance Testing and Final Acceptance: Conduct a water tightness test of the air chamber, maintain pressure at 0.05MPa for 24 hours, with an allowable pressure drop of ≤5%, conduct a leak-proof sealing test, wave energy capture simulation test, and power generation system linkage commissioning. After all indicators meet the design and specification requirements, complete the overall final acceptance and officially put the system into operation.

[0017] Compared with the prior art, the present invention has the following advantages: 1. High structural integration: The caisson and energy capture unit are prefabricated as a whole, eliminating the need for secondary drilling, rebar installation, cutting and modification. This effectively avoids damage to the caisson's load-bearing system caused by external devices, retains the independent pier load-bearing, anti-tipping, and anti-collision performance of the circular caisson, meets the requirements of the "Code for Design and Construction of Gravity Wharf", and solves the common problems of existing external OWC devices, such as large additional stiffness, eccentric stress, and reduced seismic performance.

[0018] 2. The sealing system has strong adaptability. For the first time, a three-component epoxy-modified cement-based material is used for full-section airtight and watertight sealing of the air chamber. It can be directly constructed on a high-humidity substrate with relative humidity >90% and without standing water, eliminating the traditional 28-day dry curing period and shortening the construction period by about 28 days. The thermal expansion coefficient of the sealing layer matches that of the concrete, adapting to marine high salt spray, alternating dry and wet conditions, and freeze-thaw cycles, effectively preventing peeling, cracking, and leakage. The designed service life can reach more than 20 years, reducing operation and maintenance costs.

[0019] 3. Excellent energy-concentrating and flow-guiding effect: The wave-facing slope is optimized to 1:2~1:4 for the four-chamber annular symmetrical air chamber, combined with a height difference design of 0.3~0.8m, resulting in a stable amplification of the water column oscillation amplitude by 1.4~1.6 times, and an energy capture efficiency that is 30%~35% higher than that of structures without flow guides. It adopts prefabricated assembly, eliminating the need for integrated casting, resulting in high construction precision and convenient installation. It can be adjusted and replaced later according to wave conditions, solving the problems of high flow resistance, complex construction, and poor omnidirectional performance of existing energy-concentrating structures.

[0020] 4. The gas chamber layout is reasonable, with a four-chamber 90° annular central symmetrical independent sealing layout, realizing 360° omnidirectional energy capture without blind spots. At least two chambers can independently do work when waves come from any direction. The parallel gas collection and confluence device is equipped with four independent check flow channels, with independent air intake and outlet at each chamber to drive the turbine. This effectively eliminates gas leakage, backflow, and pressure cancellation, resulting in uniform and stable energy output. It solves the problems of large energy loss and poor energy capture stability in multi-chamber series structures.

[0021] 5. The sealing system is reliable. It constructs a triple sealing system of "water-stop rubber flexible seal + wet joint rigid seal + base surface seal". The compression of the water-stop rubber is controlled to ≥10mm by positioning tooling. It is combined with the rigid connection of micro-expansion concrete wet joint. At the same time, it ensures the integrity of the caisson structure, impact resistance, overturning resistance and long-term independent airtightness of each air chamber, solving the problem of the difficulty in balancing top sealing and structural stability in the existing technology. Attached Figure Description

[0022] Figure 1 Overall elevation view of the prefabricated omnidirectional wave energy capture structure with independent caisson piers; Figure 2 This is a plan view of a four-chamber annular symmetrical independent energy-harvesting gas chamber; Figure 3 This is a detailed drawing of the sealing and connection nodes at the top of the air chamber; In the diagram: 1-Circular caisson wall; 2-Cross radial partition wall; 3-Energy-capturing chamber; 4-Assembled energy-concentrating guide sill; 5-Three-component epoxy-modified cement-based sealing and protective layer; 6-Water-stop rubber; 7-Independent flange interface; 8-Parallel gas collection and manifold device; 9-Prefabricated cover plate; 10-Wet joint; 11-Water inlet; 12-Turbine machine; 13-Caisson internal filling material. Detailed Implementation

[0023] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but the present invention is not limited to the specific embodiments.

[0024] Example 1

[0025] This embodiment is applied to the construction of a new circular caisson-type independent pier in nearshore waters. The caisson adopts a large-diameter circular shape, and the overall structure meets the port's hydraulic engineering requirements for collision prevention, anti-tipping, and load-bearing capacity. It also integrates an oscillating water column wave energy capture function. Figure 1 As shown, the circular caisson independent pier assembled omnidirectional wave energy capture structure is a fully integrated structure of oscillating water column wave energy device and circular caisson, including modular circular caisson energy capture unit, sealing and anti-corrosion unit, and top connection and confluence unit. The modular circular caisson energy capture unit uses a circular caisson wall 1 as the base. The interior of the caisson is integrally cast with a cross-shaped radial partition wall 2, which divides and forms four independent and non-interconnected 90° annular centrally symmetrical sealed energy capture gas chambers 3. The working area of ​​the gas chambers covers the designed tidal range. The underwater side wall of the energy capture gas chamber 3 has a water inlet 11. The bottom plate of the caisson cavity inside the water inlet 11 is equipped with a prefabricated energy-concentrating guide sill 4. The sealing and anti-corrosion unit includes a three-component epoxy-modified cement-based sealing and protective layer 5 installed on the concrete base surface of the energy capture chamber 3, and a water-stop rubber 6 installed on the top surface of the caisson partition wall. A prefabricated cover plate 9 is installed on the upper part of the water-stop rubber 6. The prefabricated cover plate 9 and the caisson are connected to each other through a wet joint 10 to form a sealed and stable whole. The top connection and confluence unit includes an independent flange interface 7 and a load-embedded component set on the top of each energy capture chamber 3. The four flange interfaces 7 are connected to a set of parallel gas collection and confluence devices 8. The outlet of the confluence device is connected to a set of bidirectional self-rectifying impact air turbine-generator integrated module.

[0026] The cross-shaped radial partition wall 2 is coaxially and symmetrically arranged with the circular caisson, equally dividing it into four fan-shaped independent energy-capturing air chambers 3. Each air chamber is completely isolated and the air paths are not interconnected. The prefabricated energy-concentrating guide sill 4 is an independently prefabricated sloping gradually changing cross-section component. After the caisson is formed, it is assembled and fixed to the bottom plate of the inner cavity. In this embodiment, the slope of the wave-facing surface of the prefabricated energy-concentrating guide sill is 1:3, and the height difference between the top and the bottom plate of the inner cavity of the caisson is 0.5m, which is suitable for the working conditions of the sea area with a design wave height of 1.5m and a design tidal range of 1.2m. After dual verification by physical model test and numerical simulation, the amplification factor of water column oscillation amplitude under stable working conditions can reach 1.4~1.5, and the energy capture efficiency is improved by 30%~35% compared with the structure without guide sill. By confining energy with the slope, raising the wave water level and amplifying the water column oscillation amplitude, it is used to gather wave energy, constrain the water flow path and increase the water column oscillation amplitude in the air chamber, so as to realize that at least two chambers can work independently for waves coming from any direction without energy capture blind spots.

[0027] The three-component epoxy-modified cement-based sealing and protective layer 5 fully covers the inner wall of the air chamber, the side of the partition wall, and the joint surface of the top of the caisson. The construction thickness is controlled at 0.5~3.0mm, which is suitable for the sealing requirements of the entire cross section of the air chamber and forms a continuous, closed airtight and watertight barrier. This sealing and protective layer can be directly impregnated and bonded to form a film on a high-humidity substrate with relative humidity >90% and without standing water. It works in synergy with the thermal expansion coefficient of concrete to adapt to marine salt spray and alternating wet and dry conditions, and prevents peeling, cracking and leakage.

[0028] The water-stop rubber 6 is a continuous sealing element that is embedded in the positioning groove on the top surface of the partition wall and compressed and sealed between the caisson and the precast cover plate 9. The compression amount is controlled to be ≥10mm by the positioning tool. The precast cover plate 9 is rigidly connected to the caisson through the annular wet joint 10, and together with the water-stop rubber 6, it forms a double sealing system at the top, simultaneously achieving structural integrity and long-term sealing of the air chamber.

[0029] Each independent flange interface 7 is embedded in the prefabricated cover plate 9. The parallel gas collection and confluence device 8 is equipped with four independent check flow channels that are isolated from each other. Each flow channel has a single chamber for independent air intake and only the outlet end merges to drive the turbine unit, with no gas leakage, no backflow, and no pressure cancellation.

[0030] Example 2

[0031] A construction method for a prefabricated omnidirectional wave energy capture structure with independent caisson piers, the specific steps of which are as follows: S1. Prefabrication of the caisson body and assembly installation of the energy-concentrating diversion sill: S11. Prefabrication of caisson structure: In the prefabrication yard, standard steel templates are used for steel bar binding and C40 concrete pouring to complete the integrated prefabrication of circular caisson wall 1 and cross radial partition wall 2, forming four independent and non-connected fan-shaped energy-capturing chambers 3. The chamber outline, top surface connection structure, 10mm deep positioning groove on the top surface of the partition wall and bottom assembly positioning base are precisely reserved. The dimensional deviation of the caisson prefabrication meets the requirements of JTS167-2-2009. S12. Prefabricated independent energy-concentrating guide sill: The prefabricated assembly energy-concentrating guide sill 4 is designed according to the internal flow line of the air chamber. It is prefabricated with C35 reinforced concrete, with a wave-facing slope of 1:3, a height difference of 0.5m between the top and the bottom plate of the caisson cavity, a smooth slope, accurate dimensions, and a structural dimension positioning deviation of ≤±3mm. S13. Assembly inside the caisson cavity: After the main body of the caisson is prefabricated and reaches 100% of the design strength, the assembled energy-concentrating caisson 4 is hoisted to the inside of the inlet 11 of each energy-capturing gas chamber 3, and precisely installed on the bottom plate of the caisson cavity according to the design position and fixed with M16 pre-embedded bolts. The installation plane deviation is ≤±2mm.

[0032] S2. Offshore installation of caissons and sealing of high-humidity substrates: S21. Caisson transport and offshore installation: The assembled round caisson independent piers are transported as a whole and floated to the designed sea area. The GPS-RTK system is used for sinking and fine adjustment to control the plane positioning deviation ≤ ±30mm and the tilt angle ≤ 1 / 1500, and the positioning and fixing are completed. S22. High Moisture Surface Treatment and Sealing: Use an angle grinder to grind and remove the surface slurry, ensuring the surface is free of standing water and loose particles; use Sikagard®-720EpoCem® three-component epoxy modified cementitious sealant, mixed at a weight ratio of A:B:C=1:2.5:14.9 (corresponding to a 21kg standard package), and mix with a low-speed mixer at 350 rpm for 3 minutes until uniform; apply two coats, the first coat being 1.0mm thick and the second coat 0.8mm thick, for a total thickness of 1.8mm, fully covering the interior walls, partition walls, and the bonding surfaces of the top surface; prevent rain exposure for 24 hours after application and allow to cure naturally for 7 days.

[0033] S3. The water-stop sealing structure is installed and integrally connected to the top structure: S31. Waterstop rubber positioning installation: After the sealing layer has cured, a 12mm thick neoprene rubber waterstop is laid in the positioning groove on the top surface of the partition wall. It is fixed with plastic positioning clamps, centered and straight, and the joints are connected by hot vulcanization. S32. Precast cover plate hoisting and positioning: A 50t truck crane is used to hoist C40 reinforced concrete precast cover plate 9. The four corner guide pins are used for precise positioning. The pressure sensor is used to control the compression of the water-stop rubber to 12mm, with a deviation of ≤±0.5mm. S33. Wet joint pouring and structural forming: Pour 10mm of circumferential wet joint concrete, using C45 micro-expansion concrete with a slump of 140mm. Compact the concrete with an immersion vibrator and cure it with water for 7 days.

[0034] S4. Integration and overall acceptance and commissioning of the combined generation system: S41. Installation of independent flange and manifold: Install DN150 stainless steel independent flange interface 7, use 3mm thick nitrile rubber sealing gasket, tighten bolts symmetrically in diagonal order, tightening torque 35N·m; connect the four flanges to the parallel gas collection and manifold 8. S42. Integration of power generation module and control system: Install a 10kW bidirectional self-rectifying impulse air turbine-generator integrated module, complete the line connection, insulation resistance test value of 2.5MΩ, grounding resistance test value of 2.8Ω, and complete parameter tuning; S43. Performance testing and final acceptance: The air chamber water tightness test was conducted at 0.05MPa for 24 hours, with a measured pressure drop of 2.8%; the pressure of the remaining air chambers remained unchanged after the single chamber was filled with gas; the system was put into operation after 72 hours of continuous linkage commissioning and stable operation, and all indicators met the standards.

Claims

1. A prefabricated omnidirectional wave energy capture structure with independent piers and circular caissons, characterized in that: The structure is a fully integrated structure of an oscillating water column wave energy device and a circular caisson, including a modular circular caisson energy capture unit, a sealing and corrosion protection unit, and a top connection and confluence unit; The modular circular caisson energy capture unit uses the circular caisson wall as the base. The interior of the caisson is integrally cast with a cross-shaped radial partition wall, which divides and forms four independent and non-interconnected 90° annular centrally symmetrical sealed energy capture chambers. The working area of ​​the chambers covers the designed tidal range. The underwater sidewall of the energy capture chamber has a water inlet, and the bottom plate of the caisson cavity inside the water inlet is equipped with a prefabricated energy-concentrating guide sill. The sealing and anti-corrosion unit includes a three-component epoxy-modified cement-based sealing and protective layer installed on the concrete base surface of the energy capture chamber, and a water-stop rubber installed on the top surface of the caisson partition wall. A prefabricated cover plate is installed on the upper part of the water-stop rubber. The prefabricated cover plate and the caisson are connected to each other through a wet joint to form a sealed and stable whole. The top connection and manifold unit includes an independent flange interface and a load-embedded component set on the top of each energy-capturing gas chamber. The four flange interfaces are connected to a parallel gas collection and manifold device, and the outlet of the manifold device is connected to a bidirectional self-rectifying impulse air turbine-generator integrated module.

2. The prefabricated omnidirectional wave energy capture structure with independent piers for circular caissons according to claim 1, characterized in that, The cross-shaped radial partition wall is coaxially and symmetrically arranged with the circular caisson, equally dividing it into four independent fan-shaped energy-capturing chambers. Each chamber is completely isolated and the air paths are not interconnected. The prefabricated energy-concentrating guide sill is an independently prefabricated sloping gradually changing cross-section component with a wave-facing slope of 1:2 to 1:

4. It is designed according to the internal streamline of the chamber, and the height difference between the top and the bottom plate of the caisson cavity is 0.3 to 0.8m. After the caisson is formed, it is assembled and fixed to the bottom plate of the cavity. By constraining energy concentration, raising the wave water level, and amplifying the water column oscillation amplitude through the slope, it is used to gather wave energy, constrain the water flow path, and increase the oscillation amplitude of the water column in the chamber, so that at least two chambers can work independently in any direction of wave arrival, without energy-capturing blind spots.

3. The prefabricated omnidirectional wave energy capture structure with independent piers for circular caissons according to claim 1, characterized in that, The three-component epoxy-modified cement-based sealing and protective layer uses existing mature high-humidity substrate-compatible sealing materials to fully cover the inner wall of the air chamber, the side of the partition wall, and the joint surface of the top of the caisson. The construction thickness is controlled at 0.5~3.0mm, which is suitable for the sealing requirements of the entire cross section of the air chamber, forming a continuous and closed airtight and watertight barrier. This sealing and protective layer can be directly impregnated and bonded to form a film on a high-humidity substrate with relative humidity >90% and without standing water. It works in synergy with the thermal expansion coefficient of concrete, adapting to marine salt spray and alternating dry and wet conditions, and preventing peeling, cracking and leakage.

4. The prefabricated omnidirectional wave energy capture structure with independent piers for circular caissons according to claim 1, characterized in that, The water-stop rubber is a continuous sealing element that is embedded in the positioning groove on the top surface of the partition wall and compressed and sealed between the caisson and the precast cover plate. The compression amount is controlled to be ≥10mm by the positioning tool. The precast cover plate is rigidly connected to the caisson through an annular wet joint, and together with the water-stop rubber, it forms a double sealing system at the top, simultaneously achieving structural integrity and long-term sealing of the air chamber.

5. The prefabricated omnidirectional wave energy capture structure with independent piers for circular caissons according to claim 1, characterized in that, Each independent flange interface is embedded in the prefabricated cover plate. The parallel gas collection and confluence device is equipped with four independent check flow channels that are isolated from each other. Each channel has a single chamber for independent air intake and only the outlet end merges to drive the turbine unit, with no gas leakage, no backflow, and no pressure cancellation.

6. A construction method for a prefabricated omnidirectional wave energy-capturing structure with independent caisson piers, characterized in that, The specific steps are as follows: S1. Prefabrication of the caisson body and assembly installation of the energy-concentrating diversion sill; S2. Offshore installation of caissons and sealing of high-humidity substrates; S3. The water-stop sealing structure is installed and integrally connected with the top structure; S4. Integration and overall acceptance and commissioning of the combined power generation system.

7. The construction method of a prefabricated omnidirectional wave energy capture structure with independent caisson piers according to claim 6, characterized in that, The S1 step specifically includes: S11. Prefabrication of caisson structure: In the prefabrication yard, standard steel templates are used for steel bar binding and concrete pouring to complete the integrated prefabrication of the circular caisson body and the cross radial partition wall, forming four independent and non-connected fan-shaped energy-capturing chambers. The chamber outline, top connection structure and bottom assembly positioning base are precisely reserved to ensure that the dimensional accuracy and load-bearing performance of the caisson structure meet the requirements of independent pier hydraulic engineering. S12. Precast Energy Concentration Diversion Sill: The precast assembly energy concentration diversion sill is designed according to the internal flow line of the air chamber. It is made of reinforced concrete with a concrete strength grade of not less than C30. The slope of the wave-facing surface is controlled at 1:2~1:

4. The height difference between the top and the bottom plate of the caisson cavity is controlled at 0.3~0.8m. The slope is smooth and the dimensions are accurate. The positioning deviation of the structural dimensions is controlled at ≤±5mm. It has the structural functions of energy concentration, flow stabilization and lifting water column oscillation. S13. Assembly inside the caisson cavity: After the main body of the fixed caisson is prefabricated and reaches the design strength, the assembled energy-concentrating caisson is hoisted to the inside of the inlet of each energy-capturing gas chamber, and precisely installed on the bottom plate of the caisson cavity according to the design position and fixed in a limited position. The installation plane deviation is ≤±3mm, forming an independent and stable energy-concentrating structure, and achieving a non-damaged assembly and combination with the main body of the caisson.

8. The construction method of a prefabricated omnidirectional wave energy capture structure with independent caisson piers according to claim 6, characterized in that, The S2 step specifically includes: S21. Caisson transport and offshore installation: The assembled round caisson independent piers are transported and floated to the designed sea area for sinking, fine-tuning and positioning. The planar positioning deviation is ≤ ±50mm and the tilt is ≤ 1 / 1000. The offshore installation is completed. After installation, the chamber is affected by seawater tides and environmental humidity, and is in a high humidity state with a relative humidity of >90% for a long time. S22. High Moisture Substrate Treatment and Sealing Construction: No drying treatment is required for the chamber substrate. Simply clean the substrate of laitance and stains, ensuring that there is no standing water, no loose particles, and the surface roughness meets the bonding requirements before construction. Use a three-component epoxy-modified cement-based sealant, mixed in a weight ratio of A:B:C=1:2.5:(14~15), and stir for 3 minutes at a low speed of 300~400 rpm until uniform. Apply two coats to the high moisture concrete substrate. The first coat is 0.3~1.5mm thick, and the second coat is 0.2~1.5mm thick, with a total thickness controlled at 0.5~3.0mm. Fully cover the chamber walls, partition walls, and top surfaces of the chamber, adapting to marine salt spray and alternating wet and dry environments, and preventing leakage and gas flow channels.

9. A construction method for a prefabricated omnidirectional wave energy-capturing structure with independent caisson piers according to claim 6, characterized in that, The S3 step specifically includes: S31. Water-stop rubber positioning and installation: After the sealing layer has been cured and formed, water-stop rubber is laid in the positioning groove on the top surface of the cross radial partition wall of the caisson. It is fixed with positioning clamps to ensure that the position is centered and the line is straight. The joint is connected by hot vulcanization. The joint strength is not less than 80% of the strength of the parent material, forming the first flexible sealing barrier at the top. S32. Precast cover plate hoisting and positioning: The precast reinforced concrete cover plate is hoisted using lifting equipment and precisely positioned on the top of the caisson using the guide pins embedded at the four corners of the cover plate. This ensures that the bottom surface of the cover plate is evenly pressed against the water-stop rubber to form a compression seal. The compression amount is ≥10mm and the deviation is ≤±1mm, ensuring that the top of each air chamber is independently sealed. S33. Wet joint pouring and structural forming: A ring-shaped wet joint concrete is poured at the junction of the cover plate and the top surface of the caisson. Micro-expansion concrete is used, with a strength grade one level higher than that of the caisson body. The slump is controlled at 120~160mm. It is vibrated to compact and cured for no less than 7 days. The wet joint achieves a rigid secondary connection between the precast cover plate and the caisson body.

10. A construction method for a prefabricated omnidirectional wave energy-capturing structure with independent caisson piers according to claim 6, characterized in that, The S4 step specifically includes: S41. Installation of Independent Flanges and Combination Devices: Install independent flange interfaces at the corresponding positions of each air chamber on the prefabricated cover plate. Use 3mm thick nitrile rubber gaskets to seal the flange surfaces. Tighten bolts symmetrically in a diagonal sequence, ensuring that the tightening torque meets the standard requirements and guarantees independent ventilation for each chamber. Connect the four flanges to the parallel gas collection and combination device. The internal flow channels of the device are isolated from each other, and only the outlet ends merge, achieving independent air intake, no cross-flow, and no backflow. S42. Integration of power generation module and control system: Install an integrated impulse air turbine-generator module at the outlet of the combiner device, complete the line connection, perform insulation resistance test ≥0.5MΩ and grounding resistance test ≤4Ω, and complete parameter setting and single-unit function debugging. S43. Performance Testing and Final Acceptance: Conduct a water tightness test of the air chamber, maintain pressure at 0.05MPa for 24 hours with a pressure drop of ≤5%, conduct a leak-proof sealing test, perform wave energy capture simulation test and power generation system linkage commissioning. After all indicators meet the design and specification requirements, complete the overall final acceptance and officially put the system into operation.

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