Foundation Reinforcement for Wind Turbines

A reinforcement structure for offshore wind turbine foundations in deep water to improve load-bearing capacity. The structure involves encasing the outer perimeter of the single pile foundation with a floating annular structure below the waterline. Anchor chains connect the floating structure to anchors buried in the seabed. This creates a pre-tensioned overall structure that provides additional horizontal restoring force when the foundation deforms or tilts. It constrains displacement and increases horizontal bearing capacity, allowing deeper water depths or higher turbine loads.

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A large diameter, thin-walled single pile foundation for offshore wind turbines that provides improved strength, stiffness, stability, fatigue resistance, and corrosion resistance compared to traditional steel pipe piles. The foundation consists of steel pile shoes, prefabricated UHPC (ultra high performance concrete) pipe piles, and flanges connected using prestressed steel strands and bolts. This allows using UHPC, which has superior properties compared to regular concrete, for the majority of the foundation where strength and durability are critical. The steel shoes and flanges at the ends provide transition connections to the turbine tower. The prestressing provides additional load transfer and prevents cracking.

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Tension-compression-shear foundation design for wind turbine wheel sets that provides improved resistance to wind loads while reducing foundation size and costs compared to traditional piled foundations. The design involves using a truncated cone-shaped concrete foundation with outer ring piles, inner ring piles, and tie rods. The outer ring piles resist tension and shear forces from wind loads, while the inner ring piles support the wheel weight in compression. The arrangement and density of the piles is optimized based on wheel weight, wind speed, and site geology. A buried shear-resistant member provides additional protection. This foundation configuration allows efficient transfer of forces from the wheel to the ground while mitigating wind loads.

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Pipe pile wind turbine foundation design and construction method for desert areas with poor soil conditions. The foundation consists of buried prestressed pipe piles with a mattress layer on top, followed by pouring a foundation cushion. This allows the foundation to be built entirely within the soft, sandy soil without needing deeper piles. The mattress prevents sand infiltration and stabilizes the piles. The cushion provides a solid base for the wind turbine tower.

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A hollow wind turbine foundation design to reduce concrete usage and construction time while mitigating quality issues like cracking. The foundation has a concrete cushion surrounded by a hollow structure with spoke-like radiating beams connecting an outer ring beam to the central column. This hollow foundation shape reduces surface area compared to traditional circular foundations. It also uses elastic vibration-absorbing components in the foundation piles to dampen tower vibrations.

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Offshore wind foundation suitable for shallow overburden layers that improves bearing capacity, stability and reduces costs compared to deep socket foundations. The foundation has a single pile with a gravity disc attached. Surrounding the disc are multiple screw piles. The screw piles are connected to the disc and pile to form an integrated structure. This configuration provides improved horizontal, vertical and bending resistance without needing deep rock sockets. The gravity disc and screw piles increase rigidity and load capacity. The integrated structure also reduces pile displacement and bending moments.

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Reinforcement method for extending the life of offshore wind turbine foundations without removing and replacing them. The method involves driving a new reinforced pile inside the existing pile using a grouting pipeline. As the new pile is driven, soil is squeezed into the pipeline. This soil is then grouted to reinforce the existing pile. The new pile is then removed, leaving the reinforced existing pile behind. The grouted soil provides additional load bearing capacity to extend the life of the foundation.

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Reducing the size and cost of wind turbine foundations by using a non-full rigid contact prestressed ground anchor type reinforced concrete foundation structure. The foundation has a reduced footprint compared to traditional foundations, as it uses a modified shape and prestressed ground anchors to transfer the load directly to the ground. This reduces the amount of concrete and steel required. The prestressed ground anchors have a non-full rigid contact with the ground to allow some movement and reduce forces on the anchors.

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Post-tensioning system for wind turbine foundations that improves the strength and durability of the concrete foundation compared to traditional designs. The system uses rod anchors, anchor rods, post-tensioning strands, and strand anchors. The anchor rods connect the hub to the bottom of the foundation, while the post-tensioning strands extend through the hub and are anchored at the perimeter. This transfers the tower load through the center of the foundation, reducing stress concentrations and conflicts between anchor rods and steel reinforcement.

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Reinforcement and correction method for offshore wind turbine foundations to mitigate issues like cumulative displacement and scour erosion. The reinforcement involves adding a socket around the wind turbine pile foundation that has steel frames and prefabricated piles. These are connected by anchor cables. The composite foundation formed by injecting cement into the soil around the pile also provides reinforcement. This setup strengthens the foundation and prevents displacement and scour erosion during wind turbine operation.

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Hollow wind turbine blade design with a reinforced structure that enables manufacturing with simplified fabrication steps and reduced cost while providing improved strength and stiffness. The blade has elongated reinforcing structures extending along the blade length, with each structure formed from a stack of pre-cured pultruded composite strips. The reinforcing structures are positioned within the blade shell halves and connected by an intersecting web.

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Rock-socketed single pile foundation for seabed offshore wind turbines that allows reliable and stable application of single pile foundations in rock foundation seabeds. The foundation involves sinking a steel pipe pile into the rock base and then drilling a hole through the rock around the pile. An inner casing is inserted into the drilled hole and grouted. This creates a socketed connection between the pile and rock. The drilling and grouting steps ensure the foundation verticality and stability in variable rock conditions.

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A foundation design for wind turbines that reduces size and cost compared to conventional foundations. The foundation has a platform connected to the tower and multiple piles surrounding it. The piles have spiral discs on the outer shaft that decrease in diameter away from the platform. The spiral discs allow the piles to screw into the ground, providing improved bearing capacity and overturning resistance compared to conventional piles. This eliminates the need for large concrete foundations, reducing footprint and cost.

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Vibratory cementing pile reinforced single pile foundation for offshore wind turbines in soft soil areas. The foundation has vibratory cementing piles surrounding the main pile driven into the seabed. The cementing piles have decreasing strength from inner to outer rings. The piles and soil between form a composite foundation with increased bearing capacity. The cementing process involves vibratory punching gravel and cement into the piles. This improves horizontal resistance, reduces pile deformation, and prevents soil displacement. A riprap layer on top completes the foundation.

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An airfoil pile foundation design for wind turbines in shallow soft clay seabeds that reduces material consumption compared to conventional single piles. The foundation has multiple rectangular wing plates connected to a central steel pipe pile. The wings and pipe are perpendicular to the wind direction. This configuration transfers load horizontally, improving stability and stiffness compared to a single pile. It allows using shorter, thinner piles in soft clay seabeds, reducing construction costs.

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A wind turbine comprises a pitch bearing with variable thickness reinforcing plates along its circumference to reduce stress concentration and optimize the design for varying loads. The pitch bearing connects the turbine blades to the hub and pitches the blades. The reinforcing plates are bolted onto the bearing rings. The plates gradually thicken from the ends toward the center in a wedge shape. This provides additional strength only where needed.

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A construction method for wind turbine foundations in soft seabed that reduces costs and installation difficulties compared to traditional single pile foundations. The method involves using an airfoil-shaped foundation with wings attached to the pile. The wings increase the bearing capacity and stiffness of the foundation by engaging and deforming the surrounding soft seabed. This allows smaller diameter and shorter pile lengths compared to conventional single piles for the same load. The wings also facilitate installation since they can be embedded in the seabed without damaging the pile head.

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Wind turbine with a tensioning system to increase the stiffness and fatigue resistance of pitch bearings that connect the blades to the hub. The system involves tensioning elements that exert radial compression on the outer ring of the pitch bearing. This reduces deformations and stress concentrations in the bearing, improving its load transfer capabilities and preventing premature failures. The tensioning elements are anchored to the hub or blade and apply an adjustable radial compression force to the bearing when tensioned.

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Reducing the footprint of wind turbine foundations while maintaining stability on soft ground. It uses composite pile foundations with buried prefabricated piles, shallow buried fan foundations, and anchor rods between them. The piles provide load bearing and anchoring, while the shallow foundations support the tower. A mattress between the foundations covers the pile-foundation interface. This allows reducing foundation area compared to traditional deep foundations.

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A foundation design for large megawatt wind turbines that reduces costs and improves stability compared to conventional foundations. The foundation has a base plate with a central pillar embedded in it. Transverse piles are inserted into the base plate, with one end contacting the pillar and the other end exposed outside the plate. The piles project downward from the pillar like rays. This configuration provides lateral support for the pillar while allowing the base plate to be smaller compared to a traditional square foundation. It also concentrates forces on the thicker pillar section instead of the outer base plate edges.

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