A novel wind turbine, the tower of which ending with three legs and which is also anchored to the ground by means of a characteristic anchoring system depending on the type of existing soil. It is anchored on conventional rock soil with a pile foundation, it is anchored in a hard-rock soil with an anchor-rock foundation, it is anchored in a non-rocky soil with a gravitational foundation and it is anchored on clayey or swampy soil with a gravitational foundation reinforced with piles.

In particular, a foundation for an offshore structure is disclosed. The foundation includes: a tower having an anchoring section which is anchorable in the seabed and a connection section arranged at the opposite end of the tower. An electricity generation device arrangable above the water surface is connectable with the connection section of the tower. A natural frequency of the offshore structure is below an excitation from a single revolution number 1P of at least one exciting component. Further disclosed is an offshore structure.

A tensionless concrete pier foundation for supporting a tower and a method of constructing the same is provided, the foundation having an outer CMP and an inner CMP with an annular space therebetween in which a plurality of sleeved tower anchor bolts are embedded, at least the outer CMP having an upper edge that is flush with the top of the foundation after the tower has been installed. A method of plumbing a tower anchor bolt cage using a bolt alignment ring is also provided that includes coupling the upper ends of the CMPs together with lateral spacing bolts that extend across the annular space. The tower anchor bolt cage is suspended from the lateral spacing bolts by the bolt alignment ring, and the lateral spacing bolts are shimmed on a low side as necessary for leveling the alignment ring and plumbing the bolt cage, before concrete pour.

Anchor cage for a foundation of a wind turbine. The anchor cage comprises at least an upper load distribution plate (1), at least a lower load distribution plate (2), and a plurality of first reinforcement elements (3) extending between said plates (1, 2). It further comprises at least one intermediate load distribution plate (4) placed between the upper load distribution plate (1) and the lower load distribution plate (2), and a plurality of second reinforcement elements (5) extending between the upper load distribution plate (1) and the intermediate load distribution plate (4), and being shorter than the first reinforcement elements (3). An assembly method for the anchor cage is also described. A foundation is also provided in which the total post-tensioning value provided in the upper part of the foundation (6) is different from the total post-tensioning value provided in the lower part of the foundation (7).

A vessel and a method for installation of a pile adapted to support an offshore wind turbine are described. The method includes a) suspending the pile from a hoisting cable in a substantially vertical orientation; b) providing a lower end of the pile in a pile holding system limiting horizontal motion of a pile portion held by the pile holding system; and c) lowering the pile with the pile being held by the pile holding system. The lowering includes at least lowering the pile through a splash zone of a body of water, and during step c), two tugger lines are directly or indirectly connected to the pile at a location between the pile holding system and the hoisting cable, said tugger lines being operated to damp motion of the pile in two respective horizontal directions.

A groundworks method for a foundation designed to form a foundation slab for an onshore wind turbine includes: excavating in the soil a depression intended to receive, on the one hand, an anchoring means which will be used to connect the mast to the future foundation and, on the other hand, the pouring of concrete to form said foundation after setting. According to the invention, the method further comprises digging a trench at the center of the depression, placing a compressible material in this trench, covering said material with a layer of concrete and waiting for it to set. A foundation is built for a wind turbine, by pouring concrete, the central part of which does not bear on the soil or barely bears on the soil. As a result, the pressure on the soil is increased and is delimited over a peripheral annular zone situated around its central part.

A method of installing foundation elements, in particular (mono)piles having a diameter of five meters or more, in an underwater ground formation includes lowering a leader from a surface vessel with at least the tip of the leader into the water, and lowering a foundation element and/or a noise mitigation screen along the leader.

A foundation for a tower structure, in particular for a tower of a wind power installation, comprising a soil improvement unit with piles and with a slab which is arranged on the piles and which has a foundation side, wherein the foundation side forms a foundation plane, and a shallow foundation which has an areal standing side for mounting onto the foundation plane, wherein the shallow foundation is arranged on the slab.

An off-shore wind turbine system is assembled using a platform or jack-up vessel, and a first base anchored to the seafloor at a bade assembly off-shore location. A buoyant tower is attached to the first base. A crane provided on the platform or jack-up vessel is used to lift blades and blades, which are then coupled to a turbine held in a nacelle provided at the top of the buoyant tower. The buoyant tower, the nacelle, and the blades are detached from the first base. The buoyant tower, the nacelle, and the blades are towed to a wind farm and connected to a second base provided in the wind farm. The buoyant tower, the nacelle, and the blades are further stabilized using mooring lines spanning between the buoyant towers and other bases provided in the wind farm. The first base and/or the second base include anti-rotation features.

The invention relates to a method for the installation of a marine (or in general, aquatic) wind-powered generator tower, wherein said tower advantageously comprises a foundation that is open at the top and equipped with a substantially flat lower slab and a perimeter wall. The method includes, in the different stages thereof, the depositing or removal of ballast material in or from the main cavity of the foundation, and wherein in the absence of said ballast material, the wind-powered generator or the foundation is a floating or self-floating structure. The method is particularly suitable for the installation of wind-powered generators in areas of low depth (or near-shore areas), preferably of less than 15 m.