In a general aspect, a method is presented for manufacturing support structures for offshore wind turbines. In some implementations, the method includes constructing a plurality of modular sections that assemble to define the support structure. One or more of the plurality of modular sections are configured to anchor to an underwater floor. At least one of the plurality of modular sections is constructed by operations that include forming a wall along a perimeter to bound a volume, filling the volume with a castable material, and hardening the castable material. In some instances, forming the wall includes depositing layers of printable material successively on top of each other. The method also includes joining the plurality of modular sections to assemble the support structure.

A method of forming a wind turbine foundation includes providing an anchor cage in an excavation pit, the anchor cage including an upper flange, a lower flange, and a plurality of anchor bolts extending therebetween. A first cementitious material is directed into the excavation pit so that the anchor cage becomes at least partially embedded in the material, which is allowed to cure to form a rigid body. A connecting element is selectively engaged with the upper flange and an actuating element is positioned in operative relation with the connecting element, the connecting and actuating elements positioned in non-contact relation with the anchor bolts. The actuating element is actuated relative to the connecting element to raise the upper flange from the rigid body into a leveled position. A second cementitious material is directed into a space beneath the raised upper flange and is allowed to cure to form a support layer.

A gravity based foundation for an offshore installation includes a caisson of concrete and a hollow shaft. The caisson has a bottom slab, a roof and a side wall extending between the bottom slab and the roof. The roof having a passage for the shaft into the caisson. The shaft support has embedded tensioning bars vertically projecting from the upper side of the shaft support. The shaft is mounted on the shaft support by the tensioning bars. A method of manufacturing includes providing a concrete bottom slab, arranging a full-length formwork onto the bottom slab, arranging a slip formwork onto the bottom slab, providing the tensioning bars and mounting the tensioning bars in a fixed position to the full-length formwork, and concrete pouring of the sidewall and shaft support while raising the slip formwork.

The invention relates to a method for forming a connection between two pipe segments of different widths, preferably of a tower-like structure, in particular of a wind turbine. In order to be able to connect pipe segments of different widths more easily, reliably and cost-effectively to one another, it is provided that the wider pipe segment is pushed with one end partially over an end of the narrower pipe segment , that the pipe segments are positioned apart from one another by forming an annular gap between the pipe segments, that in the annular gap between the two pipe segments a separating layer extending in the longitudinal direction of the pipe segments and/or in the radial direction is provided, that the annular gap adjacent to the separating layer and at least one side of the separating layer is at least partially cast with a casting compound, that during the hardening of the casting compound the casting compound forms a firm connection on one side of the separating layer with only one of the pipe segments and/or the casting compound forms a firm connection on the other side of the casting compound , only with the other pipe segment and that the pipe segments after the hardening of the casting compound are separated again along the separating layer with the assigned separate connecting elements in particular formed by the hardened casting compound.

A pile holding system configured to support the pile in an upright position at a pile installation location next to the vessel. The pile holding system includes a pile holder and a pile holder support system. The pile holder support system is configured to be mounted on the deck of the vessel, to moveably support the pile holder, and to move the pile holder in a first direction between an inboard position and an outboard position. The pile holder, when in the outboard position, is located outside the contour of the vessel, for holding the pile in the upright position at the installation location. The pile holder, when in the inboard position with the first and second jaw in the open position, is located within the contour of the vessel.

A foundation for an offshore structure is disclosed. The foundation includes a tower having an anchoring portion anchored in the seabed and a connecting portion arranged at the opposite end. The foundation also includes a power generation system arranged above the water surface connected to the connecting portion of the tower. A natural frequency of the offshore structure lies below an excitation component one times the rotational frequency 1P of at least one exciting component. The foundation also includes at least one restoring element connected to the tower via one or more transition pieces. The restoring element is designed such that, in a skewed position of the tower, tensile and/or compressive forces can be transferred to the tower by means of the restoring element such that the tower can be straightened up.

A reinforced 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, and the pier foundation including at least one reinforcement structure that at least partly encircles the outer CMP to provide one or more of increased lateral stiffness, increased shear resistance and overturning (upset) moment capacity, reduced bending, displacement, and deflection of the top of the pier, and improved conditioning, containment, skin friction and lateral bearing capacity of the surrounding soil and/or rock substrate that supports the tensionless pier.

A pile driving method for driving a pile, e.g. a hollow and open ended pile, e.g. a large diameter pile having an outer diameter of at least 5 meters, e.g. a monopile of an offshore wind turbine, into the soil, e.g. into the seabed. Use is made of a pile driving system which comprises a drive head member that is configured to engage the pile, and a solid mass drop weight assembly comprising a support structure and comprising solid drop weight elements supported by said support structure, preferably solid steel drop weight elements being composed of steel elements, e.g. stackable steel elements, which drop weight elements have a total mass of at least 100 tonnes, e.g. more than 500 tonnes, e.g. more than 1000 tonnes, e.g. more than 2000 tonnes, which drop weight assembly is vertically mobile relative to, e.g. above, the drive head member. Further use is made of a lift system that is configured to bring the drop weight assembly into an initial height position relative to the drive head, and a quick release system adapted to effect quick release

Disclosed is a pile-cylinder-truss composite offshore wind turbine foundation. The pile-cylinder-truss composite offshore wind turbine foundation includes a truss structure, a suction cylinder and a pile foundation. The suction cylinder is connected to a bottom portion of the truss structure, and an embedded sleeve for mounting the pile foundation is provided on the suction cylinder. The embedded sleeve is located inside, at an edge of or outside the suction cylinder. The present invention also provides a construction process of the pile-cylinder-truss composite offshore wind turbine foundation.

Offshore structure comprising a pile of a foundation and at least one offshore element, mounted on the pile, forming a slip joint, wherein between an inner surface of the offshore element and an outer surface of the pile: a coating, especially an anti-fouling coating is provided, increasing friction between the said two surfaces and/or preventing corrosion of one or both of said surfaces and/or at least two spaced apart areas are provided with a substance, forming a seal between the said outer surface and the said inner surface, near an upper end of the pile and the off shore element and between a lower end of the off shore element and the pile.