The present invention relates to a gravity-based foundation system for offshore wind turbine installation that comprises three floating concrete bases built with self-floating concrete caissons, equipped with valves for filling them with water and emptying the water out enabling their ballasting and anchoring at their final location; a metal structure which connects the floating concrete bases by means of a connecting element to the wind turbine tower, and a metal element which connects the floating concrete bases to the wind turbine, metal element on which a docking area is installed, a maintenance platform and access stairs, and it also relates to a method of installation of the gravity-based foundation system.

The present invention relates to a gravity-based foundation system for offshore wind turbine installation that comprises three floating concrete bases built with self-floating concrete caissons, equipped with valves for filling them with water and emptying the water out enabling their ballasting and anchoring at their final location; a metal structure which connects the floating concrete bases by means of a connecting element to the wind turbine tower, and a metal element which connects the floating concrete bases to the wind turbine, metal element on which a docking area is installed, a maintenance platform and access stairs, and it also relates to a method of installation of the gravity-based foundation system.

A foundation device for a wind turbine tower includes a hollow main body with a lower face and an upper face. Both the lower face and the upper face contain a hollow space. Each of the faces include an outer perimeter and an inner perimeter. The main body additionally includes an outer lateral wall disposed between the outer perimeter of the lower face and the outer perimeter of the upper face, and an inner lateral wall between the inner perimeter of the lower face and the inner perimeter of the upper face. The device further includes a plurality of columns that project from the upper face of the main body.

The invention is stay-in-place cladding for concrete, including reactive and slow-curing concretes, allowing for enhanced strength and durability of the contained concrete by allowing it to cure over time while enabling beneficial chemical reactions. The cladding is perforated with tubes or holes. A preferred embodiment is a caisson for concrete mixtures, where the caisson contains the concrete mixture, and the caisson is deployed in marine or terrestrial environments.