Abstract: The invention relates to a method of building a foundation (1) comprising a steel monopile (2) and a precast concrete part (3) on top of the monopile (2), comprising:—arranging a support structure (12) inside the monopile (2), the support structure (12) having a plurality of rods (16) extending radially with respect to a longitudinal axis of the monopile; —bringing the concrete part (3) above the monopile (2), with supporting columns (13) interposed between the support structure (12) and the concrete part (3), wherein reinforcement bars (14) protruding from a bottom surface (9) of the precast concrete part (3) extend downwardly beyond the support structure (12) by passing between the rods (16) of the support structure (12); —arranging tendons (15) between the support structure (12) and the concrete part (3) and tensioning the tendons (15); and—pouring concrete into an upper part of the monopile (2).

Abstract: The subject matter of the invention is a gravity structure intended for a marine civil-engineering construction, comprising a slab configured so as to be placed on a sea bed and secured to a shaft directed in a principal direction substantially orthogonal to said slab, characterized in that the gravity structure comprises at least one anchoring tie rod extending in said shaft and in the slab, the gravity structure being configured so that, in a service position of the gravity structure, said at least one anchoring tie rod is anchored in the sea bed.

Abstract: The invention relates to a method of building a foundation (1) comprising a steel monopile (2) and a precast concrete part (3) on top of the monopile (2), comprising:—arranging a support structure (12) inside the monopile (2), the support structure (12) having a plurality of rods (16) extending radially with respect to a longitudinal axis of the monopile;—bringing the concrete part (3) above the monopile (2), with supporting columns (13) interposed between the support structure (12) and the concrete part (3), wherein reinforcement bars (14) protruding from a bottom surface (9) of the precast concrete part (3) extend downwardly beyond the support structure (12) by passing between the rods (16) of the support structure (12);—arranging tendons (15) between the support structure (12) and the concrete part (3) and tensioning the tendons (15); and—pouring concrete into an upper part of the monopile (2).

Abstract: The subject matter of the invention is a gravity structure intended for a marine civil-engineering construction, comprising a slab configured so as to be placed on a sea bed and secured to a shaft directed in a principal direction substantially orthogonal to said slab, characterized in that the gravity structure comprises at least one anchoring tie rod extending in said shaft and in the slab, the gravity structure being configured so that, in a service position of the gravity structure, said at least one anchoring tie rod is anchored in the sea bed.