Maritime structure for laying the foundations of buildings, installations and wind turbines by means of gravity in a marine environment
The invention relates to a maritime structure for laying the foundations of buildings, installations or wind turbines by means of gravity in a marine environment, which has significant advantages for constructing, transporting, positioning and operating same, owing to the novel features introduced into the design thereof in comparison with existing types. The structure comprises a base in the shape of a chamfered equilateral triangle, having a sufficient height to optimise navigability, the base being formed by a frame of vertical walls that form hexagonal or triangular cells closed at the ends by a lower slab and an upper slab, and three closed towers having a regular hexagonal or circular cross section which are located in the corners of the base. The structure can be towed, completely installed, with a wind turbine or superstructure that same supports, and has low initial draft, high naval stability and low resistance to movement. The lowering process is performed by using gravity to ballast the cells with seawater, without needing any additional means, auxiliary large-capacity vessels or floating elements external to the structure itself. The structure can be positioned as a gravity foundation at a depth of 20 to 50 meters and can be re-floated to be transferred whole again to a port for dismantling.
1. A maritime structure for laying foundations of buildings, installations or wind turbines by means of gravity in a marine environment, characterised in that it is made up of a base and three towers, wherein the base is a prismatic concrete structure with a triangular base, truncated at the corners thereof, and is made up of vertical outer walls and an inner frame of vertical walls that form hexagonal or triangular cells, fillable with seawater and which close at ends thereof by a lower slab and an upper slab defining a support for the three towers, wherein the three towers are situated in correspondence with three corners of the base, wherein outer walls of the three towers are vertical extensions of walls in corresponding corners of the base, the three towers incorporating inner chambers fillable with ballasting seawater, the towers situated at the corners having a regular hexagonal or circular cross section and being closed at an upper part thereof by a small slab that forms a cover.
2. The maritime structure for laying foundations of buildings, installations or wind turbines by means of gravity in a marine environment according to claim 1 , characterised in that the towers are able to incorporate inner partitions that provide rigidity to the towers, or, on the other hand, can be completely or partially hollow.
3. The maritime structure for laying foundations of buildings, installations or wind turbines by means of gravity in a marine environment according to claim 1 , characterised in that a lower part of the towers is able to be reinforced by raising an alignment of triangular modules of the base surrounding the towers.
4. The maritime structure for laying foundations of buildings, installations or wind turbines in a marine environment by means of gravity in a marine environment according to claim 1 , characterised in that a framework of cells of the base is provided with a system of hydraulic communication between the cells, including devices for emptying and filling which allow a level to be regulated, both for and lowering re-flotation.
5. The maritime structure for laying foundations of buildings, installations or wind turbines by means of gravity in a marine environment according to claim 1 , characterised in that it is made up of reinforced concrete.
6. The maritime structure for laying foundations of buildings, installations or wind turbines by means of gravity in a marine environment according to claim 1 , characterised in that the upper slab is able to support a wind turbine on a central area thereof.
7. The maritime structure for laying foundations of buildings, installations or wind turbines by means of gravity in a marine environment according to claim 1 , wherein the base has a height which is approximately 1.33 times a distance between each pair of consecutive corners of said hexagonal or triangular cells.
8. The maritime structure for laying foundations of buildings, installations or wind turbines by means of gravity in a marine environment according to claim 1 , wherein a distance between each pair of consecutive corners of said hexagonal or triangular cells varies between 5 to 8 meters, and wherein each side of the base measures at least 3 times said distance.
9. A method for installing a maritime structure for laying foundations of buildings, installations or wind turbines by means of gravity in a marine environment, said maritime structure being made up of a base and three towers, wherein the base is a prismatic concrete structure with a triangular base, truncated at the corners thereof, and is made up of vertical outer walls and an inner frame of vertical walls that form hexagonal or triangular cells, fillable with seawater and which close at the ends thereof by a lower slab and an upper slab defining the support for the three towers, which are situated in correspondence with the three corners of the triangular base of the base, wherein outer walls of the three towers are vertical extensions of walls in corresponding corners of the base, the towers incorporating inner chambers fillable with ballasting seawater, the towers having a regular hexagonal or circular cross section and being closed at the upper part thereof by a small slab that forms a cover,
wherein the installation method comprises:
towing, by flotation, the maritime structure with a building, installation or wind turbine completely installed, to a service position,
lowering the base while filling the base with ballasting seawater,
ballasting the towers with seawater,
resting the base on a seabed.
10. The method of claim 9 , wherein once the installation is finished, the three towers are completely submerged.
11. The method according to claim 9 , wherein at the time the towers are submerged, the base is already completely ballasted with water.
12. The method, according to claim 9 , wherein solid ballast is not needed for the lowering step or for the service step.