Topside modules are fabricated at a production site using as a foundation for installation a gravity-based structure (GBS), which can stay afloat during water transportation. Modules fabrication includes: Stage I, fabrication of components; Stage II, fabrication of nodes from the components; Stage III, fabrication of sub-assemblies from the nodes; Stage IV, shotblasting and painting of assemblies; and Stage V, assembling modules from the assemblies. Then modules transportation, movement to their seats on the GBS and their integration include: Stage VI, moving the modules to an area near the dock using self-propelled vehicles. Stage VII, moving each module onto guides of a lifting system installed in a dry dock. Stage VIII, lifting each module until lifting system guides are connected with GBS top slab guides. Stage IX, moving each module to its seat on the GBS, installed on the GBS and integrated with other modules and the GBS.

Topside modules are fabricated at a production site using as a foundation for installation a gravity-based structure (GBS), which can stay afloat during water transportation. Modules fabrication includes: Stage I, fabrication of components; Stage II, fabrication of nodes from the components; Stage III, fabrication of sub-assemblies from the nodes; Stage IV, shotblasting and painting of assemblies; and Stage V, assembling modules from the assemblies. Then modules transportation, movement to their seats on the GBS and their integration include: Stage VI, moving the modules to an area near the dock using self-propelled vehicles. Stage VII, moving each module onto guides of a lifting system installed in a dry dock. Stage VIII, lifting each module until lifting system guides are connected with GBS top slab guides. Stage IX, moving each module to its seat on the GBS, installed on the GBS and integrated with other modules and the GBS.

A foundation having a central vertical pedestal, a plurality of radial reinforcing ribs extending radially outward from the pedestal. The pedestal and ribs forming a continuous monolithic structure. An anchoring system under the ribs with anchoring the foundation to the ground by anchoring elements connected to rock anchors, soil anchors, piles or the like. The foundation design reduces the weight and volume of materials used, reduces cost, and improves heat dissipation conditions during construction by having a small ratio of concrete mass to surface area thus eliminating the risk of thermal cracking due to heat of hydration.

This application discloses a new type of suction leg, an offshore caisson, a sit-on-bottom supporting platform. The suction leg includes a sealing long pile, this sealing long pile including a tubular pipe and a top head connected tightly to the tubular pipe to form cylindrical integral structure with sealing top and opening bottom. The top head has at least one opening to be able to open or close. The sealing long pile can be penetrated into the seabed by a gravity penetration method or/and a suction pile penetration method, or pulled out from the seabed by a buoyancy uplift method or/and a suction pile uplift method.

A steel plate and concrete composite tank unit, tank groups and offshore platforms with new type of tank units are disclosed. The tank unit comprises an outer concrete tank that comprises an outer tank shell, two heads and ring shell connections at both ends, an inner steel tank that comprises an inner tank shell, epitaxial structures at both ends of the inner steel tank. Inner tank shell is connected to the outer tank shell by epitaxial structures, and an isolation layer that is formed from the gap between the outer concrete tank and the inner steel tank where it is filled with isolation medium.

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.

A method for the autonomous anchoring of foundations for offshore structures consisting of a self-floating concrete caisson manufactured in a floating dock, capable of being towed to their final location, provided with internal vertical cells, which are divided into cells that are interconnected with each other and equipped with emptying and filling devices that allow the regulation of the ballast level for anchoring when they are filled with seawater. This method comprises the following stages: constraining the foundation, fastening and mooring by at least three tugboats pulling radially on the foundation to be anchored from at least 3 different directions; connecting the different sensors needed for controlling the operation with a control unit; gradual and controlled sinking of the foundation until it reaches its position of installation on the seabed; and final ballasting of the foundation.

The publication relates to a shallow water seabed terminal (40) for storing and loading or unloading hydrocarbons, such as LNG, oil or gas, comprising a floatable, removable module (20), and a removable seabed substructure (10) intended to be supported by a seabed (19), the floatable module (20) being releasably fixed to the seabed substructure (10) so that a harbour terminal is formed, the seabed substructure (10) comprises a base structure (11) provided with buoyancy devices, an upwards extending wall structure (12) extending up from the base structure (11) and arranged along at least a part of the periphery of the base structure (11), the base structure also being provided with an opening (18) in the wall structure (12) for allowing the floatable module (20), to be berthed in and supported by the seabed substructure (10). The base structure (11) is provided with a submerged beam or base slab structure (35) extending laterally out from the vertical wall structure (12), configured to support the floatable, removable module, the beam or slab structure (35) being provided with sleeves or ducts extending through the submerged beam or slab structure (35) configured to receive the piles to be driven down into the seabed soil.

Process for installing an offshore tower, specifically a substructure, which basically comprises the following steps: a) dry manufacturing a foundation comprising a block (1, 1) basically made of concrete and dry manufacturing a base section (25) of a shaft (2); b) applying said base section to said foundation block, forming a unit called the starting unit; c) moving said starting unit to the installation point of said substructure; and d) actuating in a controlled manner, first ballast valve means in such a manner that said starting unit sinks until resting on the seabed; having placed said foundation block or said starting unit in the body of water where the installation point said substructure is located.

A structure for mounting offshore installations such as wind turbines or oil and gas platforms. The structure comprises a base, a top piece, and a lattice structure connecting the base to the top piece. The sub-components of the structure can be pre-assembled prior to installation to facilitate ease of construction, or they may be transported to a pre-determined location and assembled on site.