A gravity-based structure (1) for supporting offshore installations comprising a foundation (4). The foundation (4) has a basal portion (11). The basal portion (11) has a plurality of openings (10) for drainage of water. There is at least one first layer (7) of filter material, with a gradation suitable for draining water entrapped beneath the basal portion (11) to the openings (10). The layer (7) is installed on the seabed (8) beneath the foundation (4). The foundation has a downwardly extending skirt (5) that is adapted to penetrate into the seabed beneath the filter material layer (7).

A method and apparatus for forming cemented ground support columns is disclosed. Namely, driving mandrels are provided for the efficient construction of incrementally enlarged diameter support columns. For example, the driving mandrel includes a feed tube that has a top portion and an expansion head portion. The expansion head portion further includes an expansion (or compaction) chamber and a flexible tubular egress port. Further, construction methods are provided of using the driving mandrels for the efficient construction of incrementally enlarged diameter support columns.

A foundation for a subsea assembly is provided. The foundation includes connection points. The connection points permit other components to be connected to the foundation and permit loads to transfer from the other components into the foundation. The foundation may be a suction anchor. A method of converting an exploration well using the foundation to a production well is also provided.

A foundation for a subsea assembly is provided. The foundation includes connection points. The connection points permit other components to be connected to the foundation and permit loads to transfer from the other components into the foundation. The foundation may be a suction anchor. A method of converting an exploration well using the foundation to a production well is also provided.

A reduced profile wind tower system includes a slim cylindrical spinal core extending up vertically from a foundation. A turbine nacelle is mounted on a top end of the core. Wind turbine blades extend out from the nacelle. A plurality of axially loaded tubular arms, braced by the core, are spaced around the core and link to the core through continuous shear wings or discrete bracket assemblies. The tubular arms and shear wings extend up from said foundation. The tubular arms can be set either vertically or slightly sloped; cables may substitute for the tubular arms and a pontoon may substitute for an on ground foundation.

A reduced profile wind tower system includes a slim cylindrical spinal core extending up vertically from a foundation. A turbine nacelle is mounted on a top end of the core. Wind turbine blades extend out from the nacelle. A plurality of axially loaded tubular arms, braced by the core, are spaced around the core and link to the core through continuous shear wings or discrete bracket assemblies. The tubular arms and shear wings extend up from said foundation. The tubular arms can be set either vertically or slightly sloped; cables may substitute for the tubular arms and a pontoon may substitute for an on ground foundation.

A reduced profile wind tower system includes a slim cylindrical spinal core extending up vertically from a foundation. A turbine nacelle is mounted on a top end of the core. Wind turbine blades extend out from the nacelle. A plurality of axially loaded tubular arms, braced by the core, are spaced around the core and link to the core through continuous shear wings or discrete bracket assemblies. The tubular arms and shear wings extend up from said foundation. The tubular arms can be set either vertically or slightly sloped; cables may substitute for the tubular arms and a pontoon may substitute for an on ground foundation.

A reduced profile wind tower system includes a slim cylindrical spinal core extending up vertically from a foundation. A turbine nacelle is mounted on a top end of the core. Wind turbine blades extend out from the nacelle. A plurality of axially loaded tubular arms, braced by the core, are spaced around the core and link to the core through continuous shear wings or discrete bracket assemblies. The tubular arms and shear wings extend up from said foundation. The tubular arms can be set either vertically or slightly sloped; cables may substitute for the tubular arms and a pontoon may substitute for an on ground foundation.

A reduced profile wind tower system includes a slim cylindrical spinal core extending up vertically from a foundation. A turbine nacelle is mounted on a top end of the core. Wind turbine blades extend out from the nacelle. A plurality of axially loaded tubular arms, braced by the core, are spaced around the core and link to the core through continuous shear wings or discrete bracket assemblies. The tubular arms and shear wings extend up from said foundation. The tubular arms can be set either vertically or slightly sloped; cables may substitute for the tubular arms and a pontoon may substitute for an on ground foundation.

A reduced profile wind tower system includes a slim cylindrical spinal core extending up vertically from a foundation. A turbine nacelle is mounted on a top end of the core. Wind turbine blades extend out from the nacelle. A plurality of axially loaded tubular arms, braced by the core, are spaced around the core and link to the core through continuous shear wings or discrete bracket assemblies. The tubular arms and shear wings extend up from said foundation. The tubular arms can be set either vertically or slightly sloped; cables may substitute for the tubular arms and a pontoon may substitute for an on ground foundation.