Offshore steel structure with integral anti-scour and foundation skirts

An offshore structure, wherein the offshore structure is a bottom-founded structure comprising:

• an adjustably buoyant hull including a plurality of vertical columns and a plurality of horizontal pontoons, wherein each pontoon extends between a pair of the columns, wherein the adjustably buoyant hull is configured to receive a topside;
• wherein each column has a central axis, an upper end, and a lower end;
• wherein each pontoon has a longitudinal axis, a first end coupled to one of the columns, and a second end coupled to another one of the columns;
• a foundation assembly attached to a lower end of the hull and configured to directly engage a sea floor and secure the hull to the sea floor, wherein the foundation assembly includes:
• a column skirt extending downward from the lower end of each column, wherein each column skirt includes an open lower end and is configured to penetrate the sea floor;
• and
• a pontoon skirt extending downward from a bottom surface of each pontoon, wherein each pontoon skirt is configured to penetrate the sea floor;
• a first plurality of anti-scour plates, wherein each of the first plurality of anti-scour plates extends horizontally from one of the columns and is configured to bear against the sea floor;
• a second plurality of anti-scour plates, wherein each of the second plurality of anti-scour plates extends horizontally from one of the pontoons and is configured to bear against the sea floor;
• wherein each of the anti-scour plates is positioned along an outer perimeter of the hull at the lower end of the hull;
• wherein the first plurality of anti-scour plates and the second plurality of anti-scour plates connect end-to-end and extend continuously around the entire outer perimeter of the hull at the lower end of the hull.