Abstract: A T-headed stirrup for anchoring reinforcing bars in concrete, to restrain lateral buckling of the reinforcing bars under severe forces. The stirrup, comprising a shaft with a T-shaped crosspiece at each end, is typically inserted between pairs of reinforcing bars. The crosspiece contacts the reinforcing bar and is shaped to restrain lateral movement of the reinforcing bar.

Abstract: A structure for use in exploiting arctic offshore areas where floating ice masses may be present. The structure is comprised of a floating hull having ice-breaking capabilities which is moored by a plurality of mooring means which extend vertically from a moonpool in the hull to the marine bottom directly under the hull. The mooring means comprises flexible lines, e.g. nylon, steel, or the like or rigid conduits, e.g. drill pipe.Means are provided within the moonpool for tensioning the mooring means to thereby draw the hull downward to a position below its normal buoyant position thereby substantially eliminating vertical heaving of the hull. When an ice mass contacts the hull, tension on the mooring means is relaxed to thereby allow the hull to rock upward against the ice thereby generating the forces necessary for the ice-breaking operation. Due to the present mooring means, the hull moves only a relatively short lateral distance in breaking an approaching ice mass.

Abstract: A gravity base offshore production platform structure and, more particularly, a production platform for use in an arctic environment, including an encircling structure having a predetermined configuration the protection of the offshore structure in iceberg-infested waters which are capable of resisting the destructive forces of an impact produced by a large iceberg. The gravity base offshore production platform structure consists of a monolithic, massive concrete structure of a configuration providing a plurality or horizontal array of upright, mostly cylindrical compartments, which is supported on a concrete or slab foundation nesting on the marine floor. Generally, although not necessarily, the compartmented structure rises above the marine surface and is covered by a concrete slab or similar covering structure to thereby form closed compartments within the monolithic structure.

Abstract: A building system for seismic-active areas includes a base structure and an upper structure connected to the base structure by a system of connector means which collectively provide a relatively rigid interconnection under normal conditions and a relatively flexible connection when subjected to seismic disturbances. When the building system is subjected to seismic disturbances, rigid connector members fail by buckling and other connector members flex without failing to provide the relatively flexible interconnection.