关键词：钢铁;重力式结构;石油;钢筋混凝土
摘 要：Gravity structures play a prominent role today in North Sea oil development.These structures are not supported by piles as are most ocean structures but rather sit directly on the ocean bottom, and depend on their foundation geometries and large weights to resist severe environmental loadings.A number of structural and foundation configurations have been proposed; however,attention will be restricted in this discussion to a general configuration typical of the most prominent structures being constructed at present (1975). An example of a gravity structure is illustrated in Fig. 1. The structure foundation consists of a large caisson placed directly on the unprepared seabed surface.The deck is supported by large columns extending from the caisson.Various combinations of steel and reinforced concrete have been proposed, but the majority of structures are being constructed almost entirely of reinforced and prestressed concrete.