| Abstrakt: |
The world has suddenly become aware of the great resources of the oceans and their potential for providing many of man's most pressing needs: energy, food, transport, minerals, and waste-disposal. However, the seas present an extremely hostile environment, requiring cooperative efforts by many engineering disciplines in order to achieve the necessary structures. These structures must be strong, safe, durable, ductile, available, and economical. Reinforced and prestressed concrete meets these criteria extremely well for many of the proposed structures, both fixed and floating. These include offshore oil storage, drilling, and production platforms: breakwaters, ocean pipelines and outfall~: offshore nuclear power plants: ocean bridges and tunnels: offshore airports and terminals: Arctic Ocean structures: barges, ships and floating stable platforms; offshore expositions and even cities: seafloor chambers and habitats. With approximately a half billion dollars in contract awards within the past year for deep sea structures in the North Sea and elsewhere, the need is emphasized for more research and development in a number of specific technical areas relating to structures, loads, foundations, and construction. Especial attention is called to the problem of very soft seafloor soils, earthquakes and tsunamis, the structural behavior of towers under cyclic loading, and construction practicability. There is a need for recommended practices for design and construction such as those developed or in progress by FIP, Det Norske Veritas, and the newly-formed ACI Committee 357, Offshore Concrete Structures. Although it is unusual to associate a material with a need, in this case, reinforced and prestressed concrete becomes more than a material; it takes on the role of a "concept" by which the oceans' vast resources may be safely and properly exploited for the benefit of man. [ABSTRACT FROM AUTHOR] |
