JOIA(Japan Ocean Industries Association) is continuing the research and development of a TLP(Tension Leg Platform) for the offshore petroleum production at sea of over 50Om. The major research work is focused on the development of a mooring system capable of diverless installation and a stable gravity template which allows slide to ultimate earthquake as well as waves and winds.
Deep sea is one of frontier for oil production. Traditional jacket type platform is no more a special type of structure for deep water. Various types of production systems has been proposed requesting R&D of marine structures applicable with reduction of increasing cost of platform at deep-water oil fields. TLP has been applied practically at Hutton Field in North Sea in 19841 and at Green Canyon in Gulf of Mexico in 19892. TLP is considered to be a promising structure to conquer the new frontier of deep water. Japan Ocean Industries Association has organized a committee for R&D of a new concept of TLP which can be installed in the oil field of earthquake districts. The committee has worked on the discussion of a new concept of TLP which is economical and performed R&D of techniques sustaining the concept.3 However, there are no suitable estimations, because it is complex to experiment and analyze the TLP system with the seabed foundation. In this paper, we describe an experimental study of the model tests with a shaking table In a water tank on which seabed foundation is rigid, and simulate the test results with numerical analyses to investigate the stabilities of the hull and tendon mated the template due to earthquakes. And we propose to calculate the slide between the template and seabed foundation during earthquakes, and propose to calculate the settlement of template during waves.