| 摘要 |
A compliant offshore platform wherein the sole foundation support for platform loads not provided by seawater buoyancy is provided by traditional skirt piles rigidly attached to the platform base near the ocean floor. Lateral flexibility of the platform is enhanced by the introduction of unbraced portal frames located throughout the platform framing in such a way as to facilitate lateral shearing displacements within the platform framing to the extent that the required compliant characteristics are obtained for the sway mode (first structural mode) of vibration while at the same time allowing the overturning moments generated by wind, wave, and current loads to be resisted by the vertical forces within the platform legs and platform foundation. The addition of these portal framed sections at selected locations into an otherwise traditional jacket provides a framing system with improved fundamental modes of vibration as are required for compliant structural behavior. In the preferred embodiment the platform skirt piles are rigidly attached to the jacket near the lowest levels of the jacket framing but somewhat above the seafloor. The skirt piles provide lateral restraint for the base of the platform.
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