Structural Analysis of the South Mooring Dolphin U.S. Navy Communications Station, H. E. Holt, Exmouth (Australia)

摘要

This report pertains to a structural analysis on the south mooring dolphin at the Naval Communications Station, H. E. Holt in Northwest Australia in the aftermath of a 3 December 1982 collision with the structure by a commercial shipping vessel. MV SARGODHA and subsequent above water repairs performed by the facility. Diver inspection before and after the repairs uncovered significant remaining underwater damage to the jacket joints on the lowest two levels. This analysis compares the structural integrity of the as-built structure to that of the structure in its current state. The main-frame computer prograam SACS III was the primary analytical tool used. The structure has been repaired adequately for continued use as a mooring dolphin in up to 50 knot winds. If the site experiences a major storm, further damage to the structure is expected, possibly resulting in a total collapse of the dolphin. Although the north dolphin, the breathing dolphins and the main pier are in excellent condition with many years of remaining useful life, the south dolphin should be considered as only temporary. No economical method is known for repairing the damaged underwater portions to their original strength. Additionally the full effect of the cracks detected can only be guessed, but it is sure to worsen with time. For this reason we recommended immediate initiation of procedures for a MILCON removal and replacement of the dolphin.