This paper summarizes results of a study performed to develop requalification criteria for platforms offshore Tampico-Tuxpan, Mexico. The environmental conditions included hurricanes and earthquakes. A special study was conducted to determine the effects of a thin layer of soft sea floor soils on hurricane wave heights. The criteria included Allowable Stress and Ultimate Limit State guidelines. These criteria were based on target reliabilities that were determined using economic, historic, and standard-of-practice approaches. In a companion paper, the criteria are applied to requalification of a platform offshore Tampico, Mexico (Bea, et al, 2000).
The objective of the work summarized in this paper was to develop hurricane and earthquake criteria and guidelines for requalification of platforms in the PEMEX (Petroleos Mexicanos) North Region offshore Tampico and Tuxpan (Fig. 1). These guidelines and criteria were founded on the criteria and guidelines developed by the American Petroleum Institute (API) for design and requalification of offshore platforms (API, 1997). These guidelines and criteria were founded on application of risk based reliability technology to help PEMEX assure appropriate adaptation of the API criteria and guidelines to conditions offshore Tampico and Tuxpan. This work involved three primary efforts:
Assessment of the oceanographic conditions developed by Oceanweather for hurricanes with special attention given to past hurricanes that have developed significant lateral loadings on the platforms and on sea bottom wave interactions that may further reduce the maximum wave heights determined by Oceanweather.
Assessment of the earthquake conditions based on information provided by the International Standards Organization (ISO), API, the U. S. Geological Survey, the Universidad Nacionai Autonoma de Mexico (UNAM), and the Earthquake Engineering Research Center at the University of California at Berkeley.
