Evaluation of Reliability of Platform Pile Foundations

Abstract

A primary consideration and concern in development and implementation of risk assessment and management based hurricane and earthquake criteria for design and requalification of platforms in the Bay of Campeche criteria is the reliability characteristics of the pile foundations that support the platforms. Analyses of the ultimate limit state (ULS) performance characteristics of the platform pile foundations are summarized. These analyses indicated that in many cases when the capacities of the piles were based on American Petroleum Institute “static” pile capacity analysis methods, the piles were the most likely to fail elements in the platforms. Results from these analyses were in dramatic contrast with the performance of pile foundations supporting more than 250 platforms during the 100-year hurricane Roxanne (1995). Detailed analytical and field studies were performed to determine the ULS performance characteristics of pile foundations subjected to hurricane induced lateral and axial loadings. This study addressed all of the phases in the life cycle of the piles. The results of this work indicate that, in general, there can be large biases in the predicted capacities of piles that support the platforms.