In this paper a novel methodology is presented to incorporate uncertainties associated with seismic loads,
characterization of structural model parameters, and description of soil properties in the probabilistic assessment
of seismic-related damage of existing jacket type offshore platforms located in seismic active areas.
The main objective of this methodology is to facilitate the probabilistic analysis of soil–pile–structure interactions
(SPSI) by implementing a Comprehensive Interaction Incremental Dynamic Analysis (Comprehensive Interaction
IDA) method that involves the convolution of uncertainties associated with three separate elements:
structure, piles and supporting soil. This quantitative seismic analysis procedure consists of: a) selecting an
appropriate suite of strong ground motion records and performing a Comprehensive Interaction IDA on a nonlinear
model of an existing fixed platform; b) summarizing the Comprehensive Interaction IDA results into various
percentile performance bounds; and c) integrating the results with respect to hazard intensity–recurrence
relations into a probabilistic seismic format. To address and propagate these uncertainties, the Latin Hypercube
Sampling technique in conjunction with the Simulated Annealing optimization is applied to evaluate their effects
on the structural responses with a relatively small number of simulations. The proposed methodology with
the ability of incorporating uncertainties in existing platforms can be effectively used to evaluate the structural
integrity in other industries.