A COMPARISON OF ANALYTICALLY PREDICTED PLATFORM DAMAGE TO ACTUAL PLATFORM DAMAGE DURING HURRICANE ANDREW

Hurricane Andrew passed through some 3,000 offshore structures in the Gulf of Mexico in August 1992. While most structures were not adversely affected, several sustained significant damage and in some cases collapsed. Since platforms were observed to survive as well as fail during the storm, there was a unique opportunity to determine if the present wave force and ultimate capacity procedures could have predicted these "observed" survivals or failures. Such a study was conducted on 13 platforms which were affected by Andrew. Each of these platforms was analyzed using nonlinear analysis to determine its performance (survived, damaged, failed) during Andrew. The analytically-based performance was then compared to the observed actual field performance. A rigorous, probabilistic-based, Bayesian updating process was used to make the comparisons. These comparisons resulted in the calibration of a bias factor that provides a general indication as to the accuracy of the wave force and ultimate capacity procedures. This paper summarises the approach used in the project and the results of the calibration process.