Reliability Analysis of Wind-sensitive Structures

The theoretical background of practical structural reliability methods encompassing numerical integration, approximate methods and simulation techniques is reviewed in the context of windexcited structures. Their relative merits, shortcomings and limitations are addressed from the standpoint of their accuracy and computational efficiency. Quantitative reliability estimates of a concrete chimney are made, using different analysis procedures. Multiple potential failure modes are represented by the exceeding of the ultimate moment capacity at any level of the chimney height. The general bounds on the system failure probability are expressed in terms of the failure probability of the individual modes. The narrower bounds are established based on the existing theory by taking into account not only the failure probability of the individual modes, but also the joint failure probabilities in any two modes. Based on the findings of this study, it is suggested that the advanced first-order second-moment approximation and the simulation methods, which combine the Monte Carlo technique with variance reduction techniques, may provide accurate results for practical reliability analysis of wind-excited structures.