Developing fragility functions for the estimation of extreme wind damage to chimneys

Abstract

The fragility analysis of tall reinforced-concrete chimneys under hurricane wind loads is presented. The analysis is carried out for the situation of limited data on hurricane wind speeds. This situation is characteristic of hurricane prone regions of Lithuania. The fragility is estimated for small-size samples of hurricane wind records. The standard mean wind velocity recorded at the standard height is used as a demand variable of a wind fragility function. It is proposed not to develop the fragility function for the entire range of probability values but to compute estimates of this function only for elements of a small-size sample of the hurricane wind records. These estimates can be used for the estimation of a chimney failure probability. The estimation of the values of chimney fragility must take into account both aleatory and epistemic uncertainties inherent in the problem. A tall reinforced concrete chimney is used to illustrate the proposed procedure of fragility analysis.