Progressive collapse fragility of reinforced concrete framed structures through incremental dynamic analysis

摘要

In conventional design approaches, structural safety is assessed without considering extreme load conditions that may cause global system collapse as a consequence of local failures in a component or localized portion of the structure. Even when extreme conditions are taken into account, structural safety is not probabilistically assessed and controlled, thus neglecting uncertainties in loads and system capacity. A few studies have been carried out so far, emphasizing the need for probabilistic risk assessment and management of structures to disproportionate (or progressive) collapse. To this aim, fragility analysis may be used to predict the probability of progressive collapse given that local damage has occurred. This approach is a well-established tool in earthquake engineering and explicitly accounts for uncertainties in both demand and capacity, providing the probability of failure as a function of a given intensity measure.