Enhanced Two-Stripe Analysis for Efficient Estimation of the Probability of Collapse

An improved method to estimate the collapse fragility function of a structure is proposed. In the proposed method, referred to as enhanced two-stripe analysis (E2SA), response history analyses are conducted at two ground motion intensity levels defined based on collapse risk deaggregation, the location of the lower intensity is updated based on results from analyses at the higher intensity and more analyses are conducted at the lower intensity level. Comparisons of this method with other proposals suggest that the proposed E2SA leads to a more efficient and more accurate estimation of the probability of collapse of a structure.