Seismic damages comparison of low-rise moderate reinforced concrete moment frames in the near- and far-field earthquakes by a probabilistic approach

Buildings and other structures experience more damages in near-field earthquakes due to existence of high period pulse in the records of near-field earthquakes. These pulses may not be existed in all near-field records. Therefore, to evaluate the effect of near-field earthquakes on structures realistically, a probabilistic approach is used to evaluate the probability of different damage state in near- and far-field earthquakes. In this method, the damage of structure is evaluated by estimation of fragility function of structure through numerous non-linear dynamic analysis subjected to different ground motion records. To compare the effect of near-field and far-field earthquakes on low-rise moderate reinforced concrete moment, a two and three story concrete frame were selected and designed according to Iranian code. The fragility function of frames was estimated in near- and far-field earthquakes. In near-field earthquakes, mixture of pulse like and non-pulse like records were considered. The results have shown that no meaningful difference between probabilities of failure of near- and far-field was observed. Therefore, it can be concluded that although the near-field earthquake may cause severe damages on structures due to existing impulses in some records, from the probabilistic point of view and considering all near-field records, this effect is not significant.