Examining the effects of foreshocks on the response of structures in terms of performance analyses

If it is known how structures will respond to earthquakes of varying intensity, it can be determined whether the structure will be retrofitted or not based on this information. For this purpose, performance analyses are carried out on buildings. By using performance analyses, force and/or displacement capacities of structures are determined by performing static pushover analyses. While structures that provide the desired performance are not retrofitted, structures that do not provide the desired performance can be retrofitted or demolished and rebuilt. When performing performance analyses, the possible harmful effects of earthquakes that structures have been exposed to in the past are not taken into account at a sufficient level. Even if a low-intensity earthquake does not cause visible damage to the structure, it can change the displacement capacities, stiffness and earthquake demands on the structures. The effect of foreshocks on building behavior has been previously examined in numerous studies. Even the effect of foreshocks on various coefficients used in performance analyses has been examined before. However, comprehensive studies that address the effects of foreshocks on static pushover curves in terms of the results of performance analysis and take the intensity of the foreshock as a parameter have not been seen in the literature. In this study, the possible effects of foreshocks on the parameters used in the performance analysis of structures were examined. For this purpose, nonlinear static pushover and nonlinear time history analyses were performed using two-dimensional reinforced concrete frames. In the light of the results obtained from these analyses, possible changes in displacement demands, which are essential in determining building performance, were examined. As a result of the analyses performed in the scope of the study, it was seen that foreshocks had an impact on the parameters examined