The effects of selection and scaling procedures of earthquake records on the seismic response dispersion of structures and recommendations toward seismic upgrading of codes

In this study, the effects of selection and scaling procedures of earthquake records on the dispersion of seismic response of structures are examined. This is according to the Standard No. 2800 seismic code and the ASCE code. So that during two case studies, seven earthquakes have been selected and scaled with the spectral acceleration of the seismic Standard No. 2800. Besides, the seismic response of a reinforced concrete (RC) bridge and a 7-story RC building is evaluated against scaled earthquakes. The results of the studies indicate that structures respond differently to earthquake records. However, in order to avoid designers' different decisions and align their views to choose suitable earthquakes and to evolve the selection and scaling methods of earthquake records for the seismic design of structures, in the end, some recommendations are presented. The results show that in selecting earthquakes, it is crucial to consider PGA, magnitude, and a classified range of intensities and durations of strong ground motion. In addition, to select earthquakes, paying attention to the frequency content of accelerograms and the shape of the response spectrum is also of particular importance. Considering the ranges of the scale of accelerograms depending on the importance of the structures is significant. By applying the mentioned recommendations, the methods of selecting and scaling earthquake records will be improved to some extent. In addition, seismic response dispersion will be prevented.