Introduction of the most suitable parameter for selection of critical earthquake

After selection of the appropriate earthquake records, various parameters including, PGA (Peak Ground Acceleration), EPA (Effective Peak Acceleration), PGV (Peak Ground Velocity), EPV (Effective Peak Velocity), PGD (Peak Ground Displacement), Arias intensity, and Dur (Duration) were obtained for these records. Finally, with the aid of the applied strategy, the linear relationships between various couples of parameters were obtained. The parameters PGV, EPA and EPV, in order of increasing importance, have the most appropriate linear relationships with the earthquake parameters. Based on this result and some other facts such as the knowledge of practicing engineers about earthquake parameters and possibility of obtaining parameters with the least possible error, EPA was chosen as the most suitable earthquake parameter for selection of the critical earthquake.