Generating synthetic ground motions reaching target spectrum with the optimization approach

Due to the scarcity of earthquake records and the necessity of the earthquakes matched with the predefined design response spectrum (DRS) for time history analysis, designers need to generate artificial earthquakes. The smoothness of the DRS prevents conformity in the majority of methods, and deviation happens, especially in the constant region. To overcome this condition, the present study intends to incorporate the optimization algorithm with the synthetic earthquake method to reach the ASCE DRS. Indeed, the statistical algorithm is utilized to explore the global optimum with more accuracy and faster convergence in comparison with other algorithms. The results demonstrate that the proposed method is ideally compatible with the DRS with trivial errors. Furthermore, the novel approach has been applied to Kobe and Tabas earthquakes in order to extract the envelope function to improve compatibility in the time domain. In essence, the proposed method is not only compatible with the DRS simply but also appropriate for simulating real earthquakes. Eventually, with regard to the recommendation of seismic regulations for applying several records in dynamic analysis, one of the robust advantages of this method is to generate various earthquakes compatible with the specific target spectrum.