Scaling Real Seismic Records to Fit the Syrian Design Spectra using Genetic Algorithm

Abstract

After real seismic records selection it is necessary to scale these records to match the intensity of the earthquake expected for the site. Generally, scaling can be made by ground motions uniform scaling in time domain which is simply scaled up or down the ground motions uniformly to best match (in average) the target spectrum within a period range of interest. It’s an engineer’s job to find the best scaling factors to best match the target spectrum, which is a complex task, so we employed the Genetic Algorithm (GA) in finding them to achieve the best results.

Genetic Algorithms (GAs) are probably the best-known types of artificial evolution search methods based on natural selection and mechanisms of population genetics. These algorithms are often applied to large, complex problems that are non-linear with multiple local optima.

In this study, basic methodologies of the GA and  the scaling procedures are summarized, the scaling criteria of real time history records to satisfy the Syrian design code are discussed. The traditional time domain scaling procedures and the scaling procedures using GA are utilized to scale a number of the available real records to match the Syrian design spectra. The resulting time histories of the procedures are investigated and compared in terms of meeting criteria.