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

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.

Record Selection Procedures Proposed By Several Countries Standards Compared With Syrian Standards

The European Standard, the New Zealand Standard, the U.S. Standard, the Syrian Standard and the Iranian Standard define a criterion for selecting ground motion records for time-history analysis by similarity between the seismological signature of earthquakes used for the analysis and those earthquakes that are expected to happen at the given location. But these standards follow different methodologies. The New Zealand Standard proposes that the spectrum of each selected record should match the design spectrum over a range of periods related to the fundamental period of the structure investigated. The energy of at least one of these record’s spectra must exceed the energy of the design spectrum. The European Standard recommends that the average spectrum of the selected records should be always higher than 90% of the design spectrum in a defined range of periods, and the value of the average spectrum at period equal zero should be larger than the value of the corresponding design spectrum. The U.S. Standard, also the Syrian and the Iranian Standard; advise that in a defined range of periods, the average spectrum of the selected records should be 40% and higher than the code spectrum. This study illustrates the differences between selecting approaches, and how these differences affect the resulting ground motion records. Some resulting recommendations for record selecting procedures are presented, and advised to be used in addition to the Syrian Standard recommendations.

Generation of Synthetic Time Histories Functions Compatible with Syrian Response Spectra in Frequency Domain and Time Domain Applicable to Dynamic Analysis

In this study, basic methodologies and procedures for generation synthetic time histories in time domain and frequency domain are summarized. These synthetic time histories are matching Syrian spectrum and compatible with wide range of buildings models and soil types according to the seismic parameters of Lattakia city. This paper will discuss the Selection and scaling criteria of three real time history records available in strong ground motion databases to satisfy the Syrian spectrum, and the suitability as input to time history analysis of civil engineering structures.

Comparison study of total displacements of multi-story buildings subjected to earthquake using synthetic timehistory records compatible with Syrian code

Response spectrum analysis and equivalent static analysis is widely used by engineers and engineering offices to estimate buildings and structures response to earthquakes. But performance based procedures to evaluate buildings and new designs according to Syrian code and other international codes require response analysis using smallest of earthquake records, where we can estimate engineeringdemandparameters(EDPs)— floordisplacements,storydrifts,memberforces,memberdeformations,etc.— ofbuildingsandspecialstructuressubjectedtogroundmotions, consecutively to verify required performance criteria. Theserecordsshouldbeproperlyselectedandscaledincompliancewithsitespecifichazardconditionstoestimate (EDPs) and ensure that they verify ―expected‖ median demands. In this study, background, selection procedures compatible with Syrian code, and review of most scaling methods were introduced. The structural response was studied by comparing displacements due to response spectrum analysis, scaled records using PGA, and synthetic time histories records in time domain and frequency domain (generated according to Syrian response spectrum). Tow three-dimensional models of real buildings in Lattakia city were used as study cases, the results obtained by 20 analysis processes. The results show that analysis using synthetic records compatible with Syrian code give noticeably less displacements estimates comparing with response spectrum analysis and analysis using records scaled by PGA scaling.