İzmir için simülasyon tabanlı zemin büyütme faktörleri

The surficial sediment is proven to alter the characteristics strong ground motion (e.g., amplitude, frequency and duration), and is usually quantified using empirical or simulated-based site amplification models or site factors recommended by the building codes. The local site factors in Turkish Earthquake Building Code (TEBC, 2019 [1]) are derived from NEHRP (2015) [2], which are tabulated values as function of VS30-dependent site classes and spectral acceleration for short and long periods. These factors are subjected to two main limitations: (i) the identical amplification are proposed for the site conditions defined over relatively large range of VS30 (e.g., 360 m/s < VS30 < 760 m/s, etc.) at which the site behavior is expected to vary, and (ii) the values were produced using the ground motion dataset dominated by the site and earthquake characteristics of Western Unites States. Considering all these deficiencies in the current TEBC (2019), this study develops site amplification factors using a simulation-based site amplification dataset produced through a suite of one-dimensional (1D) nonlinear (NL), equivalent-linear (EL), and linear (L) site reponse analyses for the city of Izmir, which is located in west side of Türkiye and is exposed to the large level of seismicity. To perform a series of 1D simulations, a relatively large-scale parameteric study to represent the uncertainty and variability in site condition at Izmir city. As a result, the comparison of simulated linear and nonlinear site amplification values with local site factors in TEBC (2019) illustrates that linear amplification factors were similar in the short period, while in the long period, the analysis results were below the code factors, nonlinear amplification factors are below the code factors for both short and long periods.