Near field ground motion synthesis for Gemlik region, Turkey based on scenario earthquakes


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Tanircan G., Yenidoğan H. C., Savas N.

9th US National and 10th Canadian Conference on Earthquake Engineering 2010, Including Papers from the 4th International Tsunami Symposium, Toronto, Canada, 25 - 29 July 2010, vol.4, pp.3261-3270 identifier

  • Publication Type: Conference Paper / Full Text
  • Volume: 4
  • City: Toronto
  • Country: Canada
  • Page Numbers: pp.3261-3270
  • Yıldız Technical University Affiliated: Yes

Abstract

In this study, strong ground motion generations of Mw 6.9 scenario events of Gemlik fault was performed to broad-frequency (0.5-10 Hz) ground motion at 9 near-field stations. In the first stage of the study, the focal mechanism of a small earthquake, which was used as the Green’s function throughout the scenario simulation, was decided by simulating it with a smaller magnitude event. Several simulations have been performed using different fault mechanisms proposed for the event, the best waveform fitting was judged with the smallest misfit value. In the second stage, near field ground motion simulation of scenario events from Gemlik fault was performed. Calculations were achieved for considering three different rupture scenarios which have the same magnitude but different asperity locations. The fault and asperity parameters for each scenario were determined from empirical scaling laws. It has been found that for periods between 0.1 and 0.5 s, the design spectra were either nearly or actually exceeded by the scenario earthquakes. The majority of the structures in the area were built to lower design spectra before the 1998 code was implemented. Thus the strength of the many structures would have been insufficient to resist the forces that may be generated by an earthquake that is similar to the Scenario I. Calculated ground motion can be used as a design ground motion both for new projects and also for the emergency improvement of earthquake performance of structures. Hence, the results of the project is believed to serve to reduce the damage at both building and infrastructure due to a possible earthquake at Gemlik Bay.