Comparison of mean site-specific response spectra in Turkey with the design spectra of AASHTO

Mestav Sarıca, Gizem
Seismic design of bridges is a significant problem for all seismically-active countries including Turkey which has gone through recent destructive earthquakes. Bridges are important elements of transportation and their robustness is important in the aftermath of major earthquakes. Turkish engineers currently employ a modified version of AASHTO (American Association of State Highway and Transportation Officials) LFD Design Specifications for bridge design. Within the scope of a national project (TÜBİTAK 110G093) a new bridge design code for Turkey is being prepared by a large team of civil and earthquake engineers. In this code, proposal of a new design spectrum is also planned. The main objective of this study is to compare the mean site-specific response spectra in Turkey based on data from past earthquakes with the design spectra in AASHTO (2007) and AASHTO (2010) by focusing on the descending part (long period range). The site-specific response spectra for different soil conditions and magnitude ranges are obtained from strong ground motion data gathered on the Turkish National Strong-Motion Observation Network. To observe the effects of these site-specific spectra on the bridge response, response spectrum analyses are performed with these empirical spectra and the results are compared with those from AASHTO (2007 and 2010). The case studies are applied on three different models of bridges that are located in Bursa (a large city located in Northwest Turkey) which are namely Balikli, Panayir and Demirtas bridges. Finally, linear time history analyses are performed with ground motions that match the site-specific and AASHTO LRFD spectra; the results are compared with each other. LARSA 4D Structural and Earthquake Engineering Integrated Analysis and Design Software is used for the response spectrum and linear time history analyses on these bridges.


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Citation Formats
G. Mestav Sarıca, “Comparison of mean site-specific response spectra in Turkey with the design spectra of AASHTO,” M.S. - Master of Science, Middle East Technical University, 2014.