Evaluation of site conditions for the Ankara Basin of Turkey based on seismic site characterization of near-surface geologic materials

2010-01-01
Kockar, M. K.
Akgün, Haluk
Rathje, E. M.
Regional site conditions relevant for seismic hazard studies can be derived from various geologic, seismologic, and geotechnical sources. In this study, site conditions are derived for the Ankara Basin in Turkey by merging in-situ seismic measurements of dynamic properties, geologic information, and some geotechnical boring information. Field seismic refraction surveys were performed at 259 sites in the project area to classify and characterize Plio-Pleistocene fluvial deposits and Quaternary alluvial and terrace deposits. The shear-wave velocity profiles of the near-surface geologic units are used to characterize site classes according to the International Building Code [international Code Council, ICC. International Building Code. Structural and fire- and life-safety provisions (seismic, wind, accessibility, egress, occupancy and roof codes), 2006. Whittier, CA.] and the Turkish Seismic Code [Ministry of Public Works and Settlement, 1998. Turkish Seismic Code, Specification for Structures to be Built in Disaster Areas, Ankara, Turkey], and to develop a regional model for the average shear-wave velocity in the top 30 m. The resulting maps of site class indicate that the classification system for the Turkish Seismic Code results in a significant portion of the Ankara Basin being classified as Z4, the softest site class. The International Building Code site classification system results in most of the Ankara Basin being classified as D, stiff soil. These differences are caused by the Turkish Seismic Code incorporating information from only the surface layer, while the International Building Code incorporates information from the top 30 m.
SOIL DYNAMICS AND EARTHQUAKE ENGINEERING

Suggestions

Optimum design of seismic isolation systems using metaheuristic search methods
ÇERÇEVİK, ALİ ERDEM; Avsar, Ozgur; Hasançebi, Oğuzhan (Elsevier BV, 2020-04-01)
This study addresses the optimum design of seismic isolated structures via metaheuristic search methods. Three recently developed bio-inspired search methods, namely crow search (CSA), whale optimization (WOA) and grey wolf optimizer (GWO), were employed to develop efficient design optimization algorithms for parameter optimization of seismic isolated structures. The developed design optimization algorithms have been applied to optimize a shear frame model with a base isolation system, where the main object...
Examination of differences between three SPT-based seismic soil liquefaction triggering relationships
Çetin, Kemal Önder; Kayen, Robert E.; Moss, Robb E. S.; Bilge, Habib Tolga; Ilgaç, Makbule (Elsevier BV, 2018-10-01)
The preceding companion paper presented the updating of the seismic soil liquefaction triggering relationship of Cetin et al. [1], and compared the resulting updated relationship with the earlier version. In this second paper, a detailed cross-comparison is made between three triggering relationships: (1) Seed et al. [2], as slightly updated by the NCEER Working Group (Youd et al. [3]), (2) Boulanger and Idriss [4], and (3) Cetin et al. [5]. Differences between these three triggering relationships, and the ...
Probabilistic seismic hazard assessment of Eastern Marmara Region
Gülerce, Zeynep (Springer Science and Business Media LLC, 2013-10-01)
The objective of this study is to evaluate the seismic hazard in Eastern Marmara Region using an improved probabilistic seismic hazard assessment methodology. Two significant improvements over the previous seismic hazard assessment practices are accomplished in this study: advanced seismic source characterization models in terms of source geometry and recurrence relationships are developed, and improved global ground motion models (NGA-W1 models) are employed to represent the ground motion variability. Plan...
Spatial sensitivity of seismic hazard results to different background seismic activity and temporal earthquake occurrence models
Yilmaz, Nazan; Yücemen, Mehmet Semih (Elsevier BV, 2011-07-01)
Spatial sensitivity of seismic hazard results to different models with respect to background seismic activity and earthquake occurrence in time is investigated. For the contribution of background seismic activity to seismic hazard, background area source with uniform seismicity and spatially smoothed seismicity models are taken into consideration. For the contribution of faults, through characteristic earthquakes, both the memoryless Poisson and the time dependent renewal models are utilized. A case study, ...
Use of simulated ground motions for the evaluation of energy response of simple structural systems
Karim Zadeh Naghshineh, Shaghayegh; Askan Gündoğan, Ayşegül; Erberik, Murat Altuğ (Elsevier BV, 2019-08-01)
The literature on energy-based seismic design and assessment methodologies of structural systems mostly relies on real ground motion datasets. However, certain bias exists due to lack of homogeneity in available ground motion datasets. In this study, a large set of ground motions is simulated. Next, the effects of various parameters on seismic behavior of SDOF systems in terms of energy are studied using nonlinear time history analyses. The stochastic finite-fault simulations are performed on the western pa...
Citation Formats
M. K. Kockar, H. Akgün, and E. M. Rathje, “Evaluation of site conditions for the Ankara Basin of Turkey based on seismic site characterization of near-surface geologic materials,” SOIL DYNAMICS AND EARTHQUAKE ENGINEERING, pp. 8–20, 2010, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/40159.