Location

New York, New York

Session Start Date

4-13-2004

Session End Date

4-17-2004

Abstract

The variation of both structural and geotechnical consequences of near-source effects are shown for densely populated environments, Kocaeli and Düzce (Turkey), situated on an alluvial fan at the western part of the 1500 km long North Anatolian fault (NAF) that resembles the San Andreas fault in California with its right-lateral and strike slip faulting mechanism as well as remarkably similar length and capability of generating damaging earthquakes. Recordings from two recent destructive earthquakes occurred in 1999 on the NAF suggest that nearsource impulse type ground motions may generate large input energy demands that have to be dissipated with few large displacement excursions. The discussion is therefore focused on the seismic wave propagation mechanism related to the unexpected damages at the nearfield sites. The observation results proved the high intensity velocity at the damage suffering areas due to the soil layer resonance and, furthermore, due to the "bump effect" by wave interferences traveling vertically and horizontally. While there are potentially other factors contributing to damage (such as topographic and basin effects, liquefaction, ground failure, or structural deficiencies), the amplification of ground motion due to local site conditions plays an important role in exacerbating the seismic damages in disaster belt area. The field observations regarding this phenomenon supplemented with the near-field strong motion interpretations are presented, and significance of local soil effects in the near-field region is assessed in the course of this study.

Department(s)

Civil, Architectural and Environmental Engineering

Appears In

International Conference on Case Histories in Geotechnical Engineering

Meeting Name

Fifth Conference

Publisher

University of Missouri--Rolla

Publication Date

4-13-2004

Document Version

Final Version

Rights

© 2004 University of Missouri--Rolla, All rights reserved.

Document Type

Article - Conference proceedings

File Type

text

Language

English

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Apr 13th, 12:00 AM Apr 17th, 12:00 AM

Near Source Effects and Engineering Implications of Recent Earthquakes in Turkey

New York, New York

The variation of both structural and geotechnical consequences of near-source effects are shown for densely populated environments, Kocaeli and Düzce (Turkey), situated on an alluvial fan at the western part of the 1500 km long North Anatolian fault (NAF) that resembles the San Andreas fault in California with its right-lateral and strike slip faulting mechanism as well as remarkably similar length and capability of generating damaging earthquakes. Recordings from two recent destructive earthquakes occurred in 1999 on the NAF suggest that nearsource impulse type ground motions may generate large input energy demands that have to be dissipated with few large displacement excursions. The discussion is therefore focused on the seismic wave propagation mechanism related to the unexpected damages at the nearfield sites. The observation results proved the high intensity velocity at the damage suffering areas due to the soil layer resonance and, furthermore, due to the "bump effect" by wave interferences traveling vertically and horizontally. While there are potentially other factors contributing to damage (such as topographic and basin effects, liquefaction, ground failure, or structural deficiencies), the amplification of ground motion due to local site conditions plays an important role in exacerbating the seismic damages in disaster belt area. The field observations regarding this phenomenon supplemented with the near-field strong motion interpretations are presented, and significance of local soil effects in the near-field region is assessed in the course of this study.