Evaluation of ground deformations induced by the 1999 Kocaeli earthquake (Turkey) at selected sites on shorelines.

Autor: Aydan, Ömer, Ulusay, Reşat, Atak, Veysel
Předmět:
Zdroj: Environmental Geology; Nov2007, Vol. 54 Issue 1, p165-182, 18p, 2 Color Photographs, 1 Chart, 7 Graphs, 8 Maps
Abstrakt: The Kocaeli earthquake ( M w = 7.4) of 17 August 1999 occurred in the Eastern Marmara Region of Turkey along the North Anadolu Fault and resulted in a very serious loss of life and property. One of the most important geotechnical issues of this event was the permanent ground deformations because of both liquefaction and faulting. These deformations occurred particularly along the southern shores of İzmit Bay and Sapanca Lake between the cities of Yalova and Adapazarı in the west and east, respectively. In this study, three sites founded on delta fans, namely Değirmendere Nose, Yeniköy tea garden at Seymen on the coast of İzmit Bay, and Vakıf Hotel site on the coast of Sapanca Lake were selected as typical cases. The main causes of the ground deformations at these sites were then investigated. Geotechnical characterization of the ground, derivation of displacement vectors from the pre- and post-earthquake aerial photographs, liquefaction assessments based on field performance data, and analyses carried out using the sliding body method have been fundamental in this study. The displacement vectors determined from photogrammetric evaluations conducted at Değirmendere and Seymen showed a combined movement of faulting and liquefaction. But except the movements in the close vicinity of shorelines, the dominant factor in this movement was faulting. The results obtained from the analyses suggested that the ground failure at Değirmendere was a submarine landslide mainly because of earthquake shaking rather than liquefaction. On the other hand, the ground failures at the Yeniköy tea garden on the coast of Seymen and the hotel area in Sapanca town resulted from liquefaction-induced lateral spreading. It was also obtained that the ground deformations estimated from the sliding body method were quite close to those measured by aerial photogrammetry technique. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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