NEHRP Clearinghouse

Title
Ground Motion Amplification Studies, Bursa, Turkey.
File
PB294401.pdf
Author(s)
Whitman, R. V.; Yegian, M. K.; Christian, J. T.; Tezcan, S. S.
Source
National Science Foundation, Washington, DC. Applied Science and Research Applications., September 1974, 60 p.
Identifying Number(s)
['MIT-CE-R74-58', 'STRUCTURES PUB-397']
Abstract
As a result of the Gediz earthquake of 28 March, 1970, the TOFAS automobile factory, located 8 km north of Bursa, experienced severe damage and in some cases collapse. The damage at the TOFAS factory is summarized. The coincidence between the predominant period of motion observed in the aftershock and the computed natural period for the collapsed building strongly suggested that there might be some site effect causing amplification of earthquake ground motions at a period of about 1.2 seconds. The study described aimed at the question: Can this hypothesis be given frther verification by theoretical analysis of site conditions. The study consisted of field studies to determine the soil and geological conditions at the site, plus theoretical amplification studies. The field studies carried out in Turkey are summarized and the theoretical studies are discussed. There seems little doubt that soil amplification played an important role in the occurrence of damage at the TOFAS factory. It seems clear also that larger more flexible buildings at the factory suffered more than smaller, stiffer buildings. However, the recorded aftershock motion does not prove that the soil amplified the motions only over a narrow range of periods. It seems more likely that the aftershock motions throughout the vicinity had a very strong component of motion with a period of 1.2 seconds.
Keywords
Industrial plants; Bursa (Turkey); Earthquake resistant structures; Turkey; Earth movements; Field tests; Ground motion; Earthquake engineering; Buildings; Soil dynamics; Gediz earthquake; TOFAS factory; Earthquakes; Dynamic structural analysis