On August 17, 1999, a major earthquake with a moment magnitude of 7.4 occurred near the densely-populated city of Izmit, Turkey. Within days of this event, Dr. Ugur Kadakal, a member of the AIR earthquake engineering team in Boston, and a citizen of Turkey, coordinated AIR’s post-disaster field survey. AIR also contracted with local engineers and seismologists in Turkey to assist with data collection and analysis. Dr. Kemel Beyen, a Professor of Earthquake Engineering at Bogazici University in Istanbul with extensive experience in conducting post-earthquake reconnaissance surveys, is heading up the local team. In addition, Dr. Kadakal has arranged that our research staff receive translated copies of every major daily newspaper and live footage from Turkish television.
Members of the AIR engineering staff, led by Dr. Mohammed Zolfaghari, have joined local experts on site in Turkey. Here are some of their preliminary findings:
Although most mid- to high-rise buildings in Turkey are constructed of reinforced concrete, AIR engineers have observed evidence of poor construction practices and buildings that were not constructed to code. In addition, construction materials appear to be of poor quality, probably due to limited or nonexistent quality control mechanisms. Most low-rise buildings, especially those in poorer areas, are constructed of unreinforced masonry.
The predominant structural failures in residential buildings were induced as a combination of inadequate connectors between the wall and foundation, poor quality concrete in foundations, and the deforming effects of liquefaction. Soft soils throughout this region of Turkey are conducive to liquefaction, which occurs when saturated soils are subject to violent shaking.
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