Effect of structural irregularities and short columns on the seismic response of buildings during the last Turkey earthquakes

During the last eight years, Turkey hasexperienced many severe earthquakes: Erzincan earthquake (M_s=6.8) of March 13, 1992, Dinar earthquake (M_s = 6.0) of October 1, 1995, Adana-Ceyhan earthquake (M _s = 6.2) of June 27, 1998, Kocaeli earthquake (M_s = 7.4) of August 17, 1999 and Duzce earthquake (M_s = 7.2) of November 12, 1999. Most of them affected heavily populated city centers leading to huge loss of human life and economical crisis in the country. The last two earthquakes were rather catastrophic and affected a wide area in the Marmara region. This study mainly aims to evaluate the effect of structural irregularities and short columns on the seismic response of buildings during the last Turkey earthquakes, based on the site investigations of the authors. In this respect, buildings having regular and irregular structural systems are discussed as reference to the old and new Turkish Earthquake Code. Common types of irregular buildings in the big cities of Turkey are typically summarized. Many outstanding photographs of damaged and undamaged buildings taken from the earthquake areas are given. In addition to their irregular structural systems, many buildings were heavily damaged or collapsed due to short column failures during the earthquakes. Since this kind of damage to reinforced concrete (RC) framed buildings is frequently encountered, short column incidents are seperately investigated. Further, architectural based damage to buildings are discussed and possible solutions are proposed to minimize collapses due to structural irregularity and short columns.