Failure analysis of newly constructed RC buildings designed according to 2007 Turkish Seismic Code during the October 23, 2011 Van earthquake

• The reasons for damages in the buildings in the recent earthquake in Turkey are investigated.
• A recently built but severely damaged building is examined.
• Damages are due to lack of inspection during project implementation.
• Although recent codes provide enough protection, the improper project changes can cause failure damage.

In the Van Earthquake of magnitude Mw = 7.2 on October 23, 2011, 48,666 buildings were severely damaged or collapsed, 604 people lost their lives and 1301 people were injured. During this earthquake, not only the buildings designed in accordance with the old earthquake codes but also the ones designed in accordance with the current Turkish Earthquake Code (TEC) were severely damaged. The purpose of this study is to reveal the reasons why the RC buildings designed in accordance with the current TEC as a result of static and dynamic calculations were severely damaged in the recent earthquakes. In this study, first, the buildings that were designed in accordance with the last two earthquake codes and damaged during the Van Earthquake on 23 October 2011 have been examined. Then, another severely damaged building that was designed in accordance with the TEC 2007 has been chosen as a possible model for similar situations. In order to explore the reasons behind the damage, detailed examination has been made both in the damaged structure and in its design calculations. Both situations in the project and implementation of the design have been analyzed by using IdeCAD and Sta4CAD modeling, as well as Sap2000 through which weak structural members have been determined. The findings have been evaluated in terms of design and implementation flaws, in compliance with the TEC 2007, modeling and acceptance error. When analyzed by modeling of its project, the building has not revealed any insufficient columns; however, in its implementation analysis, the damaged members have appeared to be insufficient. It has been determined that the damage was due to improper implementation of the project, incompatible production according to the TEC 2007 and lack of inspection. To mitigate possible fatalities and damages in the future earthquakes, implementations should be fully represented in the model of the projects, structural members in the projects should be built identically to their design, attention should be paid to the anticipated limitations in TEC 2007 during implementation, and stages of project and implementation should be inspected sufficiently.