Hayri Baytan Ozmen

Evaluations on the relation of RC building damages with structural parameters after May 19, 2011 Simav (Turkey) earthquake

Abstract An earthquake has struck Simav, Kutahya, located in the western part of Turkey on May 19, 2011. This paper focuses on the evaluation of the regional damage data and detailed investigation on a set of selected reinforced concrete buildings in Simav county center. The soil properties in Simav are examined in detail using multi-channel analysis of surface wave measurements, boreholes and laboratory test data. The damages are observed to be independent of soil conditions being hilly or plain, both in regional and Simav county center level. However, a slight relation is observed: as the soil period increases, so does the damage. The most damaged buildings are the four story buildings, resembling the case after some other earthquakes in Turkey. Regarding the detailed numerical evaluations on the building set, the properties highly correlated with seismic damage are investigated. Based on the obtained findings, it is concluded that the global building properties may not be enough to establish a strong relation with damage due to the local damages at the structural member level, especially for smaller seismic events.

Developing hybrid parameters for measuring damage potential of earthquake records: case for RC building stock

This study investigates the feasibility of using combination of present ground motion parameters to have a hybrid parameter that is more correlated with damage. Since RC buildings constitute the prevailing type of construction in many earthquake prone countries, low and mid-rise RC buildings are targeted in an example study. Displacement demand is assumed to represent the seismic damage. Its mean value is determined for 1056 capacity curves for each of 466 acceleration records. Then an optimization study is performed to select and weight the commonly used ground motion parameters to have a high correlation with displacement demands. Hence, equations for hybrid parameters are defined. It is observed that by combining the ground motion parameters, better results up to 6–28% may be achieved depending on the relevant factors and cases. This approach may be applied to other types of structures, as well. Using this type of case specific hybrid ground motion parameter relations, significant improvements may be obtained for the evaluation and assessment of seismic damage.

Evaluation of Reasons of the Damages after Simav and Van (2011) Earthquakes

Turkey is located on a region with high seismicity. The intense seismic activity in 2011, especially Simav and Van earthquakes, once again reminded of this fact. The aim of this study is to give information on the causes of the heavy damage and loss of lives after these earthquakes which are not incompliance with engineering principles. Based on the investigations, the damaged buildings are found to have similar deficiencies as inadequate detailing, material properties, faults in application and design. The most important reasons of the collapses are insufficient strength of joint regions and lap splice lengths. The following flaws are: inadequacies in amount or/and detailing of the lateral reinforcements, short column, overhang and soft story effects, deficient isolation applications and gable wall construction, low concrete strength, pounding and collision between buildings and faulty load bearing system designs. The other remarkable observations after the earthquakes are: the dependency of the seismic damages to some other parameters beside distance to the epicenter, adequate performances of the retrofitted buildings, total collapse of even shear-wall buildings with heavy flaws, buildings with high concrete strength may be heavily damaged, buildings with flexible load carrying system may take significant architectural damage without structural, for moderate and heavy damages 4-5 story buildings are the most damaged ones, even the multi story adobe buildings that are built in accordance with technical provisions may survive the earthquake without damage, therefore the main reason for the devastation is the violation of the engineering principles.