Performance Analysis of Steel Structures with A3 Irregularities

Determination of the behaviour of structures during earthquakes is a very important engineering concern. Irregularities in the structure may lead to more damage imposed on it by weakening its defence mechanism during an earthquake. Some of these irregularities may be indentations or protrusions in the plan. Such irregular buildings may be encountered in practice because of various reasons. This study examined the state of irregularity by the A3 plan in the Turkish Building Earthquake Regulation of 2016. Four different A3-type irregularity cases were considered. The building with no irregularities in its plan was taken as the reference building. The five steel structures were compared by obtaining pushover curves for both the X and Y directions. Additionally, as a rapid assessment method, the Canada Seismic Screening Method was used in the study. Both in the rapid assessment method and from the pushover curves, it was determined that buildings without irregularities are safer. The study also allows a comparison among the earthquake performances of the structures using the rapid assessment method. It may be stated that there was an agreement between the two methods. This shows that the rapid assessment method may be used for steel structures. The importance of constructing structures that do not include irregularities is emphasized with the study. If one has to construct such structures, the defence mechanism of the structure should be strengthened by taking various measures.