Progressive collapse response of reinforced concrete high-rise buildings designed according to turkish earthquake code

When a building experiences severe impact loads such as explosions, car or airplane impacts, or similar natural or man-made events on a critical structural member like a column or shear wall, failure of the critical member can lead to the ultimate collapse of the whole building if the remaining members fail to carry the extra load imposed on them due to the failed member. This progression of damage from the member level to the structural level is what is described as progressive collapse. This study investigates the progressive collapse response of tall buildings designed according to the Turkish earthquake code. In this research, a case study was done on a 40-story tall building designed according to the Turkish earthquake code. The building used was a symmetrical building with a flat plate system, perimeter beams, and shear walls at the core. A 3D model was developed using SAP 2000 version 23 to represent the building. Gravity loads were applied directly to the slabs as uniform loads. Nonlinear behavior on the beams and columns was modeled using the fiber hinge model. A progressive collapse procedure was performed for a total of 18 scenarios. This was done by removing a critical member using SAP2000 v23 and then reading the displacements on the node directly above the removed member. These results were represented as displacement time histories of the node. Plastic hinge rotations were read on the beams surrounding the removed member, where the hinges formed. The rotations were compared to the plastic hinge rotation limits given in the Turkish Earthquake Code (TEC 2018) and the American Society of Civil Engineers (ASCE/SEI 41-17) for different performance levels. The 18 scenarios were compared in various combinations to get a better insight into the results obtained. From the results, it was observed that hinges formed on perimeter beams adjacent to the removed column only in the scenarios where the column was removed from the corner and the edge of the bottom floor. In the rest of the 16 scenarios, there were no hinges formed on the perimeter beams or on the columns. This research gave useful and critical insights into the performance of tall buildings designed according to the Turkish earthquake code, since no study had been done on this subject before. The whole process was described in detail in such a way that it can be replicated by practicing engineers without any prior experience in this subject.