Progressive collapse of regular- and irregular-plan concrete structures in an earthquake

Progressive collapse, in which local failure of an element causes significant deformations leading to the collapse of a structure, is a catastrophic structural phenomenon that can occur due to natural disasters or human negligence. Common practices in progressive collapse analysis generally prevent this phenomenon due to unusual gravity loads or explosions; however, progressive collapse behaviour due to earthquakes is less evaluated. An experimental methodology was used to study the progressive collapse of concrete structures with an intermediate moment frame both in regular and irregular plan using the alternative load path method and guidelines issued by the US General Services Administration and the US Department of Defense considering three cases of column removal using OpenSees. The investigation studied the function of the structure regarding the rotation of plastic hinges and its robustness. The pushover method was used to cover non-linear static analysis and the time history method was used to perform non-linear dynamic analysis for three-, six- and ten-storey structures in three dimensions. The results showed that structures with irregular plan and low heights are more vulnerable to progressive collapse.