A Method for Modeling Successive Removal of Columns in Macromodeling Frameworks

As a well-known technique, alternate path method (APM) has been widely used to evaluate progressive collapse potential of structures. This method investigates the capability of structures to redistribute loads carried by a removed element in the remainder. However, in most cases the initiating event is so intensive that it destroys more than one load bearing element. If the destruction of members does not occur concurrently, dynamic removal of columns in APM could not be correctly modeled in common macromodeling frameworks. This problem has resulted in progressive collapse analysis and design guidelines to define less element removal cases than has been expected. In this paper, the method chosen for modeling successive removal of columns is capable of improving the guidelines to consider more realistic collapse scenarios. This method can be easily implemented by practicing engineers in commercial or open source programs. Moreover, a simple case study is defined to emphasize significance of the proposed method.