Progressive collapse of regular RC structure considering flexibility of slabs under gravity and wind loads

Abstract Progressive collapses are disastrous phenomena which occur in the structure due to manmade incidents or natural disasters. There are not any significant studies considering the flexibility of slabs in the structures, as an alternative to treating them as rigid diaphragms. The present study deals with the progressive collapse of a regular reinforced concrete structure considering flexibility of slabs, comparing the same when the slabs are considered as rigid diaphragms. 20 storey(G+19) building is modeled using ETABS software and nonlinear static analysis is performed under the action of gravity and wind loads. At the outset, the analysis is done for undamaged structure to find the behavior of structure and then the damaged models have been analyzed by removing one of the critical column in different locations at first storey, based on general services administration (GSA) guidelines 16 . Various response parameters such as base force capacity, storey stiffness and storey displacements have been compared for undamaged and damaged structures considering and not considering the flexibility of slabs. From the comparison of the results, it was noticed that the chance of progressive collapse is high when the corner column is damaged and also resistance to wind load is considerably higher when stiffness of slabs is considered for the analysis in both undamaged structure and the four cases of damaged structure (ii), which is about three times higher.