Progressive Collapse Analysis of a Medium-Rise Circular RC Building Against Blast Loads

This paper investigates the vulnerability of a typical medium-rise circular RC building against progressive collapse as a result of blast generated waves. The building is an eight storied (including one story basement) commercial complex. The likely blast threat scenario was identified by qualitatively assessing the vulnerability of the critical elements of the structure. LS-DYNA was used for the finite element modelling of the structure. The study presents local model analysis of one of its circular columns for which fluid-structure interaction through Alternate Lagrangian Eulerian (ALE) element formulation has been employed. The concrete volume in the columns was modeled using 8-node reduced integration solid hexahedron elements. The global model analysis was carried out to examine the overall response of the structure due to the failure of one of the critical columns. The building was modeled using beam and shell elements. The 2-node axial beam elements with tension, compression, torsion, and bending capabilities were employed to represent the RC beams and columns, whereas the four node quadrilateral and three node triangular shell elements were used to represent the core wall, floor slabs, retaining walls and facade. The column bases of the building were fixed at the level of raft slab. The results of the study are proposed to be used to control or prevent progressive collapse of RC buildings.