Behaviour of Mid-Rise Rc Structures under Blast Loading Using Fem Software

This study investigates the dynamic response of mid-rise reinforced concrete (RC) buildings under blast loading, driven by the increasing threat of terrorist attacks that cause severe structural damage. The objective is to evaluate the behavior of bare moment-resisting frames (comprising columns and beams), focusing on displacement, load-carrying capacity, and damage patterns. Using SAP2000, a parametric study was conducted on buildings of varying heights (G+6, G+9, and G+12), including a G+6 irregular building. Time history analyses were performed for explosive charge weights of 10 kg, 20 kg, and 30 kg at standoff distances of 15 m, 30 m, and 45 m. The results revealed peak displacements of approximately 1100 mm in the bare frame structures. The frame, acting like a mesh structure, experiences reduced abrupt loading due to blast wave diffraction. However, these deformations still indicate potential vulnerabilities in conventional frame systems under high-intensity blast loads. To enhance blast resistance, various retrofitting techniques were investigated, including single diagonal bracing, double diagonal bracing, and steel jacketing. These methods significantly improved energy dissipation and overall structural stiffness. The study provides v