Percentile influence of beam column cross section design on progressive collapse potential of low-rise reinforced concrete framed structure

Abstract

The aim of this study is to investigate the behavior of low-rise, four-story RC framed structures when subjected to abnormal loads, specifically missing column scenarios. The study uses more than 20 unique models with varying beam and column cross sections and designs them for India's four seismic zones (Z2, Z3, Z4, and Z5) in accordance with IS 456–2000 and IS 1893–2016 using FEM based ETABS V.17 Software. The study evaluates the potential for progressive collapse of structures in all three possible cases of column removal, as per the GSA (2016) Guidelines, using the linear static analysis approach. The investigation aims to determine the progressive collapse potential of low-rise reinforced concrete framed structures designed for Indian seismic zones, and the effect of different beam and column cross sections on the structures' progressive collapse potential. The study finds that structures designed for high seismic zones (seismic zone 5 with high beam column cross sections) have greater progressive collapse resistance, while those designed for low seismic zones (seismic zone 2 with low beam column cross sections) have lower resistance. The study also analyzes and designs the structural models for seismic loading and examines the behavior of critical columns (flexure) after column missing scenarios by studying the column interaction diagrams for GSA load-generating internal forces. Additionally, the study quantifies the notable effect on the material quantities (Concrete and longitudinal reinforcement), as they have a significant influence on the ductility and flexibility of the frame behavior.