Seismic acceleration amplification factor under fixed and pin supported RC frame building

Abstract

Assessing non-structural elements' vulnerability to acceleration has relied on peak horizontal floor acceleration. Given the dynamic nature of structures, estimates for forces acting on elements like mechanical, electrical, or architectural components have been crucial. The amplification factor for these non-structural components has been affected not just by building height but also by the structural support conditions. This study has examined five distinct building models spanning 2, 4, 6, 8, and 10 stories. The models have been analysed using the nonlinear time history analysis method under various near-field Chi-chi earthquake scenarios (ranging from 0.01g to 0.067g, 0.067g to 0.2g, and 0.2g to 0.32g). This analysis has aimed to determine the acceleration amplification factor (Ω), defined as the ratio of peak floor acceleration to peak ground acceleration (PGA), for both fixed and pinned support conditions. A disparity has emerged after comparing the actual acceleration amplification values under fixed and pinned support conditions with those from previous models. While some models have performed adequately under fixed support conditions, others have yielded accurate results under pinned support conditions. Consequently, there has been no singular formula capable of effectively accommodating both support conditions across the varying ranges of ground motion.