A novel optimization-based modal pushover analysis procedure for estimating the response of structures

In recent years, studies have focused on the seismic behavior of various structural systems, including single- and double-layered spatial structures. While nonlinear dynamic analyses are common for these studies, they are time-consuming and complex. To address this, many pushover procedures have been developed, but their effectiveness in spatial structures remains underexplored. This study introduces an optimized lateral loading profile for evaluating the seismic response of walled bilayer spatial structures. By combining dominant inertial forces and optimizing their corresponding coefficients with the particle swarm optimization (PSO) algorithm, an optimal loading profile is derived. The method's accuracy was tested on models with varying arch height-to-span ratios and a constant wall height-to-span ratio, as well as a 15-story frame structure. The results obtained showed that the proposed method closely matches incremental dynamic analyses (IDAs) in predicting base shear, initial stiffness, and displacements, especially for higher arch height-to-span ratios. Additionally, the method accurately estimates drift profiles and nodal displacements on roofs and walls, and performs better than similar mode-based methods for frame structures.