Seismic and direct costs comparison of conventional and nonconventional structural systems used for an irregular building

Although current structural design philosophy privileges the notion of structural regularity, contemporary architecture includes building irregularities. Often, conventional structural design is forced on nonconventional structures in this type of building, forcing a round peg in a square hole. This incongruence calls for a thorough study of irregular buildings. The present article uses a plan and vertically irregular building to compare a conventional and a nonconventional structural system, allowing for an analysis of the effect of structural configuration on seismic response and direct building costs. In this study, the NSR-10 building code is applied (Colombian Code of Seismic Design). Nonlinear static pushover analyses and nonlinear time-history analyses are performed to determine and ultimately compare each system's real capacity. Furthermore, a comparative analysis of direct building costs (in unitary terms) is done for both structural systems. The substantial impact of structural system type on both cost and seismic behavior is demonstrated, providing sufficient evidence to question the paradigm of conventional systems as both more cost effective and more seismically sound.