Seismic performance of reinforced concrete core wall buildings with and without moment resisting frames

This study aims to compare the seismic performance of two 42-story reinforced concrete buildings located in Los Angeles, California: a coupled core wall building and a similar core wall building with perimeter moment resisting frames (i.e. dual system). The buildings were designed using two different approaches. The first approach followed the traditional code prescriptive design approach as outlined in the International Building Code (2006), whereas the other approach followed a performance-based design approach outlined in the seismic design guideline published by the Pacific Earthquake Engineering Research Center. Detailed finite element models were developed for both systems with the different design approaches. The models were used to evaluate the seismic performance of the prototype model at five different earthquake shaking intensities. Detailed comparisons of the design approaches, seismic responses, and initial and annualized repair costs of these buildings are presented. Analysis results show that both structural systems generally achieved excellent performance, whereas the dual system performed slightly better (smaller inter-story drifts and lower core wall stresses). Although repair costs were lower in the dual system building (which is attributed to lesser degree of damage), total costs were higher than the core wall building due to the higher initial costs.