Seismic analysis of a modern 14-story reinforced concrete core wall building system using the BTM-shell methodology

Abstract

This paper uses computational simulation to investigate the lateral load-displacement behavior and failure modes of a modern 14-story reinforced concrete (RC) core wall building. The design complies with the minimum code requirements of the current California Building Code, which is based on ASCE 7–16 and ACI 318–14. The computational representation of the building, which accounts for the material nonlinearities of all structural components, employs the beam-truss model (BTM) for the walls and floor slabs. Analyses of the building model are conducted for static monotonic and cyclic lateral loads using the program FE-MultiPhys, which provides a user-friendly implementation of the BTM as an assemblage of rectangular shell macroelements. Two different load patterns, that is, lateral load distributions along the building height, are considered. The analyses provide insights into the evolution of damage and lateral strength degradation and their dependence on the load pattern, while also elucidating the complex interaction between the webs and flanges of the core wall and the system effects associated with coupling between the walls, beams, slabs, and columns. The presentation of the analytical results is accompanied by a discussion on the advantages of the BTM over seismic analysis methods used in current code-minimum and performance-based seismic design (PBSD) practice.