Seismic Evaluation of a Low-Rise Reinforced Concrete Commercial Building by the Capacity Spectrum Method

Abstract

This paper presents seismic evaluation of a typical low-rise reinforced concrete commercial building based on the capacity spectrum method (CSM) recommended in ATC-40. A nonlinear three-dimensional finite element (FE) model is developed for assessing the seismic capacity of the structure. To simulate a more realistic behavior of the building during ground motions, effects of foundations, masonry infills, and other site-specific features are integrated into the model. Seismic capacity of the structure is determined using pushover analysis and compared with the demand imposed by predicted ground motions. Results indicate that this building possess the most undesirable brittle failure with low level of seismic capacity. Further, this analysis method reveals several earthquake vulnerable features and the effectiveness of 3D modeling of buildings with strength and stiffness irregularities. Finally, design recommendations for eliminating earthquake vulnerable features are proposed. However, the typical details used at the foundation-superstructure connection limits the structural system seismic capacity.