PERFORMANCE-BASED PLASTIC DESIGN (PBPD) METHOD FOR EARTHQUAKE-RESISTANT STRUCTURES: AN OVERVIEW

This paper presents a brief overview of performance-based plastic design method as applied to the seismic design of building structures. The method uses pre-selected target drift and yield mechanisms as key performance criteria. The design base shear for a selected hazard level is calculated by equating the work needed to push the structure monotonically up to the target drift to that required by an equivalent single degree of freedom to achieve the same state. Plastic design is performed to detail the frame members and connections in order to achieve the targeted yield mechanism and behaviour. The method has been successfully applied to a variety of common steel framing systems and, more recently, to Reinforced Concrete (RC) moment frames. Results of extensive inelastic static and dynamic analyses showed that the frames developed desired strong column-sway mechanisms, and the storey drifts and ductility demands were well within the target values, thus meeting the desired performance objectives. The examples of 20-storey steel and RC moment frames, as presented in the paper, showed that the method is especially advantageous for tall frames, where cumbersome and lengthy iterative design work in current practice can be completely eliminated, while leading to excellent performance as targeted. The basic work-energy equation can also be used for seismic evaluation of existing structures. The results, as presented in this paper, showed excellent agreement with those obtained from more elaborate inelastic time-history analyses. Copyright (c) 2009 John Wiley & Sons, Ltd.