Reduction of inelastic seismic demands in a mid-rise rocking wall structure designed using the displacement-based design procedure

Abstract

Summary Precast post-tensioned rocking wall structural system has been developed in the recent past as a damage-avoidance structural system for seismic regions. For a widespread use of this structural system, suitable design procedures are required to ensure a reliable and well-predicted performance under different levels of seismic hazard. In the current study, a mid-rise 20-story rocking wall structure is selected and designed using the displacement-based design procedure. Furthermore, two different capacity design procedures are used to predict the increased force demands due to higher mode effects. The time history results against moderate and severe level of seismic hazards show the effectiveness of displacement-based design procedure in predicting and controlling the displacement and drift demands, while the simplified procedure and the modified modal superposition procedure for the capacity design are found to be unconservative and conservative, respectively. To further investigate the seismic demands, modal decomposition of inelastic seismic responses is carried out, and the contribution of different modes in the total responses is calculated. Based on this improved understanding, a mitigation technique of dual gap opening is employed. A detailed discussion about the location and design strength of the extra gap-opening is carried out by considering different performance parameters. Copyright © 2016 John Wiley & Sons, Ltd.