Rocking-wall moment frames (RWMFs) are unique, lateral resisting structures in which the shear wall pivots about its pinned base rather than act as a fixed base, upright cantilever. The function of the wall is to prevent soft-story failure, reduce drift concentration, and provide suitable supports for energy-dissipating devices. However, despite their favorable seismic performance, their practical design aspects have not been fully addressed in the literature. This paper proposes a new approach based on the principles of design-led analysis. It provides a lucid study of the analytic components and inner workings of RWMFs as efficient lateral resisting systems. While complementing existing literature on the subject, this study presents several interesting findings and useful design conclusions. For instance, it points out that under certain circumstances, neither the rocking wall nor its appendages can influence the ultimate carrying capacity of the frame. The proposed solutions are entirely suitab...

Performance Control and Efficient Design of Rocking-Wall Moment Frames

Optimum lateral load pattern for seismic design of elastic shear‐buildings incorporating soil–structure interaction effects

Summary

The purpose of this article is to present a new method of analysis for the structural design of pin-supported rocking wall-moment frames with supplementary devices and post-tensioned stabilizers. The function of the wall is to prevent soft story failure, impose uniform drift and provide support for the supplementary equipment. The proposed methodology lends itself well to several seismic design strategies, ranging from severe damage avoidance, to collapse prevention, to structural self-alignment and repairability. Repairability means avoiding major damage to columns and foundations. The success of the resulting solutions is due to the single degree of freedom behavior of the combined system and the fact that its overall performance is not significantly affected by minor changes in the stiffness of the wall. The sensitivity of the response to wall rigidity is addressed by comparing the maximum elastic slope of the wall with a fraction of the specified uniform drift. The limitations of rocking wall-moment frames, as viable lateral resisting systems, have been addressed. Several worked examples have been presented to provide insight and technical information that may not be readily available from electronic output. The proposed solutions are exact within the bounds of the theoretical assumptions and are ideally suited for manual as well as spreadsheet computations. Copyright © 2015 John Wiley & Sons, Ltd.

An introduction to the structural design of rocking wall-frames with a view to collapse prevention, self-alignment and repairability

Cyclic testing and performance evaluation of buckling-restrained knee-braced frames

The paper introduces a number of new analytic techniques and practical technologies that lead to the development of an efficient earthquake resistant system. The proposed structural system consists of a grade beam supported moment frame connected to a rigid rocking core through story level rigid links. The new system tends to bend and tilt as an upright simply supported beam with minimal uniform drift and prevents the formation of soft story failure within the moment frame. It is capable of preventing severe damage to its columns and footings and can be equipped to prevent catastrophic collapse due to strong ground motion and re-center itself afterwards. The analytic development is based on global, design led analysis and results in closed form, exact solutions that are highly suitable for preliminary, manual, as well as spread sheet computations. Several examples have been provided to verify and demonstrate the applications of the proposed formulations. All numerical results have been verified by independent computer analysis.

S C Goel

Papers

Performance-based plastic design method for earthquake resistant structures