Disproportionate Collapse: Terminology and Procedures

A variety of terms are used to describe structural characteristics and concepts in the context of disproportionate collapse of structures. Some of these terms, namely collapse resistance, robustness, and vulnerability as well as redundancy, continuity, ductility, and integrity are discussed in this paper. It is shown that they are often used differently by different writers and that there is not always a general agreement today as to their precise meaning. This paper distinguishes these terms and the associated structural characteristics and suggests working definitions. Based thereupon, a general performance-based framework for preventing disproportionate collapse is presented and the methods available for enhancing the collapse resistance of a structure are discussed.