ABSTRACT

The difference between progressive collapse, related to mechanisms of collapse, and disproportionate collapse, related to design, is outlined. Various mechanisms of collapse are described, which helps to clarify conceptual relationships. Ordinary design procedures are inadequate for preventing disproportionate collapse. The reasons for this are explained. After defining the terms collapse resistance and robustness, a pragmatic design approach for achieving collapse resistance of general structures is outlined. In this approach, the design objectives are established in a decision-making process. Concerning design methods, segmentation is available in addition to alternative load paths. The former method can be preferable in case of large initial local failure. This pragmatic approach can be developed into model guidelines for the design of general structures against disproportionate collapse. In contrast, it is found that current design regulations apply only to buildings of small to medium size and not to structures in general.