A Framework for Improving Building Robustness Through Segmentation

Abstract

The protection of buildings and infrastructures from extreme abnormal events due to natural hazards (e.g. hurricanes, floods), accidents (e.g. vehicle impact, gas explosions, unexpected failure due to poor design or lack of maintenance) and malicious actions (e.g. terrorist attacks), is currently of great societal and scientific concern. To prevent the spreading of a local-initial damage into progressive collapse, the current design philosophies consider that when a critical element fails (e.g. column, load-bearing wall), continuity structural details should provide alternative load paths to redistribute the load of the failed element to the rest of the structure. Although this strategy is valid in certain situations (e.g. small initial failure), in others (e.g. large initial failure due to blast loading), it has proved to be mistaken and has led to disastrous consequences. Over recent years, a debate has emerged about whether or not segmentation can improve a building’s capacity to arrest progressive collapse. Segmenting a building into individual parts can prevent failures in one zone from propagating to other parts of the structure, as was the case, for example, in the Pentagon (2001) and Terminal 3 of the Charles de Gaulle Airport (2004). However, segmentation breaks continuity, which works well for small initial failure scenarios. In the context of an ERC-Consolidator Grant project, the use of structural fuses has been proposed. While fuses will provide continuity under normal loads or for small local-initial failures currently considered by relevant standards, they will separate to prevent disproportionate collapse during more extreme situations when failure propagation is inevitable. This paper presents the first achievements of the project, involving the development of a framework that can be employed to identify situations when continuity is disadvantageous and for which segmentation is beneficial.