1. General

According to the future Eurocode 0 or the new French standard NF EN 1990 in preparation, a structure must be designed to offer an appropriate degree of robustness so that, during its design life, it is capable of resisting unforeseen and undesirable events without suffering damage of excessive magnitude in relation to its origin. Thus, a local collapse that does not lead to a progressive collapse of the entire structure is an example of damage that is not disproportionate to its initial cause (figure 1 ). In the opposite case, and to illustrate the notion of progressive collapse, this type of ruin is sometimes referred to as a "domino" effect.