Figure 4.12: Failure of a roadway bridge due to scour, Portugal, 2001.
Figure 4.13: Bridge collapse due to unforeseen dynamic behaviour in certain wind conditions, Tacoma
Narrows, USA.
Common for the situations illustrated in Figures 4.10-4.13 is that failure events occurred as a
consequence of unforeseen exposures and sequences of events, which were not fully
appreciated in regard to their potential consequences.
Different techniques for identification of scenarios have developed from various engineering
application areas such as the chemical industry, the nuclear power industry and the
aeronautical industry. Among these are: