Probabilistic modelling of exposure conditions for robustness

In the paper probabilistic models are discussed with respect to various types of exposures like wind, snow, earthquakes, internal gas-explosions and fire. In the discussions about robustness, however, also another category of actions play a role like unforeseen actions, human errors and deliberate malicious human actions aiming at destruction of the structure.

As could be expected, there is not sufficient structured data to assess firmly statistically based models. Some way out could be to neglect the actions themselves and concentrate on the extent and nature of the direct exposure effects. This is also the basic idea behind the popular design method of the missing column. In finding consistent design solutions these notional models are believed to be helpful. It would be even more helpful if some indication on the probability of occurrence could be given.