Eurocodes reliability basics

For a long time now, all structural design codes have included multiplier coefficients for actions and divisors for resistances, known as "partial coefficients". Their purpose is to achieve a sufficiently reliable design despite the many uncertainties involved in calculations, due to model approximations, uncertainties in quantities, phenomena not taken into account, etc.

In older, totally deterministic codes, so-called "safety" coefficients covered all uncertainties or lack of knowledge about the quantities under consideration, including the statistical dispersions of random variables. In recent semi-probabilistic codes, characteristic values for the effects of actions and resistances are introduced, taking into account the laws...