Partial safety factors for homogeneous reliability of nonlinear reinforced concrete columns

The design of reinforced concrete structures is based on the verification of the rules defined by standard specifications, where partial safety factors are introduced to ensure safety. However, the use of constant factors for different kinds of columns leads to inhomogeneous safety levels. In this paper, a new format for concrete and steel safety factors is proposed, in order to ensure uniform target reliability. These factors are given in terms of the column design parameters, such as material strengths, steel ratio, slenderness and loading eccentricity. The adopted mechanical model takes into account material and geometrical nonlinearities. The response surface technique is used to evaluate the structural reliability. Numerical applications show how the calibrated safety factors lead to a better design than those proposed by the Eurocode2.