Non-linear structural analyses of prestressed concrete girders: tools and safety formats

The main goal of this paper is the practical application of safety format methods to evaluate the structural response of pre-stressed concrete girders. Particular attention has been paid to the fully probabilistic method in which the design resistance is evaluated by probabilistic analyses. The effects of the choice of the adopted failure criterion on the standard deviation of NLFEA (non-linear finite element analysis) results are treated in this paper. Moreover, a new method to reduce the number of non-linear analyses is proposed (Fractiles Based Sampling Procedure, FBSP). With the aim to evaluate the use of mechanical parameters correlations reported in the Model Code 2010 (fib, 2013) in a probabilistic reliability analyses, a modified application of FBSP is also presented. Finally, the design resistance obtained by FBSP has been compared with the results of fully probabilistic method (FP), the classical partial safety factor (PSF) method and the alternative Estimation of Coefficient of Variation method (ECOV)