Development of guidelines for nonlinear finite element analyses of existing reinforced and pre-stressed beams.

The Dutch Ministry of Infrastructure and the Environment initiated a project to re-evaluate the carrying capacity of existing bridges and viaducts through the use of nonlinear finite element analyses (NLFEA) which are more and more becoming an usual instrument of calculation in the daily design procedures. Numerical simulations of several case studies taken from experimental programs have therefore been performed in order to assess and criticize the finite element approaches. In this paper guidelines for nonlinear finite element analyses are proposed to optimize the results obtained from numerical simulations of reinforced and pre-stressed beams in order to reduce model and users factor. The numerical results are also compared with analytical procedures proposed by the new Model Code 2010 which proposes different numerical and analytical procedures to evaluate the carrying capacity of existing structures based on the definition of different safety levels.