Semi and Fully-probabilistic Nonlinear Analyses of Post-tensioned Concrete Bridge Made of KT-24 Girders

Abstract

This paper deals with the assessment of the design resistance of an existing railway bridge made of KT-24 precast post-tensioned concrete girders. The load-bearing capacity of the structure is determined us- ing probabilistic nonlinear analysis by the finite element method. Load-bearing capacity is determined for the ultimate and serviceability limit states. A fully proba- bilistic approach is compared to selected recommended semi-probabilistic methods, which can greatly reduce the number of nonlinear calculations needed to estimate the design value of resistance. Two stochastic mod- els are compared, reflecting the level of knowledge of actual material properties from the diagnostic survey. The results are compared and discussed with respect to accuracy and required computational time, which is a critical issue when performing a global nonlinear anal- ysis of a complex structure.