Reliability assessment of historical reinforced concrete bridge piers based on nonlinear fracture mechanics modelling and safety formats

Many existing concrete structures have been fulfilling their purpose for several decades, but they may no longer meet current structural safety standards due to various factors.This fact highlights the urgent need for innovative solutions to ensure the durability and performance of these structures under increasing load and changing environment.Statistical study has to be included to consider uncertainties, also safety formats approaches can be utilized.The aim of this research is to show how a procedure for quality control and safety assessment of 100 m high concrete piers was developed based on non-linear finite element analysis and digital twin technology considering uncertainties involved.Piers are parts of Jauntal bridge, a 60-year-old, 450 m long railway bridge that has been equipped with a new bridge deck.The purpose of the study was to investigate structural safety, serviceability, durability, and remaining service life of the bearing socket and pier systems equipped with a new confinement concept.The research uses a reliability-based approach utilizing advanced probabilistic methods, based on reliability index determination and efficient safety format approaches.Standard ECoV and Eigen ECoV methods were employed for an estimation of mean values and standard deviations for all steps of the finite element analysis, assuming two limit cases of probability distribution of resistance -Gaussian and Lognormal.The stochastic model contains only the 4 most significant random variables of the computational model representing the material characteristics of the concrete pier.