| dc.description.abstract | The railway transportation is a crucial component of transportation infrastructure, known for its high capacity, environmental friendliness, and reliability. Despite requiring substantial initial investments, railway transportation becomes highly cost-effective once essential components are in place.
Bridges play a vital role in this infrastructure but are also susceptible to deterioration. Infrastructure owners actively monitor bridge conditions, predict potential failures, and conduct maintenance to prevent catastrophic events. Steel railway bridges, the most prevalent type in Norway requiring assessment, are particularly prone to material fatigue.
The conventional method for estimating the remaining fatigue life of a bridge involves creating a load model and calibrating it to the traffic conditions at the location of the bridge under investigation. The fatigue load model developed for Norwegian railway bridges was initially tested on several bridges, predicting failure in 7 out of 21 structures, despite inspections revealing no signs of cracks. This thesis aims to enhance the Norwegian load model for estimating the remaining fatigue life of railway bridges and contribute to the broader understanding of reliability assessment methods for such structures.
The current research begins by measuring actual railway traffic conditions in Norway using a weigh-in-motion system. Traffic loads are carefully collected, analysed, and classified using dedicated algorithms, defining measurement errors and various correlations. Subsequently, the fatigue load model for estimating the remaining fatigue life of Norwegian railway bridges is calibrated based on actual traffic conditions.
In the final phase, the study delves into the uncertainties inherent in the reliability analysis of railway bridges applying the calibrated Load model. The framework of Imprecise Structural Reliability is developed and demonstrated. By utilizing this framework, a comparison is drawn between Classic Structural Reliability and Imprecise Structural Reliability for an aging railway bridge. The research includes a sensitivity analysis of variables involved in reliability assessments and a comprehensive discussion on the implications of employing both classic and imprecise approaches. | en_US |
