| From the beginning of the twentieth century until about 1970s, many steel highway bridges in China have been constructed using rivets as the structural fastener. These riveted bridges are often under a poor situation now as carrying an increasing volume of traffic. In order to make their continued safe use possible while at the same time avoiding unnecessary repairs or replacements, methods for estimating and updating the actual fatigue life of such structures are urgently required. The development of modern nondestructive inspection techniques may facilitate early detection of flaws, allow the original life prediction model to be updated. An approach to evaluate and updating the fatigue-reliability of existing riveted steel bridges is developed in the dissertation, in which the effects of the fatigue failure mechanism, failure models of riveted steel bridge, reliability characterization of NDI technique and the Bayes theorem are included. The fatigue-updating models using nondestructive inspection have been set to assess the reliability of riveted steel bridge components. In detail, the following aspects are investigated:1. This paper reviews the developing history and present status. With the effect of single angle failure model (SAF) and Monte-Carlo method, The fatigue failure probability before updating is calculated.2. In the paper, the reliability characterization of NDI technique is discussed, and the relationship between several means are also proposed.3. According to the outputs of nondestructive inspection, a fatigue reliability updating model for riveted steel bridges is proposed in the dissertation, and based on Monte Carlo method, a fatigue reliability updating program is developed to calculate the fatigue failure probability and the reliability index after inspection of riveted bridge components..4. The updating evaluation models are applied to assess the fatigue reliability and service safety of riveted highway bridges after the nondestructive inspection.. |
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