Safety Assessment of Concrete Expressway Bridges Employing Probabilistic Concept

摘要

The study examines the assessment method for the safety of concrete bridges in the Korean expressway using the probabilistic concept. The reliability-based assessment methods available are reviewed, and the assessment results from the different methods are compared through field applications. A comparison of the assessment results from the available international assessment codes or guidelines showed that the current assessment method in Korea provides a very conservative result. The evaluation using the proposed assessment method, considering the reduced uncertainty in the assessment and corresponds to the newly issued bridge design code in the limit-state format, revealed a considerably improved rating factor. To take the characteristics of the limited truck traffic of the expressway into account, a live load model is constructed using the site-specific truck information in a statistical manner and used to evaluate the load rating. In addition, a new updating process for an analytical model of a bridge using measured response is presented. The reduced live load of the expressway increased the rating factor of the test PSC (Prestressed Concrete) girder bridge in a Korean expressway. The rating factor of the test bridge was increased further by applying the updated analytical model.