Performance Prediction And Reliability Management Of Concerete Structures Based On Information Updating

The performance of concrete structures would deteriorate with time under environmental effects. It is necessary to consider the effect of performance deterioration on the safety and reliability of particular structures, especially for some key structures such as high dams and long-span bridges. A systematic analysis so-called life-cycle reliability management including structural performance prediction, reliability analysis and maintenance decision analysis should be developed. In the present thesis, a framework of life-cycle reliability management for concrete structures based on a philosophy of information updating is established. The studies focus on the following three aspects:1,The two kinds of information resources for structural performance prediction are summarized and analyzed. A philosophy of information updating is introduced to the prediction of structural performance deterioration. The application of Bayesian methodology in structural performance prediction is investigated as an effective tool of information updating. Especially, a kind of process-based Bayesian forecasting methodology, Bayesian dynamic linear models (DLM), is introduced to the prediction of the deterioration process of structural performance. The definition of model structures and model parameters are investigated. A so-called"condition index"is defined to evaluate the structural performance, which could make the Bayesian DLM more applicable. Case studies validate the advantages of Bayesian dynamic models.2,The definition of time-dependent reliability and dynamic reliability index are analyzed and compared. The two kinds of reliability indices are jointly used in life-cycle reliability management. The key issues of reliability analysis, such as the definition of model and parameters of the action process, the definition of target reliability index are investigated by theoretic research and case studies. An effective solution method of time-dependent reliability is developed based on number theoretic methods. 3,The target, principle and procedure of maintenance decision analysis of structures are investigated based on the philosophy of information updating and Bayesian decision theory. Schemes of cost analysis and reliability control are illustrated with case studies.