Time-dependent Reliability Assessment Of Concrete Continuous Beam Bridge Based On Real-time Monitoring Information

The reliability of existing reinforced concrete bridges is one of the world-wide concerned problems in the field of the structure engineering. The reliability assessment and the service life prediction for the existing reinforced concrete structures can help make rational decisions to repair or demolition; moreover, it can also be directly applied to structural design. In this thesis, with respect to the basic characteristics of existing highway reinforced concrete bridges, some important topics of time-dependent reliability assessment and life prediction of existing bridges are studied. The major contents are summarized as follows:Firstly, considering the characteristics of the resistance degradation with time of continuous concrete girder bridges, the three general stochastic process models of the resistance are analyzed in detail, and the characteristics of the general stochastic process are given. The Bayesian dynamic model of the resistance is studied in combination of Bayesian methods and the amending process of Bayesian analysis. Finally, a numerical example is provided.Secondly, four computation methods of time-dependent reliability are studied in detail, which include time-integrated approach, time-discretized approach, time-discretized and integrated approach and first-passage probability approach. By analyzing the practical examples, the computational accuracy and shortcomings of the four methods are compared carefully.Thirdly, load probability model and updating theory of load probability model based on real-time monitoring information are analyzed in detail, and based on the load probability model, the time-dependent reliability of the safety is analyzed about the flexural members of concrete continuous beam bridge, and at last the safety-based time-dependent reliability of the components has been evaluated.Finally, life prediction model of concrete continuous beam bridge is analyzed in details, then in combination of reliability theory and numerical examples, the time-monitoring periods and real-time monitoring suspended periods are analyzed and discussed.