Time-Dependent Risk Analysis Of Cable-Stayed Bridges In Service

It is commonly convinced that numerous in-service bridges are bearing sorts of designed loads, as well as, facing time-dependent uncertain factors, such as environmental erosion, de-signed traffic flow exceeding, overloading vehicles, material aging and so on. Thus, structural deterioration and accidents may occur under the influence of these factors. Once these accidents happen, there will be an immeasurable loss. Therefore, if we can accurately predict the bridge diseases and take maintenance measures in advance, catastrophic losses will be avoided, which will achieve the best goal in terms of safety and economy. Therefore, the prediction of the risk of bridge on operation period has important theoretical and field application value.In this paper, time-dependent risk analysis of cable-stayed bridges in service was studied. Summary of main contents were as follows:1) The concept of time-dependent risk analysis of cable-stayed bridges in service was pro-posed. Then the theoretical framework was established, and finally the basic process was put forward;2) Based on the analysis of shrinkage and creep and vehicle load, the time-dependent risk of cable-stayed bridges in service was researched, and the combination of qualitative and quan-titative methods were used to estimate the risk loss;3) Time-dependent risk assessment standards of cable-stayed bridges in service was con-ducted, and the time-independent risk response measures were also suggested;4) Time-dependent resistance degradation research on steel members, cables, and rein-forced concrete were conducted, then their respective resistance degradation rules were ex-plored and the resistance deterioration formulas were also deduced;5) Based on the theory of time-dependent risk analysis proposed in this paper, the Sutong bridge’s property in service state was predicted. Then, evaluation of the SuTong bridge time-dependent risk level was obtained based on the criteria of risk grading evaluation, and sugges-tions of risk decisions were put forward.