| In the life-cycle performa nce analysis o f reinforced concrete cable-stayedbridges, factor such as carbonizatio n and corrosion caused by the naturalenvironment, fatigue and corrosion of cables caused by the externa l load, such asthe traffic load and temperature should be considered. Life-cyc le analysisenables bridge maintena nce at the right time to extend its service life and ens uresafety of the bridge. In this paper the time varying characteristics model o f thereinforced concrete me mbers are summarized by literature review. In servicedegradation and reliab ility ana lys is of cable-stayed bridge is performed bycons idering the time-varying property o f bridge components and materia ls. Themain content is as follows.Existing time-varying models for the reinforced concrete structures aresummarized. Degradatio n models for the Bin Zhou Ye llow River Bridge areselected according to the environment of the brid ge and analys is to these models.A simply supported beam model is used to ana lyze the bend ing capacitydegradation and deflection capacity degradation of the brid ge. The degradationof bond between concrete and bars are considered in the example.Taking into account of both the temperature and the vehic le load effects, therandom traffic load for the Bin Zhou Yellow River Brid ge is generated accordingthe traffic load spectrum mode l of this brid ge. The brid ge model is loaded withthe generated traffic load, and the stress time-history in a typica l one year isextracted. The rain flow count method is used to comp ute the stress amplitudeand the number of cyc les of cables, and the fatigue damage of the cables iscalc ulated according to the Miner linear cumulative damage mode l. The effect ofcorrosion on cable fatigue dama ge accumulation is further considered. Fina lly,cons idering the uncertainties of degradation and time-varying re liability ofbridges, probability density evo lution method is e mp loyed to analyze thereliability of bridge girder and cables. |
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