Based On Reliability Theory Bridge Health Status Assessment

With China’s economic construction continue the development ofhigh-speed road traffic constantly increased, so that the bridge in China’sconstruction of transport facilities play an increasingly important role. Since along time in the wild environment, over time, a series of structural damage andaging of the material, resulting in deterioration of the structural performanceand load capacity and reduce the influence of the normal use of the bridgestructure, the bridge structure may even cause severe consequences; theactive bridge structure damage identification, the remaining carryingcapacity assessment and residual life prediction, is the most pressing problemof our engineering sector. Based on reliability theory, the remaining carryingcapacity assessment of the prevalence of reinforced concrete highwaybridges issues.Reliability theory-based assessment of the bridge structure, the existingbridge components and systems reliability analysis methods and processesthrough the analysis of the reliability calculation process limit statetime-varying, depending on the bridge structure at the same time a reliableindicator of, the main failure mode of the bridge structure systemidentification method. The bridge itself dead load, vehicle load and thecrowd load to bear the main load of the existing bridge, a detailed analysis ofthe design basis the vehicle load during the period and its maximumprobability distribution, in this based on the vehicle load effects time-varyingprobability model of this paper, drawing on the results of previous studies, thebridge structure dead load and dead load effect as a random variable, thevehicle load effects as time-varying random variables, taking into account thevaluation and live load correction factor amendment in accordance with thecharacteristics of the existing bridges need to build a bridge load effects oftime-varying model. The impact of the structural resistance of existing bridgescompressive strength of concrete carbonation of concrete, steel yield strength, steel corrosion, do the analysis, taking into account existing concretegirder bridge the structural resistance kerf random variables obey alog-normal points need to be studied random variables affect the structuraldurability parameters passed by the Taylor series and error formula tocalculate the mean and standard deviation of the resistance, both concretebridge structural resistance effect change model.Finally, an example is given, the actual model of the bridge load effectsand resistance effects model calculated a reliable indicator of the bridge inthe design reference period and the results were compared with threereliability calculation method; analysis of the various basic variables statisticalparameters of the bridge reliability; comparison the bridge cracks reliability ofthe results based on our norms and norms.