Reliability Analysis Of Inland Frame Wharf Based On Resistance Time-varying Characteristic

During the long-term operation process of wharf structural, the reinforced concretestructural members are influenced by natural environment, working condition andintrinsic material. The resistance of reinforced concrete structural members wasdecreased by time cause of some things like rebar corrosion, concrete carbonation andthe reduction of binding power between rebar and concrete. The full life reliabilityanalyzing method of frame wharf has been proposed by considering RC memberstime-varying characteristic, within numerical examples illustrating how to use it tocalculate the time-dependent reliability in this paper. The main content and conclusionsare as follows:(1) Based on the randomness of concrete corrosion cracking process, a probabilitymodel of predicting the extent of reinforcement corrosion was proposed. The model alsoconsiders the steel bar corrosion caused by carbonation in inland river environment asthe main role of factor. Based on the model, using the Monte Carlo method to simulatethe pier beam degradation process, the probability distribution at different times of steelcorrosion rate was obtained. The numerical simulation of the whole performancedegradation process of concrete structures "concrete carbonation-steel corrosion-concrete cracking-steel corrosion exacerbated-member carrying capacity down" hasbeen realized. The simulation results shown that the distribution of steel corrosion ratechanges over time.(2) The resistance and the load of reinforced concrete structures were considered asstochastic processes. Moreover, the stochastic processes were discreted as randomvariables of extreme values corresponding to different periods of the design life.Assuming the reliability of the most dangerous components of the system on behalf ofthe reliability of the entire structure, the reliability calculation model of inland framewharf based on the time-varying resistance has been established by using JC method tocalculate time-dependent reliable index of the structure.(3) Taking a reinforced concrete inland frame wharf as example, using MATLABprogram to calculate time-varying reliable index of pier member according to themethod discussed previously. Based on it, it has been made quantitative assessments tothe remaining life of the structure from the perspective of structural reliability theory byanalysising the reliable indicator degradation processes of pier major components due to the reinforcement corrosion and concrete deterioration. The results show that the starttime of reinforced corrosion is an important time node for structural resistancedegradation. Postponing the time of reinforcement corrosion has important implicationsfor the safety and durability of pier structure at the pier design process.