Time-Dependent Reliability-based Assessment Of Bridge Residul Resistant

Damage indentification, evaluation the reliability and surplus life for existing structure are the problems that have to be settled urgently by civil engineer. The limitation state equation was set up on the basis of attenuation model of resistance force and bridge loading model established in this paper,the reliability varitation of bridge with the time was caculated combined with the dynamic reliability theory and damage estimation. the finite element model was founded which considered the effect of time variation model factor.Using the ex-scholars' research result for reference, considers all the affecting factors of resisting force separately, building the time-dependent models of concrete strength, steel bar strength and sectional area, felt retrogression for concrete and steel bar, builds the time-dependent construction resisting force model under multi factors compositive action. The emphases is the changing of steel bar sectional area, taking corrosion of steel bar and factor of fatigue damnification into consideration to build steel bar sectional area time-variation modelLoading is one of the main loading of bridge construction, including statistic loading and vehicle loading, considered as random variable. According to abroad investigation information, introduces random variable model of statistic loading and vehicle loading separately as per domestic. Statistic loading is normal distribution and vehicle loading is extreme-value I distribution.Derives limit condition equation of bridge loading capacity under damnification status on the basis of resisting force model and loading model. Introducing the reliability theory into the evaluation of the bridge construction, the resisting force model is the time-dependent function. In a specific project,, compares and analyzes the time-dependent reliability index of bridge calculated by weaved related program used the built time-dependent resisting force model. Then, prognosticates the residual life of the bridge system through the reliability index.Combining resisting force effect factors time variation model, the static and dynamic test, which is in different situation, is simulated. The vehicle loading dynamic model is built theoretically, and the vehicle is simulated by triple free of degree model. Selects the simple supported bridge, applys finite element software ANSYS simulating the system, simulates system model, and simulates several operating mode of static test and car running at constant speed test. The relationship between stress and strain in static test, and dynamical response of bridge in car running test is analsysed. The result is closer to the actual inspection of thebridge.