Research On Theory And Application Of Non-probabilistic Bridge Structure Evaluation Based On Ellipsoid Convex Set Model

Chinese bridge industry has entered a stage of rapid development,and the number of bridges has been increasing day by day.In the daily operation of bridges,the impact of environmental factors has led to a decline in the load-bearing capacity of the bridge and even endangers the safety of the bridge itself.Probabilistic models are difficult to apply to actual bridge evaluation due to the large amount of statistical information and many influencing parameters.However,non-probabilistic reliability methods can better solve this problem.After continuous research by scholars,non-probabilistic reliability methods are now available.Has tended to be perfected and gradually applied to actual projects.Based on the non-probabilistic reliability theory of convex set model,this paper evaluates the non-probabilistic reliability of actual bridges,proposes the basis for the classification of bridge safety grades based on the non-probabilistic reliability evaluation,and classifies the bridges according to the evaluation results.This article mainly conducts research from the following aspects:1)Aiming at the non-probabilistic reliability calculation theory of the ellipsoid convex set model structure,compare and analyze the connection between the interval model and the ellipsoid model,analyze the use conditions of the model,and compare the non-probabilistic reliability indicators under two-dimensional and multi-dimensional parameters solve;2)This paper uses short-term monitoring methods to obtain bridge actual response information,compares and analyzes the advantages of short-term monitoring and traditional load test and health monitoring systems,processes the acquired detection data,and uses finite element model correction to apply it to bridge evaluation;3)Consider the influence of the time-varying reinforced concrete of the in-service bridge on the structural resistance,consider the change of the T-beam section type under the time-varying,solve the resistance interval of the actual bridge,extract the load effect through the modified finite element model,establish the functional equation,and solve the Non-probabilistic reliability indicators of actual bridges;4)Summarize the existing standard bridge safety classification,compare the standard classification method and the probability reliability classification method,compare the relationship between the probability reliability index and the non-probabilistic reliability index,and propose a bridge safety based on the non-probabilistic reliability assessment Grade classification basis.This article applies short-term monitoring data to the evaluation of the bridge’s carrying capacity,which makes the uncertainty analysis of the structure more reliable,and proposes a non-probabilistic reliability evaluation level,which is helpful for a more objective comprehensive evaluation of the bridge structure.