Font Size: a A A

The Reliability Evaluation Method Study Of Highway Bridge Based On Bayesian Theory

Posted on:2018-09-11Degree:MasterType:Thesis
Country:ChinaCandidate:B J XuFull Text:PDF
GTID:2322330518953440Subject:Bridge and tunnel project
Abstract/Summary:PDF Full Text Request
With the rapid growth of the number of bridges in service in China,especially part of the bridge has been serving for twenty or thirty years,into the disease focused exposure period,causing the maintain funding pressure of bridge.How to scientifically and objectively evaluate the actual use situation of the bridge,and as a basis for reasonable,optimize the distribution of bridge maintenance funds become the industry's concern.The method of meticulous assessment based on reliability theory can overcome the influence of subjective factors of bridge engineers to a certain extent,and can more truly reflect the objective use situation of bridge structure,which has become one of the important development directions of bridge meticulous evaluation.However,the current reliability assessment method is mainly through the prior probability distribution and the limit state equation to evaluate the bridge structure,in which the prior probability distribution often does not take into account the actual bridge detection and monitoring,and the limit state equation of the complex structure of is not easy to obtain,making there are some limitations in the assessment method.Based on this,a modified method of parameter probability distribution based on Bayesian theory is proposed,which can effectively apply the measured data to the reliability evaluation.At the same time,the response surface method is used to solve the difficult problem of complex state equation.Combined with the two can be carried out on the assessment meticulous of bridge,obtain the objective of the actual work of the bridge,which can guide the relevant conservation departments of the rational allocation of funds for conservation.The main contents of the thesis include:?This paper summarizes the commonly used methods of bridge assessment,compares the applicability of each evaluation method,and points out the superiority of the evaluation method proposed in this paper.This paper further discusses the research status of reliability evaluation theory,and points out the necessity of the proposed method for the shortcoming of current reliability evaluation.?Based on Bayesian theory,a modified method of probability distribution of bridge structure parameters is proposed.In this paper,the compressive strength of concrete with large influence on the ultimate bearing capacity of concrete bridge is chosen as the modified variable.Based on Bayesian theory and thought,Bayesianmodified method is used to predict the probability distribution of bridge structure parameters.?In order to solve the problem that the limit state equation of the complex structure is not easy to be obtained,the response surface method is used to fit the limit state equation.The finite state model of the bridge structure is established by finite element software.On the basis of this,the sensitivity of the structural parameters is analyzed,and three parameters with large influence are selected.The central rotation method is established by large-scale statistical software JMP and the ultimate load capacity of the structure under different working conditions is calculated.According to the obtained results,the limit state equation can be fitted in JMP.According to the parameter probability distribution model modified by the Bayesian modified method,the reliability of the bridge structure is evaluated by combining the obtained limit state equation.?In order to verify the feasibility of the method,select the engineering examples to verify.The results show that the method is practical and strong,and it can provide a positive and effective technical means for the bridge maintenance department to scientifically and objectively evaluate the actual use of the bridge and make it reasonable and optimize the allocation of bridge maintenance funds.
Keywords/Search Tags:Bridge assessment, Reliability assessment, Bayesian correction, response surface, limit state equation
PDF Full Text Request
Related items