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Study On The Reliability Assessment And Prediction Of Service Life For Existing RC Bridge Strengthened

Posted on:2011-04-09Degree:DoctorType:Dissertation
Country:ChinaCandidate:C X DuanFull Text:PDF
GTID:1102360305983315Subject:Structural engineering
Abstract/Summary:PDF Full Text Request
The study on the reliability assessment and prediction of service life for the concrete bridges which have been strengthened is meaningful in two aspects:on one hand,it can assess the durability and predict the remaining life scientifically in order to evaluate the effect of strengthening for the concrete bridges in service which have been strengthened; on the other hand,it can timely make the decision whether to continuing the maintenance or strengthening or demolition for the potential crisis revealed of the structure. Therefore, the study on the reliability assessment and prediction of service life for strengthened concrete bridges not only has practical significance for the normal use of strengthened structures which are currently in service, but also has theoretical significance for the assessment of durability for the strengthening of bridge structures.For this problem, with the conclusions of previous studies by other researchers, this dissertation carries out deep study on the reliability assessment and prediction of service life. The mainly works are as follows:1. On the base of comprehensive study on the assessing procedures, criterions and assessing methods for the reliability of reinforced concrete bridge at home and abroad, the assessing procedures, criterions and assessing methods for the reliability of strengthened reinforced concrete bridge are present, and the life is predicted.2. On the base of existing research results, the calculating methods for the reliability index of reinforced concrete bridge which are currently in service are present. Considering the specificity of the structures in service, the dissertation discusses the method of determining the target reliability index, load correction method and the resistance degradation model during the remaining life. Then the calculating model of time-dependent reliability index for the strengthened reinforced concrete bridge currently in service is proposed by the method of response surface method, and its calculating method is discussed.3.The method of system theory is used to determine the main factors and the secondary factors which affect the durability and service life for strengthened concrete structures. And the fuzzy comprehensive evaluation method is proposed to assess the durability of structures by the fuzzy system theory on the base of analytic hierarchy process(AHP).This method establishes the membership functions for evaluation factors at all levels to the durability at all levels on the base of the comprehensive evaluation model for multi-level for durability of structures, considers the weight for target assessing value of evaluation factors, then the level of structure to be assessed can be gotten according to the principle of maximum membership.4.The numerical simulation system is established using the actual engineering data, theoretical results, experimental results and field test data to study the service life under actual conditions of bridges, and compare the theoretical model and experimental results.
Keywords/Search Tags:reinforced concrete bridge in service, time-dependent reliability index, response surface method, finite element method, fuzzy theory, analytic hierarchy process
PDF Full Text Request
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