Research On Seismic Assessment Method For Bridge Structures Based On Damage Analysis

Firstly,this paper introduces the principles and implementing steps of Pushover Method for bridgestructures under the seismic motion,as well as reviewes the commonly used capacity spectrummethods.Secondly, the correlation theory of the restoring force model is discussed,and the concept ofimpairment for reinforced concrete and bridge structures and several calculation methods of structuraldamage model for structural were researched.The relation between the damage grade and impairmentindex is given,then the complete process of the bridge seismic performance assessment method based onthe damage analysis is proposed, The main contents of this dissertation include:1.Based on establishing principle of the inelastic demand spectrum of the strength reductionindex,through comparative analysis a more reasonable relationship model of R-u-T is selected.Theresponse spectrum of the Road Engineering Seismic Design Code (JTJ004-89) and Guidelines for SeismicDesign of Highwan Bridges(JTG/T B02-01-2008) is derived to establish the elastoplastic demandspectra.Using the Matlab software and the preparation of these two response spectrum,considering thedifferent R-u-T relationships,the complete program is established.The ductility demand spectra spectrumestablished for the first time of the elastoplastic demand response spectrum based on the08rules,givesadvice for the assessment of the seismic performance of bridge structures based on the new specific ationresearch.2.Firstly, the model of Hei Chenghe continuous rigid frame bridge is established to construct thetime-history analysis and pushover analysis.In accordance with the flow chart of the elastic-plastic analysisof the bridge under a major earthquake,the details of the elastic-plastic time history analysis results areextracted and the corresponding conclusions are getted.3.In this paper, three kinds of structural seismic damage model are proposed, the bridge has beencalculated using the capacity spectrum method.The performance points and damage index in differentseismic intensity are computed. Combining with the relationship of the structural damage index anddamage rating in the third chapter,the level of destruction of the bridge in different earthquake isevaluationed.The evaluation results are compared with the time-history analysis in case of the samevibration input and the equivalent results verify the feasibility and reliability of the proposed seismicperformance evaluation method based on the damage analysis in this paper.