Research On Damage Identification Of Concrete Continous Box Girder

During the bridge operation the damage of bridge has occurred because of frequent load action, overloading, the unfriendly natural environment and the damage caused by traffic accident. Along with the bridge service life growth, there will be more and more damage locations. What is more the damage degree will become more and more serious. Bridge damage identification is increasingly important for grasping the state of bridge health.New methods for structural damage identification have been developed recently in the fields of civil structures. Although most of these methods are well-discussed theoretically, mang problems need to be solved when they are put into practice. So how to apply theories into practice must be further investigated. The specific studies were listed as following:1) The significance of structural damage identification in bridge and present domestic and worldwide research progress on structural damage identification were described. The main contents of the paper were concluded.2) Design of box girder model, selection of model material, model making and test device and loading equipment for collecting data during loading process were introduced. The loading plan was introduced.3) Load-deflection curve under cyclic loading was analyzed, and simplified calculation method of stiffness degradation of box girder was put forward based on measured Load-deflection curve.4) The sensitive parameter MFC(modal flexibility curvature) of structural damage was developed. The damage locations were identified based on MFC.5) The theory and method of support vector machines were introduced. The support vector regression were adopted respectively to quantify the damage and the influence of different noise level was also considered.