Research On Damage Identification Of Continuous Girder Bridge Structures Based On Influence Line Of Displacement

In recent years, the study of bridge structure health monitoring is getting more and morepeople’s attention, it’s not only because the number of bridges increases, but also because thecountries all of the world are facing the peak period of bridge maintenance and repair.Thedamage detection is the core of the health monitoring, and it can be used to evaluate bridge’shealth status and give reasonable repair maintenance advices.Therefore,studying damageidentification has important practical significance and social value.Based on the current research status of structural damage identification, especially thedamage identification based on the deflection influence line, this paper analyzes the existingproblems in the current damage identification, and in view of the continuous girder bridge,carries out the research of the relative damage identification based on deflection influenceline.The main contents are as follows:(1) Introducing the background research significance the pape, this paper reviews the researchsituation of the engineering structure damage identification and also the damage identificationbased on the deflection influence line,and clarifies the research purpose and main work of thisarticle.(2) For a typical continuous beam, the analytical expression of the deflection influence linebefore and after damage is deduced,theoretically proving the feasibility of this method ofidentification.And thus this paper establishes the damage indexes based on deflectioninfluence line.(3) Based on deflection influence line, numerical simulation is used to identify the damage ofcontinuous girder bridge.Through the recognition effect of various conditions such as a singleinjury,multiple injuries,different damage locations and damage extents,this paper comparesthe strengths and weaknesses of each damage identification index. (4) This paper also establishes the validation experiment of the damage identification methodbased on deflection influence lines. By designing a series of continuous beam models withvarying degrees of damage and different injury positions,this paper devises the correspondingtest methods.With a new measuring instrument,this paper Measures the deflection influencelines of the models and confirms the validity of the proposed identification method underlaboratory conditions.