The Research On Damage Detection Andperformance Evaluation Of Concrete Filledsteel Tube Arch Bridge

At the end of last century,concrete-filled steel tube arch bridges were build in large amount due to its light structure and beautiful shape.But after these concrete-filled steel tube arch bridges were used for some while,a series of problems rose up,like hangers failure,arch rib separation,beam concrete fracture and etc.These problems easily cause major damage and bring great loss to national economy,people's lives and property.Therefore,it's of great engineering value to develop capability evaluation by taking effective damage detection on various parts in concrete-filled steel tube arch bridge and identifying damage position and damage extent.Based on review of domestic and foreign literature,the paper analyzes the static and dynamic indicators changes of different parts in concrete-filled steel tube arch bridge after damage.Then it detects corresponding detection technology and methods regarding spot examination and damage identification.Besides,it focuses on engineering application research on monitoring suspender force of arch bridge in real-time by using fiber grating sensor.Considering structural stability analysis,it calculates weight coefficient of various parts in concrete-filled steel tube arch bridges,improving the adaption of capability evaluation using existing specification.1)Build Midas finite element model for practical bridges.Based on the assumptions of suspender and arch rib damage parts as well as damage extent,use numerical analysis to study relevant changes of mechanical properties(axial force,bending moment,displacement,frequency).Through the numerical analysis,it gets sensitive index of parts damage,which can be used for damage detection in practical engineering project.2)According to numerical analysis results,it studies detection technology and identification methods for exploring sensitive mechanics index when suspender,arch rib and beam get damaged,which makes preparations for engineering application research.3)Based on approaches stated in Highway Bridge Technical Status Evaluation Criteria(JTG/T H21-2011),it calculates weight coefficient of major parts in concrete-filled steel tube arch in light of structural stability analysis.Then according to sensitivity of stability changes,it gets weight ration of suspender,arch rib and beam for further calculation of weight coefficients of various parts in concrete-filled steel tube arch bridge,serving as supplement for specification adaptability.In compliance withnormative methods,it makes comprehensive assessment on practical bridges using weights after and before adaption and analyzes differences caused by weight changes.4)Install fiber grating sensor on the suspender of practical bridges to monitor suspender force in real time.Then try to determine the health condition of the suspender based on suspender force changes.