Exploration On Safety Inspection Of Large-span Steel Truss Arch Bridge Based On Laser Scanning Bridge Form

In view of the recruiting of the tide of infrastructure construction and the security of the existing bridge structure,more and more scholars and researchers have focused on the bridge structure damage identification and conventional safety inspection.However,there are many problems in the traditional bridge security check,mainly as follows: the means are backward,the mobility is poor;the cost is high,the time is long,the traffic influence is big;the scientific basis of the quantification is largely dependent on the observer’s business quality and subjectivity.Based on the research of bridge surface sensing method and safety evaluation theory,this paper explores the relationship between bridge deck shape and bridge structure,and explores the acquisition of bridge deck shape data under mobile laser scanning technology,based on the key research project of Chongqing natural science fund(cstc2012jjB0118)And the treatment method,and the measured deck shape data were compared and analyzed.Based on the actual engineering Daning River large span steel truss arch bridge,a feasible new bridge inspection method is proposed to predict the recent safety situation and development trend of bridge structure.The main contents and conclusions are as follows:1.After a large number of existing bridge safety inspection methods and typical bridge safety accidents,the feasibility of using the "mobile laser scanning deck form" technology based on the "bridge-oriented" theory is discussed.And technical advantages.2.To explore a set of bridge point cloud data processing methods,and better to achieve the bridge surface data visualization,feature alignment and noise reduction.Through the measurement of precision level,close-range shooting measurement technology and finite element model,the analysis data verify the accuracy of bridge surface data measured under laser scanning technology.3.Through the panoramic image of the bridge to provide rich and accurate information to complete the appearance of the bridge to check the work;remove the collection of atmospheric temperature differences on the measured deck shape data,by the previous bridge point cloud data The comparison reflects the real trend of the development of bridge structure.At the same time,the theoretical changes of bridge deck shape under typical bridge disease are given,with a view to establishing aquantifiable arch bridge alteration file,and put forward scientific and feasible bridge management and maintenance suggestions.This dissertation could provide theoretical and experimental foundation for the subsequent exploration and application of 3D laser scanning technology in bridge safety inspection.