A Forensic Investigation Of Bridge Collapse Based On Video And Wreckage Photos

Through the collection of 814 typical bridge collapse accidents at home and abroad,this article found that natural disasters,design,accidental load,durability and other factorsin the process of construction and use of the bridge,may cause bridge collapse accidents.These bridge collapse accidents not only caused huge economic losses but also caused significant casualties.According to the collection of information from domestic and foreign literature,this paper puts forward how to make full use of the wreckage data of the collapse site,the inquiry information of the people present,the combination of the collapse video and the existing finite element technology to establish scientific investigation theory and analysis methods to prevent the occurrence of similar accidents.It is of great significance to restore the cause of collapse.(1)By summing up the research and analysis of bridge collapse accidents at home and abroad,it is found that the current research and analysis focus on the analysis of the bearing capacity of structural collapse,but it is short of the inversion calculation of structural collapse which make the full use of field debris information.This paper puts forward that in the process of bridge collapse accident analysis,we should first collect the field information such as geometric information,material strength information,contact pairs information and so on to help us have a preliminary judgment on the destruction of bridge.Then we should establish scientific,reasonable and simple numerical model for bridge collapse processfrom the information of the wreckage to analyze the mechanism and causes of bridge collapse.(2)The research of this paper based on the Sichuan Minjiang bridge,Jiangxi Taihe bridge and FIU bridge in Miami,Florida.At first,investigation will be performed to establish methods for systematic evidence collection of key information pertinent to collapse analysis through measurement on photos,videos and strength testing and police inquiries about the field personnel,the field contact collision information is transformed into a boundary constraint condition,and a preliminary analysis is made to restore the small deformation stage process before the bridge collapses.Then through the site video,photos,wreckage,build the space motion process when the bridge collapse,restore the cause of bridge damage.Secondly,through the information of the size of the field bridge and the original drawing collected by photo grammetric technology,the finite element model can be established to analysis and calculate the stress condition of the bridge before the collapse,judge the initial location of bridge damage.Finally,the results of finite element calculation are compared with site video,which can systematically analyze and demonstrate the causes of bridge collapse and damage.The results show that the collapse process is inverted by making full use of the information of the wreckage of the video and the collapse site.On the basis of fully forming the bridge failure mode,the finite element model is established and the collapse process is being performed.Through the analysis of the accident of both positive and negative aspects,it can better reduce the cause of collapse and provide an effective means for accident analysis.