Study On Mechanical Behavior Of Steel Tubular Arch Bridge After Damage

As a bridge type with certain advantages in the field of large and medium span bridges,CFST arch bridges have very broad application prospects in China.According to statistics,there are many steel pipe arch bridges in China that have been in service for more than 30 years.They are affected by various unfavorable factors during their running period,resulting in damage to key components such as suspender and arch ribs,which seriously affect the safety performance of the bridge.In order to study the variation law of the cable force and the deflection of the beam of the steel pipe arch bridge after the damage of the key components,and to grasp the health of the bridge,this paper intends to analyze the damage of the boom and arch rib of the steel pipe arch bridge.This paper takes a trestle bridge at Caofeidian Ore Terminal as the research object,and uses the finite element software Midas Civil to establish the three-dimensional finite element model of the CFST arch bridge.Firstly,the difference between the temperature load and the moving load of the arch bridge in the non-destructive state is studied.The influence of force and beam deflection.Then,when the single boom damage is 5%,10%,15%,20%,30% and 50% and the double boom damage is 20%,the dead load and the moving load respectively act on the cable force and tie rod of the boom.The effect of deflection.Finally,the variation law of cable force and beam deflection of the sling bar is studied when the local arch rib damage is 10%,20%,30%,50% and the total arch rib damage is 5%,10%,15%,20% and 30%..The results show that the cable force of the boom and the deflection of the tie beam change linearly with temperature.Damage to the boom and the ribs will result in a significant decrease in the cable force of the damaged boom,which even result in a significant effect on the adjacent slings and little effect on the slings in the distance.The damage of the boom will cause the deflection of the tie beam,while the damage of the arch rib has little effect on the deflection of the tie beam.As the degree of damage increases,the cable tension of the boom and the deflection of the tie beam also increase.According to this law,the damage position and damage degree of the damaged boom can be effectively judged,and the approximate position of the arch rib damage can be discriminated,and an effective and simple new method for grasping the safety performance of the bridge can be provided,and the design,maintenance,reinforcement and operation management of t steel pipe arch bridges can be provided.Provide reference for operational status assessment to ensure safe operation of the bridge.