Application Of Vulnerability In Bridge Health Monitoring

Tied arch bridge has the advantages of short construction period and good earthquake resistance,so its application at home and abroad is more and more extensive.In order to ensure the state of the bridge during operation,it is particularly important to carry out health monitoring of the structure with purpose.The main cause of destruction of the tied arch bridge is the damage of the suspension rod as a force-transmitting structure,which in turn causes damage to the bridge deck system,and finally the destruction of the bridge.Different from the traditional health monitoring system’s construction ideas considered from the perspective of component strength and stress,this paper attempts to study the damage of the tied arch bridge from the two perspectives of structural seismic vulnerability and topological vulnerability in the scenario of boom damage.On the one hand,the nonlinear incremental dynamic analysis method and the direct regression fitting method are used to explore the damage probability of the structure under different ground motions.On the other hand,from the perspective of structural damage scenes,the impact of the damage scene of boom suspension on the structure is explored.According to the analysis results,the fragility curve is drawn to provide ideas and guidance for the construction of the bridge health monitoring system.The main research contents are as follows:1.Explore the current research status and research methods of bridge structure vulnerability,as well as the current status and development of bridge health monitoring systems at home and abroad.By exploring the key damage forms of the tied arch bridge and the impact of the earthquake,it is clear to explore the vulnerability of the tied arch bridge,and it will help the construction of the bridge health monitoring system.2.The classification and discussion of the vulnerability curve are discussed.The solution method and process,including the theoretical basis of calculation,the selection of seismic waves,the fitting method of the vulnerability curve,and the definition of the structural breakage criterion;3.According to the theoretical research method of the seismic vulnerability of the bridge,the Madis Civil software is used to establish a numerical model with the tied arch bridge as the object,and the change of the member performance is described by push-over,and the change form of the bridge plate is defined to establish the earthquake of the structure Vulnerability curve.And through the study of anti-seismic fortification targets,the damage index corresponding to different earthquake strengths is used to improve the damage index,and thereby provide a reference to the damage threshold;4.According to the topological vulnerability analysis method,The damage scenario is defined.The pseudo-static analysis method is used to analyze the structural response after the boom is broken.The vulnerability of the structure is defined according to the stress changes of the boom and the main beam.5.According to the analysis results of the fragility,for the damage of the bridge deck,the damage threshold of the anchorage and the problem of the impact of the hanger fracture,it provides recommendations for the layout of the measurement points and the damage threshold in the bridge health monitoring system.On the basis of the consequences,it provides a reference for the establishment of various damage plans in the bridge health monitoring system.