Vulnerability Analysis Of Through Concrete-filled Steel Tube Arch Bridge

Vulnerability of structure refers to the difficulty of structure damage under the action of accidents.Bridges are important hub projects of transportation system,the damage of bridges under accidents and natural disasters will lead to serious consequences,so the vulnerability analysis of bridges is particularly important.The derrick fracture is the main disease of the half-through and through arch bridge,and the earthquake is also the main cause of the damage and collapse of the bridge structure.This thesis intends to study the vulnerability of a through concrete-filled steel tube arch bridge under the action of derrick fracture and earthquake,based on the theory of topological vulnerability and seismic vulnerability.The main study contents of this thesis are as follows:(1)This thesis introduces the general situation of the development of concrete-filled steel tube arch bridges in China,summarizes and analyzes the main diseases faced by half-through and through arch bridges,and points out the existing problems in the analysis of the vulnerability of through concrete-filled steel tube arch bridges by combining the analysis and research status of the vulnerability of derrick fracture and earthquake at home and abroad.(2)The ANSYS software and Midas/Civil software are used to establish the finite element model of the through concrete-filled steel tube arch bridge respectively,and the calculation results are compared from the static and dynamic aspects to verify the correctness of the finite element model.(3)The existing derrick fracture simulation methods are compared and analyzed,and the most suitable semi-dynamic simulation method is selected to analyze derrick fracture.The damping and derrick failure time involved in the transient dynamic analysis of derrick fracture are analyzed and studied.The overall vulnerability evaluation index is sought based on the grey relational grade theory,and the derrick fracture vulnerability is analyzed.(4)This thesis introduces the theory of seismic vulnerability analysis,selects the seismic waves suitable for the bridge site conditions,takes the supports,arch ribs and tie beams as the research objects,and establishes the seismic vulnerability curves of these three components by using the "frequency statistics method".At the same time,considering the importance of different components of the bridge,the methods of establishing the vulnerability curves of the bridge system are discussed by introducing the weight,and the seismic vulnerability curves of the bridge system are established.