Analysis Of The Influence Of Lateral Brace On The Seismic Response Of Concrete-Filled Steel Tube Arch Bridge

In recent years, the concrete-filled steel tube arch bridge has been widely used in China. Many experts and scholars in China are concentrating on of the concrete-filled steel tube arch bridge static characteristic and dynamic analysis. Its seismic response analysis is cause for concern, lateral brace is the part structure of the CFST, the analysis of its influence of seismic response is worth studying.This paper analyzes the research status of the development of concrete filled steel tube arch bridge, the seismic response and the influences of lateral brace on structure etc. Arch bridge vibration theory analytical method basic equations is derived. The basic principle and the basic steps of finite element method to solve arch bridge dynamic response is introduced. And the direct integral method and modal superposition method to solve structure dynamic response differential equation is introduced. By simplified concrete-filled steel tube arch rib parallel as the research analysis object, establish the finite element model,respectively study analyzed the influence of the radial horizontal supports and tangential lateral brace's cloth hold position, cloth hold number and cloth of supporting structure form on vibration characteristics and the seismic response of the structure.Through calculation and analysis show that:the influences of the set of lateral brace position, decorate number on the first-order horizontal the fundamental frequency of the structure is greater, and on the first-order vertical fundamental frequency of the structure is smaller. When the number of lateral brace are small, its populations, which could evidently improve the first-order horizontal the fundamental frequency of the structure, but number shoulds not be too big. Compared with radial horizontal, the improve of the tangential lateral brace on the first-order horizontal the fundamental frequency of the structure is greater, both to the first-order vertical fundamental frequency of the structure almost equal. The influences of the set of lateral brace position on the structural transverse displacement seismic response is greater, on the structural vertical displacement seismic response is more complex, on the structural longitudinal displacement seismic response is greater, when the lateral brace position higher. And its on the structural section normal stress seismic response have certain effect. The growing number of lateral brace could be greatly abate structure transverse displacement seismic response, but should not be too big. Compared with radial horizontal, the reduce of the tangential lateral brace on the structural transverse displacement seismic response is greater, and both to the structural vertical displacement seismic response, longitudinal displacement seismic response and section normal stress seismic response almost equal. Recommendations should according to the structural actual situation, the design goal request of the parameters of the structure, choose reasonable lateral brace form.